DNA Hypermethylation Modification Promotes the Development of Hepatocellular Carcinoma by Depressing the Tumor Suppressor Gene ZNF334

Background: DNA methylation plays a pivotal role in the development and progression of tumors, but studies focused on the dynamic changes of DNA methylation in the development of hepatocellular carcinoma (HCC) are rare. This manuscript is aimed to construct pre- and early DNA methylation maps of liver cancer of the same genetic background, as well as to reveal the mechanism of epigenetics regulating gene expression during the development of liver cancer, thus providing new targets and clinical evidence for early diagnosis and shedding lights on the precise treatment for liver cancer. Methods: The study includes 5 patients who were chronic hepatitis B virus infected, clinically diagnosed as primary liver cancer and pathologically diagnosed as early liver cancer with liver dysplastic nodules. Liver fibrosis tissues, dysplastic nodules and early HCC tissues from these patients have been used to measure DNA methylation. Results: We report significant differences in the DNA methylation spectrum of three types of tissues. In the early stage of HCC, DNA hypermethylation of tumor suppressor genes is predominant. Additionally, DNA hypermethylation in the early stage of HCC changes the binding of transcription factor P53 to the promoter of tumor suppressor gene ZNF334, and inhibits the expression of ZNF334 at the transcription level. Furthermore, through a series of in vivo and in vitro experiments, we have clarified the exacerbation effect of tumor suppressor gene ZNF334 deletion in the occurrence of HCC. Combined with clinical data, we found that the overall survival and disease-free survival of patients with high ZNF334 expression are longer than the lower one. Conclusions: We constructed a sequential map of DNA methylation modification during the occurrence of HCC, and clarified the biological function and regulatory mechanism of the tumor suppressor gene ZNF334, which is regulated by related DNA methylation sites, and also provide new targets and clinical evidence for the early diagnosis and precise treatment of liver cancer.

JMJD4-demethylated RIG-I prevents hepatic steatosis and carcinogenesis

Hepatocarcinogenesis is driven by necroinflammation or metabolic disorders, and the underlying mechanisms remain largely elusive. Here, we interestingly found that DEN-induced hepatocarcinogenesis was enhanced while NASH-induced hepatocarcinogenesis was abolished by hepatocyte-specific RIG-I deficiency. Further, IL-6 decreased RIG-I expression in HCC progenitor cells (HcPCs), which then viciously promoted IL-6 effector signaling and drove HcPCs to fully established HCC. RIGI expression was increased by HFD, which then enhanced cholesterol synthesis and steatosis, and the in-turn NASH and NASH-induced hepatocarcinogenesis. Mechanistically, RIG-I was constitutively monomethylated at K18 and K146, and demethylase JMJD4-mediated RIG-I demethylation suppressed IL6STAT3 signaling. The constitutive methylated RIG-I associated with AMPKα to inhibit HMGCR phosphorylation, thus promoting HMGCR enzymatic activity and cholesterol synthesis. Together with clinical data that RIGI was decreased in hepatic precancerous dysplastic nodules while increased in NAFLD, we conclude that decreased RIGI in HcPCs promotes necroinflammationinduced hepatocarcinogenesis, while increased constitutive methylated RIG-I enhances steatosis and NASH-induced hepatocarcinogenesis.

RESULTS OF IMMUNOHISTOCHEMISTRY IN THE DIFFERENTIAL DIAGNOSIS OF EARLY HEPATOCELLULAR CARCINOMA AND NODULES WITH HIGH-GRADE DYSPLASIA IN PATIENTS WITH CIRRHOSIS

