Alternative lengthening of telomeres is induced by telomerase inhibitors in Barrett's esophageal cells

Qin,Xiuguang; Qi,Bo; Zhao,Baosheng

doi:10.3892/or.2013.2238

Alternative lengthening of telomeres is induced by telomerase inhibitors in Barrett's esophageal cells

Authors:
- Xiuguang Qin
- Bo Qi
- Baosheng Zhao
View Affiliations

Affiliations: Department of Thoracic Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan 453100, P.R. China
Published online on: January 17, 2013 https://doi.org/10.3892/or.2013.2238
Pages: 1399-1404

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

A crucial step in the path to the malignant transformation of cells and tumor formation is immortalization, which essentially depends on telomere maintenance. The aim of this study was to investigate the role of telomerase in the progression of Barrett's esophagus. Telomerase activity was measured in Barrett's cells using terminal restriction fragment (TRF) analysis. Telomere length was measured using Q-FISH analysis. Furthermore, the telomere recombination events were detected between sister chromatids using chromosome orientation FISH (CO-FISH). There was a reduction in telomerase activity in the CP-A cells transduced with MT-hTER/47A+siRNA, which led to an almost complete disappearance of telomerase activity. The telomere length of the CP-A cells transduced with MT-hTER/47A+siRNA was slightly shorter compared to that of the untransduced cells. The telomerase-inhibited cells were morphologically indistinguishable from those untransduced and WT-hter-transduced cells. In the control cells, the growth rate was between 0.9 to 1.1 with the population doubling per day. Although the transduction of the telomerase inhibitors in the CP-A cells did not cause a significant reduction in cell growth, these transduced cells grew generally slower compared with the control cells. The heterogeneous telomere length was also be detected in the telomerase-inhibited CP-A cells. However, the telomere length remained homogeneous in the control cells. The metaphase of the CP-A cells transduced with MT-hTER/47A+siRNA demonstrated 70% heterogeneous telomeres. In addition, no increased recombination was observed between sister chromatids in the transduced CP-A cells compared with the control cells. Our findings suggest that an alternative lengthening of telomeres (ALT) may be induced by telomerase inhibitors in CP-A cells. Therefore, telomerase inhibitors may exhibit high potency in the treatment of esophageal adenocarcinoma arising from Barrett's esophagus.

