Down-regulation of long noncoding RNA HOXA11-AS nullifies the impact of microRNA-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis.

OBJECTIVES: This study was directed towards exploring the impacts of lncRNA HOXA11-AS-mediated microRNA (miR)-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis (OA). METHODS: The articular cartilages were provided by OA patients who received total knee arthroplasty, and Human Chondrocyte (HC)-OA (HCOA) was also attained. The miR-506-3p and HOXA11-AS expressions in articular cartilages from OA patients and HCOA cells were analyzed via qPCR. After gain- and loss-of-function assays in HCOA cells, MTT assay and flow cytometry (FC) were used for assessing cell viability and apoptosis, accordingly. The levels of PIK3CA, AKT, and mTOR as well as AKT and mTOR phosphorylation levels assessed using western blotting (WB). The targeting correlation of HOXA11-AS and miR-506-3p as well as miR-506-3p and PIK3CA was assessed through Dual-Luciferase Reporter gene Assay (DLRA). RESULT: The articular cartilages from OA patients and Human Chondrocyte (HC)-OA (HCOA) cells showed increased HOXA11-AS and decreased miR-506-3p. Mechanistically, HOXA11-AS was capable of binding to miR-506-3p to increase PIK3CA, the target gene of miR-506-3p. miR-506-3p suppression facilitated HCOA cell proliferation and reduced their apoptosis, which was nullified by further silencing HOXA11-AS or silencing PIK3CA. The down-regulation of HOXA11-AS disrupted the PI3K/AKT/mTOR pathway, which was counteracted by further miR-506-3p inhibition. CONCLUSION: The silencing of HOXA11-AS might block the PI3K/AKT/mTOR pathway through miR-506-3p up-regulation, thereby restricting HCOA cell proliferation and provoking apoptosis.

Down-regulation of long noncoding RNA HOXA11-AS nullifies the impact of microRNA-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis

Abstract Objectives This study was directed towards exploring the impacts of lncRNA HOXA11-AS-mediated microRNA (miR)-506-3p on chondrocytes proliferation and apoptosis in osteoarthritis (OA). Methods The articular cartilages were provided by OA patients who received total knee arthroplasty, and Human Chondrocyte (HC)-OA (HC-OA) was also attained. The miR-506-3p and HOXA11-AS expressions in articular cartilages from OA patients and HC-OA cells were analyzed via qPCR. After gain- and loss-of-function assays in HC-OA cells, MTT assay and flow cytometry (FC) were used for assessing cell viability and apoptosis, accordingly. The levels of PIK3CA, AKT, and mTOR as well as AKT and mTOR phosphorylation levels assessed using western blotting (WB). The targeting correlation of HOXA11-AS and miR-506-3p as well as miR-506-3p and PIK3CA was assessed through Dual-Luciferase Reporter gene Assay (DLRA). Result The articular cartilages from OA patients and Human Chondrocyte (HC)-OA (HC-OA) cells showed increased HOXA11-AS and decreased miR-506-3p. Mechanistically, HOXA11-AS was capable of binding to miR-506-3p to increase PIK3CA, the target gene of miR-506-3p. miR-506-3p suppression facilitated HC-OA cell proliferation and reduced their apoptosis, which was nullified by further silencing HOXA11-AS or silencing PIK3CA. The down-regulation of HOXA11-AS disrupted the PI3K/AKT/mTOR pathway, which was counteracted by further miR-506-3p inhibition. Conclusion The silencing of HOXA11-AS might block the PI3K/AKT/mTOR pathway through miR-506-3p up-regulation, thereby restricting HC-OA cell proliferation and provoking apoptosis.

Tetrazolium violet induces apoptosis via caspases-8, -9 activation and Fas/FasL up-regulation in rat C6 glioma cells.

Tetrazolium violet (TV), a tetrazolium salt, was synthesized as a novel and potent anticancer agent with a broad spectrum of anticancer activity against many cancer cells. A previous study showed that tetrazolium violet inhibited cell growth, and induced cell cycle arrest and apoptosis in C6 Rat glioma cells. It also showed that treatment of cells with TV for 24 h resulted in a dramatic up-regulation of p53, and an increase in the activity of caspase-3, accompanied with a significant increase of Bax/Bcl-2 ratio. In this study, we further investigated which Fas/FasL and caspase were activated by TV during the apoptosis. Annexin-V-propidium iodide (PI) binding assay and nucleosome ELISA assay further indicated that TV induced a typical apoptosis, in a time-dose-dependent manner. The data showed that the activity of Fas/FasL and caspase-8 and -9 were significantly enhanced by the compound, which suggested that TV might be used as a Fas/FasL and caspases promoter to initiate brain cancer cell apoptosis.