CN110893196A

CN110893196A - Novel method for improving tumor hypoxia

Info

Publication number: CN110893196A
Application number: CN201911190153.6A
Authority: CN
Inventors: 蔡林涛; 何华美; 刘兰兰; 梁锐晶; 周海梅; 潘宏
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-03-20
Also published as: WO2021104112A1

Abstract

The invention provides living drug cyanobacteria which produce oxygen through photosynthesis under laser irradiation to improve tumor hypoxia, thereby changing the tumor microenvironment, realizing oxygen-enriched tumor treatment effect and providing a new choice for cancer treatment. The in vitro experiment proves that cyanobacteria can generate oxygen infinitely under the condition of providing 660nm laser irradiation; in vivo experiments prove that the tumor hypoxia condition is obviously improved by injecting cyanobacteria into a mouse through tail vein and irradiating the tumor of the mouse by 660nm laser.

Description

Novel method for improving tumor hypoxia

Technical Field

The invention belongs to the field of biological medicines, and particularly relates to a novel method for improving tumor hypoxia.

Background

The traditional methods for tumor treatment mainly include surgical resection, chemotherapy, radiotherapy, molecular targeting therapy and the like, which can effectively treat part of tumors and control tumor metastasis, but still have some defects, such as high recurrence rate of surgical resection, easy induction of systemic adverse reactions by chemotherapy, severe damage of ionizing radiation to normal tissues around the tumors and the like. Optical tumor therapy is a new cancer treatment method with good specificity and non-invasiveness, which has been widely studied in recent years, and is mainly classified into photothermal therapy and photodynamic therapy. Oxygen is a key raw material for photodynamic therapy to have curative effect, and can be activated into singlet oxygen with cell killing capability by photosensitive drugs under laser irradiation, so that tumors are treated. However, it is found that the oxygen content in most solid tumors is much lower than that of normal tissues, the hypoxic region in the solid tumors is a complex microenvironment, the blood supply inside the solid tumors is insufficient, and a large amount of oxygen is consumed by tumor cell proliferation, so that the tumors generate hypoxic microenvironments, which affect the treatment effects of radiotherapy, chemotherapy, photodynamic therapy, immunotherapy and the like, and are also potential sources of relapse and metastasis after the tumor treatment is completed. Therefore, the development of an efficient and safe tumor oxygenation technology changes the tumor microenvironment, realizes the oxygenation tumor treatment effect, and has great experimental significance.

In a hypoxic tumor microenvironment, on one hand, the tumor cells block metabolic activity due to lack of oxygen sources, so that the cell proliferation is slowed, or the cells are apoptotic and necrotic; on the other hand, hypoxia causes the tumor cells to adaptively generate changes of gene and protein expression, finally causes abnormal metabolism of the tumor cells, and also stimulates malignant growth and treatment resistance of the tumors. Therefore, the oxygen supply intervention treatment of the tumor is particularly important, the oxygen concentration in the tumor is improved by adopting different means, and the oxygen intervention tumor hypoxia microenvironment and the corresponding treatment resistance function are adopted to achieve the enhancement effect on radiotherapy, chemotherapy, photodynamic therapy, thermotherapy and immunotherapy. The current clinical intervention method for oxygen supply for tumor is hyperbaric oxygen therapy, which enables patients to be in hyperbaric oxygen environment (such as hyperbaric oxygen chamber) or inhale carbopol gold, and passively dissolves high-concentration oxygen into blood to force the body to provide more oxygen for tumor through blood circulation. As an adjuvant therapy, hyperbaric oxygen therapy can improve the sensitivity of tumor cells to radiotherapy and improve the therapeutic effect. However, tumor hypoxic roots result from an imbalance in their intrinsic oxygen deficiency and oxygen abundance; hyperbaric oxygen therapy supplies oxygen to tumors ultimately by oxygen delivery through tumor vessels, and the abnormal structure of tumor vessels severely limits the oxygen supply to tumors through blood oxygen. Therefore, new approaches are needed to implement more efficient tumor oxygenation intervention therapy. For example, first: can increase tumor oxygen supply by improving tumor blood vessels, and some antiangiogenic agents improve tumor blood flow by reducing peripheral resistance of blood vessels, normalize tumor vascular system, and correspondingly deliver more oxygen to tumor. In addition, endostatin and other anti-angiogenic agents, including Bevasizumab (anti-VEGF inhibitor), also have an effect of normalizing tumor blood vessels, but their mechanism of action is not clear; secondly, the method comprises the following steps: similarly, the tumor in-situ oxygenation based on the oxygen production reaction, catalase and manganese dioxide can utilize hydrogen peroxide in tumor tissues to catalyze and decompose the hydrogen peroxide into oxygen and water, or react with the oxygen and the water to generate oxygen; some photo water splitting materials can decompose water to produce oxygen under the excitation of light energy. By delivering these oxygen-generating materials to tumors, oxygen can be generated within the tumor by chemical reactions, thereby providing oxygen intervention to the tumor, eliminating the associated therapeutic resistance. However, the efficiency of tumor oxygen production depends on the concentration of the nano-drug and the reaction substrate (such as hydrogen peroxide and water) in the tumor, and the final oxygen increase amount is limited by the degree of the oxygen production chemical reaction in the tumor. In addition, the in vivo dosage of these inorganic nanomaterials is also limited in view of biosafety; thirdly, the method comprises the following steps: oxygen molecules can be stored in the artificial oxygen carrier through dissolution, non-covalent combination and the like, and when the oxygen molecules reach the tumor, the stored oxygen can be released into the tumor tissue, so that the oxygen content of the tumor is increased. However, the development of artificial oxygen carriers further exacerbates the shortage of blood resources due to the need for pathogen detection of human donated blood once it has been collected, the need for special refrigerated storage conditions (extended shelf life of about 6 weeks), and the need for cross-matching testing prior to transfusion, all of which result in time and money costs. Therefore, the development of ideal artificial oxygen carriers remains one of the most important challenges in the biomedical field.

