Profilin 1, negatively regulated by microRNA-19a-3p,serves as a tumor suppressor in human hepatocellular carcinoma

Profilin 1 (PFN1) is a critical actin-regulatory protein; however, its functional role in hepatocellular carcinoma (HCC) progression remains to be further elucidated. In the present study, we observed that the expression levels of PFN1 were significantly decreased in HCC tissues and cell lines. Low PFN1 expression was significantly correlated with aggressive clinicopathological characteristics and poor prognosis of HCC patients. Further in vitro experiments demonstrated that overexpression of PFN1 remarkably inhibited the proliferation, migration, invasion and EMT of HCC cells. Moreover, we also found that PFN1 was a direct target gene of miR-19a-3p, and in HCC tissues, and there was a significantly inverse correlation between PFN1 mRNA and miR-19a-3p expression. Collectively, our results showed that PFN1 functions as a tumor suppressor in HCC, and might serve as a diagnostic and therapeutic target for HCC patients.     

Liver-specific knockout of histone methyltransferase G9a impairs liver maturation and dysregulates inflammatory,cytoprotective, and drug-processing genes

1. Methyltransferase G9a is essential for a key gene silencing mark, histone H3 dimethylation at lysine-9 (H3K9me2). Hepatic G9a expression is down-regulated by xenobiotics and diabetes. However, little is known about the role of G9a in liver. Thus, we generated mice with liver-specific knockout (Liv-KO) of G9a.

2. Adult G9a Liv-KO mice had marked loss of H3K9me2 proteins in liver, without overt liver injury or infiltration of inflammatory cells. However, G9a-null livers had ectopic induction of certain genes normally expressed in neural and immune systems. Additionally, G9a-null livers had moderate down-regulation of cytoprotective genes, markedly altered expression of certain important drug-processing genes, elevated endogenous reactive oxygen species, induction of ER stress marker Chop, but decreased glutathione and nuclear Nrf2. microRNA-383, a negative regulator of the PI3K/Akt pathway, was strongly induced in G9a Liv-KO mice. After LPS treatment, G9a Liv-KO mice had aggravated lipid peroxidation and proinflammatory response.

3. Taken together, the present study demonstrates that G9a regulates liver maturation by silencing neural and proinflammatory genes but maintaining/activating cytoprotective and drug-processing genes, in which the G9a/miR-383/PI3K/Akt/Nrf2?(Chop) pathways may play important roles. G9a deficiency due to genetic polymorphism and/or environmental exposure may alter xenobiotic metabolism and aggravate inflammation and liver dysfunction.

     

Propofol upregulates miR-320a and reduces HMGB1 by downregulating ANRIL to inhibit PTC cell malignant behaviors

BackgroundOur previous study states that propofol suppresses proliferation and migration of papillary thyroid cancer (PTC) cells by downregulation of lncRNA ANRIL. This study intended to probe the downstream mechanism of ANRIL in PTC with potential microRNAs (miR) and genes.MethodsANRIL expression was detected in normal thyroid epithelial cells (Nthy-ori 3-1) and PTC cells (TPC-1, FTC-133, K1 and BCPAP). ANRIL expression was inhibited in TPC-1 and BCPAP cells to explore the effects of si-ANRIL in PTC malignant behaviors. The gain-and loss-of functions of ANRIL/miR-320a were performed to measure their roles in PTC. Levels of ANRIL, miR-320a, HMGB1, apoptosis- and Wnt/β-catenin and NF-κB pathways-related proteins were measured. Dual-luciferase reporter gene assay and RNA pull-down assay were applied to verify ANRIL/miR-320a/HMGB1 relation. si-ANRIL was transplanted into xenograft tumors in nude mice.ResultsANRIL was upregulated in TPC-1 and BCPAP cells. miR-320a targeted HMGB1, and ANRIL bound to miR-320a. In TPC-1 and BCPAP cells, si-ANRIL prevented PTC cell malignant behaviors, and inactivated the Wnt/β-catenin and NF-κB pathways; while si-ANRIL + miR-320a inhibition showed opposite trends. Overexpressing miR-320a promoted malignant behaviors of TPC-1 cells. In 6 μg/mL propofol-treated TPC-1 cells, miR-320a inhibition weakened propofol’s inhibitory effects on PTC cell growth. After ANRIL inhibition, the volume and weight of xenograft tumors were decreased.ConclusionPropofol upregulated miR-320a and reduced HMGB1 by downregulating ANRIL and inactivating the Wnt/β-catenin and NF-κB pathways, thus preventing PTC cell malignant behaviors. This study may offer new insights in PTC prevention and treatment.     

MicroRNA-192对结肠癌RKO细胞增殖、迁移和侵袭能力的影响及机制研究

目的:探讨microRNA-192（miR-192）对于高侵袭性结肠癌RKO细胞的增殖、迁移和侵袭能力的影响。方法:将miR-192 mimics（miR-192）通过脂质体转染至RKO细胞，应用qRT-PCR检测细胞中miR-192表达情况，采用CCK-8实验和集落形成实验研究miR-192对结肠癌RKO细胞增殖的影响，采用细胞划痕实验和Transwell小室模型检测miR-192对结肠癌细胞迁移和侵袭能力的影响，应用Western blot检测miR-192对结肠癌RKO细胞内上皮性钙黏附蛋白（E-cadherin，E-cad）和血管内皮生长因子（vascular endothelial growth factor，VEGF）蛋白表达的影响。结果:CCK-8实验和集落形成实验结果显示:转染了miR-192的结肠癌RKO细胞，癌细胞增殖显著受到抑制。细胞划痕实验、迁移实验和细胞侵袭实验结果显示:RKO细胞转染miR-192后，迁移和侵袭的细胞数量显著减少，差异有统计学意义（P<0.05）。Western blot结果显示:结肠癌细胞转染miR-192后可升高E-cad蛋白的表达，并且降低VEGF蛋白的表达。结论:转染miR-192可抑制结肠癌RKO细胞增殖，降低其迁移和侵袭能力，其可能的机制是升高结肠癌RKO细胞E-cad的表达，并且降低VEGF的表达。miR-192可能作为肿瘤诊断及治疗的新靶点。     

MicroRNA-21与骨质疏松症相关性的研究进展

骨质疏松症(osteoporosis,OP)是一种以易骨折为特点的全身代谢性骨骼疾病。在老龄化程度不断加剧的当今社会,其发病率逐年呈现显著上升趋势,尤其是骨质疏松性骨折导致的后遗症、副损伤给社会及患者带来极大的经济和生活负担。近年来诸多研究发现microRNA具有明确的抗骨质疏松作用,随着基因疗法应用的推广,microRNA在临床治疗骨质疏松起到了很好的靶向作用,同时相关文献阐释,尤其是其家族成员microRNA-21可通过调控成骨细胞和破骨细胞的分化与功能,在OP等骨疾病的发生发展过程中起着重要作用。本文将通过对microRNA-21在骨质疏松中的相关作用机制进行综述,旨在为OP靶向治疗及相关分子机制研究提供理论依据和新的思路。