JP2005289829A - Therapeutic agent for tumor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of the adverse effect on a living body caused by some delivering substance and binder for bonding a radioactive substance to the delivering substance for delivering the radioactive substance to a tumor cell. <P>SOLUTION: The subject therapeutic agent for tumor is effective for terminating the division of a tumor cell by singly depositing radioactive<SP>90</SP>Y<SP>3+</SP>in a diluted<SP>90</SP>YCl<SB>3</SB>solution to the tumor cell through the blood in contrast to the conventional agent to deposit the radioactive substance by a delivering substance such as chemical substance, antibody, protein or lipid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a therapeutic agent exhibiting a tumor cell growth inhibitory effect by using a radioactive substance ⁹⁰ Y ³⁺ in a ⁹⁰ YCL ₃ solution alone.

  Conventionally, for neoplastic growth inhibition using radioactive substances, the method of irradiating radiation from the outside, or the substance that carries the radioactive substance to the target site and the radioactive substance are combined to directly damage the limited target site A given site administration method is known (for example, Non-Patent Document 1).

  In vitro chemical substances, proteins such as antibodies, lipids, etc. are known as substances that carry radioactive substances to target cells. When these substances are used, the substances are combined with radioactive substances. A binder is required. However, since some of these transporting substances and binders may adversely affect the living body, it is difficult to search for these transporting substances and binding agents, and there is a problem that it is difficult to find the intended one.

As these specific therapeutic agents, as a tumor therapeutic agent that has excellent tumor accumulation and tumor cell killing ability in the treatment of liver cancer and the like, has no problem even when administered to a living body, and can be easily formulated ( Known is a therapeutic agent comprising a) a radioactive substance such as ⁹⁰ Y radioactive metal element, (b) a metal chelating reagent selected from naphthyridine derivatives, pyridopyrimidine derivatives and cuperone congeners, and (c) a tumor-accumulating oily solvent. (For example, Patent Document 1).

Furthermore, it is also known that a substituted metal chelate organic compound is used as a therapeutic agent for delivering a radioactive metal such as ⁹⁰ Y to a target site in a mammalian host (for example, Patent Document 2).
ICRP publication of the International Commission on Radiological Protection (ICRP), ICRP pub. 30 JP-A-9-169668 Special Publication 2002-500629

In the treatment of tumor cells such as osteosarcoma, the present invention allows a radioactive substance to be deposited alone on tumor cells without binding a radioactive substance and a substance carrying the same, a binder, etc. as in the prior art. An object of the present invention is to provide a tumor therapeutic agent that inhibits division.

In general, not only tumor cells but also cells and the like are damaged by receiving radiation, and the cell division is stopped. However, the therapeutic agent of the present invention uses a diluted ⁹⁰ YCL ₃ solution alone from a venous blood vessel. By injection, tumor cell division can be inhibited.

That is, as in the prior art, chemical substances carry it with radioactive substances, antibodies, proteins, rather than deposit on the tumor cells by lipid, etc. In the present invention, ⁹⁰ of radioactive material ⁹⁰ YCL ₃ solution Y ³⁺ alone is deposited in tumor cells via blood and inhibits cell division of the cells.

In addition, the inhibition of cell division by the therapeutic agent of the present invention is immediately effective within 30 minutes after injection, and the inhibition rate of cell division at that time is higher as the radioactivity concentration of ⁹⁰ YCL ₃ solution is higher, The longer the time elapsed since the injection, the greater the effect. Furthermore, the therapeutic agent of the present invention can be obtained by diluting an yttrium chloride solution containing ⁹⁰ Y ³⁺ with a buffer solution such as citric acid.

By injecting the therapeutic agent of the present invention into a blood vessel, it is possible to inhibit the division of osteosarcoma cells and the like, and the ⁹⁰ Y half-life is as extremely short as 64.1 hours. Recovery from normal cell radiation damage is possible.

(Adjustment of ⁹⁰ YCL ₃ solution)
The yttrium chloride ( ⁹⁰ YCL ₃ ) solution manufactured by AEA Technology QSA GmbH (braunschweig germany) and having the code number YASB11323 was used. This ⁹⁰ YCL ₃ is a pure beta-emitting nuclide whose half-life is 64.1 hours and whose beta-ray maximum energy is 2.28 MeV. This yttrium chloride solution is diluted to various concentrations using a pH 2.0 to 3.0 organic acid buffer (0.05 mol / L) to prepare the therapeutic agent solution of the cell mitotic agent of the present invention. Is done.