View Figures

View References

1	Harley CB, Futcher AB and Greider CW: Telomeres shorten during ageing of human fibroblasts. Nature. 345:458–460. 1990. View Article : Google Scholar : PubMed/NCBI
2	Hahn WC and Meyerson M: Telomerase activation, cellular immortalization and cancer. Ann Med. 33:123–129. 2001. View Article : Google Scholar : PubMed/NCBI
3	Wright WE and Shay JW: Cellular senescence as a tumor-protection mechanism: the essential role of counting. Curr Opin Genet Dev. 11:98–103. 2001. View Article : Google Scholar : PubMed/NCBI
4	Kim NW, Piatyszek MA, Prowse KR, et al: Specific association of human telomerase activity with immortal cells and cancer. Science. 266:2011–2015. 1994. View Article : Google Scholar : PubMed/NCBI
5	Schaetzlein S, Lucas-Hahn A, Lemme E, et al: Telomere length is reset during early mammalian embryogenesis. Proc Nat Acad Sci USA. 101:8034–8038. 2004. View Article : Google Scholar : PubMed/NCBI
6	Dahse R, Fiedler W and Ernst G: Telomeres and telomerase: biological and clinical importance. Clin Chem. 43:708–714. 1997.PubMed/NCBI
7	Allsopp RC, Cheshier S and Weissman IL: Telomere shortening accompanies increased cell cycle activity during serial transplantation of hematopoietic stem cells. J Exp Med. 193:917–924. 2001. View Article : Google Scholar : PubMed/NCBI
8	Son NH, Murray S, Yanovski J, et al: Lineage-specific telomere shortening and unaltered capacity for telomerase expression in human T and B lymphocytes with age. J Immunol. 165:1191–1196. 2000. View Article : Google Scholar : PubMed/NCBI
9	Masutomi K, Yu EY, Khurts S, et al: Telomerase maintains telomere structure in normal human cells. Cell. 114:241–253. 2003. View Article : Google Scholar : PubMed/NCBI
10	Hayflick L and Moorhead PS: The serial cultivation of human diploid cell strains. Exp Cell Res. 25:585–621. 1961. View Article : Google Scholar : PubMed/NCBI
11	Hahn WC and Weinberg RA: Rules for making human tumor cells. N Engl J Med. 347:1593–1603. 2002. View Article : Google Scholar : PubMed/NCBI
12	Opitz OG, Suliman Y, Hahn WC, et al: Cyclin D1 overexpression and p53 inactivation immortalize primary oral keratinocytes by a telomerase-independent mechanism. J Clin Invest. 108:725–732. 2001. View Article : Google Scholar : PubMed/NCBI
13	Goessel G, Quante M, Hahn WC, et al: Creating oral squamous cancer cells: a cellular model of oral-esophageal carcinogenesis. Proc Natl Acad Sci USA. 102:15599–15604. 2005. View Article : Google Scholar : PubMed/NCBI
14	Heeg S, Hirt N, Queisser A, et al: EGFR overexpression induces activation of telomerase via PI3K/AKT-mediated phosphorylation and transcriptional regulation through Hif1-alpha in a cellular model of oral-esophageal carcinogenesis. Cancer Sci. 102:351–360. 2011. View Article : Google Scholar
15	Lansdorp PM, Verwoerd NP, van de Rijke, et al: Heterogeneity in telomere length of human chromosomes. Hum Mol Genet. 5:685–691. 1996. View Article : Google Scholar : PubMed/NCBI
16	Li S, Rosenberg JE, Donjacour AA, et al: Rapid inhibition of cancer cell growth induced by lentiviral delivery and expression of mutant-template telomerase RNA and anti-telomerase short-interfering RNA. Cancer Res. 64:4833–4840. 2004. View Article : Google Scholar : PubMed/NCBI
17	Pickett HA, Cesare AJ, Johnston RL, et al: Control of telomere length by a trimming mechanism that involves generation of t-circles. EMBO J. 28:799–809. 2009. View Article : Google Scholar : PubMed/NCBI
18	McEachern MJ and Blackburn EH: Runaway telomere elongation caused by telomerase RNA gene mutations. Nature. 376:403–409. 1995. View Article : Google Scholar : PubMed/NCBI
19	Singer MS and Gottschling DE: TLC1: template RNA component of Saccharomyces cerevisiae telomerase. Science. 266:404–409. 1994. View Article : Google Scholar : PubMed/NCBI
20	Yu GL, Bradley JD, Attardi LD, et al: In vivo alteration of telomere sequences and senescence caused by mutated Tetrahymena telomerase RNAs. Nature. 344:126–132. 1990. View Article : Google Scholar : PubMed/NCBI
21	Bryan TM, Englezou A, Gupta J, et al: Telomere elongation in immortal human cells without detectable telomerase activity. EMBO J. 14:4240–4248. 1995.PubMed/NCBI
22	Döbele M, von Werder A, Fulda C, et al: Inhibition of telomerase by mutant template telomerase RNA and anti-telomerase short interfering RNA induces ALT in immortalized human epithelial cells. Z Gastroenterol. 44:P2812006.PubMed/NCBI
23	Cristofari G and Lingner J: Telomere length homeostasis requires that telomerase levels are limiting. EMBO J. 25:565–574. 2006. View Article : Google Scholar : PubMed/NCBI
24	Bianchi A and Shore D: How telomerase reaches its end: mechanism of telomerase regulation by the telomeric complex. Mol Cell. 31:153–165. 2008. View Article : Google Scholar : PubMed/NCBI
25	Smogorzewska A and de Lange T: Regulation of telomerase by telomeric proteins. Annu Rev Biochem. 73:177–208. 2004. View Article : Google Scholar : PubMed/NCBI
26	Smogorzewska A, van Steensel B, Bianchi A, et al: Control of human telomere length by TRF1 and TRF2. Mol Cell Biol. 20:1659–1668. 2000. View Article : Google Scholar : PubMed/NCBI
27	Collado M, Blasco MA and Serrano M: Cellular senescence in cancer and aging. Cell. 130:223–233. 2007. View Article : Google Scholar : PubMed/NCBI
28	Bechter OE, Zou Y, Walker W, et al: Telomeric recombination in mismatch repair deficient human colon cancer cells after telomerase inhibition. Cancer Res. 64:3444–3451. 2004. View Article : Google Scholar
29	Londono-Vallejo JA, Der-Sarkissian H, Cazes L, et al: Alternative lengthening of telomeres is characterized by high rates of telomeric exchange. Cancer Res. 64:2324–2327. 2004. View Article : Google Scholar : PubMed/NCBI
30	Broccoli D, Young JW and de Lange T: Telomerase activity in normal and malignant hematopoietic cells. Proc Natl Acad Sci USA. 92:9082–9086. 1995. View Article : Google Scholar : PubMed/NCBI
31	Von Werder A: Immortalized human esophageal squamous epithelial cells maintain their telomerases by either telomerase or ALT in a cell cycle-dependent fashion. http://www.biomedsearch.com/sci/immortalized-human-esophageal-squamous-epithelial/0040149415.html. 2007