Explore the vast range of titles available.

Background Amplification of chromosome 7q21-7q31 is associated with tumor recurrence and multidrug resistance, and several genes in this region are powerful drivers of hepatocellular carcinoma (HCC). We aimed to investigate the key circular RNAs (circRNAs) in this region that regulate the initiation and development of HCC. Methods We used qRT-PCR to assess the expression of 43 putative circRNAs in this chromosomal region in human HCC and matched nontumor tissues. In addition, we used cultured HCC cells to modify circRNA expression and assessed the effects in several cell-based assays as well as gene expression analyses via RNA-seq. Modified cells were implanted into immunocompetent mice to assess the effects on tumor development. We performed additional experiments to determine the mechanism of action of these effects. Results circMET (hsa_circ_0082002) was overexpressed in HCC tumors, and circMET expression was associated with survival and recurrence in HCC patients. By modifying the expression of circMET in HCC cells in vitro, we found that circMET overexpression promoted HCC development by inducing an epithelial to mesenchymal transition and enhancing the immunosuppressive tumor microenvironment. Mechanistically, circMET induced this microenvironment through the miR-30-5p/Snail/ dipeptidyl peptidase 4(DPP4)/CXCL10 axis. In addition, the combination of the DPP4 inhibitor sitagliptin and anti-PD1 antibody improved antitumor immunity in immunocompetent mice. Clinically, HCC tissues from diabetic patients receiving sitagliptin showed higher CD8 + T cell infiltration than those from HCC patients with diabetes without sitagliptin treatment. Conclusions circMET is an onco-circRNA that induces HCC development and immune tolerance via the Snail/DPP4/CXCL10 axis. Furthermore, sitagliptin may enhance the efficacy of anti-PD1 therapy in a subgroup of patients with HCC.

Histone deacetylase 6 (HDAC6), a deacetylase of p53, has emerged as a privileged inhibitory target for cancer therapy because of its deacetylating activity for p53 at K120 and K373/382. However, intricate roles of HDAC6 in hepatocellular carcinogenesis have been suggested by recent evidence, namely that HDAC6 ablation suppresses innate immunity, which plays critical roles in tumor immunosurveillance and antitumor immune responses. Therefore, it is valuable to determine whether HDAC6 ablation inhibits hepatocellular carcinogenesis using in vivo animal models. Here, we firstly showed that HDAC6 ablation increased K320 acetylation of p53, known as pro‐survival acetylation, in all tested animal models but did not always increase K120 and K373/382 acetylation of p53, known as pro‐apoptotic acetylation. HDAC6 ablation induced cellular senescence in primary MEFs and inhibited cell proliferation in HepG2 cells and liver regeneration after two‐thirds partial hepatectomy. However, the genetic ablation of HDAC6 did not inhibit hepatocarcinogenesis, but instead slightly enhanced it in two independent mouse models (DEN + HFD and DEN + TAA). Notably, HDAC6 ablation significantly promoted hepatocarcinogenesis in a multiple DEN treatment hepatocellular carcinoma (HCC) mouse model, mimicking chronic DNA damage in the liver, which correlated with hyperacetylation at K320 of p53 and a decrease in inflammatory cytokines and chemokines. Our data from three independent in vivo animal HCC models emphasize the importance of the complex roles of HDAC6 ablation in hepatocellular carcinogenesis, highlighting its immunosuppressive effects. We provide the first evidence that HDAC6 is a p53 deacetylase at K320, which is especially important for cancer cell survival in chronic DNA damage conditions. Contrary to the general assumption that HDAC6 inhibition leads to hyperacetylation of p53 at K120, resulting in tumor suppression, our findings from in vivo animal HCC modelsemphasize the importance of the opposing roles of HDAC6 ablation in hepatocellular carcinogenesis by highlighting the K320 acetylation of p53 and immunosuppressive effects.

