CREB depletion suppresses p190-A expression. (A) Effect of CREB knockdown on p190-A protein expression. HPAE cells expressing SiSc or SiCREB were lysed and immunoblotted with indicated antibodies to determine their expression. Numbers indicate densitometric values under each condition taking SiSc as 100%. (B-C) Effect of impairment of CREB function on p190-A mRNA expression. HPAE cells transfected with either SiCREB for 48 hours (B) or dn-CREB mutant for 36 hours (C) were lysed, and RNA was extracted. mRNA was analyzed by quantitative RT-PCR using primers specific for the p190-A. GAPDH expression was used as a paired control. Asterisk (*) indicates values different from SiSc-transfected monolayers (P < .05).