EARLY DETECTION OF THE METASTASIS AND IMMUNETHERAPY TARGETING TUMOR-REJECTION ANTIGENS IN HUMAN HEPATOCELLULARA CARCINOMA

我们已经阐明，肿瘤排斥抗原，如法师-1，法师-3和NY-ESO-1在mRNA和蛋白质水平上在人肝细胞癌（HCC）中表达的显着比例。这些基因在除睾丸外的正常体细胞中不表达。尽管我们已经尝试在HLA-A2阳性健康志愿者和HCC患者中检测针对法师-3或NY-ESO-1衍生肽的细胞毒性T细胞应答，但是我们至今不能检测到。由于已经报道在血清中发现抗NY-ESO-1的IgG抗体的黑素瘤患者中检测到抗NY-ESO-1的CTL活性，我们还尝试检测HCC患者中的血清抗体。结果，在100名HCC患者中的2名中观察到IgG抗体，这一结果表明在HCC患者中产生了针对NY-ESO-1的免疫应答，并且NY-ESO-1衍生肽可用于HCC患者的疫苗治疗。相反，我们分析了抗原加工和抗原呈递分子的表达，例如，LMP-2、-7、热休克蛋白、TAP、β2-微球蛋白、HLA I类和B7-1和-2。我们已经阐明，共刺激分子B7-1和B7 - 2的表达在相当大比例的HCC中丢失，HLA I类分子的表达也在较少频率中降低。这些结果表明，HCC通过这些分子的丢失，特别是通过B7分子的丢失而逃避免疫监视。对于HCC患者的下一步免疫治疗，我们必须确定B7分子转染树突状细胞作为APC或HCC细胞作为靶细胞是否可以引发针对肿瘤排斥抗原的CTL应答。此外，我们进行了SEREX，并确定了四个分子在HCC中异常表达。我们还检测了OY-TES-1基因在人HCC样品中的表达，该基因是我们大学发现的癌-睾丸抗原之一。

We have clarified that tumor-rejection antigens such as MAGE-1, MAGE-3 and NY-ESO-1 are expressed in a significant proportion of human hepatocellular carcinoma(HCC)at mRNA and protein levels. These genes are not expressed normal somatic cells except for testis. Although we have attempted to detect cytotoxic T-cell responses against MAGE-3 or NY-ESO-1 derived peplides in HLA-A2 positive healthy volunteers and HCC patients, we could not detect it to date. Since it has been reported that CTL activity against NY-ESO-1 was detected in melanoma patients in whom IgG antibodies against NY-ESO-1 was found in serum, we have also tried to detect serum antibodies in HCC patients. As a result, the IgG antibodies were observed in two of 100 patients with HCC.This result suggests that immune response against NY-ESO-1 is developed in HCC patients and NY-ESO-1 derived peptides can be used for vaccine therapy in HCC patients. In contrast, we have analyzed the expression of antigen-processing and antigen-presenting molecules, e.g., LMP-2, -7, Heat shock protein, TAP, β2-microglobulin, HLA class-I and B7-1 and -2. We have clarified that the expression of co-stimulatory molecules, B7-1 and -2 was lost in a significant proportion of HCC and that of HLA class-I molecule was also reduced in less frequency. These results indicate that HCC escape from immune surveillance via the losses of these molecules especially via the loss of B7 molecules. For the next step for immunotherapy in HCC patients, we have to determine whether the transfection of B7 molecules in dendritic cells as APC or HCC cells as the target cells can elicit CTL responses against tumor-rejection antigens. Further, we have carried out SEREX and identified four molecules are aberrantly expressed in HCC.We are also examining the expression of OY-TES-1 gene in human HCC samples, which was discovered as one of cancer-testis antigens in our university.