Multiple variants and a differential splicing pattern of kinectin in human hepatocellular carcinoma

To extend the search for hepatocellular carcinoma (HCC) associated antigens with immunogenicity for clinical applications, we constructed a cDNA expression library using resected human HCC tissue sample and screened it by serological analysis of recombinant cDNA expression library (SEREX) with autologous and allogeneic sera. A total of 24 distinct antigens were isolated and kinectin was the antigen most frequently identified. We found that kinectin was alternatively spliced at four sites and obtained all eight theoretical forms of variant, six by SEREX and two by RT-PCR, from the different splicing combinations of the last three sites. In addition, the splicing patterns of four sites were analyzed. Variant containing D2 was overexpressed in cancerous tissues and this alteration may be tumor associated. The four splicing sites, the variants generated by alternative splicing, and the humoral immune response in HCC patients, may help to analyze the role of kinectin in human HCC cell biology.