Density dependent polarized secretion of a prostatic epithelial cell line

Area of Science:

• Cell Biology
• Biochemistry
• Cancer Research

Background:

• Prostatic epithelial cells (PA-III) exhibit polarized secretion of proteins and proteases.
• The anaplastic phenotype is associated with a loss of cellular polarity.
• Understanding secretion polarity is crucial for cancer progression research.

Purpose of the Study:

• To investigate the polarized secretion of total protein and proteases in PA-III cells under different culture conditions.
• To compare the secretory patterns of normal and anaplastic-like PA-III cells.
• To correlate the loss of polarized secretion with the anaplastic phenotype.

Main Methods:

• PA-III cells cultured in dual compartment chambers with or without fetal calf serum (FCS).
• Analysis of 35S-methionine labeled total protein secretion.
• Quantification of protease secretion (metalloproteinases, t-PA, gelatinases, urokinase) in apical and basal compartments.

Main Results:

• PA-III cells in serum-free defined medium (SFDM) showed predominantly apical secretion of total protein.
• PA-III cells in FCS exhibited inverted polarity, with increased basal secretion of total protein.
• Protease secretion polarity was inverted in FCS, with basal secretion of metalloproteinases, t-PA, and gelatinases, suggesting a functional loss of polarity.

Conclusions:

• The anaplastic phenotype in PA-III cells is characterized by a loss or inversion of polarized secretion.
• Altered protease secretion may contribute to basement membrane and tissue degradation in vivo.
• This study provides insights into the functional consequences of disrupted cell polarity in cancer.