Role of GLTSCR2 in the regulation of telomerase activity and chromosome stability

Kim,Jee‑Youn; An,Yong‑Min; Park,Jae‑Hoon

doi:10.3892/mmr.2016.5427

Role of GLTSCR2 in the regulation of telomerase activity and chromosome stability

Authors:
- Jee‑Youn Kim
- Yong‑Min An
- Jae‑Hoon Park
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Affiliations: Department of Pathology, School of Medicine, Kyung Hee University, Seoul 130‑701, Republic of Korea
Published online on: June 23, 2016 https://doi.org/10.3892/mmr.2016.5427
Pages: 1697-1703

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Abstract

Telomerase is essential for regulating telomeres, and its activation is a critical step in cellular immortalization and tumorigenesis. The transcriptional activation of human telomerase reverse transcriptase (hTERT) is critical for telomerase expression. Although several transcriptional activators have been identified, factors responsible for enhancing the hTERT promoter remain to be fully elucidated. In the present study, the role of glioma tumor-suppressor candidate region gene 2 (GLTSCR2) in telomerase regulation was analyzed. A doxycyclin-inducible green fluorescent protein (GFP)-tagged GLTSCR2-expressing adenovirus (Ad‑GLT/GFP) was used for the transduction of SK‑Hep‑1 and T98G cancer cells, and normal human umbilical vein endothelial cells. Changes in telomerase activity using telomere repeat amplification protocol assay were assessed, and the gene expression levels of hTERT were then examined. To investigate chromosome instability and senescence, Giemsa and β-galactosidase staining was performed. The results revealed that overexpression of GLTSCR2 significantly increased telomerase activity in the cancer and normal cell lines. This increase was consistent with increases in the protein and mRNA expression levels of hTERT. In luciferase assays, the hTERT promoter was activated by GLTSCR2. Knockdown of GLTSCR2 led to the downregulation of telomerase activity, abnormal nuclear morphology as a marker of chromosome instability, significant suppression of growth rate, alterations in cellular morphology and, eventually, cellular senescence. Taken together, the results of the present study suggested that GLTSCR2 is crucially involved in the positive regulation of telomerase and chromosome stability.

