Long non-coding RNA Gas5 regulates proliferation and apoptosis in HCS-2/8 cells and growth plate chondrocytes by controlling FGF1 expression via miR-21 regulation

LncRNA Gas5 is known to be a key control element during growth, differentiation and development in mammalian species. However, the role and function of Gas5 in growth plate chondrocytes has not been determined. The overexpression and knockdown models of Gas5 and miR-21 in cells and animals were constructed. Cell survival was determined by MTT assay and flow cytometry. Animal biochemical indices were measured by enzyme-linked immunosorbent assay, hematoxylin/eosin staining, immunohistochemistry or in situ hybridisation. Dual luciferase reporter gene assay was carried out to study targeting. First, we found the expression levels of fibroblast growth factor 1(FGF1) were up-regulated and miR-21 were down-regulated in Gas5 overexpressing model cells. Meanwhile, the expression levels of FGF1 and Gas5 were up-regulated in miR-21 knockdown model cells. Furthermore, cell proliferation was significantly promoted after Gas5 knockdown or miR-21 overexpression. Subsequently, Gas5 promoted apoptosis, while miR-21 suppressed apoptosis. Animal assays demonstrated that both Gas5 and dexamethasone suppressed proliferation and promoted apoptosis of growth plate chondrocytes, up-regulated FGF1 expression but reduced miR-21 expression. Finally, there was a binding relationship between Gas5, miR-21 and FGF1. We concluded that Gas5 regulated proliferation and apoptosis in growth plate by controlling FGF1 expression via miR-21 regulation.