• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.879-890
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• 2007

The identification of tumor antigens is essential for the development of anticancer therapeutic vaccines and clinical diagnosis of cancer. SEREX (serological analysis of recombinant cDNA expression libraries) has been used to identify such tumor antigens by screening sera of patients with cDNA expression libraries. SEREX-defined antigens provide markers for the diagnosis of cancers. Potential diagnostic values of these SEREX-defined antigens have been evaluated. SEREX is also a powerful method for the development of anticancer therapeutics. The development of anticancer vaccines requires that tumor antigens can elicit antigen-specific antibodies or T lymphocytes. More than 2,000 antigens have been discovered by SEFEX. Peptides derived from some of these antigens have been evaluated in clinical trials. This review provides information on the application of SEREX for identification of tumor-associated antigens (TAA) for the development of cancer diagnostics and anticancer therapeutics.

• Journal of Microbiology and Biotechnology
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• v.17 no.6
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• pp.993-1001
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• 2007

The technique of serological analysis of antigens by recombinant cDNA expression library (SEREX) uses autologous patient sera as a screening probe to isolate tumor-associated antigens for various tumor types. Isolation of tumor-associated antigens that are specifically reactive with patient sera, but not with normal sera, is important to avoid false-positive and autoimmunogenic antigens for the cancer immunotherapy. Here, we describe a selection methodology to isolate patient sera-specific antigens from a yeast surface-expressed cDNA library constructed from 15 patient lung tissues with non-small cell lung cancer (NSCLC). Several rounds of positive selection using patient sera alone as a screening probe isolated clones exhibiting comparable reactivity with both patient and normal sera. However, the combination of negative selection with allogeneic normal sera to remove antigens reactive with normal sera and subsequent positive selection with patient sera efficiently enriched patient sera-specific antigens. Using the selection methodology described here, we isolated 3 known and 5 unknown proteins, which have not been isolated previously, but and potentially associated with NSCLC.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.841-846
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• 2007

The identification of tumor antigens is essential for the development of anticancer therapeutic vaccines and clinical diagnosis of cancer. SEREX (serological analysis of recombinant cDNA expression library)has been used to identify such tumor antigens by screening sera of cancer patients with cDNA ex-pression libraries. SEREX-defined antigens provide markers for the diagnosis of cancers. SEREX is also a powerful method for the development of anticancer therapeutics. The development of anticancer vaccines requires that tumor antigens can elicit antigen-specific antibodies or T lymphocytes. This re-view provides information on the application of SEREX for discovery of tumor antigens.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4041-4047
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• 2013

Cancer vaccine development is in the process of becoming reality in future, due to successful phase II/III clinical trials. However, there are still problems due to the specificity of tumor antigens and weakness of tumor associated antigens in eliciting an effective immune response. Computational models to assess the vaccine efficacy have helped to improve and understand what is necessary for personalized treatment. Further research is needed to elucidate the mechanisms of activation of antigen specific cytotoxic T lymphocytes, decreased TREG number functionality and antigen cascade, so that overall improvement in vaccine efficacy and disease free survival can be attained. T cell epitomic based in sillico approaches might be very effective for the design and development of novel cancer vaccines.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.203-220
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• 1989

Ever since the expression of new tumor-specific antigens was reported during malignant transformation, studies on separation, purification and characterization of these proteins have been so activated recently. Following experiment was performed to observe tumor-specific antigens by implanting DMBA pellet into submaxillary gland of rat for inducing salivary gland tumor. After dividing 280 rats into 2 groups, in control group, sham operation was performed on right submaxillary gland and, in experimental group, DMBA pellet (5mg) was implanted into right submaxillary gland. Then proteins from excised submaxillary gland by killing 10 rats every two weeks for 28 weeks were extracted with 3M KCl, and SDS-PAGE and PAS-staining were carried out for biochemical examination. The obtained results were summarized as follows; 1) At 12th week since implantation of DMBA pellet, tumor mass formation was inspected. And dysplasia at 6th week and invasive epidermoid carcinoma at 10th week were observed by microscope. 2) In control group, the weight ratio of both submaxillary glands had no any change, however, in experimental group, the ratio was increased remarkably. And at 28th week after DMBA implantation, there was more than 15 times of differences in weight between control and experimental group. 3) There was no DMBA remnant after 22nd experimental week. 4) In the SDS-PAGE, high molecular protein bands (more than 100 kd) were appeared much, and new prominent protein bands (66, 48, 41.5, 39, 37, 37.5 kd) were appeared after 4th week since DMBA implantation. However, 38, 27, 22kd protein bands were disappeared. 5) In PAS-staining, high molecular proteins were proteins were all glycoproteins and 37.5kd protein was proved as to be glycoprotein. And 38kd glycoprotein was disappeared after 4th week since DMBA implantation.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.

