JP6755457B2 - Modifications to maintain the intracellular uptake of synthetic amino acids and neutron capture therapy to protect normal cells - Google Patents

Description

The present invention relates to a means for selectively improving the accumulation amount of a boron-containing compound in cancer cells, a cancer treatment method by neutron capture therapy using the means, and a cancer diagnosis method by positron emission tomography or magnetic resonance imaging.

Neutron capture therapy (hereinafter referred to as "BNCT") refers to 4-boronophenylalanine (hereinafter referred to as "BPA") and mercaptoundercahydodecaborate (hereinafter referred to as "BSH"). Boron-containing compounds (compounds containing at least 90% or more of boron-10, which is a non-radioisotope of boron and is present in nature at about 20%) were administered to cancer patients in advance and accumulated in cancer cells. Later, by irradiating with safe thermal neutrons or extrathermal neutrons or mixed beams, cancer cells are killed by particle beams (alpha rays) and lithium atoms (Li) resulting from the nuclear reaction caused by boron-10 (B-10). It is a method of treating cancer. The range of alpha rays is 7 to 10 micrometers, and the range of lithium atoms is very short, along with 4 to 5 micrometers, so cancer cells incorporating boron-containing compounds can be killed in a limited manner. ..

BPA is taken up into cells by the usual amino acid transport system. Therefore, it is easily taken up by cancer cells having a high growth rate, which expresses a large amount of amino acid transport system, and as a result, the accumulation amount is selectively increased in the cancer cells. Therefore, BNCT using BPA is said to be a therapeutic method with few side effects on normal cells.

However, in practice, radiation damage may occur in normal tissues after BNCT. Therefore, when performing BNCT, the ratio (T / N) of the amount of boron-containing compound incorporated into cancer tissue and the amount of boron-containing compound incorporated into normal tissue by the positron emission tomography method (hereinafter referred to as "PET") in advance. Ratio) is obtained, and the thermal neutron or extrathermal neutron or mixed beam irradiation dose is set based on the ratio so as not to cause damage to normal tissues. When this ratio is large, it is expected that BNCT will provide a sufficient therapeutic effect because the content of boron-10 in the boron-containing compound in cancer cells is high.

On the other hand, when this ratio is small, the content of the boron-containing compound in the cancer tissue is small, and a sufficient therapeutic effect by BNCT cannot be obtained, and / or there is a concern that the effect on normal tissues may be obtained. Therefore, it may be difficult to apply BNCT to such cancers and cancer patients.

Further, it has been confirmed that the amount of the boron-containing compound incorporated into the cancer cells gradually decreases with the passage of time (Non-Patent Document 1). Therefore, if the timing of starting irradiation of thermal neutrons, extrathermal neutrons, or mixed beams is incorrect, the content of the boron-containing compound in the cancer tissue may be insufficient, and a sufficient therapeutic effect by BNCT may not be obtained.

PET is a computed tomography technique that uses positron detection, and is a test method that specializes in observing the functions of living organisms. It can be used for cancer diagnosis and pre-BNCT test as described above. .. In this test method, a compound labeled with a nuclide (for example, ¹⁸ F) in which positron β decays can be used as a radiotracer. ^{Specifically,} labeled fluorodeoxyglucose at ¹⁸ F (FDG) or 2-fluoro-4-boronophenylalanine (2-Fluoro-4-boronophenylalanine : FBPA) is utilized. ^It has been clarified that FBPA labeled with ¹⁸ F behaves equivalent to BPA in the living body of laboratory animals and humans, and is incorporated into cancer tissue from PET examination using FBPA labeled with ¹⁸ F. The BPA concentration can be predicted and determined, and the result can be used for BNCT.

It has been reported that the uptake of BPA is increased when BPA is added together with L-tyrosine, L-phenylalanine, etc. in the culture of cancer cells (Non-Patent Documents 2 and 3). It was reported that when L-tyrosine was added and cultured, washed out, and then BPA was added and cultured, the amount of BPA uptake did not change after 2 hours, but the amount of BPA uptake increased after 4 hours. Has been done. This method takes a lot of time and is not preferable as a treatment method. In any case, it has not been reported that these methods reduce the amount of uptake into normal tissues.

The mechanism of BPA uptake in cancer cells is based on the LAT (L-type amino acid transporter) family known as the amino acid transport system. In cancer cells, increased expression of LAT-1, which is an amino acid transport system, is observed. Amino acid transport by LAT-1 is exchange transport, and extracellular uptake of amino acids is performed by one-to-one exchange with amino acids in cancer cells and is strictly controlled. On the other hand, in normal cells, that is, cells that are not in a dividing / proliferating state, LAT-2, which has a relatively high homology with LAT-1, is expressed, which contributes to the uptake of BPA. The expression level of LAT-1 in cancer cells is significantly higher than the expression level of LAT-2 in normal cells, and therefore the amount of BPA uptake in cancer cells is higher than the amount of BPA uptake in normal cells. Increase the T / N ratio. Attempts to inhibit the function of LAT-1 have been undertaken with a view to the clinical stage. It inhibits the function of LAT-1 and inhibits the uptake of amino acids in cancer cells to deplete them, thereby causing cancer cells and cancer tissues. Attempts have been made to induce death.

Y. Imahori et al. , Positron emission tomography-based boron neutron capture therapy using boronophene gliomas for high-grade gliomas: part II. , Clin Cancer Res. 1998 Aug; 4 (8): 1833-41. Manfred papaspirouet al. , Preloading with L-Tyrosine Increases the Uptake of Boronophenylanine in Mouse Melanoma Cells, Cancer Research 54, 6311-6314 (1994) S. Capuani et al. , Boronophenyalanne uptake in C6 glioma model is radiantly incorporated by L-DOPA preloading, Applied Radiation and Isotopes, 67, S34-S36, 2009

As described above, in order to obtain a sufficient therapeutic effect by BNCT, it is required to selectively improve the accumulation amount of the boron-containing compound in cancer cells.

Therefore, an object of the present invention is to provide a means capable of selectively improving the accumulation amount of a boron-containing compound in cancer cells.

In addition, the present invention is newly developed by BNCT, which makes it possible to selectively improve the accumulation amount of boron-containing compounds in cancer cells, exert sufficient efficacy, and avoid damage in normal tissues. The purpose is to provide various cancer therapies.

Furthermore, the present invention is described as PET or magnetic resonance imaging (hereinafter referred to as "MRI") capable of selectively improving the accumulation amount of boron-containing compounds in cancer cells and performing cancer detection with high accuracy. ), The purpose of which is to provide a new cancer diagnostic method.

As a result of diligent studies to solve the above problems, the present inventors have administered at least one amino acid in combination with a boron-containing compound to contain at least one amino acid in normal cells such as reactive cells and immune cells. It has been found that the accumulation amount of the boron-containing compound in the cancer cells can be selectively improved by significantly reducing the uptake amount of the boron compound and increasing the uptake amount of the cancer cells accordingly.

In addition, the present inventors act on cancer cells after incorporating a boron-containing compound to inhibit the amino acid transport by at least one amino acid transport system inhibitor, thereby causing the outflow of the boron-containing compound from the cancer cells. It was found that the amount of the boron-containing compound in cancer cells can be maintained and the amount of the boron-containing compound accumulated in the cancer cells can be selectively improved.

