Currently available serum markers are not satisfactory in terms of sensitivity and specificity for early detection of hepatocellular carcinoma (HCC). Also, novel histochemical markers to ensure accurate pathological diagnosis are needed. Therefore, we conducted comprehensive proteome analyses to find novel biomarkers for HCC.
1) Search for novel serum markers
Three-step proteome analyses were carried out in a total of 22 serum samples obtained from 12 patients with HCC and 10 patients with liver cirrhosis (in collaboration with Prof. Yokosuka, Department of Medicine and Clinical Oncology, Chiba University). As a first step, serum samples were subjected to antibody-based immunoaffinity column system to remove abundant proteins. The concentrated flow-through was then fractionated using reversed-phase HPLC, followed by separation by SDS-PAGE.
A total of 83 protein bands were found to be up-regulated in HCC serum. We a are now in the process of identification of these bands.
2) Search for novel histochemical markers
Using agarose two-dimensional fluorescence difference gel electrophoresis, we analyzed HCC tissues obtained by tumor resection from 10 patients (in collaboration with Prof. Miyazaki, Department of General Surgery, Chiba University). The fluorescence volumes of 48 spots increased and 79 decreased in tumor tissues compared with adjacent non-tumor tissue; 83 proteins were identified by mass spectrometry. Immunohistochemistry confirmed that the expression of clathrin heavy chain (CHC) was significantly increased, while formiminotransferase cyclodeaminase (FTCD) significantly decreased in tumor. It was noteworthy that CHC and FTCD were useful to distinguish early HCC from benign tumors such as regenerative nodule or focal nodular hyperplasia (Hepatology 2008 in press).
