Journal Article

Suppression of N-Ras by shRNA-expressing plasmid increases sensitivity of HepG2 cells to vincristine-induced growth inhibition

Ren, K-h, Zhang, S-h, He, H-w, Sun, H-x, Liu, T-g, He, Q-y, Shao, R-g

2009

Overview

Oncogenic ras genes relate to the development of human cancers. In this study, we used a plasmid-mediated short-hairpin RNA (shRNA) targeting N-ras gene to combine with clinical drug vincristine (VCR) for the treatment of human hepatoma cells. Our results showed that anti-N-Ras shRNA expression vector (pCSH1-shNR) knocked down the target mRNA and protein. Higher efficacy on growth inhibition was observed when pCSH1-shNR was combined with VCR. This synergistic effect was associated with abrogation of VCR-induced overexpressions of P-glycoprotein and multidrug resistance-associated protein 1 by pCSH1-shNR through downregulations of N-Ras and total Ras. Western blot analysis showed that pCSH1-shNR-induced downregulations of N-Ras and total Ras were potentiated by VCR. Following Ras downregulation, phosphorylations of ERK1/2 and Akt were dramatically inhibited by combinatory treatment. The data showed that pCSH1-shNR-induced inhibition of nuclear factor-κB was enhanced by VCR. In addition, the combination of pCSH1-shNR and VCR synergistically inhibited the growth of human hepatoma HepG2 in vivo . Our findings suggested that combination of gene-specific therapeutics and appropriate chemotherapeutic agents might be a promising approach for the treatment of human hepatocellular carcinoma.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: AKT protein / Animals / Antineoplastic Agents, Phytogenic - pharmacology / Antineoplastic Agents, Phytogenic - therapeutic use / Biomedical and Life Sciences / Biomedicine / Carcinoma, Hepatocellular - genetics / Carcinoma, Hepatocellular - pathology / Carcinoma, Hepatocellular - therapy / Care and treatment / Cell Line, Tumor / Cell Proliferation - drug effects / Chemotherapy / Combined Modality Therapy / Down-Regulation / Female / Gene Expression / Gene Therapy / Genes, ras - genetics / Genetic aspects / Genetic Therapy / Health aspects / Hepatocellular carcinoma / Hepatoma / Humans / Liver cancer / Liver Neoplasms - genetics / Liver Neoplasms - pathology / Liver Neoplasms - therapy / MAP Kinase Signaling System / Mice / Mice, Inbred BALB C / Mice, Nude / mRNA / Multidrug resistance / N-ras gene / original-article / P-Glycoprotein / Plasmids / Ras genes / Ras protein / Risk factors / RNA Interference / Vincristine / Vincristine - pharmacology / Vincristine - therapeutic use / Xenograft Model Antitumor Assays