Effects Of Hypoxia On The Stemness Of Breast Cancer MDA-MB-231 Cells

Objective: 1.To investigate the effect of hypoxia on cellular function of MDA-MB-23 l stem cells.Taking special care of the changes of cellular renewal, differentiation and expression of several stem cell markers,By constructing human breast cancer MDA-MB-231 cells hypoxia model in vitro. 2. To study preliminarily the role of Notch signaling on maintaining stemness of Breast cancer stem cell by hypoxia.Methods: 1. Constructing hypoxic model of human breast cancer MDA-MB-231 cells during the phase of hypoxia induced by Co Cl2.To detect the expression of HIF-la by Western Blot,building the success of hypoxic model. 2, In vitro study of hypoxia on stemness regulation of BCSCs:Stem cell colony formation was applied to observe the effects of hypoxia on the selfrenewal. CD44+CD24- cells expression was detected by flowcytometry.Expression of stem cell markers(ALDH1) was detected by Western blot. 3.Study of the effect of Notch signaling on the stemness regulation of Breast cancer stem cell induced by hypoxia:Western blot was used to detect the protein level of several key markers of Notch signaling.Such as Notch1、Hes-1、NICD.Results: 1.Hypoxia significantly enhanced colony formation ability of MDA-MB-231 cells. Flow cytometry analysis showed that hypoxia significantly increased CD44+CD24-/low cell ratio. Under hypoxia condition, protein expression of stem cell marker increased. 2.Upon hypoxia treatment, protein of several key molecules of Notch signaling,including Notch1, Notch1 ICD and Hes-1, were upregulated.Conclusion: 1.Hypoxia can maintain or increase the stemness of breast cancer MDA-MB-231 cell. 2. Notch signaling might play an essential role in the stemness maintain or increase of BCSCs induced by hypoxia.