Objective: To characterize age-related cellular phenotype alterations and growth rates of human prostatic stromal cell cultures from the normal prostatic peripheral zone of young donors (PZ-young) and old donors (PZ-old).
Methods: We isolated stromal cells from 10 donors of different ages, assessed the cellular phenotypes by immunocytostaining for prolyl-4-hydroxylase, alpha-smooth muscle actin (alpha-SMA) and desmin, and analysed the ultrastructure by transmission electron microscopy (TEM). The proliferation and apoptosis of the cells were determined by Cell Counting Kit-8 assay and flow cytometry, respectively.
Results: All the stromal cells were positive for prolyl-4-hydroxylase regardless of the donors' age, while alpha-SMA and desmin positive cells increased with their age. The positive expressions of alpha-SMA and desmin were (2.56 +/- 1.81)% and (0.89 +/- 0.93)% in PZ-young, and (38.89 +/- 11.22)% and (14.89 +/- 5.97)% in PZ-old (P < 0.01). The alpha-SMA- and/or desmin-positive stromal cells were morphologically large, flat and polygonal. Ultrastructural analysis showed that the cell cultures from PZ-old were richer in rough endoplasmic reticulum and golgi complexes. The stromal cells of PZ-old had a lower growth rate than that of PZ-young (P < 0.01), but there was no significant difference in the apoptosis rate between the two groups.
Conclusion: Cellular phenotypes of human prostate stromal cell cultures change with the increase of age from predominantly typical fibroblasts to a mixture of fibroblasts and myofibroblasts, which might responsible for the high incidence of prostate cancer in elderly men.