Influence Of Silencing HIF-1? And Survivin Gene On Radiation Sensitivity Of Transplanted Nasopharyngeal Carcinoma In Nude Mice

Objective: To investigate the effects of Hypoxia inducible factor 1-alpha(HIF-1?)and / or Survivin interference in human nasopharyngeal carcinoma cell line CNE-2 on the radiotherapy sensitivity of xenografted tumors in nude mice through siRNA technology.Methods: The recombinant plasmids for HIF-1? and / or Survivin interference were constructed.Then the plasmids were transfected into CNE-2 cells using lipofection,respectively 35 female nude mice aged 4 ~ 6 weeks were randomly and equally divided into HIF-1? interference group,Survivin interference group,HIF-1? & Survivin interference group,the empty vector group,and negative control group.CNE-2 cells after transfection were injected to BALA/c nude mice respectively.Once xenografted tumors formed,each mouse would accept 5 Gy of X-ray radiations every three days for three times.The volume of tumors would be observed at different times.After a total of 15 Gy of X-ray radiations,the mice would be putted to death three days later.Then the volume of tumors would be measured and the radiotherapy sensitivity would be calculated.Moreover,the mRNA and protein expression levels of HIF-1? and Survivin in the xenografted tumors would be detected by RT-qPCR and Western blotting,respectively.The cell apoptosis in xenografted tumors would be evaluated using TUNEL kit.Results: After radiation therapy,the increase rates of tumor volume in HIF-1? interference group,Survivin interference group and HIF-1? & Survivin interferences group were significantly less than that in empty vector group and the negative control group(P < 0.05).Furthermore,the mRNA and protein expression levels of HIF-1? and Survivin in HIF-1? and / or Survivin interference groups were significantly lower than that in the empty vector group and the negative control group(P < 0.05).The cell apoptosis of tumors in HIF-1? and / or Survivin interference groups were significantly higher than that in the empty vector group and the negative control group(P < 0.05).However,there was no statistical significance for the increase rates of tumor volume,the mRNA and protein expression levels of HIF-1? and Survivin and the cell apoptosis of tumors among HIF-1? interference group,Survivin interference group and HIF-1? & Survivin interferences group(P > 0.05).Conclusion: HIF-1? interference,Survivin interference or HIF-1? & Survivin interferences could increase the radiotherapy sensitivity of Nasopharyngeal carcinoma xenografted tumors in nude mice.However,HIF-1? & Survivin interferences did not further improve radiotherapy sensitivity of Nasopharyngeal carcinoma xenografted tumors compared with HIF-1? interference or Survivin interference.