Routine dietary consumption of foods that contain aflatoxins is the second leading cause of environmental carcinogenesis worldwide. Aflatoxin-driven mutagenesis is initiated through metabolic activation of aflatoxin B₁ (AFB₁) to its epoxide form that reacts with N7 guanine in DNA. The resulting AFB₁-N7-dG adduct undergoes either spontaneous depurination or imidazole-ring opening yielding formamidopyrimidine AFB₁ (AFB₁-Fapy-dG). Because this latter adduct is known to persist in human tissues and contributes to the high frequency G-to-T mutation signature associated with many hepatocellular carcinomas, we sought to establish the identity of the polymerase(s) involved in processing this lesion. Although our previous biochemical analyses demonstrated the ability of polymerase ζ (pol ζ) to incorporate an A opposite AFB₁-Fapy-dG and extend from this mismatch, biological evidence supporting a unique role for this polymerase in cellular tolerance following aflatoxin exposure has not been established. Following challenge with AFB₁, survival of mouse cells deficient in pol ζ (Rev3L −/−) was significantly reduced relative to Rev3L +/− cells or Rev3L −/− cells complemented through expression of the wild-type human REV3L. Furthermore, cell-cycle progression of Rev3L −/− mouse embryo fibroblasts was arrested in late S/G2 following AFB₁ exposure. These Rev3L −/− cells showed an increase in replication-dependent formation of γ-H2AX foci, micronuclei, and chromosomal aberrations (chromatid breaks and radials) relative to Rev3L +/− cells. These data suggest that pol ζ is essential for processing AFB₁-induced DNA adducts and that, in its absence, cells do not have an efficient backup polymerase or a repair/tolerance mechanism facilitating survival.

Abstract The main objective of current study was to investigate the chemopreventive and chemotherapeutic activity of Artemisia vulgaris extract on diethylnitrosoamine induced hepatocarcinogenesis in Balb C mice. Diethylnitrosoamine (DEN: 0.9%) was prepared to induce hepatocarcinoma in Balb C mice. The extract Artemisia vulgaris (AV) was prepared by maceration technique. Mice were classified into four groups as follows: Group 1 a control group (N=7) received saline solution (3.5 μl/mg), group 2 (N=14) received diethylnitrosoamine (3.5 μl/mg) intraperitoneally once in a week for eight consecutive weeks, group 3 (N=7) received only plant extract (AV: 150 mg/kg (Body weight) once in a week, while group 4 (N=7) was given in combination of diethylnitrosoamine (3.5 μl/mg) and plant extract (AV: 150 mg/kg (body weight). After eight weeks of DEN administration, mice of group 2 were divided into two subgroups containing seven mice each; subgroup 1 was sacrificed while subgroup 2 was treated with plant extract only (150 mg/kg (body weight)) once in a week for eight consecutive weeks. The DEN injected mice significant decline in levels of albumin with concomitant significant elevations such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alpha feto protein, gamma glutamyl transferase, 5 nucleotidase, glucose-6-phosphate dehydrogenase and bilirubin. The administration of A. vulgaris significantly decreased the DEN induced hepatotoxicity. Present study revealed the potential anti-cancerous nature of Artemisia vulgaris, both in case of chemopreventive and post-treatment of A. vulgaris. Further studies are needed to explore the mechanism of prevention and therapy. Resumo O objetivo principal do presente estudo foi investigar as atividades quimiopreventiva e quimioterápica do extrato de Artemisia vulgaris em hepatocarcinogênese induzida por dietilnitrosoamina (DEN) em camundongos Balb C. Dietilnitrosoamina (DEN: 0,9%) foi preparada para induzir hepatocarcinoma em camundongos da linhagem Balb C. O extrato de A. vulgaris (AV) foi preparado pela técnica de maceração. Os camundongos foram classificados em quatro grupos conforme os seguintes: grupo 1, grupo controle (N=7) recebeu solução salina (3,5 µl/mg); grupo 2 (N=14) recebeu dietilnitrosoamina (3,5 µl/mg) por via intraperitoneal uma vez por semana durante oito semanas consecutivas; grupo 3 (N=7) recebeu apenas o extrato vegetal (AV: 150 mg/kg (peso corporal) uma vez por semana; enquanto no grupo 4 (N=7) foi administrado uma combinação de dietilnitrosoamina (3,5 μl/mg) com extrato vegetal (AV: 150 mg/kg (peso corporal). Após oito semanas de administração de DEN, os camundongos do grupo 2 foram divididos em dois subgrupos, contendo sete camundongos cada um; no subgrupo 1, os animais foram sacrificados, enquanto no subgrupo 2, os animais foram tratados apenas com extrato vegetal (150 mg/kg (peso corporal)) uma vez por semana durante oito semanas consecutivas. Os camundongos nos quais foram injetados DEN apresentaram declínio significativo nos níveis de albumina, mas elevações significativas concomitantes de: aspartato aminotransferase, alanina aminotransferase, lactato desidrogenase, alfa-fetoproteína, gama-glutamiltransferase, 5’ nucleotidase, glicose-6-fosfato desidrogenase e bilirrubina. A administração de A. vulgaris diminuiu significativamente a hepatotoxicidade induzida pelo DEN. O presente estudo apresentou a potencialidade anticancerosa da A. vulgaris, tanto nos casos de quimioprevenção quanto no pós-tratamento da A. vulgaris. Mais estudos são necessários para explorar o mecanismo de prevenção e a terapia.

