Analysis of radiosensitivity of A549 lung cancer cells with HIF-1α silencing by RNAi

Objective To observe the effect of HIF-1α silencing on human lung cancer cells radiosensitivity in nude mice.Methods A549/HIF-1α(-)cell line was established by RNAi with lentivims as vector.The expression of HIF-1α protein was analyzed by Western Blot.A549/HIF-1α(-)cells and A549 cells were injected into the male BALB/C nude mice aged 4-6 weeks.The tumors were locally irradiated with single doses(5,10,15 and 20 Gy)of X-ray irradiation when tumor sizes reached 200-350 mm3.The volumes of tumor were measured every 3 days.Time of the tumor growth delay was caculated.Results The expression 0f HIF-1αprotein of A549/HIF-1α(-)cells was inhibited significantly under both normoxia and hypoxia condjtion.A549/HIF-1α(-)tumors reproduced more slowly than A549 tumors(P＜0.05).X-ray radiation could inhibit tumor growth of all groups.The growth delay of A549/HIF-1α(-)tumors was more significant than of A549 tumors(P＜0.05).Conclusions The expression of HIF-1α can be stably blocked by RNAi.A549/HIF-1α(-)tumors appear to be more radiosensitive than A549 tumors. Key words: Hypoxia;  HIF-1α;  RNAi;  Radiosensitivity