The Roles And Mechanism Of Circ-0008285 In Early Stage Of Hepatocellular Carcinoma

Part I: The roles and mechanism of Circ-0008285 in early stage of hepatocellular carcinomaObjective: Non-coding RNAs play important roles in tumorigenesis,providing potential targets for cancer intervention.Circular RNAs,a new class of endogenous non-coding RNAs,have attracted more and more attention in the biological function regulation and the clinical diagnosis of hepatocellular carcinoma,but the underlying mechanisms in very early stage of HCC remain unknown.Design: The expression levels of Circ-0008285 in different stages of HCC and different kinds of cell lines were measured.The specific nucleic acid sequences of Circ-0008285 were detected.The location preference of Circ-0008285 was clarified.The critical signaling pathways of Circ-0008285 network were identified to make further understand of the tumor cell proliferation and self-renew in the early stage of HCC.Results: In this study,we identified a circ RNA,named Circ-0008285,was upregulated in very early stage of hepatocellular carcinoma(HCC).Circ-0008285 promoted tumorigenesis via competitively binding miR-892 a to upregulate HDGF expression in HCC cells,activating PI3K/AKT/m TOR and PI3K/AKT/GSK-3?/?-catenin signaling pathways,thus facilitated tumor cell proliferation and self-renew.Circ-0008285 promotes the tumor initiation.Therefore,our findings suggest Circ-0008285 may serve as a predictor and demonstrate the therapeutic potential of Circ-0008285-miR-892a-HDGF signal inhibition to more effectively treat early stage of HCC.Conclusions: Globally,Circ-0008285 promotes HCC progression by acting as the sponge of tumor suppressor miR-892 a to promote HDGF expression,suggesting that Circ-0008285 is a potential target in HCC treatment.The increase of Circ-0008285 in HCC tissues may serve as a prognosis predictor for poor survival of patients.Part II: The roles and mechanism of HMGB1 in nonalcoholic fatty liver diseaseObjective: The Toll-like receptor 4(TLR4)endogenous ligand high mobility group box 1(HMGB1)is indicated as the early mediator of non-alcoholic steatohepatitis,but the upstream mechanisms and signaling that lead to the upregulation and release of HMGB1 remain poorly delineated.Design: C57BL/6 mice,miR-429 wild type mice(miR-429wt)and miR-429 liver conditional knockout mice(miR-429?hep)were fed with high-fat diet(HFD)for 2weeks to 12 weeks.C57BL/6 mice maintained on HFD received intraperitoneal injection of HMGB1 neutralizing antibodies per week.The normal hepatocytes cell lines L02 was exposure to saturated palmitic acid(PA)or unsaturated oleic acid(OA).The expression and release of HMGB1 was quantified by Western Blot and Enzyme-linked immuno sorbent assay(ELISA).Results: HFD-induced inflammatory response and liver function imbalance were both mitigated after antagonists of endogenous HMGB1 by neutralizing antibody.The increases of HMGB1 were validated to be modified by dual channels.Firstly,transcriptional regulated by c-Jun NH2-terminal kinase 1/2(JNK1/JNK2)-Activating transcription factor 2(ATF2)axis.Secondary,it was post-transcriptional regulated by micro RNA-200 b /200a/429.miR-429?hep mice,either ND-or HFD-fed,showed severe liver inflammatory and function damage,accompany with higher expression of HMGB1,by compared with wild type mice.Intriguingly,the up-regulation and release of HMGB1 could in turn self-activate the TLR4-JNK1/JNK2-ATF2 signaling,forming a positive feedback.Conclusions: Our findings reveal a novel mechanism by which HMGB1 expression was dual regulated by JNK1/2-ATF2 axis and miR-200 family,which providing a potential new approach for the prevention and treatment of NAFLD in the early stage.