NY-ESO-1 tumour associated antigen is a cytoplasmic protein detectable by specific monoclonal antibodies in cell lines and clinical specimens

HCA587 antigen expression in normal tissues and cancers: correlation with tumor differentiation in hepatocellular carcinoma

The HCA587 gene, identified by serological analysis of recombinant cDNA expression library (SEREX) from a hepatocellular carcinoma (HCC) patient, encodes a new member of cancer-testis antigens. HCA587 mRNA expression in normal tissues and cancers has been previously reported. To estimate its immunogenicity to induce immune response, it is essential to analyze HCA587 expression at the protein level. In this study anti-HCA587 polyclonal antibody, termed "TC-1," was generated, and the expression of HCA587 protein was assessed by immunohistochemical staining in a panel of normal and tumor tissue sections. No HCA587 protein was shown in normal tissues except germ cells in testis and Purkinji cells in cerebellum. In HCC specimens the HCA587 protein was expressed in 37.1% (26 of 70) samples. The expressed protein was either located in the cytoplasm or nucleus depending on the individual samples. More importantly, there appears to be correlation between the tumor differentiation of HCC and HCA587 protein expression, ie, the lower differentiation, the higher percentage of protein expression. Coincidentally, seroreactivity showed that the Ab specific to recombinant HCA587 protein was detected only in the sera of three patients with poorly differentiated HCCs. HCA587 antigen was also expressed in different proportions in melanoma, lymphoma, pancreatic cancer, and lung cancer.

Expression of cancer/testis tumor associated antigens in cervical squamous cell carcinoma

We investigated the expression of tumor-associated antigens (TAA) of the cancer/testis (C/T) gene family in cervical squamous cell carcinomas. First, we focused on the HeLa cervical cancer derived cell line, and we found that it expresses MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A6, MAGE-A12, GAGE-3/6, LAGE-1, and PRAME genes, encoding defined C/T TAA. In contrast, no expression of MAGE-A10, BAGE, GAGE-1/2, or NY-ESO-1 genes was observed. Corresponding gene products could also be detected by immunoblotting and immunocytochemistry, taking advantage of monoclonal antibodies recognizing discrete TAA. Capitalizing on these data, a monoclonal antibody predominantly recognizing MAGE-A4 TAA in paraffin-embedded sections (57B) was used to investigate the C/T gene expression in clinical tumor samples. A group of 60 patients was studied, and 57B positivity was detectable to different extents in 33% of the cases (20/60). In 13 of them (21%), staining of over 50% of the tumor cells was evident, whereas healthy cells always scored negative. Remarkably, MAGE-A4 expression was significantly (p < 0.05) more frequently detectable in poorly differentiated tumors (8/13) than in well-differentiated or moderately differentiated cancers (3/15 and 9/32, respectively) and in stage FIGO II as compared with stage FIGO Ib tumors (12/23 and 5/24, respectively, p = 0.04). Interestingly, staining was mostly nuclear in well-differentiated tumors, but involved both nuclei and cytoplasm in less differentiated cancers. Positivities of comparable frequency were also detectable in a smaller series of specimens upon staining with MAGE-A1- or NY-ESO-1/LAGE-1-specific reagents. Considering the high tumor specificity of C/T TAA, our data provide the rationale for the design of immunotherapy procedures targeting these antigens in cervical cancers.

Cancer/testis-associated genes: identification, expression profile, and putative function

Cancer/testis-associated genes (CTAs) are a subgroup of tumor antigens with a restricted expression in testis and malignancies. During the last decade, many of these immunotherapy candidate genes have been discovered using various approaches. Most of these genes are localized on the X-chromosome, often as multigene families. Methylation status seems to be the main, but not the only regulator of their specific expression pattern. In testis, CTAs are exclusively present in cells of the germ cell lineage, though there is a lot of variation in the moment of expression during different stages of sperm development. Likewise, there is also a lot of heterogeneity in the expression of CTAs in melanoma samples. Clues regarding functionality of CTAs for many of these proteins point to a role in cell cycle regulation or transcriptional control. Better insights in the function of these genes may shed light on the link between spermatogenesis and tumor growth and could be of use in anti-tumor therapies. This review outlines the CTA family and focuses on their expression and putative function during male germ cell development and melanocytic tumor progression.