By selectively improving the accumulation amount of the boron-containing compound in the cancer cells, it is possible to kill the cancer cells more efficiently and with high accuracy by performing BNCT, and to detect cancer with high accuracy by PET or MRI. We have found and completed the present invention.

That is, the present invention includes the following inventions.
[1] A composition or kit containing at least one amino acid and / or at least one amino acid transport system inhibitor used for selectively improving the accumulation amount of a boron-containing compound in cancer cells.
[2] The composition or kit of [1], wherein the boron-containing compound is an aromatic amino acid containing a boron-containing substituent or an aromatic amino acid containing a labeled boron-containing substituent.
[3] The composition or kit of [1] or [2], wherein at least one amino acid contains an aromatic amino acid.
[4] The composition or kit according to any one of [1] to [3], wherein at least one amino acid transport system inhibitor comprises an L-type amino acid transporter-1 (LAT-1) inhibitor.
[5] A therapeutic agent or kit for treating cancer by neutron capture therapy (BNCT), which comprises a boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor.
[6] The therapeutic agent or kit of [5], wherein the boron-containing compound is an aromatic amino acid containing a boron-containing substituent.
[7] The therapeutic agent or kit of [5] or [6], further comprising a mercaptoundecahydrododecaborate (BSH), a liposome containing boron-10, a gadolinium, or a porphyrin compound.
[8] Diagnosis of cancer by positron emission tomography (PET) or magnetic resonance imaging (MRI), which comprises a labeled boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor. Diagnostic agent or kit to do.
[9] The diagnostic agent or kit of [8], wherein the labeled boron-containing compound is an aromatic amino acid containing a labeled boron-containing substituent.
[10] A boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor are administered in an effective amount that selectively improves the accumulation amount of the boron-containing compound in the cancer cells, and the cancer cells are administered. Neutron capture therapy (BNCT), which comprises the step of selectively improving the accumulated amount of the boron-containing compound in the above, and then irradiating the cancer cells with thermal neutrons, extrathermal neutrons, or a mixed beam to kill the cancer cells. A method for treating cancer by.
[11] At least one amino acid transport system inhibitor is an L-type amino acid transporter-1 (LAT-1) inhibitor, and after administration of an effective amount of a boron-containing compound, an effective amount of at least one kind of The method of [10], wherein an amino acid transport system inhibitor is administered.
[12] An effective amount of a labeled boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor to selectively improve the accumulation amount of the labeled boron-containing compound in cancer cells. Positron emission tomography (PET) or magnetic resonance imaging, which comprises the step of selectively improving the accumulation amount of the labeled boron-containing compound in cancer cells and then detecting the labeled boron-containing compound. A method for diagnosing cancer by imaging (MRI).
[13] At least one amino acid transport system inhibitor is an L-type amino acid transporter-1 (LAT-1) inhibitor, and an effective amount of at least an effective amount of the labeled boron-containing compound is administered after administration. The method of [12], wherein one amino acid transport system inhibitor is administered.

The present invention can provide a means capable of selectively improving the accumulation amount of a boron-containing compound in cancer cells. As a result, in BNCT, it is possible to avoid damage in normal tissues and kill cancer cells, and it is possible to treat cancer safely and efficiently. In addition, cancer can be clearly detected by PET or MRI, and highly accurate cancer diagnosis can be performed.

This specification includes the contents described in the specification and / or drawings of Japanese Patent Application No. 2016-078453, which is the basis of the priority of the present application.

Shows the brain tissue and PET images in the periphery thereof when the labeled boron-containing compound ^{(18 F-labeled} 2-fluoro-4-boronophenylalanine) was administered in the presence and absence of amino acids. Incineration of human Burkitt lymphoma cells (Ramos (RA1)) cells supplemented with 4-boronophenylalanine ( ¹⁰ BPA) and 2-aminobicyclo- (2,2,1) -heptane-2-carboxylic acid (BCH) The quantification result of ¹⁰ B contained in the treated sample is shown. The quantification result of ¹⁰ B contained in the sample which ashed the human salivary gland cell (HSG) to which ¹⁰ BPA and BCH was added is shown. Labeled with a patient ^{18 F} of different advanced cancers 2-fluoro-4 was administered boronophenylalanine shows the time course of radioactivity ratio of tumor / blood in case of performing the inspection by PET.

<1. Composition or kit>
The present invention relates to a composition or kit comprising at least one amino acid and / or at least one amino acid transport system inhibitor and used to selectively improve the accumulation of boron-containing compounds in cancer cells.

In the present invention, the "boron-containing compound" is labeled with a boron-10-containing compound that can be used in BNCT and contains at least 90% or more of boron-10, and a label that can be used in PET or MRI and contains at least 90% or more of boron-10. Includes boron-containing compounds.

Such a boron-containing compound is a compound having a boron-containing substituent, particularly an amino acid having a boron-containing substituent, and preferably an aromatic amino acid having a boron-containing substituent. Examples of the aromatic amino acid include phenylalanine, tyrosine, tryptophan, histidine, phenylglycine and the like, and phenylalanine and tyrosine are preferable, and phenylalanine is particularly preferable. As the boron-containing substituent, -B (OH) ₂ or a salt thereof, -BR ₁ R ₂ (R ₁ and R ₂ are the same or different, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec. -Represents an alkyl group having a linear or branched C1 to C4 such as butyl and tert-butyl, an aryl group such as phenyl, and an aralkyl group such as benzyl and phenethyl). Examples of such boron-containing compounds include BPA, which can be suitably used in the present invention. The labeled boron-containing compound is a compound in which the above-mentioned boron-containing compound is labeled with a positron nuclide. As the positron nuclide, those generally used in PET can be used, and although not particularly limited, for example, ¹¹ C, ¹³ N, ¹⁵ O, ¹⁸ F and the like can be used. For example, when the fluorine-containing compound is BPA, the labeled boron-containing compound includes 2-fluoro-4-boronophenylalanine (hereinafter referred to as “FBPA”), 2-tri, which is labeled with ¹⁸ F. Fluoromethyl-4-boronophenylalanine, 2-trifluoromethoxy-4-boronophenylalanine and the like can be mentioned.

As the boron-containing compound, a conventionally known compound can be used, and a compound synthesized according to a conventionally known method may be used, or a commercially available compound may be used. For example, BPA is described in Interpharma Praha, A. et al. S. Alternatively, it is sold by Stella Chemifa Co., Ltd., and these can be used in the present invention.

