The effect of hypoxia and oxygen supplementation on gynecological cancer cells

Existing data have shown that cobalt chloride or CoCl 2 , as well as 2% O 2 , introduces hypoxia and activates transcription factor HIF1‐α in ovarian cancer cells (CaOV3 cell line). We hypothesize that this transcription factor is also activated in HeLa cells in response to CoCl 2 . Initially, we analyzed the morphology of cultured HeLa cells with the addition of various concentrations of CoCl 2 in the cultured medium. The results revealed that cells with as low as 8 μM of CoCl 2 treatment differ from the untreated cells because they are less confluent and irregularly shaped. We further investigated the CoCl 2 effects through Western blot analysis and confocal imaging. We found that high concentration of CoCl 2 directly induces hypoxia leading to the degradation of the cytoskeleton and nuclear membrane. As the concentration of CoCl 2 increases, the activities of HIF1‐α and phosphorylated S6 decrease. The cell viability with MTT assay showed that there is no significant effect of CoCl 2 on HeLa cells, except at the highest concentration tested. We then tested the effect of oxygen supplement by PDMS‐CaO 2 disks on HeLa cells with MTT assay as well. The data showed that the viability of HeLa cells is lower when treated with these disks as opposed to CoCl 2 treatment. Finally, we analyzed the mitochondrial activity of cultured CaOV 3 cells with CoCl 2 as well as control and PDMS‐CaO 2 disks using MitoTraker. It was clear that 400 μM CoCl 2 induces maximal mitochondrial activity as Mitotraker signal is highly concentrated in the surrounding cytoskeleton of the cells. PDMS‐CaO 2 disks notably reduce mitochondrial activity in CaOV 3 cells, as they appear dull and darker in comparison to the untreated, control cells. Taken all together, our preliminary data suggest that the manipulation of oxygen level in gynecological cancer cells may provide insights into the understanding of the role of oxygen in solid tumors and eventually offer clinic oxygen therapy. Support or Funding Information The RI‐INBRE grant funded this research in addition to the Providence College Biology Department. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .