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The increased expression of periostin during early stages of prostate cancer and advanced stages of cancer stroma
Author(s) -
Tsunoda Toshiyuki,
Furusato Bungo,
Takashima Yasuo,
Ravulapalli Suma,
Dobi Albert,
Srivastava Shiv,
McLeod David G.,
Sesterhenn Isabell A.,
Ornstein David K.,
Shirasawa Senji
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.20988
Subject(s) - periostin , prostate cancer , prostate , immunohistochemistry , pca3 , carcinogenesis , stroma , cancer research , pathology , biology , cancer , microarray analysis techniques , gene expression , gene , medicine , extracellular matrix , microbiology and biotechnology , genetics
Abstract BACKGROUND Three‐dimensional culture (3DC) is a relevant in vitro model used to study prostate development and carcinogenesis. Recent studies have indicated that 3DC‐associated genes would be more sensitive as prognostic markers for cancer; however, no 3DC‐associated genes in prostate cancer (CaP) have thus far been elucidated. METHODS Candidate 3DC‐associated genes in non‐malignant prostatic epithelial cells, RWPE‐1 and TA2, were selected, based on a comparison of microarray gene expression data between cells grown in two‐dimensional culture (2DC) and in 3DC. To extract CaP‐associated genes among the 3DC‐associated genes, gene expression levels from the microdissected tissue samples were compared between 20 well‐differentiated or 20 poorly differentiated CaP, as well as matched normal prostate epithelium. The expression levels of CaP‐associated genes in 3DC were validated by quantitative RT‐PCR using TA2 cells in 2DC and 3DC. Protein expression of periostin (POSTN), which is one of the 3DC CaP‐associated genes, was further evaluated in the clinical samples by immunohistochemistry. RESULTS Several genes including POSTN were identified as CaP‐associated genes using a 3DC system. Immunohistochemical analyses revealed that POSTN expression was increased in the early stages of CaP (Gleason score 6–7), but not in the advanced stages of CaP. Furthermore, the positive ratio observed for the expression of POSTN in tumor‐associated stroma was significantly correlated with the degree of malignancy. CONCLUSIONS POSTN, one of the 3DC‐associated genes, may serve as a potential biomarker for predicting the pathological grade and prognosis of CaP. Prostate 69: 1398–1403, 2009. © 2009 Wiley‐Liss, Inc.