In the present invention, the term "amino acid" means that the uptake of a boron-containing compound into normal cells can be suppressed and / or the uptake into cancer cells is promoted, and as a result, the amount of accumulated boron-containing compound in cancer cells. However, it is not particularly limited as long as it can produce a state in which it is selectively improved or increased as compared with the accumulated amount of the boron-containing compound in normal cells, and is not particularly limited, but is limited to alanine, arginine, asparagine and aspartic acid. , Cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine, preferably phenylalanine and tyrosine. These amino acids may be any of L-amino acid, D-amino acid, and DL-amino acid, but L-amino acid can be preferably used. When the boron-containing compound is an amino acid having a boron substituent, the boron-containing compound is preferably an L-amino acid having a boron substituent. When the boron-containing compound is a compound having a boron substituent on a hydrophobic amino acid (valine, leucine, isoleucine), the amino acid used is preferably one containing at least one hydrophobic amino acid. Similarly, the boron-containing compounds are acidic amino acids (aspartic acid, glutamate), sulfur-containing amino acids (cysteine, methionine, cystine), aromatic amino acids (phenylalanine, tyrosine, tryptophan), iminoic acid (proline, hydroxyproline), and amide-type amino acids. When the compound has a boron substituent on (asparagine, glutamine), hydroxyamino acid (tyrosine, serine), or aliphatic amino acid, it is preferable to use at least one amino acid of the same type. For example, when the boron-containing compound is BPA, the amino acids used preferably include phenylalanine and / or tyrosine.

The amino acid used may be one type or a mixture of two or more types. The ratio of branched-chain amino acids contained in the mixture is not particularly limited, but is preferably 10% to 50%, more preferably 15% to 40%, based on the total amino acids. The ratio of essential amino acids to non-essential amino acids (E / N ratio) contained in the mixture is not particularly limited, but is preferably 5: 1 to 1: 2, and more preferably 4: 1 to 1: 1. It is 1.5. The Fisher ratio of the mixture is not particularly limited, but is preferably 1 to 50, more preferably 3 to 40. Here, the Fisher ratio is the ratio of the branched chain amino acid (BCAA) composed of valine, leucine and isoleucine to the aromatic amino acid (AAA) composed of tyrosine and phenylalanine, and is calculated by BCAA / AAA × 100. means.

The amino acid that can be used in the present invention is a conventionally known amino acid, and an amino acid synthesized according to a conventionally known method may be used, or a commercially available amino acid may be used. For example, infusion solutions containing a plurality of amino acids are sold by Otsuka Pharmaceutical Factory, Inc., Ajinomoto Corporation, Terumo Corporation, etc., and these can be used in the present invention.

In the present invention, the "amino acid transport system inhibitor" is a boron-containing compound incorporated into cancer cells by inhibiting the function of an amino acid transporter expressed in cancer cells or normal cells to suppress or inhibit amino acid transport. The outflow of the boron-containing compound can be suppressed, or the uptake of the boron-containing compound into normal cells can be suppressed. , Anything that can produce a state of selective improvement or increase. Such amino acid transport system inhibitors include amino acid transporters whose expression is observed to be enhanced in cancer cells, for example, inhibitors such as LAT-1, LAT-3, ASCT2, ATB ^{0, +} , xCT, and normal cells. Amino acid transporters that are expressed in, for example, inhibitors of LAT-2, but are not limited thereto. LAT-1 is found to be upregulated in many cancers and exchanges and transports neutral amino acids (leucine, isoleucine, valine, phenylalanine, tyrosine, tryptophan, methionine, histidine, etc.) in a Na ⁺ -independent manner. Expression of LAT-3 is also observed in normal cells such as liver, skeletal muscle, pancreas, placenta, and renal glomerular podocytes, but a marked increase in expression is observed in prostate cancer. LAT-3 transports neutral amino acids (leucine, isoleucine, valine, phenylalanine) intracellularly in a Na ⁺ -independent manner. ASCT2 is also expressed in normal cells such as lung, skeletal muscle, large intestine, kidney, testis, and adipose tissue, but its expression is significantly enhanced in cancer cells. ASCT2 transports alanine, serine, cysteine, threonine, and glutamine into cells in a Na ⁺ -dependent manner. ATB ^{0, +} is also observed in normal cells such as lung, trachea, salivary gland, mammary gland, stomach, small intestine, large intestine, uterus, and testis, but is significantly expressed in colon cancer, cervical cancer, breast cancer, pancreatic cancer, etc. Increased. ATB ^{0, +} is Na ⁺ dependent on neutral and basic amino acids (lysine, arginine, alanine, serine, cysteine, threonine, glutamine, asparagine, histidine, methionine, isoleucine, leucine, valine, phenylalanine, tyrosine, tryptophan) Transport into cells. Expression of xCT is also observed in normal cells such as brain and macrophages, but expression is also observed in cancer stem cells, and cystine and glutamate are exchange-transported independently of Na ⁺ . LAT-2 is expressed in normal cells and is Na ⁺ independent of neutral amino acids (glycine, alanine, serine, cysteine, threonine, glutamine, asparagine, leucine, isoleucine, valine, methionine, phenylalanine, tyrosine, tryptophan, Histidine) is transported into cells.

The amino acid transport system inhibitor may be any as long as it can inhibit the function of the amino acid transporter and suppress or inhibit the amino acid transport. For example, a compound or antibody (monoclonal antibody or polyclonal) capable of binding to the amino acid transporter may be used. Antibodies) and the like can be used. For example, examples of amino acid transport system inhibitors for LAT-1 include JPH203 (Yun, DW et al., J Pharmacol. Sci., 124, 208-217 (2014)) and BCH (2-aminobicyclo- (2,). 2,1) -Heptane-2-carboxylic acid), thyroid hormone triiodothyronine (T3) (Uchino, H. et al., Mol. Pharmacol., 61, 729-737 (2002)), KYT-0353 (Oda) , K et al., Cancer Sci., 101, 173-179. (2010)), a monoclonal antibody that recognizes LAT-1 (Ohkawa, M. et al., Biochem. Biophyss. Res. Commun., 406, 649-655 (2011). )), Etc., and JPH203 and / or BCH can be preferably used.

As the amino acid transport system inhibitor, one synthesized and produced according to a conventionally known method may be used, or a commercially available one may be used.

In addition to the above-mentioned at least one amino acid and / or at least one amino acid transport system inhibitor, the composition according to the present invention includes at least one additive (for example, an additive) commonly used in the manufacture of pharmaceutical products. Formants, binders, disintegrants, lubricants, solvents, solubilizers, suspending agents, isotonic agents, buffers, pH adjusters, stabilizers, preservatives, antioxidants, etc.) It can be appropriately blended according to the form and dosage form of the composition. In this case, the composition according to the present invention relates to a pharmaceutical composition containing at least one amino acid and / or at least one amino acid transport system inhibitor, and at least one additive. The "composition according to the present invention" referred to herein includes all aspects of the pharmaceutical composition. The dosage form of the composition is not particularly limited, and for example, tablets, powders, fine granules, granules, capsules, syrups, injections, infusions and the like can be used.

The composition according to the present invention may be in the form of a selected amino acid, a selected amino acid transport system inhibitor, and optionally at least one additive combined in one composition. , Or a kit or combination (eg, a pharmaceutical combination) in which the selected amino acid, the selected amino acid transport system inhibitor, and optionally at least one additive are made into separate compositions, and each composition is separately contained and combined. It may be in the form of. In this case, the kit or combination according to the present invention contains two or more compositions containing the above components. The "kit according to the present invention" referred to herein includes aspects of the above combinations (eg, pharmaceutical combinations) in any case.