Cancer/testis tumour-associated antigens: immunohistochemical detection with monoclonal antibodies

Cancer/testis tumour-associated antigens (C/T TAA) were the first human tumour-associated antigens to be characterised at the molecular level. Specific genes are expressed in the testis and in tumours of varying histological origin. The tissue expression pattern supports the notion that these antigens could be targets for active specific immunotherapy. Specific serological reagents have been developed and have helped to clarify biochemical characteristics of C/T TAA and to assess their distribution within clinical tumour samples. We review immunohistochemical evidence of the expression of C/T TAA known to be recognised by specific cytotoxic T lymphocytes. The emerging picture is consistent with a mostly heterogeneous expression in human cancers. These findings support the concept of multiantigenic tumour vaccine preparations. Moreover, the wide range of tumours in which C/T TAA have been detected urges further efforts to develop effective specific immunotherapeutic procedures.

Cancer-testis antigen expression in uterine malignancies with an emphasis on carcinosarcomas and papillary serous carcinomas

The cancer testis (CT) family of antigens are expressed in certain malignant neoplasms and are silent in normal adult tissues, except for the testis. Expression of 2 members of this family, MAGE-A4 and NY-ESO-1, has been described recently in germ cell tumors, malignant melanomas, certain carcinomas and sarcomas. Our study is the first to describe the expression pattern of CT antigens in uterine neoplasms. Ninety-eight cases of uterine neoplasms, including 41 endometrioid, 19 papillary serous and 7 clear cell carcinomas, 22 carcinosarcomas and 9 endometrial stromal sarcomas were studied. Immunohistochemistry was carried out with the 57B monoclonal antibody that recognizes predominantly the MAGE-A4 antigen in paraffinized tissues and the D8.38 antibody that recognizes NY-ESO-1. MAGE-A4 expression was found to be present in 12% of the endometrioid adenocarcinomas, 63% of the papillary serous carcinomas and 91% of the carcinosarcomas. Within the tumor population the extent of MAGE-A4 expression was highest in the carcinosarcomas. In 12 of 22 positively staining carcinosarcomas more than 50% of the tumor cells expressed MAGE-A4. NY-ESO-1 expression was seen in 19% of the endometrioid adenocarcinomas, 32% of the papillary serous carcinomas and in 45% of the carcinosarcomas. CT antigen immunoreactivity was observed in both the carcinomatous and sarcomatous components of the carcinosarcomas and strong correlation between MAGE-A4 and NY-ESO-1 expression was present in individual cases. In summary, strong MAGE-A4 expression and to a lesser degree NY-ESO-1 expression is characteristic of the vast majority of uterine carcinosarcomas and a major subset of papillary serous carcinomas. These results suggest that CT antigen expression by these tumors may represent a novel target for immunotherapy.

Identification of metallopanstimulin-1 as a member of a tumor associated antigen in patients with breast cancer

The immunological screening of breast cancer was performed with IgG autoantibodies by the serological analysis of recombinant cDNA expression library methods to explore novel tumor associated antigens. We have focused on a small zinc finger protein metallopanstimulin-1 (MPS-1). MPS-1 mRNA was ubiquitously expressed in normal human tissues except the brain and the placenta. In Western blot analysis, MPS-1 was easily detected strongly in actively proliferating cells and three breast cancer cell lines. In the tissue the protein of MPS-1 in cancer cells was more abundant than that of surrounding normal cells. Screening of tissue specimens by immunohistochemistry revealed 50.4% positive for MPS-1 in 125 cancer patients. These data suggest that MPS-1 could be applicable to the immunotherapy of breast cancer.

CT7 (MAGE-C1) antigen expression in normal and neoplastic tissues

CT7 (MAGE-C1) is a member of the cancer testis (CT) antigen family. The present study describes the generation of CT7-33, a monoclonal antibody (MAb) to CT7, and the preliminary protein expression analysis of CT7 in normal tissues and in a limited number of neoplastic lesions. CT7-33 was effective in frozen as well as formalin-fixed, paraffin-embedded tissues, and immunohistochemistry/reverse transcriptase polymerase chain reaction (RT-PCR) co-typing demonstrated antibody specificity. CT7-33 immunoreactivity in normal adult tissues is restricted to testicular germ cells. In neoplastic lesions, CT7-33 immunostaining is confined to tumor cells, and the frequency of CT7 protein expression mostly parallels previous mRNA analyses. Whereas colorectal and renal cell carcinomas, as well as sarcomas, exhibit poor or no CT7-33 staining, carcinomas of the mammary gland and ovary, nonsmall cell lung carcinoma and metastatic melanomas exhibit a high incidence of CT7 protein expression. However, as seen in previous analyses of other CT antigens, the expression pattern is mostly heterogeneous, and tumors with more than 50% of tumor staining are only infrequently encountered. In summary, our study presents a new serologic reagent for the analysis of CT7 on a protein level and confirms what is known with regard to the expression pattern of other CT antigens in tumors: frequent heterogeneity of antigen expression.

