低氧对卵巢癌A2780细胞周期阻滞的影响

Effect of Hypoxia on the Cell Cycle Arrest in A2780 Cell Line of Human Ovarian Cancer

目的 探讨低氧及其诱导产生的低氧诱导因子 1α(HIF -1α) 对卵巢癌细胞周期阻滞的影响。方法 低氧培养复制人卵巢癌A2780细胞低氧模型。“诱骗法” (decoy) 阻断 HIF 1α的功能。A2780 细胞分成 8 组, A1: 常氧组, A2: 常氧+decoy, B1: 5% O2 低氧组, B2: 5% O2 低氧+ decoy, C1: 3% O2 低氧, C2: 3% O2 低氧+ decoy,D1: 1% O2低氧组, D2: 1% O2低氧+decoy。免疫细胞化学及Western blot、RT- PCR和流式细胞术分别检测各组细胞HIF- 1α蛋白, mRNA表达水平和分析细胞周期。结果 免疫细胞化学染色发现 HIF- 1α蛋白在低氧培养 A2780 细胞核中表达呈阳性; Western blot 检测发现低氧明显增加 HIF 1α蛋白的表达水平且随低氧程度加重而增加 (P<0 .05), decoy对其蛋白表达无明显影响; RT PCR检测发现低氧明显增加HIF 1αmRNA的表达水平, 但随低氧程度加重, 其mRNA表达水平无明显变化 (P>0. 05), decoy对其 mRNA表达无明显影响; 流式细胞术检测发现低氧时卵巢癌A2780细胞G0/G1期比率显著增加 (P<0 .05), G0/G1期比率随着低氧程度加重而增加 (P<0 .05), decoy能明显降低 G0/G1期细胞比率 (P<0 .05)。结论 低氧能明显诱导卵巢癌 A2780 细胞 G0/G1 期阻滞和 HIF -1α的表达,HIF -1α在?

Objective To investigate the effect of hypoxia and hypoxia inducible factor-1α on cell cycle arrest in A2780 cell line of human ovarian cancer. Methods The sealed hypoxic cell culture chamber was used to develop physical hypoxia in A2780.“Decoy” was used to block the function of HIF-1α. A2780 cells were divided into 8 groups: A1, normoxia cell; A2,normoxia cell+decoy; B1, hypoxia cell (cultured in 5% O 2); B2, hypoxia cell (cultured in 5% O 2)+decoy; C1, hypoxia cell (cultured in 3% O 2); C2, hypoxia cell (cultured in 3% O 2)+decoy; D1, hypoxia cell (cultured in 1% O 2); D2, hypoxia cell (cultured in 1% O 2)+decoy. The expression of HIF-1α protein and mRNA was detected by immunocytochemical stain, and Western blot, reverse transcription-polymerase chain reaction (RT-PCR) respectively. The cell cycle was analyzed by FCM. Results The immunocytochemical stain showed the positive expression of HIF-1α protein in A2780 cell nucleus after hypoxic culture. Western blot analysis revealed that hypoxia could evidently increase the expression level of HIF-1α protein and was dependent on the degree of hypoxia (P<0.05), however, decoy had no effect on the expression of HIF-1α protein. RT -PCR analysis found hypoxia could evidently increase the expression of HIF-1α mRNA level, but its expression was independent on the degree of hypoxia (P>0.05). FCM displayed the ratio of G 0/G 1 phase of A2780 cell line was evidently increased in hypoxia cells and was dependent on the degree of hypoxia as compared with the normoxia cells (P<0.05), but the ratio was markedly decreased when the function of HIF-1α was blocked by the decoy (P<0.05). Conclusion Hypoxia could distinctly induce cell cycle arrest in G 0/G 1 phase and the expression of HIF-1α in human ovarian cancer cell A2780. HIF-1α has played an important role in cell cycle arrest induced by hypoxia in A2780 cells of human ovarian cancer.