G Protein-Coupled Receptor Kinase 4 Is a Novel Prognostic Factor in Hepatocellular Carcinoma

Quantitative proteomics assay reveals G protein-coupled receptor kinase 4-induced HepG2 cell growth inhibition

Background and aim

To investigate the biological effects and putative biological mechanism of G protein-coupled receptor kinase 4 (GRK4) on HepG2 cells.

Materials and methods

Cell proliferation, cycle, and apoptosis were evaluated by Cell Counting Kit-8 and flow cytometry (FCM) in HepG2 cells infected with either the GRK4-overexpressing lentivirus vector (OE) or the negative control lentivirus vector (NC). The protein profiles and differentially expressed proteins (DEPs) of the OE and NC cells were analyzed and compared using the quantitative proteomics technique, and their function, expression, and probable mechanism were investigated using bioinformatic assays and parallel reaction monitoring (PRM).

Results

HepG2 cells that received the OE grew more slowly than those that received the NC. FCM revealed that, when compared to the NC cells, the OE cells had undergone S-phase cycle arrest, and neither the OE nor NC cells underwent apoptosis. Among the 7006 proteins that were identified by quantitative proteomics, 403 DEPs were examined based on the filtering parameters, with the expressions of 135 being downregulated and 268 being upregulated. In addition to being involved in the peroxisome proliferator-activated receptor (PPAR) signaling pathway, the DEPs were implicated in the biological processes of cell proliferation, cycle, and metabolism. PRM verified the expressions of DEPs that were connected to the PPAR pathway.

Conclusions

This study shows that GRK4 prevents HepG2 cells from proliferating and causes cell cycle arrest in the S-phase, while the PPAR pathway is involved in the regulation of HepG2 cells via GRK4.

MicroRNA-204-5p Inhibits Hepatocellular Carcinoma by Targeting the Regulator of G Protein Signaling 20

Although the oncogenic roles of regulator of G protein signaling 20 (RGS20) and its upstream microRNAs (miRNAs) have been reported, their involvement in hepatocellular carcinoma (HCC) remains unexplored. We utilized the starBase, miRDB, TargetScan, and mirDIP databases, along with a dual-luciferase reporter assay and cDNA chip analysis to identify miRNAs targeting RGS20. miR-204-5p was selected for further experiments to confirm its direct targeting and downregulation of the RGS20 expression. To study the miR-204-5p/RGS20 axis in HCC, RGS20 and miR-204-5p were increased in PLC/PRF/5/Hep3B cells, and the viability, hyperplasia, apoptosis, cell cycle, and invasion/migration of the cells were assessed. RGS20 exhibited optimism, while miR-204-5p exhibited pessimism in tumors. miR-204-5p directly targeted RGS20 and downregulated its expression, whereas high RGS20 expression indicated a poor prognosis. Transfection of miR-204-5p inhibited the hyperplasia, migration, and invasion of HCC cells, but promoted apoptosis and influenced the levels of cyclin-dependent kinase 2 (CDK2), cyclin E1, B-cell lymphoma-2 (Bcl-2), Bax, and cleaved caspase-3/8. These effects were reversed by overexpression of RGS20. We recognized miR-204-5p as an upstream regulator targeting RGS20, thereby inhibiting HCC progression by downregulating RGS20 expression. RGS20 may prove to be a potential target for HCC treatment, and miR-204-5p might seem like to be a potential miRNA in gene therapy.

Cardio-oncology: Shared Genetic, Metabolic, and Pharmacologic Mechanism

PURPOSE OF REVIEW

The article aims to investigate the complex relationship between cancer and cardiovascular disease (CVD), with a focus on the effects of cancer treatment on cardiac health.

RECENT FINDINGS

Advances in cancer treatment have improved long-term survival rates, but CVD has emerged as a leading cause of morbidity and mortality in cancer patients. The interplay between cancer itself, treatment methods, homeostatic changes, and lifestyle modifications contributes to this comorbidity. Recent research in the field of cardio-oncology has revealed common genetic mutations, risk factors, and metabolic features associated with the co-occurrence of cancer and CVD. This article provides a comprehensive review of the latest research in cardio-oncology, including common genetic mutations, risk factors, and metabolic features, and explores the interactions between cancer treatment and CVD drugs, proposing novel approaches for the management of cancer and CVD.