College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
Shaheed Benazir Bhutto, University of Veterinary and Animal Sciences, Sakrand, Pakistan.
Metallomics. 2020 Mar 25;12(3):449-459. doi: 10.1039/c9mt00266a.
Selenium (Se) is an essential trace element that has several functions in cellular processes related to cancer prevention. While the cancericidal effect of Se has been reported in liver cancer, the mechanism has not been clarified. MiR-29a has widely been reported as a tumor suppressor; however, it also acts as a carcinogenic agent by increasing cell invasion in human epithelial cancer cells and hepatoma cells. In a previous study, we found that miR-29a-3p is a Se-sensitive miRNA. However, its effect in the chicken hepatocellular carcinoma cell line (LMH) is still unknown. In the present study, we found that the expression of miR-29a-3p in LMH cells was decreased by Se supplementation and increased under Se-deficient conditions. Flow cytometry and CCK-8 results suggested that Se decreased LMH cell proliferation induced by miR-29a-3p overexpression. Transwell and gap-closure assays implied that Se mediated LMH cell invasion and migration by downregulating miR-29a-3p. Quantitative real-time polymerase chain reaction and Western blotting results suggested that Se mitigated miR-29a-3p overexpression-induced LMH cell proliferation by downregulating CDK2, cyclin-D1, CDK6, and cyclin-E1. We further demonstrated that collagen type IV alpha 2 (COL4A2) is a target gene of miR-29a-3p. COL4A2 activates the RhoA/ROCK pathway to promote LMH cell invasion and migration. In conclusion, Se mediated miR-29a-3p overexpression induced LMH cell invasion and migration by targeting COL4A2 to inactivate the RhoA/ROCK pathway.
硒（Se）是一种必需的微量元素，在与癌症预防相关的细胞过程中具有多种功能。虽然已经报道了 Se 对肝癌的抗癌作用，但机制尚未阐明。miR-29a 被广泛报道为肿瘤抑制因子；然而，它也通过增加人上皮癌细胞和肝癌细胞的细胞侵袭作用为致癌剂。在之前的研究中，我们发现 miR-29a-3p 是一种对 Se 敏感的 miRNA。然而，其在鸡肝癌细胞系（LMH）中的作用尚不清楚。在本研究中，我们发现 Se 补充剂可降低 LMH 细胞中 miR-29a-3p 的表达，而 Se 缺乏条件下则增加 miR-29a-3p 的表达。流式细胞术和 CCK-8 结果表明，Se 通过下调 miR-29a-3p 减少了由 miR-29a-3p 过表达诱导的 LMH 细胞增殖。Transwell 和缝隙封闭测定表明，Se 通过下调 miR-29a-3p 介导 LMH 细胞侵袭和迁移。定量实时聚合酶链反应和 Western blotting 结果表明，Se 通过下调 CDK2、cyclin-D1、CDK6 和 cyclin-E1 缓解了 miR-29a-3p 过表达诱导的 LMH 细胞增殖。我们进一步证明了胶原 IV 型α 2（COL4A2）是 miR-29a-3p 的靶基因。COL4A2 激活 RhoA/ROCK 通路，促进 LMH 细胞侵袭和迁移。总之，Se 通过靶向 COL4A2 使 RhoA/ROCK 通路失活来介导 miR-29a-3p 过表达诱导的 LMH 细胞侵袭和迁移。
