Cancer prevention and control: hepatocellular carcinoma

MicroRNA-4317 suppresses the progression of hepatocellular carcinoma by targeting ZNF436-mediated PI3K/AKT signaling pathway

Hepatocellular carcinoma (HCC) is a major type of liver cancer with high mortality, which is a prevalent common cancer in the world. Aberrant miRNAs contribute to the progression and development of HCC. Currently, our study demonstrated that miR-4317 was decreased in HCC patient samples tissues and HCC cell lines, which was related to poor clinical features, including tumor size, advanced TNM stage and vascular invasion. Furthermore, we confirmed that miR-4317 suppressed cell viability, proliferation, invasion and migration through loss- and gain-of-function experiment in vitro. In addition, miR-4317 inhibited tumor growth in vivo experiment. Luciferase reporter assays confirmed that ZNF436 was a direct target of miR-4317. Restoration of ZNF436 reversed the role of miR-4317 on HCC. ZNF436 expression was increased in HCC tissues and cell lines, which was negatively correlated with miR-4317 expression. ZNF436 overexpression obviously promoted the cell proliferation, viability, invasion and migration of HCC cells. ZNF436 mediated the regulatory function of miR-4317 on PI3K/AKT pathway. Overall, our data suggest that miR-4317 is a novel tumor suppressor to suppress HCC progression through PI3K/AKT pathway by targeting ZNF436, and may serve as a prognostic biomarker and therapeutic target for HCC.

MiR-155 Inhibits Malignant Biological Behavior of Human Liver Cancer Cells by Regulating SRPK1

Although the treatment of liver cancer has made great progress, the mechanism of its occurrence is not completely clear. miR-155 plays an important regulatory role in tumorigenesis and development, including survival, proliferation, migration and invasion. However, the role and regulatory mechanism of miR-155 in liver cancer has rarely been reported. We analyzed miR-155 expression in liver cancer tissue samples and cell lines by qRT-PCR. The expression of miR-155 was measured by qRT-PCR before and after miR-155-mimic and sh-miR-155 transfection. CCK-8 and clonogenic assays were used to detect the proliferation of liver cancer cells. Cell scratch and invasion assays were used to detect migration and invasion. RNA-seq was used to detect the difference in RNA expression in liver cancer cells. SRPK1 expression was detected in liver cancer cells before and after transfection by qRT-PCR and western blotting. We observed that miR-155 was downregulated in liver cancer tissues compared with normal tissues. Furthermore, we demonstrated that liver cancer cell proliferation, migration and invasion are markedly suppressed by miR-155. Importantly, we also demonstrated that SRPK1 is directly regulated by miR-155 during the process of liver cancer cell proliferation and metastasis. Finally, the overexpression of miR-155 inhibits malignant biological behavior of human liver cancer cells. We report the abnormal expression of the miR-155 cluster in liver cancer cells, which inhibits cancer cell proliferation and metastasis. In addition, we identified SRPK1 as a target gene of miR-155 during the process of liver cancer cell proliferation and metastasis.

A three-mRNA status risk score has greater predictive ability compared with a lncRNA-based risk score for predicting prognosis in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents the fifth most common cause of cancer-associated mortality in men, and the seventh in women, worldwide. The aim of the present study was to identify a reliable and robust RNA-based risk score for the survival prediction of patients with hepatocellular carcinoma (HCC). Gene expression data from HCC and healthy control samples were obtained from The Cancer Genome Atlas to screen differentially expressed mRNAs and long non-coding RNAs (lncRNAs). Univariate and multivariate Cox proportional-hazards regression models and the LASSO algorithm for the Cox proportional-hazards model (LASSO Cox-PH model) were used to identify the prognostic mRNAs and lncRNAs among differentially expressed mRNAs (DEMs) and differentially expressed lncRNAs (DELs), respectively. Prognostic risk scores were generated based on the expression level or status of the prognostic lncRNAs and mRNAs, and the predictive abilities of these RNAs in TCGA and validation datasets were compared. Functional enrichment analyses were also performed. The results revealed a total of 154 downregulated and 625 upregulated mRNAs and 18 upregulated lncRNAs between tumor and control samples in TCGA dataset. A three-mRNA and a five-lncRNA expression signatures were identified using the LASSO Cox-PH model. Three-mRNA and five-lncRNA expression and status risk scores were generated. Using likelihood ratio P-values and area under the curve values from TCGA and the validation datasets, the three-mRNA status risk score was more accurate compared with the other risk scores in predicting the mortality of patients with HCC. The three identified mRNAs, including hepatitis A virus cellular receptor 1, MYCN proto-oncogene BHLH transcription factor and stratifin, were associated with the cell cycle and oocyte maturation pathways. Therefore, a three-mRNA status risk score may be valuable and robust for risk stratification of patients with HCC. The three-mRNA status risk score exhibited greater prognostic value compared with the lncRNA-based risk score.

Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) in autophagy-induced hepatocellular carcinoma

Autophagy, an evolutionarily conserved catabolic process, is the most important pathogenic events in the development and progression of liver diseases. Deregulation of Nrf2 is proposed to play a key pathogenic role in hepatocellular carcinoma (HCC). Under certain pathophysiological conditions, such as oxidative stress, impaired autophagy is accompanied by the Nrf2 activation that leads to the detrimental effects favoring the proliferation and survival of HCC. Elucidating its role and potential mechanism is essential for understanding tumorigenesis and the development of effective clinical application. Nrf2 is participated in HCC proliferation, migration and invasion through autophagy pathways. These includes the negatively regulated-Nrf2 by Keap1 that participates in HCC tumorigenesis via regulating ROS production, in which autophagy may contribute to oxidant metabolic reprogramming of HCC cells. Post-transcriptional modifications, such as phosphorylation and ubiquitination of Nrf2, can be positively or negatively induced by multiple transcription factors. Nrf2 exhibits chemoresistance through its binding sites in the promoter region of the target genes. Nrf2 may be a valuable potential biomarker and therapeutic strategy for diagnostics, prognostics and treatment of HCC.