Photosynthetic bacteria are the earliest prokaryotic photoautotrophs with an original light energy synthesis system appearing on the earth and are mainly divided into two categories, photosynthetic oxygen-producing photosynthetic bacteria and photosynthetic non-oxygen-producing photosynthetic bacteria. Cyanobacteria, a photosynthetic oxygen-producing photosynthetic bacterium, has been on earth for over thirty billion years, undergoes a transformation process from anaerobic to aerobic atmosphere, has wide distribution in a long-term evolution process, is mainly distributed in freshwater and marine environments, and can also grow under severe and extreme conditions. The cyanobacteria has the advantages of very simple nutritional requirements, only light, water, carbon dioxide and inorganic salt, high growth speed, convenient culture, low cost, relatively easy genetic manipulation means and the like, and is more dominant in biotechnological applications. We have found that cyanobacteria capable of producing oxygen under laser irradiation improve the tumor hypoxic microenvironment by self-oxygen production to enhance the tumor treatment efficiency. The cyanobacteria becomes a new generation of 'living drug' for improving hypoxia, and the cyanobacteria produces oxygen under laser to improve the tumor hypoxia microenvironment, thereby providing a new choice for cancer treatment.

Disclosure of Invention

An object of the present invention is to provide a living drug for tumor therapy, the living drug comprising live cyanobacteria, the living drug being capable of generating oxygen upon light irradiation, the light irradiation being laser irradiation of 400-700nm wavelength; preferably, the light irradiation is laser irradiation of 660nm wavelength.

Another object of the present invention is to provide an application of cyanobacteria in the preparation of a living drug having an antitumor activity.

The invention also aims to provide application of the cyanobacteria in preparation of a medicine or a reagent for improving a tumor hypoxia microenvironment.

It is another object of the present invention to provide a use of cyanobacteria in the manufacture of a reagent or medicament for combination therapy of tumors, including any one or more of photothermal therapy, photodynamic therapy, chemotherapy, and radiotherapy.

Preferably, the cyanobacteria can generate oxygen under laser irradiation, the tumor hypoxia microenvironment can be improved, and the laser wavelength is 400-700 nm; preferably, the laser wavelength is 660 nm.

Preferably, the tumor is selected from basal cell carcinoma, squamous cell carcinoma, esophageal carcinoma, glioblastoma, bladder cancer, cervical cancer, breast cancer, lung cancer, liver cancer, stomach cancer, colon cancer, rectal cancer, nasopharyngeal cancer, pancreatic cancer, thyroid cancer, prostate cancer, leukemia, lymphoma, kidney tumor, sarcoma, blastoma.

The invention also aims to provide a method for improving the tumor hypoxia microenvironment in vitro, which comprises the following steps:

(1) culturing and amplifying cyanobacteria in vitro;

(2) and (2) irradiating the cyanobacteria obtained in the step (1) by using laser with the wavelength of 400-700nm, continuously culturing, and detecting the oxygen content by using an oxygen dissolving instrument.

Preferably, the laser in the step (2) is laser irradiation with the wavelength of 660 nm; preferably, the cyanobacteria have a density of 2 × 10⁸cfu/mL。

The invention also aims to provide an application of the cyanobacteria in the research of the tumor hypoxia mechanism.

Compared with the prior art, the invention has the following beneficial effects:

the invention develops a new function of cyanobacteria naturally existing in the nature, and aims to provide a photosensitizer with simple preparation process, which targets tumors and plays an effective photodynamic role. The method comprises the following specific steps:

(1) the first report of using cyanobacteria photosynthesis to produce oxygen for improving tumor hypoxia;

(2) the cyanobacteria can generate oxygen under 660nm laser irradiation, is an ideal living drug, can be used for improving a tumor hypoxia microenvironment and provides a new choice for cancer treatment;

(3) the cyanobacteria are widely distributed in fresh water and marine environments, the materials are very easy to obtain, and the cyanobacteria have the advantages of very simple nutritional requirements, only light, water, carbon dioxide and inorganic salt, high growth speed, convenient culture, low cost, relatively easy genetic operation means and the like, so that the cyanobacteria are suitable for being widely applied in clinic.

