Effects of steroid-free fetal serum and steroid supplementation on MUC1 gene expression in human breast cancer cell line MCF7
Botti, C.; Seregni, E.; Lombardo, C.; Massaron, S.; Bombardieri, E.
Anticancer Research 17(1a): 205-208
1997
ISSN/ISBN: 0250-7005 PMID: 9066652 Document Number: 483523
MUC1 is a gene expressed by many normal epithelial tissues and aberrantly expressed by carcinomas. Studies regarding the expression of MUC1 in endometrial tissues and the constitution of its promoter region suggest a possible role for hormonal regulation of this gene. The aim of the present work was to evaluate the regulation of MUC1 expression by 17-beta-estradiol (E-2), progesterone (Pg) and by steroid-free fetal calf serum (FCS) in the hormone-sensitive cell line MCF7. MUC1 mRNA proved to be detectable by means of Northern-blot analysis in MCF7 cells, and its levels were strongly increased in cells grown with 10% steroid-free FCS. By contrast, the steady-state MUC1 mRNA levels of steroid-supplemented cells did not change compared to those of unsupplemented cells (controls). In conclusion, MUC1 expression is regulated by substances present in the steroid-stripped FCS (growth factors, e.g. Insulin-like Growth Factor). The lack of any observed MUC1 modulation by steroids could be due to: a) a low FCS concentration preventing the manifestation (permissive action) of possible gene regulation; b) an immediate stimulatory effect occurring in the first phases of the treatment, which could subsequently be lost.