The pattern of differentially expressed genes in biliary atresia.

Biliary atresia is a progressive obliterative cholangiopathy, but the etiology of this disorder remains uncertain. Identifying genes specifically expressed in biliary atresia and analyzing the pattern of expression may lead to a better understanding of the pathogenesis. Liver tissues were taken from a recipient with biliary atresia and a normal donor during liver transplantation. Total RNA was extracted from each sample and reversely transcribed to cDNA. Then radiolabeled cDNA probe pools were made by random primed DNA labeling method and used for screening of differentially expressed genes by hybridizing with expressed sequence tags (EST) dot blot panel. Northern blot hybridization was done to confirm that these genes are also differentially expressed in other liver tissues. Among 1730 EST clones, 26 cDNA clones were significantly overexpressed in biliary cirrhosis, while 2 clones were significantly decreased in biliary atresia. By Northern blot hybridization, the results of tissue inhibitor of metalloproteinase (TIMP)-1 and IGFBP-2 were well correlated with differential EST screening (DES). This study identified the pattern of differentially expressed genes in the biliary cirrhosis due to biliary atresia using DES technique.