Saied Hosseini-Asl1, Mohammad H Modarressi1, Morteza Atri2, Mohamed Salhab3, Kefah Mokbel3, Parvin Mehdipour1
1Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, IR, Iran
2Cancer Institute, Tehran University of Medical Sciences/Day Hospital, Tehran, IR, Iran
3St. George’s Hospital, London, SW17 0QT, United Kingdom
DOI: 10.1186/1477-3163-5-17
ABSTRACT
Telomerase is a ribonucleoprotein enzyme that compensates for the telomere length shortening which occurs during the cell cycle. Telomerase activity has been detected in most tumours but not in somatic cells. However, hTR; the RNA component of telomerase; has been reported to be universally expressed in both cancerous and non-cancerous tissues. Tumour samples from 50 patients with primary invasive breast cancer were collected. The TRAP assay was used to detect telomerase activity. RT-PCR on cDNA and DNased cDNA samples and control groups was used to detect the expression of hTR, GAPDH and PGM1 genes. Seventy-two percent of samples showed telomerase activity. DNA contamination was detected in 36 (72%) of RNA samples. Without performing DNase treatment, 49 (98%) of all samples showed hTR expression, but with the application of this strategy, hTR expression decreased from 98% to 64%. A significant association (p < 0.001) between hTR expression and telomerase activity was observed. Among the 32 hTR positive samples, 30 had telomerase activity and among the 18 hTR negative samples, telomerase activity was observed in 6 cases. Thus the application of this strategy could provide an applicable tool to use instead of the TRAP assay thus facilitating telomerase research in cancer genetic investigations.