RT-PCR DETECTION OF FIBRONECTIN EDA(-RNA ISOFORMS - MOLECULAR MARKERSFOR HEPATOCELLULAR-CARCINOMA() AND EDB(+) MESSENGER)

Alternative splicing of fibronectin pre-mRNA has been shown to be inde pendently regulated at the EDA and EDB regions in a tissue and develop mental stage-specific manner. In this study, RT-PCR approaches were de veloped for the detection of EDA and EDB FN mRNA isoforms in hepatocar cinoma cells (SK-Hep-1) grown in vitro and in human liver biopsies. Wh ile EDA(+) and EDB(+) isoforms were not present in control adult liver , they were detectable in the hepatocarcinoma cells and in fetal liver . The RT-PCR analysis, extended to biopsies of malignant and non-malig nant hepatic tissues, showed that FN mRNAs containing the EDA and EDB sequences were present in the 14 hepatocellular carcinomas (HCCs) test ed but absent in the non-tumorous liver tissues (i.e., normal parenchy ma, non-specific reactive and chronic hepatitis, steatosis). The EDB() FN mRNA isoforms were also detected in 3 cases of benign neoplasm (h epatocellular adenoma, HCA, 1; nodular focal hyperplasia, NFH, 2), whi le the EDA(+) was only detectable in 1 of the 2 cases of NFH. In addit ion, both EDA(+) and EDB(+) isoforms were expressed in 5 out of 9 cirr hotic livers surrounding the tumors. This molecular analysis, which ca n also be performed on small liver biopsies (2 mg), may therefore be a useful additional tool in the diagnosis of HCC. (C) 1994 Wiley-Liss, Inc.