Hormonal regulation of PKC: estrogen up-regulates PKCeta expression in estrogen-responsive breast cancer cells.
Protein kinase C (PKC) is involved in several major signal transduction pathways that control gene expression cell growth and differentiation. The PKCeta isoform appears as a candidate regulator of mammary gland proliferation or differentiation, as its expression is up-regulated in the mammary gland in the transit from resting to the pregnant state. The purpose of this study was to examine the hormonal regulation of PKCeta. Here we show that estradiol specifically up-regulates the expression of PKCeta in the estrogen-responsive lines MCF-7 and T47D but not in the estrogen non-responsive line MDA-MB 231. Interestingly, the presence of progesterone, involved in the differentiation of the mammary gland, reduced the estrogen-induced PKCeta expression in a time-dependent manner. Thus, our studies suggest that PKCeta has an important role in signalling pathways regulating mammary gland proliferation and its development.
Karp
Galia
G
Department of Microbiology and Immunology, Faculty of Health Sciences and the Cancer Research Center, Ben Gurion University, 84105 Beer Sheva, Israel.
Maissel
Adva
A
Livneh
Etta
E
D015152:Blotting, Northern; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D011374:Progesterone / Q000494:pharmacology; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism; D051571:Protein Kinase C-alpha / Q000235:genetics / Q000378:metabolism; D051745:Protein Kinase C-delta / Q000235:genetics / Q000378:metabolism; D051744:Protein Kinase C-epsilon / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects
D007527:Isoenzymes; D012333:RNA, Messenger; D011374:Progesterone; D004958:Estradiol; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D051744:Protein Kinase C-epsilon