ABSTRACT BACKGROUND: Hepatocellular carcinoma (HCC) is the most frequent primary cancer of the liver and cirrhosis is considered a pre-malignant disease. In this context, the evolutionary sequence from low grade dysplastic nodule and high grade dysplastic nodule (HGDN) to early HCC and advanced HCC has been studied. The differential diagnosis between HGDN and early HCC is still a challenge, especially in needle biopsies OBJECTIVE: To evaluate an immunohistochemistry panel to differentiate dysplastic nodules and HCC. METHODS: Patients with cirrhosis who underwent surgical resection or liver transplantation were included. The sensitivity, specificity and accuracy for the diagnosis of neoplasia were analyzed by evaluating five markers: heat shock protein 70, glypican 3, glutamine synthetase, clathrin heavy chain and beta-catenin. P≤0.05 was considered statistically significant. RESULTS: One hundred and fifty-six nodules were included; of these, 57 were HCC, 14 HGDN, 18 low grade dysplastic nodules and 67 regenerative macronodules. Sensitivity of HCC diagnosis was 64.9% for glypican 3 and 77.2% for glutamine syntetase, while specificity was 96.0% and 96.0% respectively. When the panel of four markers was considered (excluding beta catenin), the specificity ranged from 87.9% for one positive marker to 100% for at least three markers. The best accuracy for HCC diagnosis was obtained with at least two positive markers, which was associated with a sensitivity of 82.5% and specificity of 99%. CONCLUSION: Differential diagnosis of dysplastic nodules and HCC by morphological criteria can be challenging. Immunomarkers are useful and should be used for the differential diagnosis between HCC and HGDN.

Study on Diagnostic Values of Astrocyte Elevated Gene 1 (AEG-1) and Glypican 3 (GPC-3) in Hepatocellular Carcinoma

Objectives To investigate the diagnostic potential of AEG-1 and GPC-3 in hepatocellular carcinoma (HCC). Methods AEG-1 and GPC-3 immunohistochemistry were performed on HCC, adjacent nontumor tissue (ANT), and dysplastic nodules (DN). Results H score of AEG-1 or GPC-3 in HCC was significantly higher than in ANT or DN. In HCC, 92% and 54% showed AEG-1 and GPC-3 positivity, respectively. In ANT, 16.2% were AEG-1 and 7.6% GPC-3 positive. AEG-1 staining was mostly diffuse, whereas GPC-3 frequently showed focal staining. AEG-1 alone showed high sensitivity but low specificity and accuracy. GPC-3, on the other hand, showed high specificity but low sensitivity and accuracy. Combination of both stains boosted the sensitivity, specificity, and accuracy to 94.6%, 89.5%, and 90.5%, respectively, when only diffuse staining was considered as positive. Conclusions AEG-1 or GPC-3 alone seemed not an ideal marker for HCC. The combination of AEG-1 and GPC-3 might improve early diagnosis of HCC.

State-of-the-art MR Imaging of Fat-containing Focal Lesions of the Liver

Background: Fat can be identified in numerous liver lesions, and usually is not a specific finding. Distinguishing between different kinds of fatty deposits is an important part of differential diagnosis. Magnetic Resonance Imaging (MRI) is superior to other imaging techniques because it allows distinguishing intracellular from macroscopic fat. Discussion: Intracellular lipid may be found in focal hepatic steatosis, hepatic adenoma, hepatocellular carcinoma and, less commonly, in focal nodular hyperplasia as well as regenerative and dysplastic nodules. Macroscopic fat is seen in angiomyolipoma, lipoma, metastases from fatcontaining neoplasms, primary or metastatic liposarcoma, hydatid cyst, pseudolipoma of the Glisson capsule, pericaval fat collection, lipopeliosis, hepatic teratoma, focal hepatic extramedullary haematopoiesis and adrenal rest tumour. Conclusion: Liver nodules should be characterised with regard to underlying liver condition, MRI characteristics and contrast enhancement pattern, including hepatobiliary phase. In many cases, identification of fatty content may help narrowing the differential diagnosis.

Erratum: Lina Lu et al.; Low-Grade Dysplastic Nodules Revealed as the Tipping Point during Multistep Hepatocarcinogenesis by Dynamic Network Biomarkers. Genes 2017, 8, 268

The authors wish to make the following correction to their paper [...]