The association of piR-651 and piR-823 on metastatic and invasive characteristics of triple negative breast cancer cells

PIWI-Interacting RNAs are small non-coding RNAs derived from single-stranded RNAs which plays a crucial role in epigenetic regulation through transposon silencing and mRNA degradation via deamination. This study aimed to inhibit piR-651 and piR-823 in MDA-MB-231 triple-negative breast cancer cells and to explore their potential effects on healthy HUVEC cells. Non-target, anti-piR-651, and anti-piR-823 sequences were transfected in bothHUVEC and MDA-MB-231 cells using Lipofectamine. Proliferation and motility were assessed at 24, 48, and 72 h post-transfection in both cell lines. Based on the motility findings, MDA-MB-231 cells were underwent an invasion assay using crystal violet staining. The expressions of Ki-67, HIF-1α, MMP-2, and MMP-9 genes were measured at 48 h, when both cell lines exhibited the most significant effects of inhibition. The optimal time for proliferation of anti-piR-651 and anti-piR-823 transfected MDA-MB-231 cells was determined to be at 48 h, as indicated by decreased motility and invasion assay results (p p > 0.05). Asides from MMP-2 in anti-piR-823 transfected HUVECs and HIF-1α in anti-piR-823 transfected MDA-MB-231 cells, gene expressions of Ki-67, HIF-1α, MMP-2, and MMP-9 were reduced in both cell lines (p