Catalytic subunit of telomerase expression is related to RNA component expression.

Telomere length is maintained by the ribonucleoprotein enzyme telomerase. The RNA component of telomerase (hTR) is widespread, and only the expression of the mRNA encoding the catalytic protein subunit (hTRT) is correlated with telomerase activity. We have studied the level of expression of hTR and hTRT in four different models of neoplastic and preneoplastic lesions using the RT-PCR method on RNA extracted from paraffin-embedded human tissues after microdissection. The expression at the mRNA level was compared with the enzymatic activity. Our results suggest that there may be a reciprocal control at the transcriptional level of the expression of hTRT and hTR which in turn is associated with tumor progression.