The composition or kit of the present invention can be used to selectively improve the amount of boron-containing compound accumulated in cancer cells. "Selectively improving the accumulation amount of boron-containing compounds in cancer cells" means that the amount of boron-containing compounds taken up by cancer cells is higher than the amount of boron-containing compounds taken up by normal cells. For example, the concentration ratio of the boron-containing compound taken up in cancer cells and normal cells, or cancer tissue and normal tissue, or the radioactivity ratio detected by PET (hereinafter, referred to as "T / N ratio"). ) Can be 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, or 10 or more. In the case of the radioactivity ratio, in general, the region of interest in the cancer tissue can be calculated from the voxel value, and the region of interest in the normal region can be calculated using the average value of 49 to 256 pixels (Fluorine-18-). labeled fluorine blue voxel glioma PET in patients with glioma., Imahori Y, Ueda S, Ohmori Y, Kusuki T, Ono K, Fujii R, Ido39.

Cancer cells generally require more nutrients (such as sugars and amino acids) than normal cells to maintain their cell growth and metabolism. In cancer cells, high expression of their transport system is observed in order to supply more nutrients. Based on the difference in the expression level of the transport system, the cancer cells can take up the administered boron-containing compound in a larger amount than the normal cells. At least one amino acid in the composition of the present invention competes with a boron-containing compound for uptake into cancer cells and normal cells, but the expression level of the transport system differs in the presence of at least one amino acid. And, based on the difference in volume of distribution, the amount of boron-containing compounds that can be taken up in normal cells is significantly reduced (Y. Imahori et al., 1998, supra). Thereby, the T / N ratio can be increased, and the accumulated amount of the boron-containing compound in the cancer cells can be selectively improved.

In addition, at least one amino acid transport system inhibitor in the composition of the present invention can inhibit the amino acid transport system in cancer cells and / or normal cells. When the amino acid transport system inhibitor is an inhibitor for the amino acid transport system such as L-type amino acid transporter 1 (LAT-1) that is observed in cancer cells, the boron-containing compound administered to the cancer cells is sufficient. By acting the inhibitor in the incorporated state, the activity / function of the amino acid transport system is inhibited, the outflow of the boron-containing compound from the cancer cells is suppressed, and the amount of the boron-containing compound in the cancer cells is reduced. Can be retained. For example, LAT-1 exhibits Na ⁺ -independent exchange transport activity and antiport, that is, the activity of exchanging amino acid molecules existing inside and outside the cell. Therefore, when LAT-1 is inhibited, the intracellular transport (uptake) is inhibited, and at the same time, the extracellular transport (outflow) is also inhibited. As a result, the outflow of the incorporated boron-containing compound from the cancer cells can be suppressed, and the amount of the boron-containing compound in the cancer cells can be maintained.

For example, at least one amino acid transport system inhibitor in the composition or kit of the present invention is an amino acid transporter whose expression is observed to be upregulated in cancer cells (for example, LAT-1, LAT-3, ASCT2, ATB ^{0, +).} , XCT, etc.), it is preferable to administer at least one amino acid transport system inhibitor after administering the boron-containing compound to cancer cells. In this case, the administration interval between the boron-containing compound and at least one amino acid transport system inhibitor is such that the effect of the inhibitor can be obtained at the stage where the amount of the boron-containing compound incorporated into the cancer cells is at or near the maximum. In addition, it can be appropriately set based on the outflow characteristics of the boron-containing compound in the target cancer cells. For example, in the target cancer cells, the amount of the boron-containing compound in the cancer cells increases immediately after the administration of the boron-containing compound, and reaches a certain value within a predetermined time (for example, 180 minutes after the administration) from the administration. In the case of a type having characteristics (hereinafter, also referred to as "type I"), the administration interval between the boron-containing compound and at least one amino acid transport system inhibitor is such that the amount of the boron-containing compound in the cancer cell is constant. It can be set appropriately within the time range until the value is reached. Alternatively, the target cancer cell is a type having a property that the amount of the boron-containing compound in the cancer cell increases immediately after the administration of the boron-containing compound, but decreases after a certain period of time (hereinafter, "Type II"). In the case of (also referred to as), the administration interval between the boron-containing compound and at least one amino acid transport system inhibitor is the time from the time when the amount of the boron-containing compound in the cancer cell reaches the maximum value to the time when it reaches the minimum value. It can be set appropriately within the range of. In this case, the administration interval is preferably in the range of 20 to 180 minutes, more preferably in the range of 20 to 90 minutes. By using the composition or kit of the present invention in such a procedure, the outflow of the boron-containing compound from the cancer cells can be suppressed and the amount of the boron-containing compound in the cancer cells can be maintained.

When the composition or kit of the present invention is used in the above procedure, the boron-containing compound can be retained in cancer cells, so that the irradiation start timing of thermal neutrons or extrathermal neutrons or mixed beams in BNCT can be delayed. .. In general, the concentration of a boron-containing compound in serum peaks after a lapse of a certain period of time after administration to a cancer patient, and decreases sharply after the end of administration (Non-Patent Document 1). Therefore, when the composition or kit of the present invention is used in the above procedure, the occurrence of damage to the vascular endothelium due to BNCT is substantially delayed by delaying the irradiation start timing of thermal neutrons, extrathermal neutrons, or mixed beams. It can be reduced and the therapeutic effect on cancer can be substantially improved. Furthermore, when BNCT is applied to a cancer patient who needs to lengthen the irradiation time of thermal neutrons or extrathermal neutrons or mixed beams due to factors such as tumor size and / or localization, the present invention is described in the above procedure. By using the composition or kit of the above, a predetermined therapeutic effect can be obtained by a single administration without additional administration of a boron-containing compound.

The outflow characteristics of the boron-containing compound in the target cancer cells are not limited, but for example, a boron-containing compound labeled on the cancer cells (for example, ¹⁸ FBPA) is administered and incorporated into the cancer cells by PET. By investigating the time course of the labeled boron-containing compound amount, the administration time of the LAT-1 inhibitor and the neutron irradiation plan can be determined (Fig. 4).

When the amino acid transport system inhibitor is an inhibitor for the amino acid transport system such as LAT-2, which is expressed in normal cells, it is normal to administer the boron-containing compound in the presence of the inhibitor. It is possible to suppress the uptake of boron-containing compounds into cells.

As described above, by inhibiting the amino acid transport system in cancer cells and / or normal cells by utilizing the amino acid transport system inhibitor, the accumulation amount of the boron-containing compound in the cancer cells can be selectively improved. The T / N ratio can be increased.

According to the present invention, it is possible to selectively improve the accumulation amount of boron-containing compounds in cancer cells, thereby enabling selective destruction / removal of cancer cells in BNCT and cells other than cancer cells (cells other than cancer cells (). Normal cells, immune cells, etc.) can be prevented from radiation damage. That is, the composition or kit of the present invention can be used to prevent cells other than cancer cells from radiation damage. Further, according to the present invention, the accumulated amount of the labeled boron-containing compound in the cancer cells can be selectively improved, the detection of the cancer cells by PET or MRI can be clarified, and the accuracy thereof can be improved. In addition, the accumulated amount of boron-containing compounds in cancer cells can be evaluated with high accuracy, and a good treatment plan for BNCT can be obtained.

