Let-7 inhibits self-renewal of hepatocellular cancer stem-like cells through regulating the epithelial-mesenchymal transition and the Wnt signaling pathway.

BACKGROUND: Tumor suppressive let-7 miRNAs are universally down-regulated in human hepatocellular carcinoma (HCC) versus normal tissues; however, the roles and related molecular mechanisms of let-7 in HCC stem cells are poorly understood. METHODS: We examined the inhibitory effect of let-7 miRNAs on the proliferation of MHCC97-H and HCCLM3 hepatic cancer cells by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, which was further confirmed by apoptosis and cell cycle studies. The sphere-forming assay was used to study the effects of let-7a on stem like cells. Through western blot, immunofluorescence and the luciferase-reporter assay, we explored the activity of epithelial-mesenchymal transition (EMT) signaling factors in HCC cells. qRT-PCR was applied to detect miRNA expression levels in clinical tissues. RESULTS: Let-7a effectively repressed cell proliferation and viability, and in stem-like cells, also let-7a decreased the efficiency of sphere formation.in stem-like cells. The suppression of EMT signaling factors in HCC cells contributed to let-7's induced tumor viability repression and Wnt activation repression. Besides, Wnt1 is critical and essential for let-7a functions, and the rescue with recombinant Wnt1 agent abolished the suppressive roles of let-7a on hepatospheres. In clinical HCC and normal tissues, let-7a expression was inversely correlated with Wnt1 expression. CONCLUSIONS: Let-7 miRNAs, especially let-7a, will be a promising therapeutic strategy in the treatment of HCC through eliminating HCC stem cells, which could be achieved by their inhibitory effect on the Wnt signaling pathway.

Curative Analysis of Several Therapeutic Methods for Primary Hepatocellular Carcinoma with Portal Vein Tumor Thrombus.

BACKGROUND/AIMS: To evaluate the efficacy of different therapeutic methods for finding a promising treatment to this satanic disease and determined the prognostic factors affecting the survival time. METHODOLOGY: A retrospective study was carried out on 589 patients who underwent different treatment for Primary hepatocellular carcinoma with portal vein tumor thrombus from January, 2005 to June, 2013. Patients were divided into 4 groups according to the initial treatment: Group A (N = 48), conservative treatment; Group B (N = 86), chemotherapy; Group C (N = 122), surgical resection; and Group D (N = 333), surgical resection with postoperative chemotherapy. RESULTS: There was no significant differences in clinical information (i.e., the number of tumor, the size of tumor, and the state of portal vein tumor thrombus) among the 4 groups (P > 0.05). Both surgical resection and chemotherapy can improve the survival rate of the patients, and comprehensive treatments are of greater effect over surgical resection or chemotherapy alone. Univariate and multiple analyses revealed that the levers of AFP(p=.001), the size of tumor (p < .001), the number of tumor(p < .001), the state of portal vein tumor thrombus(p < .001), and the number of chemotherapy(p = .000) affected the conditions of prognosis: CONCLUSIONS: Positive operation treatment is the most effective therapeutic strategy for this advanced disease. Surgical resection followed by postoperative chemotherapy would increase the survival rate.

KDM5C Represses FASN-Mediated Lipid Metabolism to Exert Tumor Suppressor Activity in Intrahepatic Cholangiocarcinoma.

Background: KDM5C is a histone H3K4-specific demethylase, which has multiple biological functions during development and disease. However, the role of KDM5C in intrahepatic cholangiocarcinoma (ICC) remains unknown. Methods: Expression levels of KDM5C in ICC patients were determined by qRT-PCR, western blotting and immunohistochemical assay. The functions of KDM5C in cell proliferation and invasion were determined in human ICC cells and mouse xenograft model using KDM5C overexpression and knockdown strategies in vivo. RNA-seq analysis was applied to investigate the transcriptional program of KDM5C. In addition, ChIP-qPCR was used to determine the regulation of FASN by KDM5C. Results: Here, we show that KDM5C was downregulated in human ICC, where its diminished expression was associated with poor prognosis. ICC cell proliferation and invasion were inhibited by KDM5C overexpression. Moreover, KDM5C suppressed ICC proliferation and metastasis in vivo. RNA-sequencing showed that KDM5C inhibits key signal pathways of cell proliferation, cell invasion and fatty acid metabolism. ChIP-qPCR revealed that overexpression of KDM5C led to the reduction of H3K4me3 on the promoter and the corresponding downregulation of the expression of FASN, which represents the major target gene of KDM5C to mediate the proliferation and invasion of ICC cells. Conclusions: Our results revealed the role of KDM5C as a novel tumor suppressor in ICC largely by repressing FASN-mediated lipid acid metabolism and thus KDM5C may contribute to the pathogenesis of ICC.