Colorectal Cancer
Copyright ©The Author(s) 2004. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 1, 2004; 10(23): 3455-3458
Published online Dec 1, 2004. doi: 10.3748/wjg.v10.i23.3455
Effects of phosphorothioate anti-sense oligodeoxynucleotides on colorectal cancer cell growth and telomerase activity
Xi-Shan Wang, Kuan Wang, Xue Li, Song-Bin Fu
Xi-Shan Wang, Kuan Wang, Department of Abdominal Surgery, Tumour Hospital of Harbin Medical University, Harbin 150040, Heilongjiang Province, China
Xue Li, Song-Bin Fu, Department of Genetics, Harbin Medical University, Harbin 150086, Heilongjiang Province, China
Author contributions: All authors contributed equally to the work.
Supported by the Youth Science Foundation of Heilongjiang Province, China, No.QC01C08, and Heilongjiang Provincial Technology Council Foundations, China, No.GC03C605-6
Correspondence to: Dr. Xi-Shan Wang, Department of Abdominal Surgery, Tumour Hospital of Harbin Medical University, Harbin 150040, Heilongjiang Province, China. 1966120808@sina.com
Telephone: +86-451-86677583 Ext. 2146 Fax: +86-451-86663760
Received: February 14, 2004
Revised: February 20, 2004
Accepted: February 24, 2004
Published online: December 1, 2004
Abstract

AIM: To investigate the inhibitory effect of phosphorothioate anti-sense oligodeoxynucleotides (PASODN) on colorectal cancer LS-174T cells in vitro and the mechanism of inhibition of telomerase activity in these cells.

METHODS: PASODN were used to infect LS-174T cells and block human telomerase RNA (hTR) through anti-sense technology. The inhibitory effect of PASODN was evaluated by colony-forming inhibition assay and growth curve. Changes of telomerase activity in LS-174T cells were detected by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), and the level of apoptosis was analyzed by flow cytometry (FCM) assay.

RESULTS: PASODN showed a dose and time-dependent inhibition of cell proliferation. The optimal dosage of PASODN was 10 μmol/L. The colony-forming efficiency was 10.3% in PASODN group after 10 d, whereas that in phosphorothioate mis-sense oligodeoxynucleotides (PMSODN) group with the same concentration and in PBS group (blank control) was 49.1% and 50.7%, respectively. PCR-ELISA results indicated that telomerase activity in the PASODN group was obviously inhibited in comparison with in the control groups (P < 0.01, t = 3.317 and 3.241, t0.01(20) = 2.845). Meanwhile, before the number of cells was decreased, the morphological changes were observed in the cells of PASODN group. The cells in PASODN group showed the apoptotic peak at 72 h after infection, whereas the control group did not show.

CONCLUSION: Specific sequence oligonucleotides can inhibit telomerase activity and lead to cell apoptosis, suggesting a novel treatment strategy for malignant tumors induced by telomerase.

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