Identification of UCHL1 as a potential biomarker for human gastric adenocarcinoma by subcellular proteomics

AIM: To search the biomarker for illustrating the pathogenesis of human gastric adenocarcinoma by differential proteome analysis of the cytosol of human gastric adenocarcinoma cell line SGC7901 and the corresponding immortalized normal gastric gland cell line GES. METHODS: The differential expression of cytosol protein between SGC7901 and GES cells was identified with subcellular protein separation and two-dimensional SDS-PAGE combined with MALDI-TOF-MS. The differential proteins were confirmed by Western blotting and semi-quantity RT-PCR. RESULTS: Ten repeatable differential proteins were identified. Compared with the expression level in normal gastric cell line GES, ubiquitin carboxyl-terminal hydrolase L1(UCHL1) was obviously down-regulated one both at protein and mRNA levels in gastric adenocarcinoma cell lines of SGC7901, AGS, BGC823 and MKN45. The expression of UCHL1 was also far lower in gastric cancer tissues than that in the corresponding normal tissues. CONCLUSION: Our finding suggests that UCHL1 has potential value as a biomarker for the diagnosis of gastric adenocarcinoma.