0 05) However, the positive expression of SSX genes in the PBMC had close correlation with prognosis of HCC patients Metastasis and/or recurrence took place in 50% (8 out of l6) patients with positive expression of SSX genes in their PBMC,while only 10 5% (2 out of l9) patients with negative expression of SSX genes in their PBMC developed metastasis and/or recurrence ( P =0 028) Conclusion SSX genes mRNA may be used as specific tumor markers for the detection of the circulating HCC cells

OBJECTIVETo investigate the possibility of using melanoma antigen-1 (MAGE-1) peptide as a tumor vaccine to treat hepatocellular carcinoma (HCC).

METHODSThe expressions of MAGE-1 in 8 HCC cell lines and in liver cancer tissue from a patient were detected using RT-PCR. The type of human leucocyte antigen I(HLA I) of both 8 HCC cell lines and peripheral blood mononuclear cells of the patient was detected using a microcytotoxicity method to screen out target cell lines for the cytotoxicity assay. Peripheral blood mononuclear cells from the HCC patient pulsed with an MAGE-1 peptide (NYKCRFPEI) were used as antigen presenting cells. Autogenous peripheral blood mononuclear cells were stimulated with antigen presenting cells every 7 days for 4 times to elicit cytotoxic T lymphocytes. The phenotype of effector cells was analyzed using flow cytometry. The cytotoxicity of effector cells was detected with a lactate dehydrogenase releasing assay.

RESULTSThe expressions of both MAGE-1 and HLA-A24 were detected in BEL7405 cell line which were used as the positive target cell line in the cytotoxicity assay. The expression of MAGE-1 alone was detected in HLE, BEL7402, BEL7404, QGY7703 and SMMC7721 cell lines, and the expression of neither MAGE-1 nor HLA-A24 was shown in QGY 7701 and HpG2 cell lines. The last 7 cell lines could be used as negative target cell lines in the cytotoxicity assay. Peripheral blood mononuclear cells expanded 32 folds during 28-day culture. The ratio of CD3(+) T cells increased by 16% (from 54% to 70%), and the ratio of CD8(+) T cells increased by 20% (from 36% to 56%) during 28-day culture. When the ratio of effector cells to target cells was 10:1, effector cells exhibited 62.5% cytotoxicity against autogenous lymphoblasts pulsed with the peptide (NYKCRFPEI) of MAGE-1 antigen, 40.25% cytotoxicity against BEL7405 cells, compared with 17.88% cytolysis observed against autogenous lymphoblasts, 19.55% against HLE cells, and 1.6% against QGY7701 cells. When the ratio of effector cells to target cells was 3.3:1, the cytotoxicity of effector cells against the peptide pulsed autogenous lymphoblasts was 53.6%, which was much higher against autogenous lymphoblasts, HLE cells and QGY7701 cells at 15.6%, 13% and 1%, respectively.

CONCLUSIONThe results demonstrate that cytotoxic T lymphocytes with the ability to specifically lyse target cells expressing both MAGE-1 and HLA-A24 could be successfully induced by the MAGE-1 peptide NYKCRFPEI in vitro. This indicates that a good result might be anticipated if this peptide is used as a tumor vaccine to treat HLA-A24 HCC patients.

Adult ; Antigens, Neoplasm ; Cancer Vaccines ; immunology ; Carcinoma, Hepatocellular ; immunology ; HLA-A Antigens ; analysis ; HLA-A24 Antigen ; Humans ; Liver Neoplasms ; immunology ; Male ; Melanoma-Specific Antigens ; Neoplasm Proteins ; genetics ; immunology ; RNA, Messenger ; analysis ; T-Lymphocytes, Cytotoxic ; immunology ; Tumor Cells, Cultured