OBJECTIVETo compare the 2-DE profiles for serum proteins of different pathological stages during hepatocarcinogenesis.

METHODSSera from hepatocellular carcinoma patients, cirrhosis patients, chronic hepatitis patients and healthy controls were collected. After sonication, albumin and immunoglobulin (IgG) depletion, and desalination, sera were subjected to 2-DE, the differential protein spots were identified by MALDI-TOF-MS. Western blot was used to validate these differentially expressed proteins.

RESULTS2-DE sera protein profiles were obtained from the patient suffering from HCC, liver cirrhosis, chronic hepatitis, healthy controls in each group. From optimized 2-DE gel images of the above groups, 96 protein spots with more than 2-fold difference in intensity between the two groups were selected by image master 6.0 software, differential proteins including haptoglobin, SAA1 and SP40 were identified by MALDI-TOF-MS/MS. 7 different spots within more than 30 protein spots belonged to the same haptoglobin family. The differential expression of haptoglobin was confirmed by western blot.

CONCLUSIONSFour protein expression patterns have been identified during the pathological stages of hepatocarcinogenesis. Haptoglobin is significantly increased from liver cirrhosis to HCC. It implies that haptoglobin might be a potential biomarker in the early diagnosis of liver cancer.