The cancer-testis gene, NY-ESO-1, is expressed in normal fetal and adult testes and in spermatocytic seminomas and testicular carcinoma in situ

Cancer/testis genes are potential targets for therapeutic genetic and immunologic approaches, and are highly expressed in a large variety of human cancers. However, they are not expressed in normal tissues, with the exception of the testis. The NY-ESO-1 gene is the most recently identified member of the cancer/testis family and its product is one of the most immunogenic tumor antigens. We used immunohistochemistry to investigate the expression of NY-ESO-1 in healthy human prenatal and adult testes and in 59 human testicular tumors of different subtypes. We found that NY-ESO-1 was expressed from 18 weeks until birth in human fetal testes. In the adult testis, NY-ESO-1 was strongly expressed in spermatogonia and in primary spermatocytes, but not in post-meiotic cells or in testicular somatic cells. NY-ESO-1 was not expressed in the Sertoli cells, Leydig cells, classical seminomas, or nonseminomatous germ cells in the 59 testicular tumors. In contrast, NY-ESO-1 was expressed both in carcinomas in situ, which are the earliest stage of testicular tumors (7 of 15 cases), and in spermatocytic seminomas, which are believed to be derived from spermatogonia or primary spermatocytes (8 of 16 cases). We conclude that NY-ESO-1 is a marker that can be used to follow the early progression of testicular tumorigenesis when the tumors present a similar pattern of expression to the cells from which they originated, although the later tumors cease to express NY-ESO-1.

Subcellular localization of the melanoma-associated protein Melan-AMART-1 influences the processing of its HLA-A2-restricted epitope

The peptide derived from the melanoma-associated protein Melan-A (Melan-A(26-35)/HLA-A2) is an attractive candidate for tumor immunotherapy but little is known about the intracellular processing of this antigen. Here we show that Melan-A is a single-pass membrane protein with an NH(2) terminus exposed to the lumen of the exocytic compartment. In transfected melanoma cells, Melan-A accumulates in the Golgi region. Inversion of the membrane topology leads to the retention of Melan-A in the endoplasmic reticulum. Most strikingly, melanoma cells expressing this form of Melan-A are more effectively recognized by specific CTL than those expressing either Melan-A in its native membrane orientation or Melan-A artificially localized in the cytosol. Our data are compatible with the notion that proteins retained in the endoplasmic reticulum are more efficiently degraded and produce more antigenic peptides.

Expression profile of genes coding for melanoma differentiation antigens and cancer/testis antigens in metastatic lesions of human cutaneous melanoma

Vaccination-based therapy of melanoma has so far mainly focused on monovalent approaches using either melanoma differentiation antigens or cancer/testis antigens. To study the complementarity of expression from these two families of antigens recognized by T-cells, we screened 47 metastatic lesions of cutaneous melanoma for the expression of three melanoma differentiation antigens and eight cancer/testis antigens using reverse transcription-polymerase chain reaction (RT-PCR). The melanoma differentiation antigens were expressed in a somewhat higher percentage of lesions (94% positive for at least one marker) than the cancer/testis antigens (91% positive for at least one marker). Nearly all the melanoma metastases (98%) expressed at least one of the markers tested. One melanoma metastasis was negative for all the markers. Two out of 47 lesions did not express any of the three differentiation markers but expressed one or more of the cancer/testis antigens, indicating some additional potential for these antigens compared with the melanoma differentiation antigens. Therefore, we conclude that polyvalent immunotherapy using multiple epitopes from both families of antigens might increase the eligibility of melanoma patients and the efficacy of the treatment.

Expression of multiple cancer-testis antigen genes in gastrointestinal and breast carcinomas

Cancer-testis antigens (CTAs) such as MAGE are selectively expressed in various types of human neoplasms but not in normal tissues other than testis. This characteristic feature of CTAs makes them promising antigens for cancer-specific immunotherapy. A critical requirement for this therapy is identification of promising antigens. In this study, we investigated the expression of 6 genes recently identified by serological analysis of antigens by recombinant expression (SEREX) libraries: NY-ESO-1, LAGE-1, SCP-1, SSX-1, SSX-2, and SSX-4, in many surgical samples of gastrointestinal and breast carcinomas using reverse transcription-polymerase chain reaction. We found relatively high expression of SCP-1 (23.5%) and SSX-4 (20.6%) in gastric carcinoma, LAGE-1 (39.1%) and NY-ESO-1 (23.9%) in oesophageal carcinoma, and SCP-1 (34.1%) in breast carcinoma. We also found frequent synchronous expression with MAGE, including LAGE-1 (46.2%) in oesophageal carcinoma, SSX-4 (46.7%) in gastric carcinoma, and SCP-1 (38.3%) in breast carcinoma. Immunohistochemical analysis of the tumour samples expressing both MAGE-4 and NY-ESO-1 genes demonstrated differences in distribution between MAGE-4 and NY-ESO-1 in serial sections. We concluded that NY-ESO-1, LAGE-1, SCP-1 and SSX-4 genes may be promising candidates for cancer-specific immunotherapy in addition to MAGE, and that polyvalent cancer vaccines may be useful in cases of heterogeneous expressions of CTA genes in gastrointestinal and breast carcinomas.