<2. Therapeutic agents or kits used for BNCT>
The present invention comprises a boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor used to selectively improve the accumulation of the boron-containing compound in cancer cells. The present invention relates to a therapeutic agent or treatment kit for treating cancer by BNCT.

In the present invention, the "boron-containing compound" may be any one that can be used in BNCT, and examples thereof include amino acids having a boron-containing substituent, preferably an aromatic having a boron-containing substituent and the like. As the boron-containing compound, those described in the above "1. Composition or kit" can be used, and BPA is preferable.

As the "at least one amino acid" in the present invention, those described in the above "1. Composition or kit" can be used. For example, when the boron-containing compound is BPA, the amino acids used preferably include phenylalanine and / or tyrosine.

In the present invention, as the "at least one amino acid transport system inhibitor", those described in the above "1. Composition or kit" can be used. For example, an amino acid transport system inhibitor for L-type amino acid transporter 1 (LAT-1) can be used, and JPH203 and / or BCH can be preferably used.

The therapeutic agent according to the present invention can include the above-mentioned boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor, as well as additional compounds used for cancer treatment. Such compounds may include BSH and boron-10 liposomes and gadolinium available in BNCT, porphyrin compounds available in photodynamic therapy (PDT), and the like.

In addition to the above-mentioned boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor, the therapeutic agent according to the present invention includes at least one commonly used in the manufacture of pharmaceutical products. Additives can be added. As the additive, those described in the above "1. Composition or kit" can be used, and can be appropriately selected according to the form and dosage form of the therapeutic agent.

The therapeutic agent according to the present invention is a form in which a boron-containing compound, a selected amino acid and / or a selected amino acid transport system inhibitor, and optionally at least one additive are combined and blended in one composition. Alternatively, the boron-containing compound, the selected amino acid and / or the selected amino acid transport system inhibitor, and optionally at least one additive are made into separate compositions, and each composition is contained separately. It may be in the form of a combination of treatment kits or combinations (for example, a pharmaceutical combination).

The dosage form of the therapeutic agent is not particularly limited, and for example, tablets, powders, fine granules, granules, capsules, syrups, injections, infusions and the like can be used. When the boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor are separate compositions, each composition may have the same form or each. It may be in a different form. For example, the boron-containing compound can be an injection or an infusion, and at least one amino acid and / or at least one amino acid transport system inhibitor can be an infusion or an injection.

The therapeutic agents or kits of the present invention can be used in methods for treating cancer by BNCT. In this method, a boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor are administered to selectively improve the accumulation amount of the boron-containing compound in cancer cells. It includes a step of irradiating cancer cells with thermal neutrons, extrathermal neutrons, or a mixed beam to kill the cancer cells.

Examples of cancers that can be treated by this method include solid cancers, invasive cancers, recurrent cancers treated with radiation, and specifically, mesenteric tumors, breast cancers, brain tumors, melanomas, head and neck tumors, gliomas, and gastric cancers. , Lung cancer, liver cancer, inflammatory breast cancer, pancreatic cancer, bile duct cancer, colon cancer, prostate cancer, uterine cancer, ovarian cancer, oviduct cancer, vaginal cancer, genital cancer, chorionic villi cancer, metastatic cancer, lymph node metastatic cancer, Examples include, but are not limited to, malignant melanoma.

When carrying out this method, it is desirable to confirm the T / N ratio with PET using a labeled boron-containing compound in advance to determine the dose of the boron-containing compound.

In this method, the dose of the boron-containing compound is appropriately changed according to factors such as the type of cancer, the amount of the boron-containing compound accumulated in the cancer cells, and the T / N ratio. For example, in the case of BPA, adult 1 It can be appropriately selected from the range of 1 mg to 2000 mg, preferably 10 mg to 1000 mg, and more preferably 150 mg to 500 mg per 1 kg of body weight.

The method for administering the boron-containing compound is not particularly limited as long as it is a method for efficiently accumulating in cancer cells as a target site, and for example, it can be administered in the form of an injection or an infusion solution. When the boron-containing compound is used as an injection, it can be used by dissolving or suspending it in physiological saline. At this time, additional additives such as a pH adjuster, a surfactant, and a dissolution accelerator may be added. When a boron-containing compound is used as an infusion solution, it can be mixed with an infusion solution containing various components such as glucose and amino acids.

In this method, the dose of amino acid is appropriately changed depending on factors such as the type of cancer, the amount of accumulated boron-containing compound in cancer cells, and the T / N ratio, but 1 mg to 5000 mg per 1 kg of adult body weight. It can be appropriately selected from the range of 10 mg to 1000 mg. The ratio of the dose of the boron-containing compound to the amino acid is not particularly limited, but the amino acid may be 0.1 to 1000 parts by weight, preferably about 1 to 100 parts by weight, based on 1 part by weight of the boron-containing compound.

As for the method of administering the amino acid, it is preferable to administer the amino acid so that the amino acid coexists in the blood at the stage when the boron-containing compound is taken up into the cell. The amino acid may be administered before the boron-containing compound is administered, after the boron-containing compound is administered, or together with the boron-containing compound. For example, administration can be started from 0 (simultaneous administration) to 1 hour before administration of the boron-containing compound.

In this method, the dose of the amino acid transport system inhibitor is appropriately changed according to factors such as the type of cancer, the amount of accumulated boron-containing compounds in cancer cells, the type of amino acid transport system inhibitor used, and the T / N ratio. However, it can be appropriately selected from the range of 10 μg / m ^{2 to} 1000 mg / m ² . For example, when the amino acid transport system inhibitor is JPH203 ^{is, 5mg / m 2 ~500mg / m} 2, can be preferably used in an amount which is suitably selected from the range of 10mg ^{/ m 2} ~200mg ^/ m 2 ..

The method for administering the amino acid transport system inhibitor is not particularly limited as long as it is a method for efficiently accumulating the boron-containing compound in the cancer cells at the target site, and is appropriately determined according to the target and type of the amino acid transport system inhibitor to be used. be able to. If the amino acid transport system inhibitor used is intended to inhibit the amino acid transport system in cancer cells (for example, an amino acid transport system inhibitor for LAT-1), the amount of boron-containing compound incorporated into the cancer cells. It is preferable to administer the inhibitor so that the effect of the inhibitor can be obtained at the stage where the amount is at or near the maximum. For example, it is preferable to administer at least one amino acid transport system inhibitor after administering the boron-containing compound to cancer cells. This step can be determined by performing PET with the labeled boron-containing compound in advance and examining the change over time in the accumulated amount of the labeled boron-containing compound in cancer cells. For example, in the target cancer cells, the amount of the boron-containing compound in the cancer cells increases immediately after the administration of the boron-containing compound, and reaches a certain value within a predetermined time (for example, 180 minutes after the administration) from the administration. In the case of the characteristic type (type I), the administration interval between the boron-containing compound and at least one amino acid transport system inhibitor is the time until the amount of the boron-containing compound in the cancer cell reaches a certain value. It can be set appropriately within the range of. Alternatively, if the target cancer cell is of a type (type II) in which the amount of the boron-containing compound in the cancer cell increases immediately after administration of the boron-containing compound but decreases after a certain period of time, it is included. The administration interval between the boron compound and at least one amino acid transport system inhibitor is appropriately set within the time range from the time when the amount of the boron-containing compound in the cancer cell reaches the maximum value to the time when the amount reaches the minimum value. be able to. In this case, the administration interval is preferably in the range of 20 to 180 minutes, more preferably in the range of 20 to 90 minutes. If the amino acid transport system inhibitor used is intended to inhibit the amino acid transport system in normal cells (for example, an amino acid transport system inhibitor for LAT-2), the boron-containing compound is taken up into the cell. It is preferable to administer the inhibitor in stages so that the effect of the inhibitor can be obtained. For example, administration can be started from 0 (simultaneous administration) to 1 hour before administration of the boron-containing compound so that the amino acid transport system inhibitor coexists in the blood. In addition, any type of amino acid transport system inhibitor further inhibits the amino acid transport system after completion of administration of the boron-containing compound and / or during thermal neutron or extrathermal neutron or mixed beam irradiation, if necessary. The agent may be administered.

