摘要: ObjectivesWhen rat chloroleukaemia (CHL) cells are grown undisturbed in a confined space, a genomic long interspersed nuclear element (LINE) is transcriptionally activated at a relatively low population density, followed by the retrotransposition of LINE and population death. This death programme is fundamentally different from conventional cell death pathways. Materials and methodsThis work is essentially based on the re-analysis of relevant, old experimental data. Elemental analysis of a highly purified, long-stored inhibitor sample was performed. Genomic sequence searches were performed using the basic local alignment search tool (BLAST). ResultsThis death programme is initiated by an endogenous inhibitor secreted by CHL cells. The inhibitor is almost certainly identical to the pentapeptide pyroGlu-Glu-Asp-Cys-Lys, shown to be a cell line-specific inhibitor of normal granulocytic cells. The inhibitor is derived from a highly conserved short open reading frame in mammalian genomes. ConclusionsAlthough spontaneous population death may be a biological oddity restricted to rat CHL cells, we suggest that this death programme is responsible for the eradication of cancer cells following treatment with an inhibitor administered exogenously.

摘要: Objectives Accumulating evidence demonstrated that the long noncoding RNA (lncRNA) HOTAIR (Hox transcript antisense intergenic RNA) plays key role in renal cell carcinoma (RCC) malignancy, while microRNA-124 (miR-124) is a tumour suppressor in RCC. The aim of this work was to assess the biological function of HOTAIR and to explore underlying mechanism involved in HOTAIR/miR-124/alpha-2, 8-sialyltransferase 4 (ST8SIA4) axis-regulated progression in RCC. Materials and methods Real-time PCR analyses and western blots were performed to the levels of HOTAIR, miR-124 and ST8SIA4 expression in human RCC tissues and RCC cell lines (ACHN and 786-O). Bioinformatics analysis and dual-luciferase reporter assay were used to illustrate relationship between HOTAIR and miR-124 in RCC. Colony formation assays, EdU assays, Ki67 assays and apoptosis assays were taken to evaluate cell proliferation. Tumour xenograft was created to explore the functions of HOTAIR and ST8SIA4 in tumorigenesis in vivo. Migration assays, invasion assays and cell adhesion assays and were also taken to analyse the carcinoma progression. Results In this study, HOTAIR level was confirmed to be significantly upregulated in RCC samples and RCC cell lines compared with those in the paired adjacent tissues and normal renal cell line. Overexpression of HOTAIR promoted the capability of proliferation, migration and invasion in RCC cell lines. HOTAIR directly bound to miR-124, while miR-124 mediated the expression of ST8SIA4 in RCC cell lines. ST8SIA4 was upregulated in RCC tissues and RCC cell lines. Ectopic expression of ST8SIA4 modulated the proliferation, migration and invasion of RCC cells. Further results indicated that HOTAIR promoted the proliferation and metastasis as a competing endogenous RNA to regulate ST8SIA4 expression by sponging miR-124 in RCC. Conclusions Our results demonstrated that HOTAIR mediated RCC progression in part through miR-124/ST8SIA4 axis, which functioned as a new prognostic biomarker in RCC.

摘要: Objectives This study aims to reveal the roles and related mechanisms of LncRNA B4GALT1-AS1 in osteosarcoma (OS) cells stemness and migration. Materials and methods Real-time quantitative PCR (RT-qPCR) was used to detect the expression of several LncRNAs in OS tissues and normal adjacent tissues and in OS mammospheres and cells. Cell viability, transwell migration, tumour spheres formation and in vivo tumour formation assays were used to examine the effects of LncRNA B4GALT1-AS1 on OS progression. In addition, RNA immunoprecipitation (RIP) and Luciferase reporter assays were performed to determine the binding site of RNA-binding protein HuR on B4GALT1-AS1 and transcriptional factor YAP. Immunofluorescence analysis was used to examine YAP nuclear-cytoplasm translocation. Results LncRNA B4GALT1-AS1 expression was significantly increased in OS tissues and cells spheres. Knockdown of B4GALT1-AS1 inhibited OS cells proliferation, migration, stemness and chemotherapeutic sensitivity. Mechanistically, B4GALT1-AS1 recruited HuR to enhance YAP mRNA stability and thus its transcriptional activity. Conclusions We indicate that lncRNA B4GALT1-AS1 promotes OS cells stemness and migration via recruiting HuR to enhance YAP activity.

摘要: Objectives Prolyl hydroxylases (PHDs) play essential roles in oxygen-sensing system, whereas the effects of PHDs on inflammation have not been totally uncovered. Our study aimed to investigate the role of PHDs in lipopolysaccharide (LPS)-induced inflammation of human gingival fibroblasts (HGFs) and clarify the potential mechanisms. Materials and methods A pan hydroxylase inhibitor, dimethyloxallyl glycine (DMOG), and RNA interference were used to explore the role of PHDs in inflammation. Cytotoxic effect of DMOG was determined by cell-counting kit-8 and flow cytometry respectively. The secretion levels of IL-6 and IL-8 were assessed by ELISA. The mRNA levels of inflammatory cytokines, Toll-like receptor (TLR) 4 and MyD88 were evaluated by quantitative real-time PCR. The activation of NF-kappa B, mitogen-activated protein kinase (MAPK) and PI3K/AKT pathways were detected by western blot and the nuclear translocation of NF-kappa B p65 was examined by immunofluorescence. Downregulation of PHD1 and PHD2 was performed with siRNA transfection. Results Dimethyloxallyl glycine inhibited LPS-induced inflammatory cytokine, TLR4 and MyD88 expression in gene level and the elevated secretion of IL-6 and IL-8 was also downregulated. Additionally, LPS-induced activation of NF-kappa B, MAPK and AKT pathways was abolished by DMOG treatment. Importantly, LPS-induced inflammatory cytokine expression was merely suppressed by PHD2 knockdown. Conclusions Prolyl hydroxylases acted as a positive regulator in LPS-induced inflammation of HGFs via TLR4/MyD88-mediated NF-kappa B, MAPK and AKT signalling pathways and PHD2 among three isoforms was principally responsible for the effects.

摘要: ObjectivesDiabetic nephropathy (DN) is a nerve damaging disorder, characterized by glomerular mesangial cell expansion and accumulation of extracellular matrix (ECM) proteins. In this study, we aimed to investigate mesangial cell proliferation and ECM accumulation when promoting or suppressing endogenous miR-382 in glomerular mesangial cells of DN. Materials and methodsModel establishment consisted of DN induction by streptozotocin (STZ) in mice. The underlying regulatory mechanisms of miR-382 were analysed in concert with the treatment of miR-382 mimics, miR-382 inhibitors or siRNA against FoxO1 in cultured glomerular mesangial cells isolated from DN mice. ResultsFoxO1 was identified as the downregulated gene in DN based on the microarray data of GSE1009. We found that miR-382 was significantly upregulated in renal tissues of DN mice and its downregulation dephosphorylated FoxO1, reduced glomerular mesangial cell proliferation and ECM accumulation in vitro. The determination of luciferase activity suggested that miR-382 negatively targeted FoxO1. Expectedly, distinct levels of phosphorylated FoxO1 were observed in the renal cortices of DN mice, while the silencing of FoxO1 was found to increase glomerular mesangial cell proliferation and ECM accumulation in vitro. Reduced glomerular mesangial cell proliferation and ECM accumulation elicited by miR-382 inhibitors were reversed by silencing FoxO1. ConclusionsThis study demonstrates miR-382 suppression exerts a potent anti-proliferative effect that may be applied to inhibit glomerular mesangial cell proliferation and ECM accumulation in DN.