[Cloning and characterization of syap1, a down regulated gene in human hepatocellular carcinoma]

Using a different fragment DE6 obtained from DD-PCR as probe, a full-length cDNA has been cloned from human liver cDNA library and named as syap1 (Synapse-associated protein 1) because its deduced amino acid sequence is homologous to SAP47 of D. melanogaster. Northern blot analysis reveals that two transcripts of syap1 mRNA are expressed in cultured human liver L-02 cells. Moreover, the syap1 mRNA was also detected in most of adult human tissues by RT-PCR analysis. Down-regulated expression of syap1 mRNA was confirmed by semi-quantitative RT-PCR assay in 5 of 10 (50%) cases of human hepatocellular carcinoma (HCC).