MicroRNAs (miRNAs) are a class of small non-coding RNAs that, in general, negatively regulate gene expression. They have been identified in various tumor types, showing that different sets of miRNAs are usually deregulated in different cancers. Some miRNA genes harboring CpG islands undergo methylation-mediated silencing, a characteristic of many tumor suppressor genes. To identify such miRNAs in hepatocellular carcinoma (HCC), we first examined the methylation status of 43 loci containing CpG islands around 39 mature miRNA genes in a panel of HCC cell lines and non-cancerous liver tissues as controls. Among 11 miRNA genes frequently methylated in HCC cell lines but not in non-cancerous liver tissues, three miRNA genes, i.e. miR-124, miR-203 and miR-375, were selected as silenced miRNAs through CpG-island methylation by comparing methylation and expression status and evaluating restored expression after treatment with 5-aza-2'-deoxycytidine. In primary tumors of HCC with paired non-tumorous liver tissues, only miR-124 and miR-203 showed frequent tumor-specific methylation, and their expression status was inversely correlated with methylation status. Ectopic expression of miR-124 or miR-203 in HCC cells lacking their expression inhibited cell growth, with direct downregulation of possible targets, cyclin-dependent kinase 6 (CDK6), vimentin (VIM), SET and MYND domain containing 3 (SMYD3) and IQ motif containing GTPase activating protein 1 (IQGAP1) or ATP-binding cassette, subfamily E, member 1 (ABCE1), respectively. Our results suggest that miR-124 and miR-203 are novel tumor-suppressive miRNAs for HCC epigenetically silenced and activating multiple targets during hepatocarcinogenesis.

ObjectiveTo identify the perioperative risk factors for postoperative bile leakage after hepatic resection, to evaluate the intraoperative bile leakage test as a preventive measure, and to propose a treatment strategy for postoperative bile leakage according to the outcome of these patients. Summary Background DataBile leakage remains a common cause of major complications after hepatic resection. MethodsBetween January 1985 and June 1999, 781 hepatic resections without bilioenteric anastomosis were performed at the authors' institution. Perioperative risk factors related to postoperative bile leakage were identified using univariate and multivariate analysis. The characteristics of patients with intractable bile leakage and the effect of intraoperative bile leakage test were also examined. Management was evaluated in relation to the outcomes and the clinical characteristics of the patients with bile leakage. ResultsBile leakage developed in 31 (4.0%) of 781 hepatic resections. This complication carried high risks for surgical death (two patients [6.5%] died). The stepwise logistic regression analysis identified high-risk surgical procedure, in which the cut surface exposed the major Glisson's sheath and included the hepatic hilum (i.e., anterior segmentectomy, central bisegmentectomy, or total caudate lobectomy), as the independent predictor of the development of postoperative bile leakage. None of the 102 cases in which an intraoperative bile leakage test was performed were subsequently complicated by postoperative bile leakage, and the preventive effect of the test was statistically significant. Patients with fisterographically demonstrable leakage from the hepatic hilum and with postoperative uncontrollable ascites had poor outcomes. ConclusionPatients with bile leakage from the hepatic hilum and postoperative uncontrollable ascites tend to have a poor prognosis. Therefore, especially when a high-risk surgical procedure is performed in patients with liver cirrhosis, more careful surgical procedures and use of an intraoperative bile leakage test are recommended.Because of recent advances in liver surgery, hepatic resections are being performed with increasing frequency, and the surgical death rate for such resections is decreasing. [1][2][3][4][5][6][7] Bile leakage, of course, is the primary complication occurring after liver surgery, and it can not only debase the quality of the postoperative course of patients, but also can lead to hospital death. Despite a significant decrease in the overall surgical complication rate in hepatic resections, the rate of bile leakage has not changed, with an incidence of 4.8% to 7.6% reported in recent large series.2-8 The presence of bile, blood, and devitalized tissues in the dead space after hepatectomy may provide the ideal environment for bacterial growth and impair the normal host defense mechanisms.9, 10 The combination of sudden reduction in the liver volume and development of an intraperitoneal septic complication after hepatectomy (IPSCH) frequently results in live...

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MethodsPatients. We studied 23 patients with resectable HCC. Tumor size varied from 1.8 cm to 14.5 cm, and all individuals had a single tumor. At the time of surgery, wide resection margins allowed us to obtain enough tissues to compare gene expres-

BackgroundHepatocellular carcinoma (HCC) is a heterogeneous disease with various etiological factors, and ranks as the second leading cause of cancer-related mortality worldwide due to multi-focal recurrence. We herein identified three major subtypes of HCC by performing integrative analysis of two omics data sets, and clarified that this classification was closely correlated with clinicopathological factors, immune profiles and recurrence patterns.MethodsIn the test study, 183 tumor specimens surgically resected from HCC patients were collected for unsupervised clustering analysis of gene expression signatures and comparative analysis of gene mutations. These results were validated by using genome, methylome and transcriptome data of 373 HCC patients provided from the Cancer Genome Atlas Network. In addition, omics data were obtained from pairs of primary and recurrent HCC.FindingsComprehensive molecular evaluation of HCC by multi-platform analysis defined three major subtypes: (1) mitogenic and stem cell-like tumors with chromosomal instability; (2) CTNNB1-mutated tumors displaying immune suppression; and (3) metabolic disease-associated tumors, which included an immunogenic subgroup characterized by macrophage infiltration and favorable prognosis. Although genomic and epigenomic analysis explicitly distinguished between HCC with intrahepatic metastasis (IM) and multi-centric HCC (MC), the phenotypic similarity between the primary and recurrent tumors was not correlated to the IM/MC origin, but to the classification. Interpretation: Identification of these HCC subtypes provides further insights into patient stratification as well as presents opportunities for therapeutic development.FundMinistry of Education, Culture, Sports, Science and Technology of Japan (16H02670 and 18K19575), Japan Agency for Medical Research and Development (JP15cm0106064, JP17cm0106518, JP18cm0106540 and JP18fk0210040).