The expression of hTR and hTERT in human breast cancer: correlation with clinico-pathological parameters

Saied Hosseini-Asl,Mohammad H Modarressi,Morteza Atri,Kefah Mokbel,Mohamed Salhab,Parvin Mehdipour

doi:10.1186/1477-7800-3-20

Abstract

BackgroundTelomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any association between telomerase sub-units: hTERT and hTR and the prognostic indicators including tumour's size and grade, nodal status and patient's age.MethodsTumour samples from 46 patients with primary invasive breast cancer and 3 patients with benign tumours were collected. RT-PCR analysis was used for the detection of hTR, hTERT, and PGM1 (as a housekeeping) genes expression.ResultsThe expression of hTR and hTERT was found in 31(67.4%) and 38 (82.6%) samples respectively. We observed a significant association between hTR gene expression and younger age at diagnosis (p = 0.019) when comparing patients ≤ 40 years with those who are older than 40 years. None of the benign tumours expressed hTR gene. However, the expression of hTERT gene was revealed in 2 samples.No significant association between hTR and hTERT expression and tumour's grade, stage and nodal status was seen.ConclusionThe expression of hTR and hTERT seems to be independent of tumour's stage. hTR expression probably plays a greater role in mammary tumourogenesis in younger women (≤ 40 years) and this may have therapeutic implications in the context of hTR targeting strategies.

Highlights

Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization
We reported no significant association between tumour hTERT expression and patient's age, tumour size, grade, nodal metastasis, estrogen receptor (ER) positivity and lymphovascular (LVI) [28,29]
HTERT and hTR genes expression were detected in 38 (82.6%) and 31 (67.4%) breast cancers respectively (Figure 1) (Table 2). hTR gene was expressed in all cancers from patients aged ≤ 40 years (10/10) compared to 60 % (21/35) of patients aged > 40 years (p = 0.019)

Summary

Introduction

Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization. Telomerase is an RNA dependant DNA polymerase, the function of which is to synthesise the repetitive nucleotide sequence (TTAGGG in humans) forming the telomeres at the end of chromosomes [1]. These telomeres form caps on the chromosomes that prevent fusion of chromosomal ends during cell division. Telomerase activity seems to stabilize telomeres and to be responsible for compensating about 65 bp in eukaryotic chromosomal ends, leading to cellular immortality [1,2,3,4,5,6,7,8] and, may be a critical step in carcinogenesis [9,11].

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