The Effects Of KLT Combine Radiotherapy On Hypoxia Inducible Factor-1α(hif-1α) And Myeloid-derived Suppressor Cell(MDSC) In Lewis Lung Carcinoma Mice

Objective: Surgery, radiotherapy and chemotherapy, as traditional tr-eatment of malignant tumor treatment, which is difficult to solve the pr-oblem of recurrence and metastasis of the malignant tumor. The changeof the tumor microenvironment is the key to tumor recurrence and meta-stasis. Traditional Chinese medicine can be individualized, multilevel, m-any targets to control tumor growth, metastasis, reduce recurrence, and can be attenuated synergies combined with radiotherapy and chemothera-py. Kanglaite(KLT) has been widely used in treatment of lung cancer a-nd confirmed improve radiotherapy effect and decrease toxicity. The ai-m is to detect the effects of KLT combine Radiotherapy on immunosup-pression and hypoxia stacoixseed extratte of tumor, further analysis the effects of KLT combine Radiotherapy on tumor microenvironment by de-tecting the number of myeloid-derived suppressor cell(MDSC) and th-e expression of hypoxia inducible factor-1α(HIF-1α) in Lewis lung carc-inoma mice.Methods:1 Lewis lung carcinoma cells were cultured in vitro and were subcutaneously injected in the left axilla of each mouse when they reached senescence at passages 3-4, in order to establish mouse models with Lewis lung carcinoma. General condition of the mice was observed and recorded. 24 Lewis lung carcinoma mice with similar tumor sizes were selected and randomly divided into four groups of 6 animals in each: the control group(control), KLT group(KLT), radiotherapy group(RT) and combination-therapy group(KLT+RT). normal saline(NS) treatment as control group, With the processing of KLT, RT, KLT+RT as treatment group. 6 healthy animals were as healthy control group.2 Mice were killed after treatment for one week, stripping the tumor, the spleen and the lung issue and measure the size of the tumors.3 Detection HIF-1α m RNA of tumor tissue and lung tissue in mice by real-time PCR(RT-PCR).4 Detection the percentage of MDSC in mice spleen and tumor tiss-ue by flow cytometry(FCM).5 All statistical analyses were performed using SPSS 17.0 for Windows software. The count data were said to rate(%), Quantitative data were expressed as mean ± standard deviation(X±S), Single-factor analysis of variance was performed to evaluate the differences within groups and LSD test for multiple comparisons between groups. P<0.05 for the difference was statistically significant.Results:1 General condition of the mice: Lewis lung carcinoma models wer-e established after one week subcutaneous injection of Lewis lung carci-noma cells to Kunming mice. The maximum diameter of the tumors m-easured 1.5-2.0cm 14 days after the injection. Diet, activity, hair were worse gradually, and control group mice were the most obvious.2 Antitumor effects of each group: the mean tumor volume of the control group, KLT group, RT group and RT-KLT group was respectively.(6.78±0.90)cm3,(6.52±0.92)cm3,(0.87±0.53)cm3,(0.08±0.30)cm3.The tumor volume of the control group was bigger than the other threegroups, Compared with NS group, tumor volume in KLT group are red-uced, but not statistically significant(P>0.05); tumor volume in RT group and KLT+RT group are reduced, statistically significant(P<0.05); Co-mpared with KLT group, tumor volume shrinkage in RT group and KLT+RT group are more obvious, statistically significant(P<0.05); Compa-red with RT group, tumor volume in KLT+RT group are statistically si-gnificant(P<0.05)(Table 2).3 The effect on HIF-1α gene expression in tumor tissue and lung tissue: There is no HIF-1α gene expression in lung tissue of Healthy controls mice, but are HIF-1α gene expression both in tumor tissue and lung tissue of Lewis lung cancer mice, and the HIF-1α gene expression in tumor tissue is significantly higher than lung cancer of Lewis lung cancer mice, statistically significant(P < 0.05); Compared with the NS group, the HIF-1α gene expression of mice tumor tissue in KLT group decreased, statistically significant(P<0.05); HIF-1α gene expression have reduced in KLT+RT group, statistically significant(P<0.05); however, HIF-1α gene expression is higher in RT, statistically significant(P<0.05); Compared with KLT+RT group, KLT group more significantly decreased, there is a statistically significant(P<0.05)(Fig.3-8, T-able 3).4 Percentage of MDSC in tumor tissues and spleen tissue of each group: There is no MDSC gene expression in lung tissue of Healthy co-ntrols mice; Compared with the NS group, the percentage of MDSC in KLT group is lower, There is no statistically significant(P<0.05); Co-mpared with the NS group, MDSC percentage is higher in RT group, ithas not statistically significant(P>0.05); Compared with the NS group, MDSC percentage is lower in KLT+RT group, there is statistically sign-ificant(P<0.05); MDSC percentage in KLT group are lower than in KLT+RT group(P<0.05)(Fig.9-17, Table 4).Conclusions:1 KLT can inhibit tumor growth of Lewis lung mice, enhance the immune function, improve oxygen, its mechanism may be related to inh-ibition of MDSC and HIF- 1α m RNA.2 Kanglaite combined radiotherapy have synergy to improve effect and decrease toxicity. Which may be through acting on hypoxia microen-vironment and immunosuppressional microenvironment induced by radiot-herapy.