The differentiation status of primary gonadal germ cell tumors correlates inversely with telomerase activity and the expression level of the gene encoding the catalytic subunit of telomerase.

Mark Schrader,Bernd Straub,Martin Schostak,Hans Krause,Markus Müller,Kurt Miller,Angelika M Burger,Wolfgang Schulze,Heidrun Lauke

doi:10.1186/1471-2407-2-32

Abstract

BackgroundThe activity of the ribonucleoprotein enzyme telomerase is detectable in germ, stem and tumor cells. One major component of telomerase is human telomerase reverse transcriptase (hTERT), which encodes the catalytic subunit of telomerase. Here we investigate the correlation of telomerase activity and hTERT gene expression and the differentiation status of primary testicular germ cell tumors (TGCT).MethodsTelomerase activity (TA) was detected by a quantitative telomerase PCR ELISA, and hTERT mRNA expression was quantified by online RT-PCR in 42 primary testicular germ cell tumors. The control group consisted of benign testicular biopsies from infertile patients.ResultsHigh levels of telomerase activity and hTERT expression were detected in all examined undifferentiated TGCTs and in the benign testicular tissue specimens with germ cell content. In contrast, differentiated teratomas and testicular control tissue without germ cells (Sertoli-cell-only syndrome) showed no telomerase activity and only minimal hTERT expression.ConclusionsThese findings demonstrate an inverse relationship between the level of telomerase activity and hTERT mRNA expression and the differentiation state of germ cell tumors. Quantification of telomerase activity and hTERT mRNA expression enables a new molecular-diagnostic subclassification of germ cell tumors that describes their proliferation potential and differentiation status.

Highlights

The activity of the ribonucleoprotein enzyme telomerase is detectable in germ, stem and tumor cells
Telomerase activity (TA) was detected by a quantitative telomerase PCR ELISA, and human telomerase reverse transcriptase (hTERT) mRNA expression was quantified by online RT-PCR in 42 primary testicular germ cell tumors
High levels of telomerase activity and hTERT expression were detected in all examined undifferentiated testicular germ cell tumors (TGCT) and in the benign testicular tissue specimens with germ cell content

Summary

Introduction

The activity of the ribonucleoprotein enzyme telomerase is detectable in germ, stem and tumor cells. One major component of telomerase is human telomerase reverse transcriptase (hTERT), which encodes the catalytic subunit of telomerase. We investigate the correlation of telomerase activity and hTERT gene expression and the differentiation status of primary testicular germ cell tumors (TGCT). This study evaluates the suitability of telomerase activity and the gene encoding the catalytic subunit of telomerase (human telomerase reverse transcriptase, hTERT) as a potential diagnostic marker for evaluating the differentiation status of testicular germ cell tumors. One major component of the active enzyme is the catalytic subunit human telomerase reverse transcriptase (hTERT) [7,8,9,10]. The telomerase catalytic subunit appears to play a central role in human carcinogenesis

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Conclusion