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Testis Antigen (testis + antigen)
Selected AbstractsEpigenetic aberrations and therapeutic implications in gliomasCANCER SCIENCE, Issue 6 2010Atsushi Natsume Almost all cancer cells have multiple epigenetic abnormalities, which combine with genetic changes to affect many cellular processes, including cell proliferation and invasion, by silencing tumor-suppressor genes. In this review, we focus on the epigenetic mechanisms of DNA hypomethylation and CpG island hypermethylation in gliomas. Aberrant hypermethylation in promoter CpG islands has been recognized as a key mechanism involved in the silencing of cancer-associated genes and occurs at genes with diverse functions related to tumorigenesis and tumor progression. Such promoter hypermethylation can modulate the sensitivity of glioblastomas to drugs and radiotherapy. As an example, the methylation of the O6-methylguanine DNA methyltransferase (MGMT) promoter is a specific predictive biomarker of tumor responsiveness to chemotherapy with alkylating agents. Further, we reviewed reports on pyrosequencing , a simple technique for the accurate and quantitative analysis of DNA methylation. We believe that the quantification of MGMT methylation by pyrosequencing might enable the selection of patients who are most likely to benefit from chemotherapy. Finally, we also evaluated the potential of de novo NY-ESO-1, the most immunogenic cancer/testis antigen (CTA) discovered thus far, as an immunotherapy target. The use of potent epigenetics-based therapy for cancer cells might restore the abnormally regulated epigenomes to a more normal state through epigenetic reprogramming. Thus, epigenetic therapy may be a promising and potent treatment for human neoplasia. (Cancer Sci 2010) [source] Vakzinationstherapie kutaner T-Zell-LymphomeJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 12 2002Vaccination therapy for cutaneous T-cell lymphoma primary cutaneous T cell lymphomas (CTCL); vaccination; antigenic targets Zusammenfassung: Primär kutane T-Zell-Lymphome (CTCL) sind definiert als klonale Proliferation hautinfiltrierender T-Lymphozyten. Unabhängig von der Heterogenität dieser Krankheitsgruppe besteht derzeit keine kurative Therapiemöglichkeit, was zur Entwicklung verschiedener Behandlungsstrategien, einschließlich der Vakzination, führte. Dieser Artikel gibt eine Übersicht über den Entwicklungsstand der Vakzinationstherapie für Lymphome mit besonderer Rücksicht auf die CTCL. Da bisher kein universelles Tumorantigen identifiziert wurde, sind verschiedenste antigene Agenzien (komplette Tumorzellen, Idiotypen, Cancer/Testis-Antigene, Proteine aus tumorassoziierten Mutationen und Mimotope) hinsichtlich ihrer Eignung für die Vakzinationstherapie von CTCL untersucht worden. Die antigene Information dieser Präparationen kann dem körpereigenen Immunsystem über verschiedene Wege (Carrier) dargeboten werden, bisher sind dazu mit Tumorzellen fusionierte dendritische Zellen, Idiotyp-Proteine oder -Peptide sowie DNA- und RNA-Präparationen eingesetzt worden. Da die verwendeten Antigene allesamt schwache Immunogene darstellen, sind Adjuvanzien (dendritische Zellen, immunogene Peptide, Oligonukleotide, Zytokine, virale Vektoren) notwendig, um eine suffiziente Antigenpräsentation und Aktivierung des Immunsystems zu erreichen. Erste klinische Daten bestätigen die prinzipielle Wirksamkeit einer Vakzinationstherapie bei CTCL. Die große Anzahl bisher verwendeter Antigene, Carrier, Adjuvanzien und Applikationsschemen macht die Identifizierung eines optimalen Protokolls jedoch nahezu unmöglich. Da auch die Wechselwirkungen zwischen Lymphom und Immunsystem sehr komplex und nicht vollständig verstanden sind, ist bis zur Einführung der Vakzinationstherapie in die klinische Praxis noch großer Forschungsaufwand nötig. Summary: Primary cutaneous T,cell lymphomas (CTCL) are defined as clonal proliferation of skin-infiltrating T lymphocytes. Despite their heterogeneity, CTCL are generally incurable, which lead to the development of various treatment strategies including vaccination. Here, the attempts to vaccinate against lymphoma will be reviewed with special emphasis on CTCL. Since an universal tumour antigen is not available so far, different targets, including whole tumour cells, idiotypes, cancer/testis antigens, proteins derived from tumour-associated mutations, and mimotopes, have been investigated for their applicability in CTCL vaccination. The antigenic information can be delivered in different ways. So far, tumour cells fused to dendritic cells, idiotypic proteins/peptides and DNA/RNA preparations have been applied in lymphoma. Since most targets are weak immunogens, adjuvants and other helpers, including dendritic cells, immunogenic peptides and oligonucleotides, cytokines, and viral vectors, are required to enable proper presentation of the antigens and sufficient activation of the immune system. Although first data from CTCL patients prove the suitability of vaccination in CTCL therapy, the number of available antigens, carriers, adjuvants