Keratin profiling in the developing human prostate. A different approach to understanding epithelial lineage.

Background: Keratin profiling studies in the developing human prostate have characterized cells thought to be stem cells and so-called intermediate cells. In a series of human prostates of various gestational ages, we extended on these studies using a comprehensive panel of keratin antibodies.

Materials And Methods: Autoptic tissue from 19 fetal prostates, gestational ages between 16 and 40 weeks, were immunostained with a panel of keratin antibodies: these recognize the luminal type keratins 7, 8, 18, 19, 20 and the basal/squamous type keratins 5, 6, 13, 14, 17.

Reserve cells in human uterine cervical epithelium are derived from müllerian epithelium at midgestational age.

The role of endocervical reserve cells in squamous metaplasia and neoplasia is still debated. Their origin in the cervix is open to speculation and it is unclear how they are targeted during carcinogenesis. To further understand the primary characteristics of reserve cells, we phenotyped them in the developing human cervix.

Changing patterns of keratin expression could be associated with functional maturation of the developing human bladder.

Purpose: We investigate the keratin phenotype of human transitional epithelium at various gestational ages and whether keratin composition of transitional epithelium is related to bladder function and morphology.

Materials And Methods: Consecutive sections from formalin fixed paraffin embedded blocks of autopsy bladder tissue from 21 male and 5 female fetuses, gestational age 12 to 40 weeks and 7 infants 2 days to 19 months old were cut and stained with antibodies recognizing basal cell keratins 5, 14 and 17, intermediate squamous cell keratin 13 and columnar cell keratins 7, 8, 18 and 20.

Results: With gestational age there were distinct changes in expression of keratins recognizing columnar cells, consisting of focal loss of keratin 7 in transitional epithelium, restriction of keratin 20 expression to umbrella cells and expression of keratin 18 throughout the full thickness of transitional epithelium.