Irradiation of thermal neutrons or extrathermal neutrons or mixed beams can be performed using techniques commonly practiced in BNCT. It can be carried out using a nuclear reactor as a neutron source for thermal neutrons. As the reactor, for example, the reactors of the Reactor Laboratory attached to Kyoto University and the Japan Atomic Energy Agency can be used for neutron capture therapy (BNCT). Alternatively, a small accelerator for a neutron source that can be installed and used in a hospital may be used.

Irradiation with thermal neutrons or extrathermal neutrons or mixed beams can be performed at a stage where the concentration of the boron-containing compound in serum is low and the T / N ratio is high so as not to damage normal tissues.

In general, the concentration of boron-containing compound in serum peaks after a certain period of time has passed since administration to a cancer patient, and decreases sharply after administration. The amount of boron-containing compound incorporated into cancer tissue reaches a maximum or near the maximum within 20 to 40 minutes after administration, and then gradually decreases. The amount of boron-containing compound incorporated into normal tissues gradually increases after administration (Y. Imahori et al., 1998, supra). The behavior of the boron-containing compound can be evaluated by a PET examination using FBPA labeled with ¹⁸ F. By this test, for example, the concentration of the boron-containing compound in serum ( ¹⁸ F (cps / mL)) is cancerous. The amount of boron-containing compound incorporated into the tissue ( ¹⁸ F (cps / mL)) is 80% or less, 70 or less, 60% or less, 50% or less, or 40% or less, and the T / N ratio is 2. Or more, 3 or more, 4 or more, 5 or more, 6 or more, 8 or more, or 10 or more, the irradiation can be performed.

Hereinafter, an example of a particularly preferable embodiment in this method will be described.
In this method, BPA is used as a boron-containing compound, and intravenous administration of an amino acid infusion containing phenylalanine and / or tyrosine is started 0 to 30 minutes before administration of BPA. Rest for 20 minutes to 1 hour after administration of BPA to allow cancer cells to take up BPA. In addition to or instead of intravenous administration of amino acid infusion, at the stage where the amount of boron-containing compound incorporated into cancer cells or cancer tissue is at or near the maximum (for example, 0 to 90 minutes after the end of BPA administration). , Preferably after 0 to 60 minutes, more preferably after 20 to 40 minutes), the intravenous administration of the amino acid transport system inhibitor to LAT-1 is started. After that (for example, 10 to 20 minutes after administration of the amino acid transport system inhibitor), thermal neutrons or extrathermal neutrons or mixed beams are irradiated. When irradiating with thermal neutrons, administration of the amino acid infusion and / or the amino acid transport system inhibitor may be continued or discontinued.

Traditionally, BNCT has usually been performed only once for the same cancer patient. Generally, phagocytic cells such as macrophages, which have a high ability to take up boron-containing compounds, exude around cancer cells destroyed by performing BNCT. If a second BNCT is performed in this state, radiation damage to phagocytic cells may occur. For this reason, it has been virtually impossible to carry out BNCT multiple times.

On the other hand, according to this method, the accumulated amount of boron-containing compound in cancer cells can be selectively improved, and uptake of boron-containing compound in cells other than cancer cells (normal cells, phagocytic cells such as macrophages, etc.) and Accumulation can be suppressed and these cells can be prevented from radiation damage. This makes it possible to carry out BNCT multiple times for the same cancer patient, and to carry out more effective treatment.

Further, according to this method, since the boron-containing compound can be retained in cancer cells, it is possible to delay the irradiation start timing of thermal neutrons or extrathermal neutrons or mixed beams in BNCT. As described above, in general, the concentration of the boron-containing compound in serum peaks after a certain period of time has passed since the administration to the cancer patient, and decreases sharply after the administration is completed. Therefore, in this method, by delaying the irradiation start timing of thermal neutrons or extrathermal neutrons or mixed beams, the occurrence of damage to the vascular endothelium due to BNCT is substantially reduced, and the therapeutic effect on cancer is substantially reduced. Can be improved. Furthermore, when BNCT is applied to cancer patients who need to lengthen the irradiation time of thermal neutrons or extrathermal neutrons or mixed beams due to factors such as tumor size and / or localization, this method includes A predetermined therapeutic effect can be obtained by a single administration without additional administration of a boron compound.

<3. Diagnostic agent or kit used for PET or MRI>
The present invention transports at least one amino acid and / or at least one amino acid used to selectively improve the labeled boron-containing compound and the accumulation of the labeled boron-containing compound in cancer cells. The present invention relates to a diagnostic agent or a diagnostic kit for diagnosing cancer by PET or MRI, which comprises a system inhibitor.

In the present invention, "diagnosing cancer" means detecting cancer cells and cancer tissues and / or evaluating the amount of boron-containing compounds accumulated in the cancer cells and cancer tissues.

In the present invention, the "labeled boron-containing compound" may be any compound that can be detected by PET or MRI, and for example, the aromatic amino acid having a boron substituent described in "1. Composition or kit" above may be used. Further, compounds labeled with positron nuclei can be utilized, preferably BPA (eg, FBPA) labeled with ¹⁸ F. Alternatively, as the "labeled boron-containing compound" in the present invention, a compound detectable by CT can also be used in the same manner.

As the "at least one amino acid" in the present invention, those described in the above "1. Composition or kit" can be used. For example, when the labeled boron-containing compound is a labeled BPA, the amino acids used preferably include phenylalanine and / or tyrosine.

In the present invention, as the "at least one amino acid transport system inhibitor", those described in the above "1. Composition or kit" can be used. For example, an amino acid transport system inhibitor for L-type amino acid transporter 1 (LAT-1) can be used, and JPH203 and / or BCH can be preferably used.

In addition to the above-labeled boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor, the diagnostic agent according to the present invention includes at least one commonly used in the manufacture of pharmaceutical products. One kind of additive can be blended. As the additive, those described in the above "1. Composition or kit" can be used, and can be appropriately selected according to the form and dosage form of the diagnostic agent.

The diagnostic agent according to the present invention comprises a labeled boron-containing compound, a selected amino acid and / or a selected amino acid transport system inhibitor, and optionally at least one additive in one composition. It may be in the form of a combination, or a labeled boron-containing compound, selected amino acids and / or selected amino acid transport system inhibitors, and optionally at least one additive in separate compositions. It may be in the form of a diagnostic kit or a combination (for example, a pharmaceutical combination) in which each composition is separately contained and combined.

