CPSF4 activates telomerase reverse transcriptase and predicts poor prognosis in human lung adenocarcinomas. Issue 3 (14th February 2014)

• Record Type: Journal Article
• Authors: Chen, Wangbing; Qin, Lijun; Wang, Shusen; Li, Mei; Shi, Dingbo; Tian, Yun; Wang, Jingshu; Fu, Lingyi; Li, Zhenglin; Guo, Wei; Yu, Wendan; Yuan, Yuhui; Kang, Tiebang; Huang, Wenlin; Deng, Wuguo
• Is Part Of: Molecular oncology. Volume 8:Issue 3(2014:May)
• Page Start: 704
• Page End: 716
• Publication Date: 2014-02-14
• Subjects: CPSF4 -- Telomerase -- hTERT -- Promoter -- Lung cancer; Cancer -- Molecular aspects -- Periodicals; 616.994005
• DOI: 10.1016/j.molonc.2014.02.001
• Languages: English
• ISSNs: 1574-7891

Abstract

Abstract : 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 of CPSF4 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 lung cells. In contrast, the knockdown of CPSF4 by siRNA had the opposite effects. CPSF4 knockdown also significantly inhibited tumor cell growth in lung 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 of CPSF4 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 CPSF4 plays a critical role in the regulation of hTERT expression and lung tumorigenesis and may be a new prognosis factor in lung adenocarcinomas. Highlights: We discover and identify CPSF4 as a novel hTERT promoter‐regulating factor in lung cancer cells. CPSF4 upregulates hTERT promoter activity, hTERT expression and telomerase activity. Knockdown of CPSF4 inhibits lung cancer growth by downregulating hTERT expression and activity. CPSF4 and hTERT are highly expressed in lung cancer cells and adenocarcinoma tumor tissues. CPSF4 and hTERT overexpression is associated with poor progonsis in lung adenocarcinoma patient.