摘要: Background & Aims Hepatocellular carcinoma (HCC) is a common malignant tumour with high morbidity and mortality. Metabolic regulation by oncogenes is necessary for tumour growth. Testes-specific protease 50 (TSP50) has been found to promote cell proliferation in multiple tumour types. However, the mechanism that TSP50 promotes HCC progression are not known. Methods Hepatocyte proliferation was analysed by MTT and BrdU incorporation after TSP50 transfection. Furthermore, LC-MS/MS, co-immunoprecipitation and GST pull-down assays were performed to analyse protein(s) binding to TSP50. Moreover, the site-specific mutation of G6PD was used to reveal the key site critical for G6PD acetylation mediated by TSP50. Finally, the role of G6PD K171 acetylation regulated by TSP50 in cell proliferation and tumour formation was investigated. Results Our data suggest that the overexpression of TSP50 accelerates hepatocyte proliferation. In addition, G6PD is an important protein that binds to TSP50 in the cytoplasm. TSP50 activates G6PD activity by inhibiting the acetylation of G6PD at the K171 site. In addition, TSP50 promotes the binding of G6PD to SIRT2. Furthermore, the K171ac of G6PD regulated by TSP50 is required for TSP50-induced cell proliferation in vitro and tumour formation in vivo. Additionally, according to The Cancer Genome Atlas (TCGA) programme, TSP50 and G6PD are negatively correlated with the survival of HCC patients. Conclusions Collectively, our findings demonstrate that TSP50-induced cell proliferation and tumour formation are mediated by G6PD K171 acetylation.

摘要: Objectives The mammalian tongue develops from the branchial arches (1-4) and comprises highly organized tissues compartmentalized by mesenchyme/connective tissue that is largely derived from neural crest (NC). This study aimed to understand the roles of tumour suppressor Neurofibromin 2 (Nf2) in NC-derived tongue mesenchyme in regulating Hippo signalling and cell proliferation for the proper development of tongue shape and size. Materials and methods Conditional knockout (cKO) of Nf2 in NC cell lineage was generated using Wnt1-Cre (Wnt1-Cre/Nf2(cKO)). Nf2 expression, Hippo signalling activities, cell proliferation and tongue shape and size were thoroughly analysed in different tongue regions and tissue types of Wnt1-Cre/Nf2(cKO) and Cre(-)/Nf2(fx/fx) littermates at various stages (E10.5-E18.5). Results In contrast to many other organs in which the Nf2/Hippo pathway activity restrains growth and cell proliferation and as a result, loss of Nf2 decreases Hippo pathway activity and promotes an enlarged organ development, here we report our observations of distinct, tongue region- and stage-specific alterations of Hippo signalling activity and cell proliferation in Nf2(cKO) in NC-derived tongue mesenchyme. Compared to Cre(-)/Nf2(fx)(/)(fx) littermates, Wnt1-Cre/Nf2(cKO) depicted a non-proportionally enlarged tongue (macroglossia) at E12.5-E13.5 and microglossia at later stages (E15.5-E18.5). Specifically, at E12.5 Nf2(cKO) mutants had a decreased level of Hippo signalling transcription factor Yes-associated protein (Yap), Yap target genes and cell proliferation anteriorly, while having an increased Yap, Yap target genes and cell proliferation posteriorly, which lead to a tip-pointed and posteriorly widened tongue. At E15.5, loss of Nf2 in the NC lineage resulted in distinct changes in cell proliferation in different regions, that is, high in epithelium and mesenchyme subjacent to the epithelium, and lower in deeper layers of the mesenchyme. At E18.5, cell proliferation was reduced throughout the Nf2(cKO) tongue.

摘要: Circular RNAs (circRNAs), a type of non-coding RNA, are single-stranded circularized molecules characterized by high abundance, evolutionary conservation and cell development- and tissue-specific expression. A large body of studies has found that circRNAs exert a wide variety of functions in diverse biological processes, including cell cycle. The cell cycle is controlled by the coordinated activation and deactivation of cell cycle regulators. CircRNAs exert mutifunctional roles by regulating gene expression via various mechanisms. However, the functional relevance of circRNAs and cell cycle regulation largely remains to be elucidated. Herein, we briefly describe the biogenesis and mechanistic models of circRNAs and summarize their functions and mechanisms in the regulation of critical cell cycle modulators, including cyclins, cyclin-dependent kinases and cyclin-dependent kinase inhibitors. Moreover, we highlight the participation of circRNAs in cell cycle-related signalling pathways and the clinical value of circRNAs as promising biomarkers or therapeutic targets in diseases related to cell cycle disorder.