The dosage form of the diagnostic agent is not particularly limited, and for example, tablets, powders, fine granules, granules, capsules, syrups, injections, infusions and the like can be used. If the labeled boron-containing compound, at least one amino acid and / or at least one amino acid transport system inhibitor, and optionally at least one additive are separate compositions, each composition It may have the same form or different forms. For example, the labeled boron-containing compound can be an injection or infusion, and at least one amino acid and / or at least one amino acid transport system inhibitor can be an infusion or injection.

The diagnostic agent or kit of the present invention can be used in a method for diagnosing cancer by PET or MRI. Alternatively, the diagnostic agent or kit of the present invention can be similarly utilized in a method for diagnosing cancer by CT. The method administered a labeled boron-containing compound and at least one amino acid and / or at least one amino acid transport system inhibitor to improve the accumulation of the labeled boron-containing compound in cancer cells. After that, the step of detecting the labeled boron-containing compound is included.

Examples of cancers that can be diagnosed by this method include solid cancers, invasive cancers, recurrent cancers treated with radiation, and specifically, mesenteric tumors, breast cancers, brain tumors, melanomas, head and neck tumors, gliomas, and gastric cancers. , Lung cancer, liver cancer, inflammatory breast cancer, pancreatic cancer, bile duct cancer, colon cancer, prostate cancer, uterine cancer, ovarian cancer, oviduct cancer, vaginal cancer, genital cancer, chorionic villi cancer, metastatic cancer, lymph node metastatic cancer, Examples include, but are not limited to, malignant melanoma.

In this method, the dose of the labeled boron-containing compound is described in "Guidelines for PET Examination Using FDG Produced in Hospital" (Nuclear Medicine, Japan, 38, 131-137, 2001). Therefore, it can be appropriately selected.

The method for administering the labeled boron-containing compound can be the same as that for the boron-containing compound described in "2. Therapeutic agent or kit" above.

In this method, the dose of amino acid is appropriately changed according to factors such as the type of cancer, the accumulated amount of labeled boron-containing compound in cancer cells, and the T / N ratio, but is 1 mg per 1 kg of adult body weight. It can be appropriately selected from the range of ~ 5000 mg, preferably 10 mg to 1000 mg. The ratio of the dose of the labeled boron-containing compound to the amino acid is not particularly limited, but the amino acid may be 0.1 to 1000 parts by weight, preferably about 1 to 100 parts by weight, based on 1 part by weight of the boron-containing compound. it can.

As for the method of administering the amino acid, it is preferable to administer the amino acid so that the amino acid coexists in the blood at the stage when the labeled boron-containing compound is taken up into the cell. Amino acids may be administered before administration of the labeled boron-containing compound, after administration of the labeled boron-containing compound, or with the labeled boron-containing compound. You may. For example, administration can be started from 0 (simultaneous administration) to 30 minutes before administration of the labeled boron-containing compound.

In this method, the dose of the amino acid transport system inhibitor is appropriately changed depending on factors such as the type of cancer, the accumulated amount of the labeled boron-containing compound in the cancer cells, and the T / N ratio, but is 10 μg / m. It can be appropriately selected from the range of ^{2 to} 1000 mg / m ² . For example, when the amino acid transport system inhibitor is JPH203 ^{is, 5mg / m 2 ~500mg / m} 2, can be preferably used in an amount which is suitably selected from the range of 10mg ^{/ m 2} ~200mg ^/ m 2 ..

The administration method of the amino acid transport system inhibitor is not particularly limited as long as it is a method for efficiently accumulating the boron-containing compound labeled on the cancer cell as the target site, and it should be appropriately determined according to the amino acid transport system inhibitor to be used. It can be administered in the same manner as the amino acid transport system inhibitor described in "2. Therapeutic agent or kit" above. If necessary, an amino acid transport system inhibitor may be further administered after the administration of the labeled boron-containing compound is completed.

Detection of labeled boron-containing compounds can be performed using techniques commonly performed in PET or MRI, depending on the labeling used. The boron atom, which is an NMR nuclide, can be detected by MRI for its accumulation or accumulation. Alternatively, even in the case of a label that can be detected by CT, the detection of the labeled boron-containing compound can be performed by using a method generally performed in CT.

Hereinafter, an example of a particularly preferable embodiment in this method will be described.
In this method, FBPA is used as a labeled boron-containing compound, and intravenous administration of an amino acid infusion containing phenylalanine and / or tyrosine is started 0 to 30 minutes before administration of FBPA. After administration of FBPA, rest for 20 minutes to 1 hour to allow FBPA to be taken up by cancer cells. In addition to or in place of intravenous administration of the amino acid infusion, at a stage where the amount of FBPA taken up into cancer cells or tissues is at or near the maximum (for example, 0 to 90 minutes after the end of FBPA administration, preferably After 0 to 60 minutes, more preferably 20 to 40 minutes), intravenous administration of the amino acid transport system inhibitor to LAT-1 is started. After that, FBPA is detected, cancer is detected using the presence or absence of FBPA accumulation as an index, and / or the amount of FBPA accumulated is evaluated. Upon detection of FBPA, administration of the amino acid infusion and / or the amino acid transport system inhibitor may be continued or discontinued.

According to this method, the accumulation amount of the labeled boron-containing compound in cancer cells can be selectively improved, and the uptake and accumulation of the labeled boron-containing compound in phagocytic cells such as normal cells and macrophages are suppressed. be able to. This facilitates the detection of cancer by PET or MRI and enables more accurate diagnosis of cancer. In addition, this method can be similarly applied to the detection of cancer by CT, facilitates the detection of cancer by CT, and enables more accurate diagnosis of cancer.

In addition, the labeled boron-containing compound used in this method is an analog of an unlabeled boron-containing compound, and both exhibit the same pharmacokinetics. Therefore, according to this method, the pharmacokinetics (for example, T / N ratio, etc.) of the boron-containing compound in combination with at least one amino acid and / or at least one amino acid transport system inhibitor can be estimated. .. This makes it possible to investigate the pharmacokinetics of the boron-containing compound required for performing BNCT described in the above "2. Therapeutic agent or kit used for BNCT", and a BNCT treatment plan suitable for each case. Can be obtained.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to these Examples.

BPA, which is the active ingredient of BNCT, is known to be taken up in cancer cells and normal cells at a similar ratio up to at least 500 mg / kg (Advances in the control of neutron cutaneous primary and metastatic melanoma bisphenol). Mishima et al., KURRI Technical Report, Vol. 357, 1-6, 1991).

(Example 1)
A 24-year-old man who developed a metastatic brain tumor of malignant melanoma (pituitary gland and lateral ventricular wall) was infused with a comprehensive amino acid preparation injection (200 ml) having the composition shown in Table 2 (about 4 ml /). min) was started. Five minutes after the start of the infusion, 5 ml (158 MBq) of FBPA was intravenously injected, and the patient was rested in a dark room for 30 minutes. After that, PET was carried out. The amino acid infusion was infused until the end of PET, and 160 ml was administered.

