The Radiosensitization Study Of Sodium Danshensu In Vivo Of Lewis Lung Carcinoma Animal Models

Objective: To establish a C57BL/6Lewis lung carcinoma mousemodel to study whether sodium danshensu have radiosensitization effect andinitial exploration of its mechanism. Methods: First, the Lewis lung carcinomacells is inoculated into the right thigh of the mice to establish subcutaneoustumor model, when the tumor grew to a diameter of0.6-0.7cm, randomized intothe experimental group, the whole experiment is divided into: control group,administered alone group, radiotherapy group, radiotherapy combined druggroup.Which alone treatment group divided into simple and pure cisplatin60mg/Kg group, sodium danshensu60mg/Kg group, dose of radiotherapygroup were:2Gy,4Gy,6Gy,8Gy,16Gy,24Gy,radiotherapy combined drug groupwere: cisplatin60mg/Kg+2Gy, cisplatin60mg/Kg+4Gy, cisplatin60mg/Kg+6Gy, cisplatin60mg/Kg+8Gy, cisplatin60mg/Kg+16Gy, cisplatin60mg/Kg+24Gy; sodium danshensu60mg/Kg+2Gy, sodium danshensu+4Gy,sodium danshensu60mg/Kg+6Gy, sodium danshensu60mg/Kg+8Gy, sodiumdanshensu60mg/Kg+16Gy, sodium danshensu60mg/Kg+24Gy; cisplatinthroughout the experiment as a positive control. Half an hour beforeradiotherapy, we give every mouse a single injection of asodium danshensu orcisplatin through intraperitoneal, and ensure that the injected volume of liquidin each group were0.2ml, blank control group and radiotherapy group of miceby intraperitoneal injection of a single injection of0.2ml sterile water. The micein wakefulness box fixed on a special fixed, fixed and paraffin gauze boxesunderlay of2.3cm, cover a total of paraffin and gauze3.5cm tumor in micethigh arrangement between two solid water radiotherapy specific ways: Go-60low-dose irradiation, SSD=80cm, conventional radiotherapy, tumors and theright leg of mouse were in the radiation field, the rest body is out of the irradiation field. Every three days after irradiation, measure tumor diameter andvertical diameter, calculated tumor volume, tumor growth curve based on tumorsize, dose-response curves plotted according to tumor growth curve, calculatedSER value that determines whether sodium danshensu have radiosensitizationeffection. Salvia natriuretic peptide derived sensitizing effect with radiotherapyin vivo, and select a dose based on the dose-response curve of tumor growth asa follow-dose in the next study. A preliminary study about the radiosensitizationmechanism of Salvia sodium were proceeded in the next experiment. Specificresearch methods: Select10Gy as irradiation dose, experimental groups asfollows: control group, radiotherapy group, sodium danshensu group, sodiumdanshensu combined with radiotherapy group. Administrated drugs to micethrough intraperitoneal continuously a week and one time per day. Then let themouse in irradiation and within four hours after irradiation, picking out theright eyeball to collect blood, ELISA assay in mouse blood thromboxane B2(TXB2),6-keto-prostaglandin (6-keto-PGF1ɑ),calculated T/P value; HIF-1ɑ,VEGF and CD31was detected by immunohistochemistry in tumor tissue.Experimental data using the mean±standard deviation, the comparison amongevery group used analysis of variance, average number of pairwise comparisonsusing Tamhane’s T2test between multiple groups, statistical process usingSPSS17.0statistical analysis software. Results:1. the SER of cisplatin plusradiotherapy is2.538, greater than1, suggesting that cisplatin hasradiosensitizing effect; the SER of sodium danshensu combined withradiotherapy is1.748, greater than1, suggesting that sodium danshensu hasradiosensitizing effect, but its radiosensitization sensitizing effect was weakerthan cisplatin.2. Immunohistochemistry results in positiveimmunohistochemical quantitative indicators index (PI value): a.HIF-1ɑ, eachgroup of PI values: negative group80.143±5.445, sodium danshensu group83.164±1.812, radiotherapy group50.444±1.911, sodium danshensu combinedwith radiotherapy group28.533±1.105. The results suggest sodium danshensu can reduce the HIF-1ɑ of the tumor tissue and improve tumor tissue hypoxiacondition. b. PI values of each group VEGF: negative group35.763±1.470,sodium danshensu group12.374±0.245, radiotherapy group21.192±1.002,sodium danshensu combined with radiotherapy group6.442±0.986, the resultssuggesting that sodium danshensu combined with radiotherapy can inhibitvascular endothelial growth factor production. c. PI values of each group ofCD31: negative group3.485±0.216, sodium danshensu group2.500±0.193，radiotherapy group0.524±0.070, sodium danshensu combined withradiotherapy group0.024±0.003, the results indirect prompt sodium danshensuhave anti-angiogenesis effect.3. ELISA results: The measured values of TXB2in the blood of mice in each experimental group: control group155.538±158.716pg/ml, radiotherapy group255.191±175.857pg/ml, sodium danshensugroup221.255±164.169pg/ml, sodium danshensu combined with radiotherapygroup93.160±52.354pg/ml. Each experimental group compared with thenegative group, P values were greater than0.05, not statistically significant.Comparison with sodium danshensu combined with radiotherapy group andradiotherapy group Salvia, the P value is less than0.05. Hint that sodiumdanshensu combined with radiotherapy can significantly reduce the amount ofblood TXB2after radiotherapy, played diastolic capillaries, the role ofmicrocirculation. b. The measured values of each experimental group6-keto-prostaglandin (6-keto-PGF1ɑ): control group106.878±47.415pg/ml,radiotherapy group198.008±119.479pg/ml, sodium danshensu group68.681±35.786pg/ml, sodium danshensu combined with radiotherapy group180.148±101.752pg/ml, all the P values were greater than0.05. c. the value ofT/P: control group1.455, radiotherapy group1.289, sodium danshensu group3.22, sodium danshensu combined with radiotherapy group0.517. The resultssuggest that sodium danshensu combined with radiotherapy can significantlyreduce the T/P value, improve blood vessels, improve microcirculation.Conclusion: Sodium danshensu has radiosensitizing effect. The sodium danshensu may improve elements of sodium microvascular circulation, inhibithypoxia-inducible factor (HIF-1ɑ),VEGF, thereby inhibiting tumorangiogenesis, then manifest the radiosensitizing effect. Inaddition the sodiumdanshensu could improve the microcirculation by reducing thromboxane B2(TXB2), and the T/P ratio.