Effects of knocking down miR-221-3p expression on the stemness maintenance and angiogenesis in breast cancer cells under hypoxia conditions
- VernacularTitle:低氧条件下敲低miR-221-3p表达对乳腺癌细胞干性维持及血管生成的影响
- Author:
Qian ZHANG
1
;
Qi LI
1
;
Nan MA
1
;
Wei-qun ZHANG
1
Author Information
- Publication Type:Journal Article
- Keywords: breast cancer; hypoxia; microRNA-221-3p; stemness; angiogenesis
- From: Journal of Regional Anatomy and Operative Surgery 2025;34(6):471-477
- CountryChina
- Language:Chinese
- Abstract: Objective To investigate the expression of microRNA-221-3p(miR-221-3p)in breast cancer cells under hypoxia conditions,and the effects of knocking down its expression on the stemness maintenance and angiogenesis in breast cancer cells.Methods Human breast cancer cell line MCF-7 were cultured under normoxic and hypoxic conditions,and the expression of miR-221-3p in cells was detected by quantitative real-time polymerase chain reaction(RT-qPCR).MCF-7 cells were divided into normoxic group(MCF-7 cells were cultured under normoxic conditions),hypoxic group(MCF-7 cells were cultured under hypoxic conditions),hypoxia+miR-221-3p NC group(MCF-7 cells were cultured under hypoxic conditions and transfected with miR-221-3p NC),hypoxia+miR-221-3p inhibitor group(MCF-7 cells were cultured under hypoxic conditions and transfected with miR-221-3p inhibitor).The proliferation activity of cells in each group was detected by CCK-8 method;the number of cell tumor spheres in each group was detected by tumor sphere formation assay;the proportion of cells labeled with the stemness marker aldehyde dehydrogenase 1(ALDH1)in each group was detected by flow cytometry;the expression of cluster of differentiation 133(CD133),cluster of differentiation 44(CD44)and sex determination region Y-box protein 2(SOX2)of cells in each group was detected by Western blot;the number of human umbilical vein endothelial cells(HUVEC)tubes formed by cell supernatant culture in each group was detected by in vitro tube formation experiment;the expression of hypoxia-inducible factor-1α(HIF-1α)and vascular endothelial growth factor(VEGF)of cells in each group was detected by Western blot.Results Compared with normoxic group,the expression levels of miR-221-3p,and CD133,CD44,SOX2,HIF-1α,VEGF protein of cells in hypoxic group were significantly up-regulated(P<0.05),and the cell proliferation activity,the number of tumor spheres,the proportion of ALDH1+cells and the number of HUVEC tubes were significantly increased(P<0.05).Compared with hypoxia+miR-221-3p NC group,the expression levels of miR-221-3p,and CD133,CD44,SOX2,HIF-1α,VEGF protein of cells in hypoxia+miR-221-3p inhibitor group were significantly down-regulated(P<0.05),and the cell proliferation activity,the number of tumor spheres,the proportion of ALDH1+cells,and the number of HUVEC were significantly decreased(P<0.05).Conclusion Under hypoxic conditions,the expression of miR-221-3p in breast cancer cells is up-regulated,and knocking down the expression of miR-221-3p can reduce the stemness and angiogenesis ability of breast cancer cells.
