Objective: To evaluate the effect of hypoxia improvement in Hep-2 cell on cisplatin-induced apoptosis.
Method: Human laryngeal squamous cell carcinoma Hep-2 cells and HIF-1α-RNAi-Hep-2 cells were cultured in normoxic, hypoxic and reoxygenation condition. The inhibition of cisplatin on cell proliferation was evaluated by MTT assay. The influence of cisplatin on cell cycle and apoptosis were detected by flow cytometry.
Result: The inhibition of cisplatin on cell proliferation was reduced by hypoxia. After HIF-1α gene was silenced, the inhibition of cisplatin on Hep-2 cell proliferation was increased apparently, but was still interfered partly by hypoxia. Hypoxia could induce cell apoptosis decreased and enhance chemotherapeutic resistance. After reoxygenation, cell apoptosis induced by cisplatin was increased significantly (P < 0.05). HIF-1α-RNAi-Hep-2 cells under hypoxia also showed certain resistance to apoptosis but the sensitivity to cisplatin was higher than that of Hep-2 cells. When cells were returned from hypoxic condition to normoxic condition for some time, the apoptosis induced by cisplatin was increased significantly (P < 0.05).
Conclusion: The improvement of hypoxic microenvironment with HIF-1α gene knockout could increase the sensitivity of Hep-2 cells to chemotherapy.