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Telomere 1 POT1 gene expression and its association with telomerase activity in colorectal tumor samples with different pathological features     
Yazarlar
Izgi Ahu
Gunal Armagan
Prof. Dr. Serap YALÇIN AZARKAN
Ahi Evran Üniversitesi, Türkiye
Ufuk Gündüz
Orta Doğu Teknik Üniversitesi, Türkiye
Özet
The ends of chromosoms, telomeres are bound with a number of proteins which protect and stabilize telomeres against degredation, end to end fusion and aberrant recombinations. Telomeric DNA is bound of two groups of proteins, which are double-stranded telomeric DNA bindings proteins, and single stranded telomeric binding proteins. Among telomere binding proteins, protections of telomere 1 protein is a single stranded telomere binding proteins and suggested to be a significant player for telomere elongation and has an association with an enzyme called as telomerase which is an intrinsic reverse transcriptase. Telomerase synthesizes hexameric telomeric repeats onto the chromosomes thereby compansating telomere loss in immortal cells, such as tumor cells, whereas telomeres are shorthened with each division in normal cells. PCR-based TRAP (telomeric repeat amplification protocol) assay is a very sensitive assay for the detection of enzymatic activity of telomerase even if a few numbers of cancerous cells are available. The association between telomerase activity and hPOT1 expression in colorectal cancer is still unclear. Protein extraction was performed from specimens of matched normal and colorectal cancer specimens. Protein concentrations were determined by Bradford assay. Optimized protein concentrations were used for TRAP Assay. TRAP products were seperated by vertical gel electrophoresis on 12.5% polyacrylamide gels and visualized by silver staining. Gene expression of hPOT1 was determined by qPCR analysis. The results demonstrated that all tumor tissues were telomerase positive whereas all corresponding normal tissue was telomerase negative. Among clinicopathological findings, telomerase activity was found to be associated with stage, histology, localization, distant metastasis and lymph node metastasis of tumor in the current study. Although all of the clinicopathological findings differed in the expression of hPOT1 compared to normal tissues, they did not differ from each other significantly, except side of tumor and lymph node metastasis. Telomerase activity and hPOT1 gene expression may serve as a promising tumor marker for colorectal cancer and there is a close association between the enzymatic activty of telomerase and the expression of human protection of telomere 1 gene. (C) 2014 Elsevier Masson SAS. All rights reserved.
Anahtar Kelimeler
Telomerase activity, Colorectal cancer, hPOT1, TRAP assay
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı Biomedicine & Pharmacotherapy
Dergi ISSN 0753-3322
Dergi Tarandığı Indeksler SCI-Expanded
Makale Dili İngilizce
Basım Tarihi 08-2014
Doi Numarası 10.1016/j.biopha.2014.08.014
Makale Linki http://linkinghub.elsevier.com/retrieve/pii/S0753332214001085