Experimental Study On HCPT To The Radiation Sensitization Of Transplanted Tumor Of H22 Liver Cancer Mice

Objective:In this study,we constructed a subcutaneous xenograft liver cancer model of H22 mice,and observed the effect of Hydroxycamptothecin(HCPT)combined with different doses of radiotherapy on sensitizing and radiosensitizing of H22 hepatoma cell mouse subcutaneous tumor.By detecting the positive expression level of HIF-1?and VEGF protein,we analyzed the relationship between HCPT and cell hypoxia and anti angiogenesis,and preliminarily discussed the mechanism of HCPT radiosensitization.Method:1.According to the method of random number were randomly divided into A:control group,B:hydroxycamptothecin group(HCPT),C:radio-therapy 2 Gy(Rt1),D:radiotherapy 4 Gy(Rt2),E:radiotherapy 8 Gy(Rt3),F:HCPT+radiotherapy 2 Gy(HCPT+Rt1),G:HCPT+radiotherapy 4 Gy,H:HCPT+radiotherapy 8 Gy(HCPT+Rt3).A total of 8 groups,each group of 10,a total of 80(10 reserve).2.Observe the general condition of mice,monitor tumor volume and calculate tumor growth inhibition rate of each group every other day,draw mouse volume curve and growth inhibition rate curve,and calculate the Q value of sensitization and the EF value of sensitization coefficient.3.After fourteenth days of treatment,4 rats in each group were killed in each group.The weight of subcutaneous tumor was taken out and weight was weighed,and the tumor inhibition rate was calculated.The morphological changes,necrosis and apoptosis of transplanted tumor cells after HE staining were observed with light microscope.Immuno-histochemical method was used to detect the expression of HIF-1?and VEGF.4.6 mice were left in each group.The quality of life,the time of survival were recorded and the life lengthening rate was calculated.And then draw the survival map.5.Statistical analyze of data:The experimental data was analysised using SPSS 21.0 statistical software.One-way ANOVA was used to compare among groups of samples.The data between the inspection group was analysis with LSD inspection.The Kaplan-Meier method was used to analyze the survival data of each group.Each tests were based on P<0.05 considered statistically significant.Results:1.In the 8 groups,3 groups of H22 subcutaneous transplanted tumor mice with HCPT combined with radiotherapy were generally better,and the mice responded flexibly,and the water intake and foraging were good.The longest living time were longer.Compared with other groups,their recent toxic and side effects were lighter.2.On the fourteenth day of treatment,the volume of subcutaneous tumors in each group was significantly different(P<0.05).The average Q values of the 3 groups combined with HCPT group were all>1,and the EF values were all>1.Among them,the volume of HCPT+8 Gy group was the smallest(2585+109.47)mm~3,the tumor growth inhibition rate(52.1%)and tumor inhibition rate(47.69%)were the largest,the average Q value was maximum(2.02+0.61),and the EF value was maximum(1.73).3.HE staining:in all treatment groups,there were different degrees of increased apoptosis area and no structural red staining area.HCPT combined with 8 Gy radiotherapy group is the most significant.4.HIF-1?and VEGF positive expression:after radiotherapy,the expression of HIF-1?and VEGF increased in the 3 groups of radiotherapy group,and the expression of 8 Gy radiotherapy group was the most obvious.However,the expression of HIF-1?and VEGF in HCPT group and HCPT combined radiotherapy group decreased,and the most significant was HCPT+radiotherapy 8 Gy.Conclusion:1.HCPT combined with radiotherapy can significantly inhibit the growth of H22 liver cancer transplantation tumor,effectively improve the general living conditions and prolong the survival time of mice.And the effect of 8 Gy radiotherapy combined with HCPT group was especially significant2.HCPT can enhance the radiosensitivity of H22 hepatoma cells,and the effect of 8 Gy+HCPT sensitization by radiotherapy is the best in a certain range.3.The mechanism of HCPT radiation sensitization may be related to the reduction of HIF-1?and VEGF expression.It can effectively improve the hypoxic state of tumor,inhibit the proliferation of blood vessels and improve the curative effect of radiotherapy.