OBJECTIVETo explore the effect of microRNA-30a-5p (miRNA-30a-5p) on the biological behavior of human hepatoma cells.

METHODSThe liver cancer cell line SMCC-7721 cells and the normal liver cell line L02 cells (control) were transiently transfected with miRNA-30a-5p mimics and an miRNA-30a-5p inhibitor by Lipofectamine 2000 (Life Technologies). miR-30a-5p mRNA expression was detected by quantitative real-time (q)PCR. Cell proliferation was evaluated using the Cell Counting Kit-8 (CCK-8) assay and apoptosis was assessed by flow cytometry.Invasion and migration were measured by transwell chamber assays. The SMCC-7721 cells was injected subcutaneously into nude mice to establish a tumor animal model.

RESULTSThe SMCC-7721 cells transfected with miRNA-30a-5p mimics showed significantly higher miRNA-30a-5p mRNA expression than the non-transfected SMCC-7721 cells and the transfected control L02 cells (P<0.01). The miRNA-30a-5p mRNA expression was significantly lower in the SMCC-7721 cells transfected with the miRNA-30a-5p inhibitor than the non-transfected SMCC-7721 cells the control L02 cells (P<0.01). The overexpression of miRNA-30a-5p inhibited the viability, colony formation rate, and invasion and migration abilities, as shown in the cells transfected with the miRNA-30a-5p mimics (P<0.05); in addition, the miRNA-30a-5p promoted proliferation of cells (P<0.05), as shown by more S phase cells detected by flow cytometry. SMCC-7122 cells transfected with miRNA-30a-5p mimics produced tumors with significantly higher average weight than tumors produced by SMCC-7122 cells that were untransfected or transfected with empty vector (both P<0.01).

CONCLUSIONOverexpression ofmiR-30a-5p had an inhibitory effect on cell proliferation, induced apoptosis, increased the number of cells in S phase, and markedly inhibited invasion and migration of SMCC-7721 HCC cells in vitro and in vivo.

Animals ; Apoptosis ; Carcinoma, Hepatocellular ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Humans ; Liver Neoplasms ; Mice ; Mice, Nude ; MicroRNAs ; Neoplasm Invasiveness ; Transfection

Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.
Adrenomedullin ; metabolism ; Animals ; Blood Pressure ; drug effects ; physiology ; Hypertension ; etiology ; Lipopolysaccharides ; pharmacology ; Male ; Neuropeptides ; metabolism ; Obesity ; complications ; Rats, Sprague-Dawley ; Receptors, Adrenomedullin ; drug effects ; metabolism ; Sympathetic Nervous System ; drug effects ; metabolism ; Toll-Like Receptor 4 ; metabolism