Effect of MiRNA-136-targeted Regulation of FGFR1 on Proliferation and Apoptosis of Triple-negative Breast Cancer Cells

Purpose: This study was designed to investigate the effect of micro RNA-targeted regulation of FGFR1 on the proliferation and apoptosis of triple-negative breast cancer (TNBC) cells.

Methods: TNBC (MAD-MB-231), three types of breast cancer (MCF10A, MCF7, ZR751) cell lines, and normal breast tissue cell lines were extracted. Real-time PCR was used to detect the expression of miRNA-136 in different types of breast cells. The MAD-MB-231 cell lines were transfected with miRNA-136 mimic by lipofection. The effects of miRNA-136 on FGFR1 expression and apoptosis rate of MAD-MB-231 cell lines were determined using western blotting.

Results: miRNA-136 expression in TNBC cells was lower than that of controls, and was negatively correlated with TNM staging. miRNA-136 expression in MCF10A, MCF7, ZR751, and MAD-MB-231 cell lines was gradually decreased, and MCF10A expression in the other three cell lines was significantly higher than that of MAD-MB-231 cell line (P<0.05). Transfection with miRNA-136 significantly reduced the proliferation rate of MAD-MB-231, and a higher concentration and longer duration exhibited a more pronounced inhibitory effect on proliferation (P<0.05). Transfection with miRNA-136 significantly reduced FGFR1 expression in the MAD-MB-231 cell lines, without significantly affecting apoptosis.

Conclusion: miRNA-136 shows a very low expression level in TNBC cells. Transfection with miRNA-136 can significantly inhibit the proliferation of TNBC cells by external transfection, and has little effect on cell apoptosis. This may be related to miRNA-mediated changes in FGFR1 protein expression.