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Expression of PTEN in malignant and non‐malignant human prostate tissues: comparison with p27 protein expression
Author(s) -
Fenic Irina,
Franke Folker,
Failing Klaus,
Steger Klaus,
Woenckhaus Joachim
Publication year - 2004
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1545
Subject(s) - pten , prostate , carcinogenesis , cancer research , immunohistochemistry , biology , prostate cancer , messenger rna , tumor suppressor gene , cell cycle , malignant transformation , cell , pathology , gene , medicine , cancer , pi3k/akt/mtor pathway , signal transduction , microbiology and biotechnology , immunology , biochemistry , genetics
The role of the putative tumour suppressor PTEN in prostate carcinogenesis is controversial. There are conflicting data regarding the rate of its gene inactivation, the role of transcriptional and post‐transcriptional factors, as well as its relationship to tumour progression and to the potential downstream regulator, the cell‐cycle inhibitor p27. The present study has assessed the in situ expression of PTEN mRNA and protein in 26 prostate intraepithelial neoplasias (PINs), 58 primary prostate carcinomas, and 15 metastases. Although there was a correlation between PTEN mRNA and protein expression, mRNA detection exceeded detection of protein in 19% of PINs and 30% of all invasive tumours. Using RT‐PCR and western blotting on microdissected tissue, this discrepancy was attributed, at least in part, to transcription of the PTEN pseudo‐gene, which lacks introns. Total or partial loss of PTEN protein occurred with tumour progression but this association was not statistically significant. Analysing the relationship between PTEN and p27 protein expression on consecutive sections by immunohistochemistry, the results do not support a direct link between the two oncosuppressors, other than an associated loss of expression in advanced tumour stages. However, in the basal cells of prostate glands and in most PINs, an inverse relationship was observed between PTEN and p27. This may reflect the existence of a functional balance that controls the cell cycle in prostatic epithelium and that is probably disturbed in invasive tumour cells. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.