Catalytic subunit of telomerase expression is related to RNA component expression

Telomere length is maintained by the ribonucleoprotein enzyme telomerase. T he RNA component of telomerase (hTR) is widespread, and only the expression of the mRNA encoding the catalytic protein subunit (hTRT) is correlated wi th 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 af ter microdissection, The expression at the mRNA level was compared with the enzymatic activity. Our results suggest that there may be a reciprocal con trol at the transcriptional level of the expression of hTRT and hTR which i n turn is associated with tumor progression. (C) 1999 Federation of Europea n Biochemical Societies.