involucrin and Prostatic-Neoplasms

Progenitor cells within the prostate basal layer may play important roles in differentiation and carcinogenesis; however, prostate stem cell populations remain uncharacterized.. Immunohistochemical and immunoblot analyses were used to characterize prostate epithelial cells (PrEC), a commercially available prostate basal cell isolate.. Proliferating PrECs exhibited immunophenotypic characteristics most consistent with basal cells, but during senescence PrECs up-regulated androgen receptor (AR) mRNA, p27, and low-molecular-weight cytokeratin (LMWCK) expression, suggestive of partial differentiation. PrECs also stained strongly for involucrin, which marked a subset of intermediate prostate basal cells in vivo. Basal hyperplasia consisting of involucrin-positive cells was prevalent in prostate tissue from androgen-ablated patients, and formed epithelial clusters flanked by involucrin-negative basal and luminal monolayers. Cultivation of PrECs on matrigel together with androgen-treated stromal conditioned media resulted in dense aggregates, with a peripheral rim of basal-like cells expressing p63 and basal cytokeratins.. PrEC represents an epithelial population whose basal characteristics are modified in response to matrigel, stromal factors, and senescence, consistent with a transient amplifying population. These cells may derive from a previously unrecognized, involucrin-positive subset present in vivo.

Topics: Blotting, Western; Cell Differentiation; Cellular Senescence; Epithelial Cells; Humans; Immunohistochemistry; Keratins; Male; Prostate; Prostatic Neoplasms; Protein Precursors; Receptors, Androgen; Reverse Transcriptase Polymerase Chain Reaction; RNA; Stem Cells

Using immunoperoxidase stain for involucrin, 50 well-differentiated adenocarcinomas of the lung were compared with similarly well-differentiated adenocarcinomas of other organs, 30 from the stomach, 30 from the colon, 12 from the pancreas and 12 from the prostate. Thirty (60%) adenocarcinomas of the lung were positive for involucrin; in 24 of 30 cases from 10% to more than 60% of tumor cells were positive and in the remaining 6 cases a few cells were positive. The positive cells included columnar or cuboidal tumor cells as well as some squamoid tumor cells. In contrast, only 4 (4.8%) of 84 tumors in the other organs were involucrin positive. Most of the involucrin positive foci of these four cases seemed to show squamous differentiation. These findings suggest that pulmonary adenocarcinoma is more prone to show squamous differentiation, compared with gastric, colonic, pancreatic and prostatic adenocarcinomas. The result may be applied for the differential diagnosis between primary and metastatic well-differentiated adenocarcinomas in the lung.

Topics: Adenocarcinoma; Cell Differentiation; Colonic Neoplasms; Humans; Immunoenzyme Techniques; Lung Neoplasms; Male; Pancreatic Neoplasms; Prostatic Neoplasms; Protein Precursors; Stomach Neoplasms