(Determination of ability to inhibit cell division)
Determination of cytostatic capacity when using the therapeutic agent of the present invention ^was performed using ^{[2 -14 C] Thymidine (14} C -thymidine). The ^[2 -14 C] Thymidine is a Amersham Pharmacia Biotech, it is commercially available under the code number CFA2189 batch 266.

That is, after the therapeutic agent of the present invention is injected into a mouse, the thymidine is injected 10 minutes before the sacrifice. If cell division of a cancer cell is active, this thymidine is taken up by the dividing cell. After thymidine administration, the mouse is killed and tumor tissue cells are removed from the mouse. The ¹⁴ C of thymidine taken up by the dividing cells was confirmed by confirming the intensity of the ¹⁴ C using microautoradiography to determine the cancer cell division inhibitory effect.

This determination is performed by a two-dimensional rapid determination method (Japanese Patent Application No. 2002-534827) developed by the Institute for Bioscience, and the cell division inhibition rate (%) determined by this method is calculated by the following equation: Indicated.
Mitosis inhibition rate (%) = (1− (number of silver particles in ⁹⁰ Y administration group / number of silver particles in subject group)) × 100
(Types of planted cancer cells: human osteosarcoma-derived cell line: Hu09)
This Hu09 was purchased from the Human Science Foundation. When this cell line was planted in a mouse, Hu09 was cultured according to the method of Kawai. That is, the culture cell RPMI-1640 (with 10% fetal bovine serum) was used for monolayer culture in a 5% CO ₂ incubator at 37 ° C., and the cultured cancer cell suspension was used.

(Photos of evaluating the effects of therapeutic agents containing cell division inhibitors)
FIG. 1 is a photograph showing that tumor cell division is inhibited as a result of administration of 10 YCi of ⁹⁰ YCL ₃ to tumor cells. In this case, tumor cell division is inhibited.
¹⁴ C thymidine is not incorporated into DNA. This shows that tumor cell division is inhibited by administration of the therapeutic agent of the present invention.

FIG. 2 is a photograph showing that cell division of tumor cells is actively carried out as a result of ⁹⁰ YCL _{3 not} being administered to the tumor cells. In this case, ¹⁴ C thymidine is incorporated into DNA. It is shown that. This shows that tumor cells are dividing (proliferated) when the therapeutic agent of the present invention is not administered. That is, FIG. 2 is a photograph when the therapeutic agent of the present invention is not administered. In this case, since cell division of the tumor cells is actively performed, ¹⁴ C thymidine is incorporated into DNA. As a result, silver particles (black spots) are formed. This silver particle is a silver particle precipitated by radiation from ¹⁴ C contained in thymidine by reducing silver halide on the photographic emulsion, and it is judged that thymidine is present indirectly by looking at the silver particle. it can.

(Raising test animals)
BALB / c nude mice were purchased from Claire Japan at the age of 4-5 weeks, and after preliminary breeding, those with good health were used for the test. Feed (CE-2 manufactured by CLEA Japan) and water during pre-breeding and testing were freely ingested. The breeding was performed in an environment with a temperature of 20.7 to 23.5 ° C., a humidity of 43 to 72% RH, and a light / dark cycle of 12 hours / 12 hours. Cages and flooring were changed and the breeding room was cleaned three times a week.

Hereinafter, the present invention will be described based on examples.
(Example 1)
107 BALB / c nude mice purchased at 4 to 5 weeks of age were planted with 10 ⁷ human cancer cells (Hu09) subcutaneously on the back and raised for 2 weeks. This mouse was injected with 0.1 ml of a ⁹⁰ YCL ₃ diluted citric acid solution from the tail vein, and the state of cancer cells 0.5 hours later was observed. As 0.1 ml of this diluted solution, ⁹⁰ YCL ₃ contains 3.7 kBq (0.1 μCi), 37 kBq (1 μCi), 370 kBq (10 μCi), 3.7 MBq (100 μCi), and 37 MBq (1,000 μCi), respectively. We used what was done.

A two-dimensional rapid determination method developed by the Bioscience Institute, Inc. was carried out on the cell inhibitory effect 0.5 hours after injecting the above five types of dilutions containing ⁹⁰ YCL ₃ into the mice. The results of measurement and determination using the mitotic inhibition rate formula are as follows.