(4) The cyanobacteria can not grow without being irradiated, is easy to control, and can ensure the safety in vivo use.

(5) The cyanobacteria has specific targeting effect on tumors, improves the treatment efficiency and reduces the damage to normal tissues. Cyanobacteria can carry antitumor drug targets to tumor cells and are dispersed throughout tumor tissues, which can greatly improve the delivery efficiency of therapeutic molecules.

Drawings

FIG. 1 shows the oxygen production of cyanobacteria under intermittent irradiation with 660nm laser.

FIG. 2 is a confocal contrast diagram of laser treatment for improving hypoxia in cyanobacteria, wherein the upper two diagrams show that the hypoxia inside the tumor of the PBS control group is severe, and the lower two diagrams show that the cyanobacteria are given to the laser irradiation group with 660nm, the fluorescence area is obviously reduced, and the tumor hypoxia is obviously improved.

Detailed Description

The present invention will be described in further detail with reference to specific examples below so that those skilled in the art can better understand the present invention and practice the present invention, but the examples are not intended to limit the present invention.

The experimental procedures used in the following examples are conventional unless otherwise specified. The materials, reagents and the like used are commercially available unless otherwise specified.

Examples

Preparation of the experiment: preparing a 500 ml triangular flask, pouring cyanobacteria and sterilized BG11 culture medium into a sterile operating platform, sealing the flask opening with a sealing film capable of ventilating, and culturing and amplifying in sunlight.

Experiment one: unlimited oxygen production in vitro by cyanobacteria

Preparing a colorless transparentBright glass vial with density of 2 × 10⁸8mL of cfu/mL bacterial solution is added with 2mL of ethyl acetate, and the oxygen generation condition is monitored by an oxygen dissolving instrument under the irradiation of 660nm laser or no laser;

an oxygen dissolving instrument is adopted to measure the infinite oxygen production capacity of the cyanobacteria, the oxygen release amount is shown in figure 1, 660nm laser irradiation is always given, the oxygen release value is always increased, and when no laser irradiation exists, the oxygen release value is rapidly reduced to zero.

Experiment two: improving hypoxia effect of cyanobacteria in vivo

Taking the density as 1 x 10⁷MCF-7 breast cancer cells per mL are resuspended in 100 μ l serum-free DMEM medium and seeded into Balb/c nude mice subcutaneously to give a tumor volume of approximately 200mm³When in use, tail vein is injected with 2X 10⁸100 mu l of cfu/mL cyanobacteria (wherein PBS is a control group), 660nm laser is given to irradiate the tumor for 30 minutes after 24 hours, 60mg/kg of hypoxia probe (Hypopyprobe-1 plus kit) is injected into each mouse after 24 hours, and the tumor is taken out after 1.5 hours, sliced, stained with hypoxia antibody and cell nucleus, and focused.

The confocal results are shown in fig. 2, the PBS control group had severe hypoxia inside the tumor, and the cyanobacteria administered to the light group significantly improved the tumor hypoxia.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A living body drug for tumor treatment, the living body drug comprises living cyanobacteria, the living body drug can generate oxygen when being irradiated by light, and the light irradiation is laser irradiation with the wavelength of 400-700 nm; preferably, the light irradiation is laser irradiation of 660nm wavelength.

2. An application of cyanobacteria in preparing a living body medicine with anti-tumor activity is provided.

3. An application of cyanobacteria in preparing a medicament or a reagent for improving a tumor hypoxia microenvironment.

4. Use of cyanobacteria in the manufacture of a medicament or medicament for use in a combination therapy for a tumour, including any one or more of photothermal therapy, photodynamic therapy, chemotherapy, radiotherapy.

5. The in vivo drug as defined in claim 1 or the use as defined in any one of claims 2-4, wherein the cyanobacteria under laser irradiation can generate oxygen to improve the tumor hypoxia microenvironment, and the laser wavelength is 400-700 nm; preferably, the laser wavelength is 660 nm.

6. The live medicament of claim 1, or the use of any one of claims 2 to 4, wherein said tumor is selected from basal cell carcinoma, squamous cell carcinoma, esophageal cancer, glioblastoma, bladder cancer, cervical cancer, breast cancer, lung cancer, liver cancer, stomach cancer, colon cancer, rectal cancer, nasopharyngeal cancer, pancreatic cancer, thyroid cancer, prostate cancer, leukemia, lymphoma, kidney tumor, sarcoma, blastoma.

7. A method for improving tumor hypoxic microenvironment in vitro, comprising the following steps:

(1) culturing and amplifying cyanobacteria in vitro;

(2) the cyanobacteria obtained in the step (1) is irradiated by laser with the wavelength of 400-700nm, preferably 660nm, and then is continuously cultured, and the oxygen content is detected by an oxygen dissolving instrument.

8. The method according to claim 7, wherein the laser in the step (2) is laser irradiation with a wavelength of 660 nm; the cyanobacteria have a density of 2X 10⁸cfu/mL。

9. An application of cyanobacteria in the research of in vivo and in vitro hypoxia mechanisms of tumors.