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 <i>via</i> 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 (<i>p</i> &lt; 0.001). NeverthelessHowever, there was no significant difference in the motility and proliferation of HUVECss transfected with anti-piR-651 and anti-piR-823 compared to the control group (<i>p</i> &gt; 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 (<i>p</i> &lt; 0.001). Inhibition of piR-651 and piR-823 decreased the survival and metastasis of cancer cells, without causing vital structural changes in healthy cells. Future research in cancer gene therapy or genetic modification may benefit from investigating piR-651 and piR-823 as possible inhibitors of breast cancer invasion and metastasis.

PIWI互作RNA（PIWI-Interacting RNAs，piRNAs）是一类源自单链RNA的小型非编码RNA，可通过转座子沉默与脱氨基作用介导的mRNA降解途径，在表观遗传调控中发挥关键作用。本研究旨在抑制MDA-MB-231三阴性乳腺癌细胞中的piR-651与piR-823，并探究其对健康人脐静脉内皮细胞（human umbilical vein endothelial cells，HUVEC）的潜在影响。研究团队采用脂质体转染试剂（Lipofectamine）介导的转染方法，将非靶向序列、抗piR-651序列与抗piR-823序列分别转染至HUVEC与MDA-MB-231细胞中。分别于转染后24、48、72小时，检测两种细胞系的增殖能力与细胞运动性。基于细胞运动性的检测结果，研究人员对MDA-MB-231细胞开展了结晶紫染色法介导的侵袭实验。在转染后48小时，即两种细胞系均呈现出最显著抑制效果的时段，检测Ki-67抗原（Ki-67）、缺氧诱导因子-1α（HIF-1α）、基质金属蛋白酶-2（MMP-2）与基质金属蛋白酶-9（MMP-9）的基因表达水平。结果显示，抗piR-651与抗piR-823转染的MDA-MB-231细胞的增殖最优观测时间为48小时，该时段的细胞运动性与侵袭能力均显著降低（p < 0.001）。然而，与对照组相比，转染抗piR-651与抗piR-823的HUVEC的细胞运动性与增殖能力无显著差异（p > 0.05）。除抗piR-823转染的HUVEC中MMP-2的表达，以及抗piR-823转染的MDA-MB-231细胞中HIF-1α的表达外，两种细胞系中Ki-67、HIF-1α、MMP-2与MMP-9的基因表达均显著下调（p < 0.001）。抑制piR-651与piR-823可降低癌细胞的存活与转移能力，且不会对健康细胞造成显著的结构损伤。未来针对癌症基因治疗或基因改造的相关研究，可将piR-651与piR-823作为乳腺癌侵袭与转移的潜在抑制剂展开进一步探究。