Published online Oct 21, 2005. doi: 10.3748/wjg.v11.i39.6110
Revised: December 23, 2004
Accepted: December 29, 2004
Published online: October 21, 2005
AIM: To investigate the relation between the expression of cyclooxygenase-2 (COX-2) and liver cancer, to construct the recombinant adenovirus encoding human COX-2 antisense RNA, and to explore its effects on liver cancer cell proliferation.
METHODS: We studied the expression of COX-2 in 34 cases of hepatocellular carcinoma (HCC) and SMMC7402 and SMMC7721 by immunohistochemical technique. Recombinant adenovirus Ad-AShcox-2 was constructed and transfected into human HCC cell lines SMMC7402 and SMMC7721, and its effects on COX-2 expression, cell apoptosis and cell cycle were analyzed by flow cytometry. Cell proliferation was determined by colony-forming efficiency.
RESULTS: We observed COX-2 expression in 82.4% of HCC and SMMC7402 cells, but no COX-2 expression in SMMC7721 cells. In addition, recombinant adenovirus encoding antisense COX-2 fragment Ad-AShcox-2 was obtained with the titer of 1.06×1012 PFU/mL. Ad-AShcox-2 could reduce the expression of COX-2 and enhance the percentage of cells in G1/G0 phase in SMMC7402 cell line. The difference of apoptotic index between the Ad-AShcox-2 group and control group was statistically significant (tcontrol group = 32.62 and tAd-LacZ = 10.93, P<0.001) in SMMC7402 but not in SMMC7721. Similarly, colony-forming rates of SMMC7402 and SMMC7721 cell lines, after the transfer of Ad-AShcox-2, were (2.7±0.94)% and (33.6±4.24)%, respectively.
CONCLUSION: Reduction in the expression of COX-2 can inhibit COX-2 expressing HCC cells.