Curcumin suppresses cell viability in breast cancer cell line by affecting the expression of miR-15a-5p

Abstract Objectives Curcumin plays a leading role as an epigenetic regulator in cancer. miR-15a-5p is a crucial non-coding RNA for breast cancer (BRCA) and various cancers due to its tumor suppressor role. In our study, we aimed to examine the curcumin/miR-15a-5p/target gene interaction in BRCA cells. Methods The effects of curcumin and miR-15a-5p on cell viability in the MCF7 cells were examined using the WST8 technique. The cell migration was determined using scratch wound assay. miR-15a-5p level was detected in curcumin-treated cells and miR-15a-5p transfected cells compared to control groups by RT-qPCR. Overexpressed genes in BRCA were found by bioinformatics tools (GSE41970 and TCGA). miR15a-5p potential target genes in the miRNet tool were selected in overlapped genes between GSE41970 and TCGA. Survival analysis of the selected genes was examined using the GEPIA2 tool. Relative expression levels of four selected genes were examined via qPCR. Results Cell viability and scratch-wound closure rate were reduced in curcumin-treated and miR-15a-5p mimic transfected MCF7 cells. miR15a-5p overexpressed in curcumin-treated and miR-15a-5p transfected cells. Eighty-three dysregulated upregulated genes were detected (in GSE41970 and TCGA). Among the possible target genes of miR-15a-5p in the miRNet tool, 10 upregulated genes were detected overlapping with GSE41970 and TCGA. CCNE1 and CHEK1 genes were found to be important for survival in BRCA. CCNE1 and BMI1 were decreased in curcumin-treated and miR-15a-5p transfected cells. Conclusions Curcumin treatment increased miR-15a-5p and downregulated selected target genes. Curcumin/miR-15a-5p interaction may be a much stronger negative regulator of the CCNE1 and BMI1 genes in BRCA.