Cell division inhibitory effect 0.5 hours after administration
⁹⁰ YCL ₃ 3.7 kBq (0.1 μCi) administration: 37%
Of ⁹⁰ YCL ₃ ^{37kBq (1μCi)} administration: 41%
Of ⁹⁰ YCL ₃ ^{370kBq (10μCi)} administration: 59%
⁹⁰ YCL ₃ 3.7 MBq (100 μCi) administration: 58%
Administration of ⁹⁰ YCL ₃ at 37 MBq (1,000 μCi): 100%
(Example 2)
107 BALB / c nude mice purchased at 4-5 weeks of age were planted with 10 ⁷ human cancer cells (Hu09) subcutaneously in the back and raised for 2 weeks. This mouse was injected with 0.1 ml of a ⁹⁰ YCL ₃ citrate diluted solution from the tail vein, and the state of cancer cells 6 hours later was observed. As 0.1 ml of this diluted solution, ⁹⁰ YCL ₃ contains 3.7 kBq (0.1 μCi), 37 kBq (1 μCi), 370 MBq (10 μCi), 3.7 MBq (100 μCi), and 370 MBq (1,000 μCi), respectively. We used what was done.

Measurement of cell inhibitory effect 6 hours after injection of the above 5 kinds of dilutions containing ⁹⁰ YCL ₃ into the mice by carrying out a two-dimensional rapid determination method developed by the Institute for Biological Sciences. The results of determination using the division inhibition rate formula are as follows.

Cell division inhibitory effect 6 hours after administration
⁹⁰ YCL ₃ 3.7 kBq (0.1 μCi) administration: 49%
⁹⁰ 37 YCL ₃ kBq (1μCi) administration: 57%
Of ⁹⁰ YCL ₃ ^{370kBq (10μCi)} administration: 77%
⁹⁰ YCL ₃ 3.7 MBq (100 μCi) administration: 83%
Administration of ⁹⁰ YCL ₃ at 37 MBq (1,000 μCi): 100%
(Example 3)
107 BALB / c nude mice purchased at 4 to 5 weeks of age were planted with 10 ⁷ human cancer cells (Hu09) subcutaneously on the back and raised for 2 weeks. This mouse was injected with 0.1 ml of a ⁹⁰ YCL ₃ diluted citric acid solution from the tail vein, and the state of cancer cells 24 hours later was observed. In ⁹⁰ ml of this diluted solution, ⁹⁰ YCL ₃ contains 3.7 kBq (0.1 μCi), 37 kBq (1 μCi), 370 kBq (10 μCi), 3.7 MBq (100 μCi), and 37 MBq (1,000 μCi), respectively. We used what was done.

Measurement of cell inhibitory effect 24 hours after the injection of the above-mentioned five types of dilutions containing ⁹⁰ YCL ₃ into the mice by carrying out a two-dimensional rapid determination method developed by the Institute for Biological Sciences. The results of determination using the division inhibition rate formula are as follows.

Cell division inhibitory effect 24 hours after administration
⁹⁰ YCL ₃ 3.7 kBq (0.1 μCi) administration: 53%
⁹⁰ YCL ₃ 37 kBq (1 μCi) administration: 29%
Of ⁹⁰ YCL ₃ ^{370kBq (10μCi)} administration: 100%
90 YCL ₃ 3.7 MBq (100 μCi) administration: 97%
Administration of ⁹⁰ YCL ₃ at 370 MBq (1,000 μCi): 100%

It is the photograph which evaluated the effect of the therapeutic agent of this invention (It has shown that ¹⁴ C thymidine is not taken up into DNA since the cell division has stopped). It is a photograph when the therapeutic agent of the present invention is not administered (showing that ¹⁴ C thymidine is incorporated into DNA (silver particles can be seen because cell division of tumor cells is actively performed) )

Claims (5)

A therapeutic agent having a therapeutic effect on tumor cells by using ⁹⁰ Y ³⁺ alone, comprising ⁹⁰ YCL ₃ dissolved. The therapeutic agent according to claim 1, comprising adjusting the pH of an yttrium chloride solution containing 99.5% or more of ⁹⁰ Y ³⁺ using an organic acid buffer such as citric acid or an inorganic acid buffer such as phosphoric acid. 148 kBq (4 μCi) to 14.8 MBq (400 μCi) per kg body weight
The therapeutic agent according to claim 1 or 2, wherein a diluent of ⁹⁰ YCL ₃ solution containing ⁹⁰ Y ³⁺ is injected intravenously. The therapeutic agent according to any one of claims 1 to ³ , comprising an yttrium chloride solution containing ⁹⁰ Y ³⁺ having a property of accumulating in a tumor or the like only by blood circulation. The therapeutic agent according to any one of claims 1 to 4, comprising an yttrium chloride solution containing ⁹⁰ Y ³⁺ having an immediate effect that exhibits an effect within 30 minutes after intravascular injection.

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