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Novel localization of low affinity NGF receptor (p75) in the stroma of prostate cancer and possible implication in neoplastic invasion: An immunohistochemical and ultracytochemical study
Author(s) -
Rende Mario,
Rambotti Maria G.,
Stabile Anna M.,
Pistilli Alessandra,
Montagnoli Claudia,
Chiarelli Maria T.,
Mearini Ettore
Publication year - 2009
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.21089
Subject(s) - stroma , pathology , stromal cell , immunohistochemistry , biology , prostate , prostate cancer , carcinogenesis , malignancy , neoplastic transformation , cancer , medicine , genetics
BACKGROUND The localization of low affinity nerve growth factor receptor (p75) in prostate carcinogenesis is still unclear. Our aim was to reinvestigate the localization of p75 in normal and pathological prostate and to check a possible correlation to neoplastic grading. METHODS Specimens from 33 prostate cancers and from normal prostatic tissue were analyzed for p75 expression at light and ultrastructural levels. RESULTS In normal tissue p75‐immunoreactivity was restricted to basal cells in the epithelial compartment and to nerves and blood vessel in stroma. During carcinogenesis, p75‐immunoreactivity progressively decreased at the periphery of the foci according to the increase in malignancy. No p75‐immunoreactivity was detected inside of the foci. On the contrary, in stroma we found a dramatic increase in p75‐immunoreactivity correlated to an increase in malignancy. In this compartment, for the first time ultrastructural analysis identified p75‐immunoreactivity in smooth muscle cells (SMC) that are p75‐negative in normal conditions. CONCLUSION The present study confirms at ultrastructural level a malignant‐dependent p75 decrease in basal cells of neoplastic foci. Furthermore, we show a novel, malignant‐dependent localization of p75 in SMC in the stroma around the neoplastic foci. Since p75 expression is present in muscle cells only during the earliest stages of differentiation and mature muscle cells lose this expression, we hypothesize that p75 re‐expression in stromal SMC is a further mechanism related to the general de‐differentiation of the stroma connected to the neoplastic invasion. According to this hypothesis, our results suggest that p75 analysis could be a novel prognostic marker for prostate cancer. Prostate 70: 555–561, 2010. © 2009 Wiley‐Liss, Inc.