CN102204900A - Application of sodium oxamate in preparing drugs for radiotherapy sensitization - Google Patents

Abstract

The invention belongs to the field of radiotherapy sensitizing drugs, and relates to the new application of sodium oxamate, that is, the application in the preparation of radiotherapy sensitizing drugs. The structural formula of the sodium oxamate is as follows:

. The sodium oxamate described in the present invention can be used to prepare radiotherapy sensitization drugs, and can improve the radiotherapy sensitivity of tumor cells at a low concentration without toxic and side effects.

Description

Application of sodium oxamate in the preparation of radiosensitizing drugs

technical field

The invention belongs to the field of radiotherapy sensitizing drugs, and relates to a new application of sodium oxamate, that is, an application in preparing radiotherapy sensitizing drugs.

Background technique

Malignant tumor is a common and frequently-occurring disease, and has become one of the major diseases that seriously threaten human life and health. As one of the three main means of tumor treatment, radiotherapy has been widely and routinely used in tumor treatment. According to the statistics of major cancer prevention and treatment centers in China, about 65%-75% of cancer patients who have been diagnosed and treated need radiotherapy, especially head and neck cancer, prostate cancer, and esophageal cancer. However, even for patients with nasopharyngeal carcinoma who have a good radiotherapy effect, there will still be high local recurrence and radiation resistance after radiotherapy. But relying on simply increasing the radiation dose will bring more serious side effects at the same time. Therefore, reducing the radiation resistance of tumor cells and increasing the radiation sensitivity of tumor cells has become a hot and difficult point in cancer treatment research in recent years.

Sodium oxamate (sodium oxamate), a pure chemical pharmaceutical, is prepared by the reaction of oxalic acid or amidoethyl oxamate and sodium hydroxide, and is widely used in biochemical reagents, organic synthesis, and pharmaceuticals. Foreign studies have found that sodium oxamate can affect the growth of breast cancer MDA-MB-231 cells by affecting the glucose metabolism in the cells.

There is no report on radiosensitization of sodium oxamate in the prior art.

Contents of the invention

The purpose of the present invention is to provide a new application of sodium oxamate, that is, the application in the preparation of radiosensitizing drugs.

。In order to achieve the above-mentioned purpose of the invention, the technical solution adopted in the present invention is: the application of sodium oxamate in the preparation of radiosensitizing drugs, and the structural formula of said sodium oxamate is as follows:

.

The inventors directly added different concentrations of sodium oxamate to the exponentially growing nasopharyngeal carcinoma CNE-1 cell culture medium, and the cells continued to be cultured for 12, 24 or 48 hours at different times before collecting samples, and the CCK8 colorimetric method was used to detect the cell growth. growth, the results showed that sodium oxamate could significantly inhibit the growth of CNE-1 cells, and showed a significant dose- and time-dependent relationship. The median lethal concentrations (IC ₅₀ ) of cells treated with sodium oxamate in 24 hours and 48 hours were respectively 2.3 μmol/L and 1.6 μmol/L.

At the same time, the inventor pretreated the cells with a low concentration of 0.75 μmol/L sodium oxamate (more than 90% of the cells survived after 24 hours of treatment with this concentration of sodium oxamate) and received different doses (0-8 Gy) for 24 hours. The ⁶⁰ Co-γ ray was irradiated, and the culture was continued for 24 hours after irradiation, and then the fresh medium was replaced, and the culture was continued for 2-3 weeks to complete the cell clone formation experiment. The single-click multi-target model was used to fit the two groups of cell survival curves. The results showed that: compared with the single γ-ray irradiation group, the survival curve of the combined irradiation group after 0.75 μmol/L sodium oxamate pretreatment significantly shifted down, and the downward shift was more obvious with the increase of the irradiation dose. The radiosensitivity detection indicators showed that giving sodium oxamate at a dose below 1 μmol/L within 72 hours before exposure to ionizing radiation could reduce the radiosensitivity of tumor cells and effectively reduce the cell survival rate.

In a preferred technical solution, the radiosensitizing drug is a radiosensitizing drug suitable for nasopharyngeal carcinoma.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1. The sodium oxamate described in the present invention can be used to prepare radiotherapy sensitization drugs, and can improve the radiotherapy sensitivity of tumor cells at a low concentration without toxic and side effects.