and application schemes creates a multitude of vaccine formulations and identification of the best-suited approach difficult. Furthermore, the relationship between lymphoma and the host immune system is complex and still not completely understood. In consequence, CTCL vaccination requires a lot of research to be done before its breakthrough. [source] Cancer/testis antigen MAGE-A4 expression pattern differs in epithelial skin tumors of organ-transplant recipients and immunocompetent patientsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2007Beda Muehleisen Background:, Lifetime risk for squamous cell carcinoma (SCC) of the skin is 1:30. Risk in organ-transplant recipients (OTR) is increased over 60-fold through long-term drug-induced immunosuppression. MAGE family-derived peptides are cancer/testis antigens recognized by specific CD8+ T cells and employed for immunotherapy. We were interested in the frequency and distribution of MAGE-A4 in epithelial skin tumors of OTR and immunocompetent patients. Methods:, mAb 57B predominantly recognizing MAGE-A4 was used to stain 119 formalin-fixed, paraffin-embedded epithelial skin tumors (actinic keratosis, bowenoid actinic keratosis, Bowen's disease, and SCC; n = 17, 25, 61, 16, respectively) in immunocompetent patients (n = 84) and OTR (n = 35). Results:, All four epithelial skin tumors showed comparable immunoreactivity ranging from (25,71%, p = 0.361). Scattered immunoexpression pattern was more frequent in OTR (p = 0.025). SCC showed polarized immunoreactivity basally (p = 0.002). Conclusion:, MAGE-A4 was expressed in a large part of epithelial skin tumors with predominantly scattered immunoexpression pattern in OTR. The difference in immunoexpression pattern for immune status was limited, suggesting important non-immunosuppressor-mediated mechanisms for increased skin carcinogenesis in OTR. mAb 57B may be a helpful tool for immunohistochemistry and micrographic surgery using formalin-fixed paraffin-embedded tissue. [source] A yeast two-hybrid system using Sp17 identified Ropporin as a novel cancer,testis antigen in hematologic malignanciesINTERNATIONAL JOURNAL OF CANCER, Issue 7 2007Zhanfei Li Abstract Since most intracellular proteins are expressed with their ligands, ligands of cancer,testis (CT) antigens may also be CT in their distribution. Applying Sperm protein 17 (Sp17) as the bait in a yeast 2-hybrid system of a testicular cDNA library, 17 interacting clones were isolated and all encoded Ropporin, a spermatogenic cell-specific protein that serves as an anchoring protein for the A-kinase anchoring protein, AKAP110. Ropporin showed a very restricted normal tissue gene expression, detected only in testis and fetal liver. Ropporin mRNA could also be detected in tumor cells from patients with multiple myeloma, chronic lymphocytic leukemia and acute myeloid leukemia. Interestingly, expression of Sp17 did not necessarily predict for the expression of Ropporin suggesting that their coexpression in these tumor cells was random rather than coordinated. Ropporin gene expression in tumor cells is associated with the presence of high titer IgG antibodies against Ropporin, suggesting the in vivo translation of the mRNA into protein and the immunogenicity of the protein to the autologous hosts. Using a CT antigen as the bait in a yeast 2-hybrid system may, therefore, identify novel tumor antigen. Our results also suggest that Ropporin is a novel CT antigen in hematologic malignancies. © 2007 Wiley-Liss, Inc. [source] CD109 expression in squamous cell carcinoma of the uterine cervixPATHOLOGY INTERNATIONAL, Issue 4 2005Jing-min Zhang CD109 is a cell surface protein, a member of the ,2 macroglobulin/C3,C4,C5 family of thioester-containing proteins. The authors have recently reported that high expression of the CD109 gene was detected in approximately half of the examined lung and esophageal squamous cell carcinomas as well as in the testis, and that CD109 has the characteristics of a cancer,testis antigen. In the present study CD109 expression in cervical squamous cell carcinoma was compared with that in endometrial adenocarcinoma by reverse transcription polymerase chain reaction (RT-PCR). The result demonstrated that CD109 expression is significantly higher in cervical squamous cell carcinomas than in endometrial adenocarcinomas and normal cervix and endometrium. In contrast, when expression of RET finger protein (RFP) and bromodomain testis-specific (BRDT) genes, which are also known to be highly expressed in the testis, was examined, no significant difference in their expression levels was observed between squamous cell carcinomas and adenocarcinomas. These findings suggest that CD109 may become a molecular target for the development of new therapeutics for squamous cell carcinoma of various tissue origins. [source] Novel BRCA2-interacting protein BJ-HCC-20A inhibits the induction of apoptosis in response to DNA damageCANCER SCIENCE, Issue 4 2008Go Tomiyoshi The major hereditary breast cancer susceptibility gene BRCA2 is associated with familial