REGULATION OF PTP1D MESSENGER-RNA BY PEPTIDE GROWTH-FACTORS IN THE HUMAN ENDOMETRIAL CELL-LINE HEC-1-A

OBJECTIVE: To assess, in the human endometrial cell line HEC-1-A, the presence of protein tyrosine phosphatase 1D (PTP1D) and the possible r egulation of its mRNA expression by mitogens such as forskolin (an age nt that increases intracellular cyclic adenosine monophosphate [cAMP] levels), epidermal growth factor (EGF), and insulin-like growth factor -I (IGF-I). METHODS: Cells were grown to confluence and maintained in serum-free media for 24 hours before treatment. Cells were exposed to forskolin, EGF, and IGF-I for increasing time periods (0, 1, 3, 6, and 24 hours), and PTP1D mRNA expression was determined by Northern blot analysis. In addition, cells were incubated with increasing doses of f orskolin (final concentrations: 1, 5, 10, 20, and 30 mu mol/L) for 6 h ours. RESULTS: When treated with the various mitogens, cells increased their stimulation of PTP1D mRNA expression in a time- and dose-depend ent fashion. Specifically, forskolin, EFG, and IGF-I induced maximal m RNA expression at 6, 3, and 6 hours, respectively. Expression induced by forskolin, EGF, and IGF-I was five, three, and six times control le vels, respectively. At a dose of 10 mu mol/L, forskolin induced PTP1D mRNA expression almost two times higher than control values. CONCLUSIO N: These data suggest that in human endometrial carcinomas, cAMP, EFG, and IGF-I may regulate the expression of PTP1D mRNA, which may, in tu rn, play a role in uncontrolled cell proliferation and neoplastic tran sformation. Copyright (C) 1997 by the Society for Gynecologic Investig ation.