Serologic Autoantibodies against Tumor Associated Antigens as Potential Biomarkers in Patients Suffering from Hepatocellular Carcinoma and Cholangiocarcinoma

Background: Hepatocellular carcinoma (HCC) and Cholangiocarcinoma (CC) are primary liver cancers. HCC develops in hepatocytes while CC originates from bile duct epithelium. Due to the lack of early diagnosis, the incidence of HCC and CC are ever increasing and providing effective therapy to the patients suffering from these cancers have increasingly become difficult. The significance of clinical diagnosis of HCC by the detection of tumor markers has not been well documented. So far, none of the studies that indicate the presence of specific autoantibodies in CC, on the contrary to HCC, has been reported. The aim of our current study is to identify new immunological tumor markers for the diagnosis of HCC and CC. Methods: In present study, we analyzed thirty three sera ( 28 male and 5 female, mean age = 62 years) from patients with HCC of different etiologies. Alcoholic ( n= 12), Hepatitis B virus infection ( n= 3), hepatitis C virus infection ( n= 8) and cryptogenic ( n= 10). Six sera (3 male and 3 female, mean age= 51 years) from patients with cholangiocarcinoma (CC) and sera from healthy subjects (n= 15). Sera were tested using immunoblots performed with nuclear, mitochondrial, microsomal and cytosolic proteins. SDS-PAGE resolved gels obtained from rat liver homogenate. Results: We have observed several autoantibodies (AAb) were seen on immunoblots performed both with microsomal and cytosolic fractions. AAb showing double bands of 54 kDa and 38 kDa microsomal proteins were found in 7 (21 %) and 3 (9%) HCC sera respectively. With cytosol as antigen, a 72 kDa band reacted with 8 (24%) HCC sera, and a 54 kDa band with 10 (30%) HCC sera. These AAbs were not detected in the sera of healthy controls. Concerning CC, we found two cytosolic proteins with molecular weights of 72-kDa and 54-kDa reacting only with the sera of 2 patients out of 6 CC sera, a 38-kDa microsomal protein stained by 2 sera and a 27-kDa nuclear protein by only 1 patient serum. Conclusion: Here, we conclude that the protein specific autoantibodies in HCC and CC may be the future candidates for the diagnosis of these carcinomas and must be further characterized using appropriate methods.