CXCL1促进乳腺癌干细胞样特性的表达OACSTPCD

Objective To explore the effect of CXC motif ligand 1(CXCL1),an endogenous and exogenous chemokine,on the expression of stem cell like characteristics of breast cancer cells.Methods In the external experiment,MDA-MB-231 and MCF-7 breast cancer cells were divided into four groups,and treated with exogenous CXCL1 at concentrations of 0,1,10 nmol/L,and CXCL1 receptor(CXCR2)blocker before adding 10 nmol/L exogenous CXCL1(anti-CXCR2 group),respectively.In the internal experiment,MDA-MB-231 and MCF-7 cells were divided into three groups:control group(PBS),siNC group(blank transfection reagent)and siCXCL1 group(transfected with CXCL1 specific small interfering RNA).The proliferation ability of breast cancer cells was detected by plate cloning assay.The microsphere formation test was performed to observe the formation ability of cell spheres in evaluation of the self-renewal ability of breast cancer stem cells.The proportions of MDA-MB-231 cells expressing CD133+and MCF-7 cells expressing CD44+/CD24-/low were detected by flow cytometry.The proportion of the breast cancer expressing the stem cell marker ALDH1 was also detected by flow cytometry.The expressions of ALDH1 and Oct3/4 were determined by Western blot.To explore the role of PI3K signaling pathway,MDA-MB-231 and MCF-7 cells were pretreated with PI3K specific inhibitor Ly294002,and then given 10 nmol/L exogenous CXCL1,and the expressions of ALDH1 and Oct3/4 were detected.Results Compared with 0 nmol/L CXCL1 group,the clone formation was significantly increased in 1,10 nmol/L CXCL1 groups(P＜0.001),the number of microspheres formed by breast cancer cells were increased(P＜0.001),and the diameter was enlarged(P＜0.05),the number of MDA-MB-231 cells expressing CD133+and the number of MCF-7 cells expressing CD44+/CD24-/low were increased(P＜0.05),and the proportions of MDA-MB-231 and MCF-7 cells expressing ALDH1+were increased(P＜0.05).Western blot results showed that the expressions of stem cell marker ALDH1 and Oct3/4 in both MDA-MB-231 and MCF-7 breast cancer cells were increased significantly by CXCL1 in a dose dependent manner.Compared with 10 nmol/L CXCL1 group,the number of clone formation,the proportion of stem cells,and the expression of ALDH1 were all reduced in anti-CXCR2 group(P＜0.05).Compared with control group and siNC group,the diameter of cell spheres was decreased in siCXCL1 group(P＜0.001),the quantity of cell spheres was also decreased(P＜0.01),the proportion of MDA-MB-231 breast cancer cells expressing CD133+was decreased(P＜0.001),and the expressions of ALDH1 and Oct3/4 were significantly reduced(P＜0.001).The expressions of ALDH1 and Oct3/4 in MDA-MB-231 and MCF-7 cells in Ly294002 group were reduced compared to CXCL1 group.Conclusion Both endogenous and exogenous CXCL1 can promote the transformation of breast cancer cells into breast cancer stem cells,and promote the expression of their stem cell like characteristics,which may be related by PI3K/Akt pathway.