Although great progresses have been made in the diagnosis and treatment of hepatocellular carcinoma (HCC), its prognostic marker remains controversial. In this current study, weighted correlation network analysis and Cox regression analysis showed significant prognostic value of five autophagy-related long non-coding RNAs (AR-lncRNAs) (including TMCC1-AS1, PLBD1-AS1, MKLN1-AS, LINC01063, and CYTOR) for HCC patients from data in The Cancer Genome Atlas. By using them, we constructed a five-AR-lncRNA prognostic signature, which accurately distinguished the high- and low-risk groups of HCC patients. All of the five AR lncRNAs were highly expressed in the high-risk group of HCC patients. This five-AR-lncRNA prognostic signature showed good area under the curve (AUC) value (AUC = 0.751) for the overall survival (OS) prediction in either all HCC patients or HCC patients stratified according to several clinical traits. A prognostic nomogram with this five-AR-lncRNA signature predicted the 3- and 5-year OS outcomes of HCC patients intuitively and accurately (concordance index = 0.745). By parallel comparison, this five-AR-lncRNA signature has better prognosis accuracy than the other three recently published signatures. Furthermore, we discovered the prediction ability of the signature on therapeutic outcomes of HCC patients, including chemotherapy and immunotherapeutic responses. Gene set enrichment analysis and gene mutation analysis revealed that dysregulated cell cycle pathway, purine metabolism, and TP53 mutation may play an important role in determining the OS outcomes of HCC patients in the high-risk group. Collectively, our study suggests a new five-AR-lncRNA prognostic signature for HCC patients.

Purpose: Radiofrequency ablation (RFA) is widely accepted as a curative treatment for small hepatocellular carcinoma (HCC). However, insufficient RFA (IRFA) can lead to rapid local recurrence. The underlying mechanisms remain poorly understood. This study aimed to elucidate the role and regulatory mechanisms of autophagy in the recurrence of HCC after IRFA. Materials and methods: SMMC7721 and Huh7 cells were exposed to sublethal heat stress to stimulate the transition zone of IRFA treatment. The levels of autophagy were measured by western blot, immunofluorescence and transmission electron microscopy. Functional assays, such as CCK-8, EdU incorporation and flow cytometry, were performed to determine the role of heat-induced autophagy. The involved signaling pathways were explored by western blot. Finally, the antitumor effects of chloroquine (CQ) on heat-treated HCC cells were evaluated via an in vivo xenograft tumor model. Results: Sublethal heat stress induced autophagy in a temperature-and time-dependent manner in HCC cells. Furthermore, the inhibition of autophagy by CQ or siRNA targeting the autophagy-related genes Beclin-1 and Atg5 enhanced heat-induced apoptosis. The combination of CQ and heat treatment significantly suppressed tumor growth both in vitro and in vivo. Mechanistically, we reported for the first time that the ATP-AMPK-mTOR signaling pathway was involved in heat-induced autophagy. Conclusions: Heat stress induced protective autophagy against heat-induced apoptosis in HCC via the ATP-AMPK-mTOR axis, suggesting that targeting autophagy may be a promising strategy for improving the efficacy of RFA treatment for HCC.

Insufficient radiofrequency ablation (iRFA) often leads to residual hepatocellular carcinoma (HCC) progression. However, the mechanism is still poorly understood. In the present study, we demonstrated that LC3B protein expression levels were significantly increased in the residual hepatocellular carcinoma cells after radiofrequency ablation (RFA) treatment in vivo. Moreover, iRFA promoted autophagy, autophagosome formation and autophagic flux in Huh-7 and SMMC7721 cell lines in vitro. In addition, iRFA induced HCC cell viability and invasion. However, blockade of autophagy by the autophagosome inhibitor 3-methyladenine (3-MA) suppressed iRFA-induced cell viability and invasion. Furthermore, we revealed that the expression of liver cancer stem cell marker CD133 was also significantly increased in the residual hepatocellular carcinoma cells after RFA treatment in vivo, and was positively correlated with LC3B protein expression. iRFA also promoted CD133 protein expression in Huh-7 and SMMC7721 cell lines in vitro. CD133 was localized to autophagosomes, and was suppressed by 3-MA or chloroquine (CQ) after iRFA treatment. CD133 downregulation also suppressed iRFA-induced cell viability, invasion and autophagy. Collectively, our results indicated that RFA may promote residual HCC cell progression by autophagy and CD133 feedback loop.

Background and Aims: Extrachromosomal circular DNAs (eccDNAs) are prevalent in cancer genomes and emerge as a class of crucial yet less characterized oncogenic drivers. However, the structure, composition, genomewide frequency, and contribution of eccDNAs in HCC, one of the most fatal and prevalent cancers, remain unexplored. In this study, we provide a comprehensive characterization of eccDNAs in human HCC and demonstrate an oncogenic role of microRNA (miRNA)-17-92-containing eccDNAs in tumor progression.Approach and Results: Using the circle-sequencing method, we identify and characterize more than 230,000 eccDNAs from 4 paired samples of HCC tumor and adjacent nontumor liver tissues. EccDNAs are highly enriched in HCC tumors, preferentially originate from certain chromosomal hotspots, and are correlated with differential gene expression. Particularly, a series of eccDNAs carrying the miRNA-17-92 cluster are validated by outward PCR and Sanger sequencing. Quantitative PCR analyses reveal that miRNA-17-92-containing eccDNAs, along with the expression of their corresponding miRNAs, are elevated in HCC tumors and associated with poor outcomes and the age of HCC patients. More intriguingly, exogenous expression of artificial DNA circles harboring the miR-17-92 cluster, which is synthesized by the ligase-assisted minicircle

Background Radiofrequency ablation (RFA) for the treatment of small hepatocellular carcinoma (HCC) has a drawback of high recurrence rate. No-touch technique was developed to overcome it. However, it has barely been studied in Chinese populations. The aim of this study is to determine the safety and efficacy of no-touch RFA in the treatment of cirrhosis-based small HCC patients. Methods A total of 130 patients of small HCC in Southwest Hospital were enrolled in this study, 46 cases treated by no-touch RFA and 84 cases by conventional RFA. Treatment complications and tumor-free survival rate and overall survival rate were compared and analyzed. Results There were no significant differences in baseline confounding factors between the two groups. The ablation volume of no-touch RFA technique was significantly higher than conventional RFA ( P = 0.002) but the remaining liver volume and treatment complications of the two techniques were the same ( P = 0.702 and P = 0.269, respectively). Cox regression model revealed that conventional RFA was a predictive factor for short-term HCC recurrence ( P = 0.041 for 2-year recurrence rate). Kaplan-Meier survival showed that tumor-free survival in no-touch group was significantly higher than conventional group ( P = 0.047). Conclusions Our data showed that no-touch RFA provided a higher short-term tumor-free survival rate than conventional RFA but was as safe as conventional RFA.