Identification of microRNAs specific for epithelial cell adhesion molecule-positive tumor cells in hepatocellular carcinoma: HEPATOLOGY, Vol. XX, No. X, 2015

Therapies that target cancer stem cells (CSCs) hold promise in eliminating cancer burden. However, normal stem cells are likely to be targeted due to their similarities to CSCs. It is established that EpCAM is a biomarker for normal hepatic stem cells and EpCAM+AFP+ hepatocellular carcinoma (HCC) cells have enriched hepatic CSCs. We sought to determine if specific miRNAs exist in hepatic CSCs that are not expressed in normal hepatic stem cells. We performed a pair-wised comparison of the miRNA transcriptome of EpCAM+ and corresponding EpCAM− cells isolated from two primary HCC specimens, as well as from two fetal livers and three healthy adult liver donors via small RNA deep sequencing. We found that miR-150, miR-155 and miR-223 were preferentially highly expressed in EpCAM+ HCC cells, which was further validated. Their gene surrogates, identified using miRNA and mRNA profiling in a cohort of 292 HCC patients, were associated with patient prognosis. We further demonstrated that miR-155 was highly expressed in EpCAM+ HCC cells compared to corresponding EpCAM− HCC cells, fetal livers with enriched normal hepatic progenitors, and normal adult livers with enriched mature hepatocytes. Suppressing miR-155 resulted in a decreased EpCAM+ fraction in HCC cells and reduced HCC cell colony formation, migration and invasion in vitro. The reduced levels of identified miR-155 targets predicted the shortened overall survival and time to recurrence of HCC patients. Conclusion: MiR-155 was highly elevated in EpCAM+ HCC cells and might serve as a molecular target to eradicate the EpCAM+ CSC population in human HCCs

EpCAM-Positive Hepatocellular Carcinoma Cells Are Tumor-Initiating Cells With Stem/Progenitor Cell Features

Cancer progression/metastases and embryonic development share many properties including cellular plasticity, dynamic cell motility, and integral interaction with the microenvironment. We hypothesized that the heterogeneous nature of hepatocellular carcinoma (HCC) may be, in part, due to the presence of hepatic cancer cells with stem/progenitor features

Identification of microRNA-181 by genome-wide screening as a critical player in EpCAM-positive hepatic cancer stem cells

MicroRNAs (miRNAs) are endogenous small non-coding RNAs that regulate gene expression with functional links to tumorigenesis. Hepatocellular carcinoma (HCC) is the most common type of liver cancer and it is heterogeneous in clinical outcomes and biological activities. Recently, we have identified a subset of highly invasive EpCAM+ HCC cells from AFP+ tumors with cancer stem/progenitor cell features, i.e., the abilities to self-renew, differentiate and initiate aggressive tumors in vivo. Here, using a global microarray-based microRNA profiling approach followed by validation with quantitative reverse transcription polymerase chain reaction, we have demonstrated that conserved miR-181 family members were upregulated in EpCAM+AFP+ HCCs and in EpCAM+ HCC cells isolated from AFP+ tumors. Moreover, miR-181 family members were highly expressed in embryonic livers and in isolated hepatic stem cells. Importantly, inhibition of miR-181 led to a reduction in EpCAM+ HCC cell quantity and tumor initiating ability, while exogenous miR-181 expression in HCC cells resulted in an enrichment of EpCAM+ HCC cells. We have found that miR-181 could directly target hepatic transcriptional regulators of differentiation (i.e., CDX2 and GATA6) and an inhibitor of wnt/β-catenin signaling (i.e., NLK). Taken together, our results define a novel regulatory link between miR-181s and human EpCAM+ liver cancer stem/progenitor cells and imply that molecular targeting of miR-181 may eradicate HCC

Genetic susceptibility to hepatocellular carcinoma in chromosome 22q13.31, findings of a genome-wide association study.

Background and Aim: Chronic hepatitis C virus (HCV) infection, long-term alcohol use, cigarette smoking, and obesity are the major risk factors for hepatocellular carcinoma (HCC) in the United States, but the disease risk varies substantially among individuals with these factors, suggesting host susceptibility to and gene-environment interactions in HCC. To address genetic susceptibility to HCC, we conducted a genome-wide association study (GWAS). Methods: Two case-control studies on HCC were conducted in the United States. DNA samples were genotyped using the Illumian microarray chip with over 710 000 single nucleotide polymorphisms (SNPs). We compared these SNPs between 705 HCC cases and 1455 population controls for their associations with HCC and verified our findings in additional studies. Results: In this GWAS, we found that two SNPs were associated with HCC at Conclusions: SNPs i

Tumor Biology and Immune Infiltration Define Primary Liver Cancer Subsets Linked to Overall Survival After Immunotherapy

Primary liver cancer is a rising cause of cancer deaths in the US. Although immunotherapy with immune checkpoint inhibitors induces a potent response in a subset of patients, response rates vary among individuals. Predicting which patients will respond to immune checkpoint inhibitors is of great interest in the field. In a retrospective arm of the National Cancer Institute Cancers of the Liver: Accelerating Research of Immunotherapy by a Transdisciplinary Network (NCI-CLARITY) study, we use archived formalin-fixed, paraffin-embedded samples to profile the transcriptome and genomic alterations among 86 hepatocellular carcinoma and cholangiocarcinoma patients prior to and following immune checkpoint inhibitor treatment. Using supervised and unsupervised approaches, we identify stable molecular subtypes linked to overall survival and distinguished by two axes of aggressive tumor biology and microenvironmental features. Moreover, molecular responses to immune checkpoint inhibitor treatment differ between subtypes. Thus, patients with heterogeneous liver cancer may be stratified by molecular status indicative of treatment response to immune checkpoint inhibitors

Tumor metabolism and associated serum metabolites define prognostic subtypes of Asian hepatocellular carcinoma.

Treatment effectiveness in hepatocellular carcinoma (HCC) depends on early detection and precision-medicine-based patient stratification for targeted therapies. However, the lack of robust biomarkers, particularly a non-invasive diagnostic tool, precludes significant improvement of clinical outcomes for HCC patients. Serum metabolites are one of the best non-invasive means for determining patient prognosis, as they are stable end-products of biochemical processes in human body. In this study, we aimed to identify prognostic serum metabolites in HCC. To determine serum metabolites that were relevant and representative of the tissue status, we performed a two-step correlation analysis to first determine associations between metabolic genes and tissue metabolites, and second, between tissue metabolites and serum metabolites among 49 HCC patients, which were then validated in 408 additional Asian HCC patients with mixed etiologies. We found that certain metabolic genes, tissue metabolites and serum metabolites can independently stratify HCC patients into prognostic subgroups, which are consistent across these different data types and our previous findings. The metabolic subtypes are associated with β-oxidation process in fatty acid metabolism, where patients with worse survival outcome have dysregulated fatty acid metabolism. These serum metabolites may be used as non-invasive biomarkers to define prognostic tumor molecular subtypes for HCC

The genomic landscape of Mongolian hepatocellular carcinoma

Mongolia has the highest incidence of—and mortality from—hepatocellular carcinoma (HCC) in the world. Here, the authors examine the genomic and transcriptomic landscape of Mongolian HCC, uncover novel driver mutations, and suggest distinct disease etiologies