Cloning of mouse telomerase reverse transcriptase gene promoter and identification of proximal core promoter sequences essential for the expression of transgenes in cancer cells

  • Authors:
    • Shao-Yan Si
    • Shu-Jun Song
    • Jian-Zhong Zhang
    • Jun-Li Liu
    • Shuang Liang
    • Kai Feng
    • Gang Zhao
    • Xiao-Qing Tan
  • View Affiliations

  • Published online on: Tuesday, May 10, 2011
  • Pages: 377-382
  • DOI: 10.3892/or.2011.1303

Abstract

Telomerase is a ribonucleoprotein complex, whose function is to add motif-specific nucleotides to the end of chromosomes. Telomerase consists of three major subunits, the telomerase RNA template (hTR), the telomerase-associated protein (TEP1) and telomerase reverse transcriptase (TERT). TERT is the most important component responsible for the catalytic activity of telomerase and a rate-limiting determinant of the activity. Telomerase activities were at high levels in approximately 90% of mouse cancers or tumor-derived cell lines through TERT transcriptional up-regulation. Unlike human telomerase, telomerase activity exists in colon, liver, ovary and testis but not in brain, heart, stomach and muscle in normal mouse tissues. In this study, we prepared 5' truncations of 1086 bp fragments upstream of the initiating ATG codon of the mTERT gene to construct luciferase reporter gene plasmids, and transfected these plasmids into a normal mouse cell line and several cancer lines to identify the core promoter region essential for transcriptional activation in cancer cells by a luciferase assay. We constructed a eukaryotic expression vector of membrane-expressing staphylococcal endotoxin A (SEA) gene driven by the core promoter region of the mTERT gene and observed if the core promoter region could express the SEA gene in these cancer cells, but not in normal cells following transfection with the construct. The results showed that the transcriptional activities of each fragment of the mTERT gene promoter in the cancer cell lines Hepa1-6, B16 and CT26 were higher than those in NIH3T3 cells, and the proximal 333-bp fragment was the core promoter of the mTERT gene in the cancer cells. The proximal 333-bp fragment was able to make the SEA express on the surface of the cancer cells, but not in NIH3T3 cells. It provides a foundation for cancer targeting gene therapy by using the mTERT gene promoter.
Journal Cover

August 2011
Volume 26 Issue 2

Print ISSN: 1021-335X
Online ISSN:1791-2431

2013 Impact Factor: 2.191
Ranked #33/202 Oncology
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APA
Si, S., Song, S., Zhang, J., Liu, J., Liang, S., Feng, K., Zhao, G., & Tan, X. (2011). Cloning of mouse telomerase reverse transcriptase gene promoter and identification of proximal core promoter sequences essential for the expression of transgenes in cancer cells. Oncology Reports, 26(2), 377-382.
MLA
Si, Song, Zhang, Liu, Liang, Feng, Zhao, and Xiao-Qing Tan. "Cloning of mouse telomerase reverse transcriptase gene promoter and identification of proximal core promoter sequences essential for the expression of transgenes in cancer cells." Oncology Reports Oncology Reports 26.2 (2011): 377-382.
Chicago
Si, Song, Zhang, Liu, Liang, Feng, Zhao, and Xiao-Qing Tan. "Cloning of mouse telomerase reverse transcriptase gene promoter and identification of proximal core promoter sequences essential for the expression of transgenes in cancer cells." Oncology Reports Oncology Reports 26 no. 2 (2011): 377-382.