Background Circular RNAs (circRNAs), which are endogenous non-coding RNAs, are associated with various biological processes including development, homeostatic maintenance, and pathological responses. Accumulating evidence has implicated non-coding RNAs in cancer progression, and the role of circRNAs in particular has drawn wide attention. However, circRNA expression patterns and functions in hepatocellular carcinoma (HCC) remain poorly understood. Methods CircRNA sequencing was performed to screen differentially expressed circRNAs in HCC. Northern blotting, quantitative real-time polymerase chain reaction, nucleocytoplasmic fractionation, and fluorescence in situ hybridization analyses were conducted to evaluate the expression and localization of circSLC7A11 in HCC tissues and cells. CircSLC7A11 expression levels were modified in cultured HCC cell lines to explore the association between the expression of circSLC7A11 and the malignant behavior of these cells using several cell-based assays. The modified cells were implanted into immunocompetent nude mice to assess tumor growth and metastasis in vivo. We applied bioinformatics methods, RNA pulldown, RNA immunoprecipitation, and luciferase reporter assays to explore the mechanisms of circSLC7A11 in HCC. Results CircSLC7A11 (hsa_circ_0070975) was conserved and dramatically overexpressed in HCC tissues and cells. HCC patients showing high circSLC7A11 expression had worse prognoses. Our in vitro and in vivo experiments showed that circSLC7A11 markedly accelerated HCC progression and metastasis through the circSLC7A11/miR-330-3p/CDK1 axis. Conclusions The acceleration of HCC progression and metastasis by circSLC7A11 through the circSLC7A11/miR-330-3p/CDK1 axis suggests that circSLC7A11 is a potential novel diagnostic and therapeutic target for HCC treatment.

Background Transmembrane 4 L six family member 5 (TM4SF5) translocates subcellularly and functions metabolically, although it is unclear how intracellular TM4SF5 translocation is linked to metabolic contexts. It is thus of interests to understand how the traffic dynamics of TM4SF5 to subcellular endosomal membranes are correlated to regulatory roles of metabolisms. Methods Here, we explored the metabolic significance of TM4SF5 localization at mitochondria‐lysosome contact sites (MLCSs), using in vitro cells and in vivo animal systems, via approaches by immunofluorescence, proximity labelling based proteomics analysis, organelle reconstitution etc. Results Upon extracellular glucose repletion following depletion, TM4SF5 became enriched at MLCSs via an interaction between mitochondrial FK506‐binding protein 8 (FKBP8) and lysosomal TM4SF5. Proximity labeling showed molecular clustering of phospho‐dynamic‐related protein I (DRP1) and certain mitophagy receptors at TM4SF5‐enriched MLCSs, leading to mitochondrial fission and autophagy. TM4SF5 bound NPC intracellular cholesterol transporter 1 (NPC1) and free cholesterol, and mediated export of lysosomal cholesterol to mitochondria, leading to impaired oxidative phosphorylation but intact tricarboxylic acid (TCA) cycle and β‐oxidation. In mouse models, hepatocyte Tm4sf5 promoted mitophagy and cholesterol transport to mitochondria, both with positive relations to liver malignancy. Conclusions Our findings suggested that TM4SF5‐enriched MLCSs regulate glucose catabolism by facilitating cholesterol export for mitochondrial reprogramming, presumably while hepatocellular carcinogenesis, recapitulating aspects for hepatocellular carcinoma metabolism with mitochondrial reprogramming to support biomolecule synthesis in addition to glycolytic energetics.

To elucidate the influence of a glycyrrhizin therapy on hepatocarcinogenesis rate in interferon (IFN)-resistant hepatitis C, we retrospectively analyzed 1249 patients with chronic hepatitis with or without cirrhosis. Among 346 patients with high alanine transaminase value (twice or more of upper limit of normal), 244 patients received intravenous glycyrrhizin injection and 102 patients did not, after judgment of IFN resistance. Crude carcinogenesis rates in the treated and untreated group were 13.3%, 26.0% at the 5th year, and 21.5% and 35.5% at the 10th year, respectively (P = .0210). Proportional hazard analysis using time-dependent covariates disclosed that glycyrrhizin treatment significantly decreased the hepatocarcinogenesis rate (hazard ratio 0.49, 95% confidence interval 0.27-0.86, P = .014) after adjusting the background features with significant covariates. Glycyrrhizin injection therapy significantly decreased the incidence of hepatocellular carcinoma in patients with IFN-resistant active chronic hepatitis C, whose average aminotransferase value was twice or more of upper limit of normal after interferon.