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1	Oh BK, Yoon SM, Lee CH and Park YN: Rat homolog of PinX1 is a nucleolar protein involved in the regulation of telomere length. Gene. 400:35–34. 2007. View Article : Google Scholar : PubMed/NCBI
2	Bekaert S, Derradji H and Baatout S: Telomere biology in mammalian germ cells and during development. Dev Biol. 274:15–30. 2004. View Article : Google Scholar : PubMed/NCBI
3	Wills LP and Schnellmann RG: Telomeres and telomerase in renal health. J Am Soc Nephrol. 22:39–41. 2011. View Article : Google Scholar : PubMed/NCBI
4	Nakamura TM, Morin GB, Chapman KB, Weinrich SL, Andrews WH, Linger J, Harley CB and Cech TR: Telomerase catalytic subunit homologs from fission yeast and human. Science. 277:955–959. 1997. View Article : Google Scholar : PubMed/NCBI
5	Meyerson M, Counter CM, Eaton EN, Ellisen LW, Steiner P, Caddle SD, Ziaugra L, Beijersbergen RL, Davidoff MJ, Liu Q, et al: hEST2, the putative human telomerase catalytic subunit gene, is up-regulated in tumor cells and during immortalization. Cell. 90:785–797. 1997. View Article : Google Scholar : PubMed/NCBI
6	Hashimoto M, Kyo S, Hua X, Tahara H, Nakajima M, Takakura M, Sakaguchi J, Maida Y, Nakamura M, Ikoma T, et al: Role of menin in the regulation of telomerase activity in normal and cancer cells. Int J Oncol. 33:330–340. 2008.
7	Okahara F, Itoh K, Nakagawara A, Murakami M, Kanaho Y and Maehama T: Critical role of PICT-1, a tumor suppressor candidate, in phosphatidylinositol 3,4,5-trisphosphate signals and tumorigenic transformation. Mol Biol Cell. 17:4888–4895. 2006. View Article : Google Scholar : PubMed/NCBI
8	Yim JH, Kim YJ, Ko JH, Cho YE, Kim SM, Kim JY, Lee S and Park JH: The putative tumor suppressor gene GLTSCR2 induces PTEN-modulated cell death. Cell Death Differ. 14:1872–1879. 2007. View Article : Google Scholar : PubMed/NCBI
9	Okahara F, Ikawa H, Kanaho Y and Maehama T: Regulation of PTEN phosphorylation and stability by a tumor suppressor candidate protein. J Biol Chem. 279:45300–45303. 2004. View Article : Google Scholar : PubMed/NCBI
10	Kim JY, Seok KO, Kim YJ, Bae WK, Lee S and Park JH: Involvement of GLTSCR2 in the DNA damage response. Am J Pathol. 179:1257–1264. 2011. View Article : Google Scholar : PubMed/NCBI
11	Metcalfe JA, Parkhill J, Campbell L, Stacey M, Biggs P, Byrd PJ and Taylor AM: Accelerated telomere shortening in ataxia telangiectasia. Nat Genet. 13:350–353. 1996. View Article : Google Scholar : PubMed/NCBI
12	Hande MP, Balajee AS, Tchirkov A, Wynshaw-Boris A and Lansdorp PM: Extra-chromosomal telomeric DNA in cells from Atm(−/−) mice and patients with ataxia-telangiectasia. Hum Mol Genet. 10:519–528. 2001. View Article : Google Scholar : PubMed/NCBI
13	Kishi S, Zho XZ, Ziv Y, Khoo C, Hill DE, Shiloh Y and Lu LP: Telomeric protein Pin2/TRF1 as an important ATM target in response to double strand DNA breaks. J Biol Chem. 276:29282–29291. 2001. View Article : Google Scholar : PubMed/NCBI
14	Bradshaw PS, Stavropoulos DJ and Meyn MS: Human telomeric protein TRF2 associates with genomic double-strand breaks as an early response to DNA damage. Nat Genet. 37:193–197. 2005. View Article : Google Scholar : PubMed/NCBI
15	Banerjee PP and Jagadeesh S: Non-radioactive assay methods for the assessment of telomerase activity and telomere length. Methods Mol Biol. 1288:305–316. 2015. View Article : Google Scholar : PubMed/NCBI
16	Marone M, Mozzetti S, De Ritis D, Pierelli L and Scambia G: Semiquentitative RT-PCR analysis to assess the expression levels of multiple transcripts from the same sample. Biol Proced Online. 16:19–25. 2001. View Article : Google Scholar
17	Hahn WC, Stewart SA, Brooks MW, York SG, Eaton E, Kurachi A, Beijersbergen RL, Kmoll JH, Meyerson M and Weinberg RA: Inhibition of telomerase limits the growth of human cancer cells. Nat Med. 5:1164–1170. 1999. View Article : Google Scholar : PubMed/NCBI
18	Kim NW, Piatyszek MA, Prowse KR, Harley CB, West MD, Ho PL, Coviello GM, Wright WE, Weinrich SL and Shay JW: Specific association of human telomerase activity with immortal cells and cancer. Science. 266:2011–2015. 1994. View Article : Google Scholar : PubMed/NCBI
19	Gisselsson D, Björk J, Höglund M, Mertens F, Dal Cin P, Akerman M and Mandahl N: Abnormal nuclear shape in solid tumors reflects mitotic instability. Am J Pathol. 158:199–206. 2011. View Article : Google Scholar
20	Horikawa I and Barrett JC: Transcriptional regulation of the telomerase hTERT gene as a target for cellular and viral oncogenic mechanisms. Carcinogenesis. 24:1167–1176. 2003. View Article : Google Scholar : PubMed/NCBI
21	Zhao Y, Cheng D, Wang S and Zhu J: Dual roles of c-Myc in the regulation of hTERT gene. Nucleic Acids Res. 42:10385–10398. 2014. View Article : Google Scholar : PubMed/NCBI
22	Daniel M, Peek GW and Tollefsbol TO: Regulation of the human catalytic subunit of telomerase (hTERT). Gene. 498:135–146. 2012. View Article : Google Scholar : PubMed/NCBI
23	Chebel A, Rouault JP, Urbanowicz I, Baseggio L, Chien WW, Salles G and Ffrench M: Transcriptional activation of hTERT, the human telomerase reverse transcriptase, by nuclear factor of activated T cells. J Biol Chem. 284:35725–35734. 2009. View Article : Google Scholar : PubMed/NCBI
24	Gladych M, Wojtyla A and Rubis B: Human telomerase expression regulation. Biochem Cell Biol. 89:359–376. 2011. View Article : Google Scholar : PubMed/NCBI
25	Wong JM, Kusdra L and Collins K: Subnuclear shuttling of human telomerase induced by transformation and DNA damage. Nat Cell Biol. 4:731–736. 2002. View Article : Google Scholar : PubMed/NCBI
26	Yang Y, Chen Y, Zhang C, Huang H and Weissman SM: Nucleolar localization of hTERT protein is associated with telomerase function. Exp Cell Res. 277:201–209. 2002. View Article : Google Scholar : PubMed/NCBI
27	Mitchell JR, Cheng K and Collins K: A box H/ACA small nucleolar RNA-lie domain at the human telomerase RNA 3′end. Mol Cell Biol. 19:567–576. 1999. View Article : Google Scholar
28	Lin J, Jin R, Zhang B, Yang PX, Chen H, Bai YX, Xie Y, Huang C and Huang J: Characterization of a nobel effect of hPinX1 on hTERT nucleolar localization. Biochem Biophys Res Commum. 353:946–952. 2007. View Article : Google Scholar
29	Denchi EL: Give me a break: How telomeres suppress the DNA damage response. DNA Repair (Amst). 8:1118–1126. 2009. View Article : Google Scholar
30	Tanaka H, Mendonca MS, Bradshaw PS, Hoelz DJ, Malkas LH, Meyn MS and Gilley D: DNA damage-induced phosphorylation of the human telomerase-associated protein TRF2. Proc Natl Acad Sci USA. 102:15539–15544. 2005. View Article : Google Scholar