OBJECTIVETo screen hepatocellular carcinoma (HCC) autoantibodies as diagnostic biomarkers or therapy targets by serologic proteome analysis (SERPA).

METHODSTotal proteins extracted from human HCC cell line HCCLM3 were separated by two-dimensional electrophoresis (2-DE) and then transferred onto PVDF membranes, which were subsequently incubated with sera from HCC, hepatitis B virus (HBV) infected patients or healthy volunteers. All immuno-reactive protein spots on blot films were matched to those on 2-DE gel maps by image analysis and identified by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS/MS).

RESULTS2-DE gel maps of HCCLM3 and corresponding blot films of good quality and reproducibility were established. The number of spots on HCCLM3 2-DE reference gel totaled 603 and those on HCC, HBV and healthy sera blotted films were 70.75+/-24.25, 68.5+/-23.44 and 41.38+/-15.05, respectively. Blot films of HCC and HBV groups had more spots than those of the healthy group (P < 0.05) while no significance was found between films of HCC and HBV groups. By identification, those HCC autoantibodies could be classified as nuclear proteins, cytoskeleton proteins, heat shock proteins and metabolic enzymes.

CONCLUSIONSerological proteome analysis is a high throughput technique for screening tumor autoantibodies. Those newly identified HCC associated tumor antigens and corresponding autoantibodies can be used in the early diagnosis or immuno-therapy of HCC.