SciELO - Scientific Electronic Library Online

vol.52IRF2-INPP4B-mediated autophagy suppresses apoptosis in acute myeloid leukemia cellsFunctional and transcriptomic characterization of carboplatin-resistant A2780 ovarian cancer cell lines author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links

  • On index processCited by Google
  • Have no similar articlesSimilars in SciELO
  • On index processSimilars in Google


Biological Research

Print version ISSN 0716-9760


RANA, Nishant Kumar; SINGH, Priya  and  KOCH, Biplob. CoCl2 simulated hypoxia induce cell proliferation and alter the expression pattern of hypoxia associated genes involved in angiogenesis and apoptosis. Biol. Res. [online]. 2019, vol.52, 12.  Epub June 13, 2019. ISSN 0716-9760.


Hypoxia microenvironment plays a crucial role during tumor progression and it tends to exhibit poor prognosis and make resistant to various conventional therapies. HIF-1α acts as an important transcriptional regulator directly or indirectly associated with genes involved in cell proliferation, angiogenesis, apoptosis and energy metabolism during tumor progression in hypoxic microenvironment. This study was aimed to investigate the expression pattern of the hypoxia associated genes and their association during breast cancer progression under hypoxic microenvironment in breast cancer cells.


Cell proliferation in MCF-7 and MDA-MB-231 cell lines treated with different concentration of CoCl2 was analyzed by MTT assay. Flow cytometry was performed to check cell cycle distribution, whereas cell morphology was examined by phase contrast microscopy in both the cells during hypoxia induction. Expression of hypoxia associated genes HIF-1α, VEGF, p53 and BAX were determined by semiquantitative RT-PCR and real-time PCR. Western blotting was performed to detect the expression at protein level.


Our study revealed that cell proliferation in CoCl2 treated breast cancer cells were concentration dependent and varies with different cell types, further increase in CoCl2 concentration leads to apoptotic cell death. Further, accumulation of p53 protein in response to hypoxia as compare to normoxia showed that induction of p53 in breast cancer cells is HIF-1α dependent. HIF-1α dependent BAX expression during hypoxia revealed that after certain extent of hypoxia induction, over expression of BAX conquers the effect of anti-apoptotic proteins and ultimately leads to apoptosis in breast cancer cells.


In conclusion our results clearly indicate that CoCl2 simulated hypoxia induce the accumulation of HIF-1α protein and alter the expression of hypoxia associated genes involved in angiogenesis and apoptosis.

Keywords : Hypoxia; Apoptosis; CoCl2; HIF-1α; VEGF; p53; BAX.

        · text in English     · English ( pdf )