• IMMUNE NETWORK
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• v.6 no.2
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• pp.102-110
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• 2006

Background: Dendritic cells (DC) are professional antigen-presenting cells in the immune system and can induce T cell response against virus infections, microbial pathogens, and tumors. Therefore, immunization using DC loaded with tumor-associated antigens (TAAs) is a powerful method of inducing anti-tumor immunity. For induction of effective anti-tumor immunity, antigens should be efficiently introduced into DC and presented on MHC class I molecules at high levels to activate antigen-specific $CD8^+$ T cells. We have been exploring methods for loading exogenous antigens into APC with high efficiency of Ag presentation. In this study, we tested the effect of the cationic liposome (Lipofectin) for transferring and loading exogenous model antigen (OVA protein) into BM-DC. Methods: Bone marrow-derived DC (EM-DC) were incubated with OVA-Lipofectin complexes and then co-cultured with B3Z cells. B3Z activation, which is expressed as the amount of ${\beta}$-galactosidase induced by TCR stimulation, was determined by an enzymatic assay using ${\beta}$-gal assay system. C57BL/6 mice were immunized with OVA-pulsed DC to monitor the in vivo vaccination effect. After vaccination, mice were inoculated with EG7-OVA tumor cells. Results: BM-DC pulsed with OVA-Lipofectin complexes showed more efficient presentation of OVA-peptide on MHC class I molecules than soluble OVA-pulsed DC. OVA-Lipofectin complexes-pulsed DC pretreated with an inhibitor of MHC class I-mediated antigen presentation, brefeldin A, showed reduced ability in presenting OVA peptide on their surface MHC class I molecules. Finally, immunization of OVA-Lipofectin complexes-pulsed DC protected mice against subsequent tumor challenge. Conclusion: Our data provide evidence that antigen-loading into DC using Lipofectin can promote MHC class I- restricted antigen presentation. Therefore, antigen-loading into DC using Lipofectin can be one of several useful tools for achieving efficient induction of antigen-specific immunity in DC-based immunotherapy.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.180-185
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• 2005

Purpose: Among tumor-associated antigens, MAGE (melanoma antigen) was named as cancer/testis specific antigens because they are detected exclusively in the testis or cancer cells, including gastric carcinomas. Due to the elicitation of autoimmunitiy to tumors by these antigens either in vitro or in vivo and their tumor specificity, these antigens, thus, appear to be potential targets for tumor-specific immunotherapy. Materials and Methods: The fresh tumor tissue and normal gastric tissue samples were obtained from resected surgical specimens in 53 patients with gastric carcinomas. From the obtained cells, total cellular mRNA was extracted, and RT-PCR and nested PCR were run in 30 and 35 cycles respectively, with two different kinds of primers specially designed to detect six subtypes of MAGE DNA simultaneously. Results: In the 53 normal tissue, there was no expression of MAGE, but in the 53 cancer tissues, MAGE was expressed in 13 tissues (24.5%). Our data did not exhibit any correlation with the expression of the MAGE gene and clinicopathological factors. Conclusion: In our data, since 24.5% of gastric cancer tissues expressed MAGE, it should become possible to immunize a significant proportion of patients with advanced gastric carcinomas against the antigens encoded by these genes, provided that more antigenic peptides encoded by the genes of the MAGE family can be identified in the near future. (J Korean Gastric Cancer Assoc 2005;5:180-185)

• IMMUNE NETWORK
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• v.1 no.1
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• pp.1-6
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• 2001

The identification of tumor-specific antigens has represented a critical milestone in cancer diagnosis and therapy. Clinical research in this area for leukemia has also been driven over the past few decades by the hope that surface antigens with restricted tissue expression would be identified. Disappointingly, only a small number of the leukemic antigens identified to date, meet sufficient criteria to be considered viable immunophenotypic markers. In this paper, we nominate anti-JL1 monoclonal antibody as an immunodiagnostic and immunotherapeutic candidate for leukemia. The JL1 molecule appears to be a novel cell surface antigen, which is strictly confined to a subpopulation of limited stages during the hematopoietic differentiation process. Despite the restricted distribution of the JL1 antigen in normal tissues and cells, anti-JL1 monoclonal antibody specifically recognizes various types of leukemia, irrespective of immunophenotypes. On the basis of these findings, we propose JL1 antigen as a tumor-specific marker, which shows promise as a candidate molecule for diagnosis and immunotherapy in leukemia, and one that spares normal bone marrow stem cells.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7703-7705
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• 2014

Cancer-testis (CT) antigens are a group of tumor-associated antigens with restricted expression in normal tissues except for testis and expression in a wide variety of tumor tissues. This pattern of expression makes them suitable targets for immunotherapy as well as potential biomarkers for early detection of cancer. However, some genes attributed to this family are now known to be expressed in other normal tissues which put their potential applications in immunotherapy and cancer detection under question. Here we analyzed expression of two previously known CT antigens, RHOXF2 and PIWIL2, in AML patients versus normal donors and found no significant difference in the expression of these genes between the two groups. As these two genes showed expression in normal leukocytes, their expression pattern seems to be wider than to be attributed to the CT gene family. Future research should focus on the expression profiles of so called CT antigens to find those with more testis specific expression.