Identification of Protein Targets for Development of Diagnostics and Chemotherapeutics for Cholanigiocarcinoma

Abstract

Cholangiocarcinoma (CA) is a rare but devastating neoplasm that accounts for about
3% of all gastrointestinal cancers and 15% of all primary liver cancers worldwide. The lack
of early detection and limited therapeutic options are major problems in controlling CA.
This study was aimed to identify differentially expressed proteins in plasma obtained from
CA patients (n=30) and healthy subjects (n=30). Protein patterns and spots were identified in
pooled and each individual sample from each group using two-dimensional gel
electrophoresis (2-DE) and mass spectrometry. There were a number of protein spots which
were either up- or down-regulated in pooled and individual plasma samples from CA
patients. Five spots with up-regulation of proteins were focused on for further analysis, one
of which was identified as α1-antitrypsin. The up-regulation of α1-antitrypsin was observed
in all CA patients (10/10), and the spot density was significantly higher in these patients than
the control group (75.49 vs 19.98). Apart from α1-antitrypsin, it is noteworthy that among the
down-regulated protein spots, one spot identified as transferrin, had markedly low expression
in CA patients. Study to investigate the association between the up- and down-regulation of
α1-antitrypsin and transferrin, and the levels of both proteins in plasma/serum of patients is
underway.