Gene expression profile analysis of 4-phenylbutyrate treatment of IB3-1 bronchial epithelial cell line

Most individuals with cystic fibrosis (CF) carry one or two mutations that result in a maturation defect of the full-length CFTR protein. The deltaF508 mutation results in a mutant protein that is degraded by the proteasome instead of progressing to the apical membrane where it functions as a cyclic AMP-regulated chloride channel. 4 phenylbutyrate modulates heat shock protein expression and promotes trafficking of deltaF508 thus permitting maturation and membrane insertion. The goal of this study was to gain insight into the genetic mechanism of PBA action through a large-scale analysis of gene expression. The Affymetrix genome spanning U133 microarray set was used to compare mRNA expression in untreated IB3-1 cell line cultures with cultures treated with 1mM 4-phenylbuyterate for 12 and 24 hr. IB3-1 deltaF508/W1282X) bronchial epithelial cells were cultured in T75 flasks with gentamicin-free LHC-8 medium. Cells were fed with 10 ml of media every 2 to 3 days. After reaching 80% confluence cells were treated with 1 mM PBA. A T75 flask of confluent IB3-1 cells was rinsed twice with ice cold Hanks buffer then scraped into 3ml of ice cold TRIzol (Gibco BRL) then rinsed with 3 ml ice cold TRIzol and the mRNA was isolated according to the TRIzol protocol. A total of 5 control cultures, 3 cultures with 12 hr BPA application and 3 cultures with 24 hr PBA application were processed

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Wright JM, Zeitlin PL, Cebotaru L, Guggino SE, Guggino WB