CD52 mRNA is modulated by androgens and temperature in epididymal cell cultures.

Cultured rat epididymal tissue explants formed >90% pure, adherent growing epithelial cell monolayers. Despite their flattened and apparently androgen receptor-negative phenotype, these cells for a short period kept characteristics of the epididymal duct epithelium, i.e., expression of the tissue-specific marker CD52 and responsiveness of its mRNA toward temperature elevation and androgen withdrawal. When cells were grown on permeable supports at 33 degrees C, androgen supplementation or withdrawal specifically modulated the levels as well as the length of the CD52 mRNA. Elevation of the culture temperature to a quasi abdominal milieu of 37 degrees C selectively reduced the CD52 mRNA levels under all culture conditions. This reduction was not affected by the presence of androgens and was not accompanied by changes in length, suggesting that the modulation of CD52 mRNA in epididymal cells by androgens and by temperature is synergic, but may involve different molecular mechanisms. CD52 mRNA levels, however, were not stable in the primary cultures but decreased rapidly to undetectable levels after 4-5 days at all culture conditions. GAPDH mRNA levels, on the other hand, were stable throughout the culture period.