Research On The Expression Of Survivin Gene Suppressed By Preirradiation And Intratumor Injection SiRNA In Lung Cancer Of Mouse

Objective: This study was to explore the effects of the expression of survivin gene suppressed by intratumor injection siRNA and radiation in lung cancer.Method: Mouse subcutaneous transplanted with tumors were randomly divided into four groups: untreated group(groupA)、group with intratumor injection siRNA(groupB)、group with radiation(groupC)、group 4Gy pre-irradiation combination with intratumor injection siRNA(group D).Two days later, mouse with different treatments were executed by cervical dislocation and stripped the subcutaneous tumors. m RNA and protein levels of survivin gene were detected by rquantitative Real-time PCR(qRT-PCR) and Western blot;Cell cycle and cell apoptosis were assayed by flow cytometry(FCM).Result: The expression of survivin gene in mRNA and protein levels in group B、C、D was significantly reduced compared with group A. The differences of survivin expression in mRNA level between group A and group D were statistically significant.Compared with another three groups, the expression of survivin gene in group D was significantly reduced, the differences were statistically significant( P=0.036); the proportion of cells in S-phase of group D was 2.70±0.34%, compared with group B(8.93±0.75%) and group C(6.71±0.51%),that was significantly reduced.The differences of the proportion of S-phase cells in group A and group D were statistically significant;cell apoptosis in group D was 25.67±0.65%,which was significantly increased compared with the cell apoptosis in other three groups,variance analysis showed F =78.82, P<0.05,the differences were statistically significant.Conclusion: Pre-irradiation can enhance the transduction rate of siRNA, reduce the expression of survivin gene in lung cancer,promote cell apoptosis, and increase thesensitivity of the radiotherapy.