Downregulation of xIAP Expression by Small Interfering RNA Inhibits Cellular Viability and Increases Chemosensitivity to Methotrexate in Human Hepatoma Cell Line HepG2

• Published in: Journal of chemotherapy (Florence) 2006-10, Vol.18 (5), p.525-531
• Main Authors: Chen, Jun, Xiao, Xin-Qiang, Deng, Chun-Ming, Su, Xian-Shi, Li, Gui-Yuan
• Format: Article
• Language: English
• Subjects: Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimetabolites, Antineoplastic - therapeutic use; Apoptosis - drug effects; Base Sequence; Biological and medical sciences; Carcinoma, Hepatocellular - drug therapy; Carcinoma, Hepatocellular - metabolism; Cell Line, Tumor; Cell Survival - drug effects; chemotherapy; Down-Regulation; Drug Resistance, Neoplasm - drug effects; Gastroenterology. Liver. Pancreas. Abdomen; Genetic Vectors - chemical synthesis; hepatocellular carcinoma; Humans; Liver Neoplasms - drug therapy; Liver Neoplasms - metabolism; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Medical sciences; Methotrexate - therapeutic use; Molecular Sequence Data; Pharmacology. Drug treatments; RNA, Small Interfering - pharmacology; Sequence Homology, Nucleic Acid; siRNAs; Substrate Specificity; Tumors; X-Linked Inhibitor of Apoptosis Protein - metabolism; xIAP
• ISSN: 1120-009X; 1973-9478
• DOI: 10.1179/joc.2006.18.5.525

The aim of this study was to investigate whether downregulating the expression of xIAP by RNAi (RNA interference) technology can induce the apoptosis of HepG2 cells, inhibit cellular viability and increase chemosensitivity of cancer cells. HepG2 cells were transfected with U6 promoter plasmids coding for short interfering RNAs (siRNAs) targeting xIAP. RT-PCR and western blot analysis were used to assess the mRNA and protein levels of xIAP expression. The suppression efficiency of xIAP by RNAi was evaluated using the MTT assay for cellular viability and Annexin V-PI binding assay for apoptosis. These results showed that siRNAs reduced cellular viability and increased cellular apoptosis. Moreover, downregulation of xIAP expression enhanced the chemosensitivity of HepG2 cells to methotrexate. These results suggest that the downregulation of xIAP by RNAi could potentially be used as a therapeutic strategy for human hepatocellular carcinoma.