(Comparative Example 1)
FBPA (155MBq) was administered in the same manner as in Example 1 except that the infusion of amino acid infusion was not performed, and PET was performed. FIG. 1 shows PET images of the brain tumor tissue and its surroundings when FBPA labeled with ¹⁸ F was administered in the presence of amino acids (Example 1) and in the absence of amino acids (Comparative Example 1).

As can be seen from the results of Table 1 and FIG. 1, it can be seen that the PET value in Example 1 is higher in the tumor tissue and lower in the normal tissue than in Comparative Example 1. The T / N ratio also increased about 1.5 times.

(Example 2)
Examination of extracellular outflow inhibitory effect of accumulated ¹⁰ BPA LAT-1 inhibitors in a cancer cell experimental system Human Burkitt lymphoma cells (JCRB9119, Ramos (RA1)) so as to have a cell number of 1 × 10 ⁷ Was seeded in a cell culture flask. ¹⁰ A solution containing BPA was added to the cells and incubated for 1.5 hours. Then, a PBS solution containing BCH, which is a LAT-1 inhibitor, was added to the above cells, adjusted to a final concentration of 5 mM in the whole solution, and incubated for 20 minutes. In the control group, the same amount of PBS was added to the cells instead of the PBS solution containing BCH, and the cells were incubated under the same conditions. Cells were washed with PBS. The washed cells were incinerated with hydrogen peroxide and perchloric acid. ¹⁰ B contained in the incinerated sample was quantified using ICP-AES. FIG. 2 shows the quantification results of ¹⁰ B contained in the sample obtained by incinerating Ramos (RA1) cells.

The amount of ¹⁰ B contained in the sample obtained by ashing the cells is considered to represent the amount of ¹⁰ B taken up by the cells by the addition of ¹⁰ BPA. As shown in FIG. 2, in the case of Ramos (RA1) cells, by adding BCH after the addition of ¹⁰ BPA, the amount of ¹⁰ B taken up by the cells was significantly higher than that of the control group without BCH added. Increased. From the above results, it was shown that BCH, which is a LAT-1 inhibitor, has an extracellular outflow inhibitory effect of ¹⁰ BPA accumulated in cancer cells.

The effect of the LAT-1 inhibitor of ¹⁰ BPA accumulated in HSG cells on the extracellular outflow of ¹⁰ BPA was investigated by the same procedure as described above except that the cells used were replaced with human salivary gland cells (HSG). FIG. 3 shows the quantification results of ¹⁰ B contained in the sample obtained by incineration of HSG cells.

As shown in FIG. 3, in the case of HSG cells as well, by adding BCH after the addition of ¹⁰ BPA, the amount of ¹⁰ B taken up by the cells was significantly increased as compared with the control group without BCH added. ..

The extracellular outflow inhibitory effect of ¹⁰ BPA by BCH varied depending on the type of target cell. For example, in the case of HSG cells, the extracellular outflow inhibitory effect of ¹⁰ BPA by BCH was more significantly expressed as compared with the case of Ramos (RA1) cells (FIGS. 2 and 3). It is known that HSG cells have a high expression level of LAT-1 but a low affinity for BPA. Therefore, in the case of HSG cells, in the control group, the amount of ¹⁰ B taken up by the cells was reduced by the action of highly expressed LAT-1, whereas in the BCH-added group, the action of LAT-1 was inhibited. Therefore, it is considered that the amount of ¹⁰ B taken up by the cells was higher than that of the control group.

FIG. 4 shows the time course of the tumor / blood radioactivity ratio when ¹⁸ FBPA was administered to patients with various advanced cancers and examined by PET. As shown in FIG. 4, in the case of normal cancer patients, after administration of ¹⁸ FBPA, the tumor / blood radioactivity ratio increased and reached a constant value within 180 minutes after administration (Type I). In contrast, in certain cancer patients, the tumor / blood radioactivity ratio increased after administration of ¹⁸ FBPA, but decreased after a period of time (Type II). Patients with type II cancer were observed in 20 to 30% of the total group of patients with advanced cancer.

When BNCT is applied to patients with advanced cancer, in Type II patients, the administered ¹⁰ BPA may not accumulate inside the cancer cells and may flow out of the cells. For such a patient, when applying the combined administration of ¹⁰ BPA and LAT-1 inhibitor shown in this embodiment, the outflow inhibitory effect on extracellular ¹⁰ BPA by LAT-1 ^inhibitor, 10 BPA Is thought to be able to be retained in cancer cells.

All publications, patents and patent applications cited herein are incorporated herein by reference in their entirety.

Claims (16)

It is used to selectively increase the amount of accumulation of boron-containing compounds in cancer cells, a composition or kit comprising two or more amino acids including an aromatic amino acid, boron-containing compounds, boron-containing substituents The composition or kit which is an aromatic amino acid containing, or an aromatic amino acid containing a labeled boron-containing substituent . The composition or kit according to claim 1, wherein the boron-containing compound is 4-boronophenylalanine . The composition or kit according to claim 1 or 2, wherein the two or more amino acids contain at least phenylalanine and tyrosine . The composition or kit according to any one of claims 1 to 3, further comprising at least one amino acid transport system inhibitor. The composition or kit according to claim 4 , wherein at least one amino acid transport system inhibitor comprises an L-type amino acid transporter-1 (LAT-1) inhibitor. Comprising a boron-containing compound, and two or more amino acids including an aromatic amino acid, a therapeutic agent or kit for treating cancer by neutron capture therapy (BNCT), boron-containing compounds, boron-containing substituents The therapeutic agent or kit, which is an aromatic amino acid containing . The therapeutic agent or kit according to claim 6 , wherein the boron-containing compound is 4-boronophenylalanine . The therapeutic agent or kit according to claim 6 or 7, wherein the two or more amino acids contain at least phenylalanine and tyrosine. The therapeutic agent or kit according to any one of claims 6 to 8, further comprising at least one amino acid transport system inhibitor. The therapeutic agent or kit according to claim 9, wherein at least one amino acid transport system inhibitor comprises an L-type amino acid transporter-1 (LAT-1) inhibitor. The therapeutic agent or kit according to any one of claims 6 to 10, further comprising a mercaptoundecahydrododecaborate (BSH), a liposome containing boron-10, a gadolinium, or a porphyrin compound. And labeled boron-containing compound comprises two or more amino acids including an aromatic amino acid, positron emission tomography (PET) or magnetic resonance imaging and a diagnostic agent or kit for diagnosing cancer by (MRI) The diagnostic agent or kit, wherein the labeled boron-containing compound is an aromatic amino acid containing a labeled boron-containing substituent . Labeled boron-containing compound is a ^{18 F} becomes labeled with 4-boronophenylalanine, diagnostic agent or kit according to claim 12. The diagnostic agent or kit according to claim 12 or 13, wherein the two or more amino acids contain at least phenylalanine and tyrosine. The diagnostic agent or kit according to any one of claims 12 to 14, further comprising at least one amino acid transport system inhibitor. The diagnostic agent or kit according to claim 15, wherein at least one amino acid transport system inhibitor comprises an L-type amino acid transporter-1 (LAT-1) inhibitor.

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