breast and ovarian cancer. BRCA2 plays a role in DNA repair, transcription, cell cycle regulation, maintenance of genomic stability in response to DNA damage, centrosome regulation, and cytokinesis. To further understand the function of BRCA2, we used a yeast two-hybrid method and identified a novel BRCA2-interacting protein, BJ-HCC-20A, which is reported to be a potential cancer,testis antigen. We confirmed the interaction between endogenous BJ-HCC-20A and BRCA2 in mammalian cells, and showed that BJ-HCC-20A interacts with a portion of the highly conserved region of BRCA2 in various mammals, and M phase-specific phosphorylation of the binding region of BRCA2 modulates BJ-HCC-20A binding. Overexpression of BJ-HCC-20A increases cell growth, and downregulation of endogenous BJ-HCC-20A expression using small interfering RNA suppresses cell growth and leads to the induction of apoptosis. Importantly, the BJ-HCC-20A mRNA level is downregulated by adriamycin (ADR)-induced DNA damage and depletion of BJ-HCC-20A expression by small interfering RNA promotes the reduction of BRCA2 expression and enhances cell apoptosis in response to DNA damage. Additionally, the recovery of BJ-HCC-20A expression in ADR-induced DNA damage inhibits ADR-induced apoptosis. The data suggest that BJ-HCC-20A promotes cell growth and may regulate the induction of cell apoptosis in response to DNA damage in cooperation with BRCA2 in an M phase-dependent manner. Therefore, we speculate that targeting BJ-HCC-20A may aid in the treatment of breast tumors. (Cancer Sci 2008; 99: 747,754) [source] Involvement of kinesin family member 2C/mitotic centromere-associated kinesin overexpression in mammary carcinogenesisCANCER SCIENCE, Issue 1 2008Arata Shimo To elucidate the molecular mechanisms of mammary carcinogenesis and discover novel therapeutic targets for breast cancer, we previously carried out genome-wide expression profile analysis of 81 breast cancer cases by means of cDNA microarray coupled with laser microbeam microdissection of cancer cells. Among the dozens of transactivated genes, in the present study we focused on the functional significance of kinesin family member 2C (KIF2C)/mitotic centromere-associated kinesin (MCAK) in the growth of breast cancer cells. Northern blot and immunohistochemical analyses confirmed KIF2C/MCAK overexpression in breast cancer cells, and showed that it is expressed at undetectable levels in normal human tissues except the testis, suggesting KIF2C/MCAK to be a cancer,testis antigen. Western blot analysis using breast cancer cell lines revealed a significant increase in the endogenous KIF2C/MCAK protein level and its phosphorylation in G2/M phase. Treatment of breast cancer cells with small interfering RNA against KIF2C/MCAK effectively suppressed KIF2C/MCAK expression and inhibited the growth of the breast cancer cell lines T47D and HBC5. In addition, we found that KIF2C/MCAK expression was significantly suppressed by ectopic introduction of p53. These findings suggest that overexpression of KIF2C/MCAK might be involved in breast carcinogenesis and is a promising therapeutic target for breast cancers. (Cancer Sci 2008; 99: 62,70) [source] Immunohistochemical expression of tumor antigens MAGE-A1, MAGE-A3/4, and NY-ESO-1 in cancerous and benign prostatic tissueTHE PROSTATE, Issue 1 2006Tvrtko Hudolin Abstract OBJECTIVE To investigate immunohistochemical expression of MAGE-A and NY-ESO-1/LAGE-1, cancer testis antigens in prostate tissues showing evidence of malignant transformation or benign hyperplasia. METHODS 112 prostate samples from patients undergoing surgery at the Urology Clinic at the Zagreb Clinical Hospital Center from 1995 to 2003 were investigated in this study. Of these, 92 carcinoma samples were obtained by radical prostatectomy, and 20 benign prostatic hyperplasia samples by transvesical prostatectomy. Three monoclonal antibodies were used for immunohistochemical staining: 77B for MAGE-A1, 57B for multi-MAGE-A and D8.38 for NY-ESO-1 expression. RESULTS Expression of MAGE-A1 was observed in 10.8% of carcinoma samples, whereas multi-MAGE-A and NY-ESO-1/LAGE-1 stained 85.9% and 84.8% of samples. Immunohistochemical staining was only detectable in the cytoplasm. A significant heterogeneity could be observed within a same tissue sample where areas with strong positivities coexisted with cancer testis antigens negative areas. Interestingly, a majority of 57B positive cases were also found to be D8.38 positive (correlation coefficient r,=,0.727 (P,<,0.01)). Cancer testis antigens expression was neither significantly correlated with PSA values nor with Gleason score. In benign prostatic hyperplasia tissues MAGE-A1 expression was detected in 5%, while 57B and D8.38 staining was observed in 15% samples, and in all cases percentages of positive cells were always <10%. CONCLUSION Our data underline the peculiar relevance of cancer testis antigens expression in prostate cancers, with potential implications regarding both diagnosis and therapy. © 2005 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||