Hypoxia-inducible factor HIF-1α modulates drugs resistance in colon cancer cells
Revista de la Facultad de Medicina
Drug resistance mechanisms may be associated with decreased cell death and its induction may depend on the response to oxidative stress caused by hypoxia. The correlation between hypoxia-inducible factor HIF-1α, the number of reactive oxygen species and their effect on cell survival has not yet been evaluated.Objective: The purpose of this study was to evaluate the effect of HIF-1α activity and reactive oxygen species (ROS) accumulation in apoptosis of colon cancer cells.Materials and methods:
... rials and methods: HT29 colon cancer cells were treated with CoCl2 or doxorubicin and the activity of HIF-1α was determined by ELISA assay. ROS were determined using fluorescence probe carboxy-H2DFFDA. Apoptosis was assessed by caspase-3 activation analysis, and PUMA and BAX mRNA levels by qRT-PCR. The reduction of the antiapoptotic effect due to hypoxia was attenuated by use of the endonuclease APE-1 (E3330) inhibitor. The endonuclease E3330 APE-1 inhibitor allowed evaluating the effect of ROS generated by doxorubicin and CoCl2 on apoptosis.Results: Chemical hypoxia in combination with doxorubicin is an oxidative stressor in HT29 cells and induces a reduction in the apoptotic process in a time-dependent manner.Conclusion: Resistance to hypoxia and doxorubicin-mediated cell death could be controlled by a mechanism related to the activity of HIF-1α and the amount of reactive oxygen species generated.