ABCC6 Knockdown Fuels Cell Proliferation by Regulating PPARα in Hepatocellular Carcinoma

ARHGAP18 is Upregulated by Transcription Factor GATA1 Promotes the Proliferation and Invasion in Hepatocellular Carcinoma

Rho GTPase activating protein 18 (ARHGAP18), a member of the RhoGAP gene family that increases GTP hydrolysis and inhibits RhoGTPase, was recently discovered to play a role in the development of breast cancer. However, its exact biological role in hepatocellular carcinoma (HCC) remains unclear. In our present study, we comprehensively assessed ARHGAP18 expression and its correlation with the prognostic value of cancer patients in databases. Cell proliferation and colony formation assays were employed to monitor cell growth. Luciferase reporter assay, Chromatin immunoprecipitation qPCR (ChIP-qPCR), immunofluorescence were performed for mechanism research. The expression of genes and proteins was detected by real-time PCR and western blotting. According to the findings of this research, ARHGAP18 protein levels are increased in HCC tissues compared to adjacent nontumor tissues, and ARHGAP18 overexpression is associated with poor survival. The results of a gain- and loss-of-function experiment with HCC cells in vitro demonstrated that ARHGAP18 stimulated cell proliferation, migration, and invasion. Mechanistically, we found that the transcription factor GATA binding protein 1 (GATA1) could bind to the ARHGAP18 promoter and facilitate ARHGAP18 expression. Further studies revealed that the effects of ARHGAP18 silencing on HCCLM3 and Bel-7402 cells were blocked by GATA1 overexpression. In conclusion, GATA1-mediated ARHGAP18 up-regulation plays an important role in HCC tumorigenesis and might be a potential therapeutic target for HCC.

Dysregulated cholesterol regulatory genes in hepatocellular carcinoma

Cholesterol is an indispensable component in mammalian cells, and cholesterol metabolism performs important roles in various biological activities. In addition to the Warburg effect, dysregulated cholesterol metabolism is one of the metabolic hallmarks of several cancers. It has reported that reprogrammed cholesterol metabolism facilitates carcinogenesis, metastasis, and drug-resistant in various tumors, including hepatocellular carcinoma (HCC). Some literatures have reported that increased cholesterol level leads to lipotoxicity, inflammation, and fibrosis, ultimately promoting the development and progression of HCC. Contrarily, other clinical investigations have demonstrated a link between higher cholesterol level and lower risk of HCC. These incongruent findings suggest that the connection between cholesterol and HCC is much complicated. In this report, we summarize the roles of key cholesterol regulatory genes including cholesterol biosynthesis, uptake, efflux, trafficking and esterification in HCC. In addition, we discuss promising related therapeutic targets for HCC.

Roles of peroxisome proliferator-activated receptors in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the main pathological type of liver cancer, is linked to risk factors such as viral hepatitis, alcohol intake and non-alcoholic fatty liver disease (NAFLD). Recent advances have greatly improved our understanding that NAFLD is playing a major risk factor for HCC. Peroxisome proliferator-activated receptors (PPARs) are a class of transcription factors divided into three subtypes: PPARα (PPARA), PPARδ/β (PPARD) and PPARγ (PPARG). As important nuclear receptors, PPARs are involved in many physiological processes, and PPARs can improve NAFLD by regulating lipid metabolism, accelerating fatty acid oxidation and inhibiting inflammation. In recent years, some studies have shown that PPARs can participate in the occurrence and development of HCC by regulating metabolic pathways. In addition, PPAR modulators have been reported to inhibit the proliferation and metastasis of HCC cells and can enhance the curative effect of conventional treatments. This article reviews the role of PPARs in the occurrence and development of HCC, as well as its value in the diagnosis, treatment and prognosis of HCC, in order to provide directions for future research.

A Regulator Role for the ATP-Binding Cassette Subfamily C Member 6 Transporter in HepG2 Cells: Effect on the Dynamics of Cell-Cell and Cell-Matrix Interactions

There is growing evidence that various ATP-binding cassette (ABC) transporters contribute to the growth and development of tumors, but relatively little is known about how the ABC transporter family behaves in hepatocellular carcinoma (HCC), one of the most common cancers worldwide. Cellular model studies have shown that ABCC6, which belongs to the ABC subfamily C (ABCC), plays a role in the cytoskeleton rearrangement and migration of HepG2 hepatocarcinoma cells, thus highlighting its role in cancer biology. Deep knowledge on the molecular mechanisms underlying the observed results could provide therapeutic insights into the tumors in which ABCC6 is modulated. In this study, differential expression levels of mRNA transcripts between ABCC6-silenced HepG2 and control groups were measured, and subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. Real-Time PCR and Western blot analyses confirmed bioinformatics; functional studies support the molecular mechanisms underlying the observed effects. The results provide valuable information on the dysregulation of fundamental cellular processes, such as the focal adhesion pathway, which allowed us to obtain detailed information on the active role that the down-regulation of ABCC6 could play in the biology of liver tumors, as it is involved not only in cell migration but also in cell adhesion and invasion.