Inhibition of human telomerase reverse transcriptase by nonsteroidal antiinflammatory drugs in colon carcinoma

• Published in: Cancer 2006-03, Vol.106 (6), p.1243-1249
• Main Authors: He, Hua, Xia, Harry Hua‐Xiang, Wang, Ji De, Gu, Qing, Lin, Marie C.M., Zou, Bing, Lam, Shiu Kum, Chan, Annie O.O., Yuen, Man Fung, Kung, Hsiang Fu, Wong, Benjamin Chun‐Yu
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - drug therapy; Adenocarcinoma - enzymology; Adenocarcinoma - genetics; Anti-Inflammatory Agents, Non-Steroidal - pharmacology; aspirin; Aspirin - pharmacology; Biological and medical sciences; Blotting, Western; Colonic Neoplasms - drug therapy; Colonic Neoplasms - enzymology; Colonic Neoplasms - genetics; cyclooxygenase; Cyclooxygenase 2 - chemistry; Cyclooxygenase 2 - metabolism; Cyclooxygenase Inhibitors - pharmacology; DNA-Binding Proteins - antagonists & inhibitors; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Gastroenterology. Liver. Pancreas. Abdomen; Gene Expression Regulation, Neoplastic; human telomerase reverse transcriptase; Humans; indomethacin; Indomethacin - pharmacology; Luciferases - metabolism; Medical sciences; nonsteroidal antiinflammatory drugs; Promoter Regions, Genetic - genetics; Pyrazoles - pharmacology; Response Elements; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Neoplasm; SC‐236; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Sulfonamides - pharmacology; telomerase; Telomerase - antagonists & inhibitors; Telomerase - genetics; Telomerase - metabolism; Transcription, Genetic; Tumor Cells, Cultured; Tumors
• ISSN: 0008-543X; 1097-0142
• DOI: 10.1002/cncr.21694

BACKGROUND Telomerase activation, which is observed in most human cancers, plays an important role in carcinogenesis. Human telomerase reverse transcriptase (hTERT) is a subunit of telomerase that is essential for telomerase activity. The aim of the study was to investigate whether nonsteroidal antiinflammatory drugs (NSAIDs) inhibit telomerase activity and hTERT. METHODS Four colon carcinoma cell lines, HT‐29, COLO205, CRL‐2134, and SW1116, were used in the experiments. Polymerase chain reaction‐based telomeric repeat amplification (TRAP) enzyme‐linked immunosorbent assay (ELISA) was used to measure telomerase activity in the cells after treatment with aspirin, indomethacin, or SC‐236 (a specific cyclooxygenase‐2 [COX‐2] inhibitor). Expression of hTERT mRNA and protein was detected by reverse transcription–polymerase chain reaction (RT‐PCR) and Western blotting, respectively. The dual luciferase reporter assay was performed to identify the potential cis‐response elements to NSAIDs in the promoter region of hTERT. RESULTS Aspirin, indomethacin, and SC‐236 inhibited telomerase activity in HT‐29, COLO205, and CRL‐2134 cell lines, but not in the SW1116 cell line. NSAIDs inhibited hTERT mRNA and protein expression through suppression of hTERT transcriptional activity. The hTERT promoter fragment −145 to −330 basepairs (bp) upstream of the ATG starting site was sufficient to respond to the NSAID‐induced inhibitory effect and the inhibition was COX‐2‐independent. CONCLUSION NSAIDs inhibit telomerase activity at hTERT transcriptional, mRNA, and protein levels in colon carcinoma cells. The hTERT promoter fragment −145 to −330 bp may be the cis‐response element to NSAIDs. Cancer 2006. © 2006 American Cancer Society. Telomerase activation, which is observed in most human cancers, plays an important role in carcinogenesis. Human telomerase reverse transcriptase (hTERT) is a subunit of telomerase that is essential for telomerase activity. The aim of the study was to investigate whether nonsteroidal antiinflammatory drugs inhibit telomerase activity and hTERT.