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World J Gastroenterol. Mar 21, 2006; 12(11): 1774-1779
Published online Mar 21, 2006. doi: 10.3748/wjg.v12.i11.1774
Melanoma differentiation-associated gene-7, MDA-7/IL-24, selectively induces growth suppression, apoptosis in human hepatocellular carcinoma cell line HepG2 by replication-incompetent adenovirus vector
Cong-Jun Wang, Xin-Bo Xue, Ji-Lin Yi, Kun Chen, Jian-Wei Zheng, Jian Wang, Jian-Ping Zeng, Rong-Hua Xu
Cong-Jun Wang, Xin-Bo Xue, Ji-Lin Yi, Kun Chen, Jian-Wei Zheng, Jian Wang, Jian-Ping Zeng, Rong-Hua Xu, Department of Biliary and Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
Co-correspondence author: Dr. Cong-Jun Wang
Correspondence to: Professor Xin-Bo Xue, Department of Biliary and Pancreatic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China. xuexinbo@163.com
Telephone: +86-27-83662590
Received: October 18, 2005
Revised: October 28, 2005
Accepted: November 18, 2005
Published online: March 21, 2006
Abstract

AIM: To investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis in human hepatocellular carcinoma (HCC) cell line HepG2 and normal liver cell line L02.

METHODS: We constructed the recombinant replication-incompetent Ad.mda-7 virus vector and infected it into the human HCC cell line HepG2 and normal liver cell line L02. RT-PCR was performed to detect the mRNA expressing in cells. by ELISA was used to detect MDA-7/IL-24 protein expression in the culture supernatant. The effect of apoptosis induced by Ad.mda-7 was confirmed by Hoechst staining and flow cytometry assay with Annexin-V and PI staining. MTT assay was used to determine growth inhibition of HepG2 cells, and cell-cycle and hypodiploidy analyses were performed by flow cytometry.

RESULTS: Recombinant replication-defective virus expressing MDA-7/IL-24 was constructed successfully. RT-PCR showed that the Ad.mda-7 could mediate the expression of the exogenous gene MDA-7/IL-24 into HepG2 and L02. The concentration of MDA-7/IL-24 protein in supernatant was 130 pg/mL and 110 pg/mL in Ad.mda-7-infected L02 and HepG2 cells, respectively. Ad.mda-7 infection obviously induced apoptosis (from 2.60±0.72% to 33.6±13.2%, P  = 0.00012) and growth suppression in HepG2 (inhibition ratio IR = 68%) and an increase in the percentage of specific cancer cell types at the G2/M phase of the cell cycle (from 6.44% to 32.29%, P < 0.01), but not in L02 cells.

CONCLUSION: These results confirm selectively induction of apoptosis and growth suppression by the mda-7/IL-24 gene with replication-incompetent adenovirus vector in human hepatocellular carcinoma cell line HepG2.

Keywords: Cancer gene therapy, Hepatocellular carcinoma (HCC), Apoptosis, Growth suppression, MDA-7/IL-24