Journal Article

Sorafenib Inhibits Ribonucleotide Reductase Regulatory Subunit M2 (RRM2) in Hepatocellular Carcinoma Cells

Lin, Li-Shan, Yang, Pei-Ming, Liu, Tsang-Pai

2020

Overview

The main curative treatments for hepatocellular carcinoma (HCC) are surgical resection and liver transplantation, which only benefits 15% to 25% of patients. In addition, HCC is highly refractory and resistant to cytotoxic chemotherapy. Although several multi-kinase inhibitors, such as sorafenib, regorafenib, and lenvatinib, have been approved for treating advanced HCC, only a short increase of median overall survival in HCC patients was achieved. Therefore, there is an urgent need to design more effective strategies for advanced HCC patients. Human ribonucleotide reductase is responsible for the conversion of ribonucleoside diphosphate to 2′-deoxyribonucleoside diphosphate to maintain the homeostasis of nucleotide pools. In this study, mining the cancer genomics and proteomics data revealed that ribonucleotide reductase regulatory subunit M2 (RRM2) serves as a prognosis biomarker and a therapeutic target for HCC. The RNA sequencing (RNA-Seq) analysis and public microarray data mining found that RRM2 was a novel molecular target of sorafenib in HCC cells. In vitro experiments validated that sorafenib inhibits RRM2 expression in HCC cells, which is positively associated with the anticancer activity of sorafenib. Although both RRM2 knockdown and sorafenib induced autophagy in HCC cells, restoration of RRM2 expression did not rescue HCC cells from sorafenib-induced autophagy and growth inhibition. However, long-term colony formation assay indicated that RRM2 overexpression partially rescues HCC cells from the cytotoxicity of sorafenib. Therefore, this study identifies that RRM2 is a novel target of sorafenib, partially contributing to its anticancer activity in HCC cells.

• Publisher: MDPI AG,MDPI
• Subject: Antibiotics / Antibodies / Antineoplastic Agents - pharmacology / Antitumor activity / Apoptosis / Autophagy / Autophagy - drug effects / Cancer therapies / Carcinoma, Hepatocellular - drug therapy / Carcinoma, Hepatocellular - genetics / Cell Line, Tumor / Chemotherapy / Cytotoxicity / FDA approval / Gene expression / Gene Expression Regulation, Neoplastic - drug effects / Genomics / Growth factors / Growth inhibition / Hep G2 Cells / Hepatitis / Hepatocellular carcinoma / Homeostasis / Humans / Inhibitor drugs / Kinases / Laboratories / Liver cancer / Liver diseases / Liver Neoplasms - drug therapy / Liver Neoplasms - genetics / Liver transplantation / Medical prognosis / Phagocytosis / Proteins / Proteomics / Reagents / Reductase / Ribonucleoside Diphosphate Reductase - antagonists & inhibitors / Ribonucleoside Diphosphate Reductase - genetics / Ribonucleotide reductase / sorafenib / Sorafenib - pharmacology / Targeted cancer therapy / Therapeutic targets / Tumors