Description of drawings

Fig. 1 is the influence that is less than 5 μ mol/L sodium oxamate treatment 24 hours on CNE-1 cell growth and proliferation in embodiment one;

Fig. 2 is the radiotherapy sensitivity change of CNE-1 cells pretreated with sodium oxamate in Example 2.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing and embodiment:

Materials: Cell lines and cell culture: Human nasopharyngeal carcinoma CNE-1 cell line is a cell line passed down and preserved in our laboratory. Cells were cultured in DMEM medium containing 10% heat-inactivated calf serum (containing 100 U/mL penicillin and 100 μg/mL streptomycin), and placed in a 37 ^o C incubator with 5% CO ₂ and saturated humidity. nourish. Drugs and main reagents: drug sodium oxamate, dissolved in absolute ethanol, made into a mother solution of 5mmol/L, and stored in a 4-degree refrigerator. 1640 medium dry powder, calf serum, and trypsin powder were purchased from Gibco; CCK-8 reagent was purchased from Dojin Chemical Research Institute, Japan.

Embodiment one:

(1) Cell culture: Cells were cultured in DMEM medium containing 10% calf serum, glutamine and 1 million U/L penicillin and streptomycin. The cells were cultured in a 5% CO ₂ , 37°C incubator, passaged once every 2-3 days, and the cells in the logarithmic growth phase were used for experiments.

(2) CCK-8 colorimetric method: cells in logarithmic growth phase (5×10 ⁴ /mL) were inoculated into 96-well plates 24 hours before drug treatment, and 6 parallel wells were set for each concentration. Different concentrations of sodium oxamate were added to continue culturing for 12, 24 or 48 hours. Add 10 μL CCK-8 reagent to the cell culture medium and continue culturing for 1-4 hours. The absorbance at 450 nm was measured using a microplate reader. Finally, the cell survival rate was calculated by the formula of cell survival rate=dosage group value/control group value×100%.

The results obtained are shown in Figure 1, and the results show that sodium oxamate can significantly inhibit the growth of CNE-1 cells, and present a significant dose- and time-dependent relationship. The median lethal concentrations (IC ₅₀ ) of cells treated with sodium oxamate at 24 hours and 48 hours were 2.3 μmol/L and 1.6 μmol/L, respectively.

Embodiment two

(1) cell culture is the same as embodiment one;

(2) Cell clone formation method: Take cells in the logarithmic growth phase, and inoculate different numbers of cells into 60 mm culture dishes according to different irradiation dose requirements (400 cells for 0, 2, 4, 6, 8 Gy doses, respectively , 2000, 6000, 1000 and 15000). After 24 hours, the combined sodium oxamate and radiation group was treated with 0.75 μmol/L sodium oxamate for 24 hours, and the control group was treated with an equal amount of absolute ethanol as a negative control. The two groups of cells were irradiated with different doses (0-8Gy) of γ-rays at the same time, and continued to culture for 24 hours after irradiation. Both groups were replaced with ordinary medium, and continued to stop the culture until obvious cell clones visible to the naked eye appeared in the culture dish. . Discard the medium, wash twice with PBS, fix with anhydrous methanol for 30 minutes, stain with Gimsa stain for 30 minutes, rinse with running water and dry in the air. Count the clonal colonies of more than 50 cells under a microscope, set at least 3 parallel samples at each measurement point, take the average value, and calculate the cell survival rate. And using Sigma Plot 9.0 software, using the single-click multi-target model to fit the curve (see Figure 2), the average lethal dose (D ₀ ), SER (Radiation Sensitization Ratio), quasi-threshold dose (D _q ), K and For n values, etc., see Table 1.

The irradiation conditions in step (2) were as follows: ⁶⁰ Co γ-ray irradiation was used, the irradiation field was 10 cm × 10 cm, the source-to-skin distance was 100 cm, a single irradiation was adopted, the machine head was irradiated from above the petri dish at 0 degrees, and the dose The rate was 0.58 Gy/min.

Table 1. Results of radiation cloning experiment of sodium oxamate on nasopharyngeal carcinoma CNE-1 cells

treatment group K N _Q D ₀ SF ₂ gamma ray irradiation group 0.44 1.38 1.19 2.26 0.52 Sodium oxamate + radiation combination group 0.51 1.46 0.98 1.95 0.46 SER 1.21 1.16 1.13

Figure 2 shows: the cell survival curves of the single-irradiation cell group and the sodium oxamate+irradiation cell group were fitted by the single-click multi-target model. The survival curve of combined irradiation group moved down significantly, and with the increase of irradiation dose, the downward shift was more obvious.

± S表示。采用SAS统计软件对相关数据进行t检验，以P<0.05为有显著性差异。Statistical processing: all experiments of above-mentioned embodiment are all repeated more than 3 times, the result adopts

±S means. SAS statistical software was used to conduct t -test on relevant data, and P <0.05 was considered significant difference.

Claims (2)

1. the application of Sodium oxamate. in the preparation radiotherapy hypersitization medicine, the structural formula of described Sodium oxamate. is as follows:

2. according to the application of the described Sodium oxamate. of claim 1 in the preparation radiotherapy hypersitization medicine, it is characterized in that described radiotherapy hypersitization medicine is for being suitable for the radiotherapy hypersitization medicine of nasopharyngeal carcinoma.

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