Effect of miR-662 and miR-24-2-5p overexpressions on gene expression in human MDA-MB-231-luc2-NW1 (NW1) and MCF7 cell lines.

MicroRNAs (miRNAs), small non-coding RNAs, are powerful and extremely versatile regulators of the gene expression in cells, playing an important role in every step of cancer progression. Here, we report a list of transcripts regulated by miR-662 and miR-24-2-5p transient overexpressions using miRNA MIMIC transfection (MIMIC-miR-662 and MIMIC-miR-24-2-5p, respectively) compared to control (MIMIC-negCTRL-FAM+) at 36 hours post-transfection in human MDA-MB-231-luc2-NW1 (NW1) (for miR-662 and miR-24-2-5p) and MCF7 (only for miR-24-2-5p) breast cancer cell lines. We found 38 transcripts significantly deregulated (17 downregulated, 21 upregulated) in miR-662-overexpressing NW1 cells compared to mock-transfected cells; 222 (187 downregulated, 35 upregulated) and 34 (32 downregulated, 2 upregulated) transcripts deregulated in miR-24-2-5p-overexpressing NW1 and MCF7 cells, respectively, compared to mock-transfected cells. Furthermore, a total of 30 transcripts (29 downregulated, 1 upregulated) were shared between miR-24-2-5p-overexpressing NW1 and MCF7 cells compared to mock-transfected cells. For miR-662, which we found to promote breast cancer metastasis by stimulating cancer cell stemness (Puppo et al., 2023), we observed the deregulation of Cell Migration Inducing Hyaluronidase 1 (CEMIP), Interleukin 6 receptor (IL6R), High Mobility Group AT-Hook 2 (HMGA2), Small Ubiquitin Like Modifier 3 (SUMO3), and Polymerase (DNA) Delta Interacting Protein 2 (POLDIP2), which reinforced the evidence of the involvement of miR-662 in the acquisition of a stem-like phenotype by human NW1 breast cancer cells and miR-662 contribution to breast cancer bone metastasis formation. For miR-24-2-5p, we found that the downregulation of two transcripts, WD Repeat and FYVE Domain Containing 1(WDFY1) and SH3 Domain Binding Glutamate Rich Protein Like 2 (SH3BGRL2), might explain a possible role of miR-24-2-5p as a tumour suppressor by reducing breast cancer cell invasive properties.