Effect of hypoxia on adhesion and invasion of human cervical cancer cell HeLa

Objective To investigate the potential effect of hypoxia on adhersion and invasion of human cervical carcinoma cells HeLa. Methods Reverse transcription-polymerase chain reaction (RT-PCR) was used to investigate the level of HIF-1α mRNA and E-cadherin mRNA of HeLa cells cultured under normoxia, 5%O2, 3%O2, 1%O2. The invasiveness of HeLa cells was investigated by transwell chamber assay. Results Under the condition of normoxia, 5%O2, 3%O2 and 1%O2, the optical density ratio of HIF-1α mRNA/β-actin was (0.423±0.116), (0.764±0.111), (1.687±0.126) and (0.215±0.099), showing that the level of HIF-1α mRNA had a tendency of first inceasing and then decreasing with the decreasing oxygen content. The optical density ratio of E-cadherin/β-actin was (1.045±0.171), (0.719±0.114), (0.386±0.105) and (0.157±0.063), showing a decreasing tendency with the decreasing of oxygen content. The invasiveness of HeLa cells was (112.5±20.7), (254.3±27.5), (333.6±45.2) and (124.5±24.6), showing that the invasiveness of HeLa cells had a tendency of first inceasing and then decreasing with the decreasing oxygen content. Conclusion Moderate hypoxia up-regulates the mRNA levels of HIF-1α, and down-regulates the mRNA levels of E-cadherin, and enhances the tumor invasiveness. The possible mechanism is the increasing mRNA levels of HIF-1α.