Hepatitis B virus (HBV) X protein (HBx) is a 17-kDa transcriptional coactivator that plays a significant role in the regulation of genes involved in inflammation and cell survival. It has been known to be involved in the development of liver cancer and alteration of the cellular HBx level may influence the pathogenesis of HBV-induced liver diseases. The transcription factor GLI1, a member of the glioma-associated oncogene homologue (GLI) subfamily of Krüppel-like zinc finger proteins is involved in signal transduction within the hedgehog (Hh) signaling pathway, which is involved in the development of many human malignancies. GLI activation is important for cell proliferation and anti-apoptosis in various cancers. To investigate whether the transcriptional coactivator HBx binds to the zinc finger transcription factor GLI1, recombinant HBx and GLI1 were isolated. Expression and purification of the HBx and GLI1 proteins were successfully performed in Escherichia coli . The binding of HBx to GLI1 was detected by surface plasmon resonance spectroscopy (BIAcore), fluorescence measurement, and a His-tagged pull-down experiment. After measuring the fluorescence emission spectra of purified HBx and GLI1, it was found that the interaction of these proteins is accompanied by significant conformational changes in one or both. This study provides important clues for the structural identification of signal transduction pathways involving the HBx and GLI1 proteins.

Objective: The influence of hepatitis C virus (HCV) subtypes on hepatocellular carcinogenesis was prospectively investigated. Methods: A total of 593 patients with HCV-related cirrhosis were recruited and their HCV subtype was determined. Results: The carcinogenesis rates in the patients with HCV group 1 (genotype 1a +1b, n = 442) and group 2 (genotype 2a +2b, n = 136) were 32.0 and 26.6% at the end of the 5th year, 57.4 and 48.1% at the end of the 10th year and 71.8 and 71.0% at the end of the 15th year, respectively (p = 0.10). As to those patients without a history of regular drinking (i.e. less than 200 kg on a pure alcohol basis), the carcinogenesis rates in group 1 (n = 277) and group 2 (n = 90) were 30.8 and 16.3% at the end of the 5th year, 52.8 and 34.4% at the end of the 10th year and 70.6 and 67.1% at the end of the 15th year, respectively (p = 0.025). Although HCV subtype did not influence carcinogenesis in patients with a drinking history of 200 kg or more (p = 0.62), it significantly affected the carcinogenesis rate in patients without a history of regular drinking. Multivariate analysis showed that HCV subtype group 1 significantly increased the carcinogenesis in the group without a history of regular drinking after adjustment for age and gender (hazard ratio = 2.57, p = 0.0085). Conclusion: The interaction between HCV subtype and drinking history should be considered in the prediction of carcinogenesis using a multiplicative proportional hazard model.

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, is a leading cause of cancer-related death worldwide. It is highly refractory to most systemic therapies. Recently, significant progress has been made in uncovering genomic alterations in HCC, including potentially targetable aberrations. The most common molecular anomalies in this malignancy are mutations in the TERT promoter, TP53 , CTNNB1 , AXIN1 , ARID1A, CDKN2A and CCND1 genes . PTEN loss at the protein level is also frequent. Genomic portfolios stratify by risk factors as follows: (i) CTNNB1 with alcoholic cirrhosis; and (ii) TP53 with hepatitis B virus-induced cirrhosis. Activating mutations in CTNNB1 and inactivating mutations in AXIN1 both activate WNT signaling. Alterations in this pathway, as well as in TP53 and the cell cycle machinery, and in the PI3K/Akt/mTor axis (the latter activated in the presence of PTEN loss), as well as aberrant angiogenesis and epigenetic anomalies, appear to be major events in HCC. Many of these abnormalities may be pharmacologically tractable. Immunotherapy with checkpoint inhibitors is also emerging as an important treatment option. Indeed, 82% of patients express PD-L1 (immunohistochemistry) and response rates to anti-PD-1 treatment are about 19%, and include about 5% complete remissions as well as durable benefit in some patients. Biomarker-matched trials are still limited in this disease, and many of the genomic alterations in HCC remain challenging to target. Future studies may require combination regimens that include both immunotherapies and molecularly matched targeted treatments.