Mol Oncol 8:704 (2014)
Chen W1, Qin L2, Wang S3, Li M1, Shi D1, Tian Y1, Wang J1, Fu L1, Li Z4, Guo W4, Yu W4, Yuan Y4, Kang T1, Huang W5, Deng W6.
The elevated expression and activation of human telomerase reverse transcriptase (hTERT) is associated with the unlimited proliferation of cancer cells. However, the excise mechanism of hTERT regulation during carcinogenesis is not well understood. In this study, we discovered cleavage and polyadenylation specific factor 4 (CPSF4) as a novel tumor-specific hTERT promoter-regulating protein in lung cancer cells and identified the roles ofCPSF4 in regulating lung hTERT and lung cancer growth. The ectopic overexpression of CPSF4 upregulated the hTERT promoter-driven report gene expression and activated the endogenous hTERT mRNA and protein expression and the telomerase activity in lung cancer cells and normal lungcells. In contrast, the knockdown of CPSF4 by siRNA had the opposite effects. CPSF4 knockdown also significantly inhibited tumor cell growth inlung cancer cells in vitro and in a xenograft mouse model in vivo, and this inhibitory effect was partially mediated by decreasing the expression of hTERT. High expression of both CPSF4 and hTERT proteins were detected in lung adenocarcinoma cells by comparison with the normal lung cells. Tissue microarray immunohistochemical analysis of lung adenocarcinomas also revealed a strong positive correlation between the expression ofCPSF4 and hTERT proteins. Moreover, Kaplan-Meier analysis showed that patients with high levels of CPSF4 and hTERT expression had a significantly shorter overall survival than those with low CPSF4 and hTERT expression levels. Collectively, these results demonstrate that CPSF4plays a critical role in the regulation of hTERT expression and lung tumorigenesis and may be a new prognosis factor in lung adenocarcinomas.
Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.