NY-ESO-1 and CTp11 expression may correlate with stage of progression in melanoma

BACKGROUND

As tumor cells spread beyond their primary site they undergo changes in their gene expression that may be detectable and useful for microstaging. The cancer/testis (CT) antigens are a family of proteins that include MAGE 1-3, NY-ESO-1, SSX 1-5, and others that are potential markers for microstaging melanoma. CT antigens are produced by many tumor types but few normal tissues other than testis. One CT antigen, CTp11, was shown to be expressed by metastasizing melanoma cell lines but not by nonmetastasizing variants. We tested this finding by studying the expression of CTp11 and NY-ESO-1 by melanoma samples from different stages of progression.

MATERIALS AND METHODS

We collected 20 primary, 22 locoregional, and 10 distant metastatic melanoma samples. We extracted total RNA, and reverse transcription yielded cDNA, which was PCR-amplified using primers to detect beta-actin, tyrosinase, MART-1, NY-ESO-1, and CTp11. The PCR products were separated on ethidium bromide-stained agarose gels and visualized by UV transillumination.

RESULTS

All samples were positive for beta-actin and MART-1 and all but two were positive for tyrosinase, confirming RNA integrity and the presence of melanoma. Twenty-seven samples were positive for NY-ESO-1, CTp11, or both. CTp11 tended to be expressed by primary melanomas and NY-ESO-1 by metastatic samples (P < 0.02).

CONCLUSIONS

There is a statistically significant difference in the distribution of the expression of CTp11 and NY-ESO-1 in melanoma from different stages of progression. NY-ESO-1 may be a marker of more advanced disease and CTp11 of less advanced disease.

Sequential 5-Aza-2 deoxycytidine-depsipeptide FR901228 treatment induces apoptosis preferentially in cancer cells and facilitates their recognition by cytolytic T lymphocytes specific for NY-ESO-1

Global alterations in chromatin structure profoundly influence gene expression in thoracic neoplasms, silencing tumor suppressors while facilitating the expression of various cancer testis antigens such as NY-ESO-1. Although recent studies have shown that histone deacetylase inhibitors can potentiate tumor suppressor gene induction mediated by demethylating agents in cancer cells, the ability of these agents to augment cancer testis antigen expression have not been fully defined. The authors designed the current study to determine whether the histone deacetylase inhibitor, depsipeptide FR901228 (DP), could enhance NY-ESO-1 induction mediated by the DNA demethylating agent 5-Aza-2'-deoxycytidine (DAC) in cell lines established primarily from thoracic cancers. Quantitative reverse-transcriptase polymerase chain reaction analysis revealed that, under exposure conditions potentially achievable in clinical settings, DAC dramatically induced NY-ESO-1 expression in cultured cancer lines. DP alone mediated negligible target gene induction but significantly augmented DAC-mediated induction of NY-ESO-1. After DAC or sequential DAC-DP treatment, HLA-A*0201 cancer cells were recognized by an HLA-A*0201 CTL specific for NY-ESO-1. Although sequential DAC/DP exposure did not uniformly enhance immune recognition of target cells compared with DAC alone, this treatment mediated profound induction of apoptosis in cancer cells but not normal human bronchial epithelia. The apoptotic effects of DAC, DP, or sequential DAC-DP did not correlate in an obvious manner with histology, or the magnitude of NY-ESO-1 induction in cancer cells. Although the mechanisms have not been fully defined, sequential DAC-DP treatment may be a novel strategy to augment antitumor immunity in cancer patients.

Efficient simultaneous presentation of NY-ESO-1/LAGE-1 primary and nonprimary open reading frame-derived CTL epitopes in melanoma

Recent studies have shown that CTL epitopes derived from tumor-associated Ags can be encoded by both primary and nonprimary open reading frames (ORF). In this study we have analyzed the HLA-A2-restricted CD8(+) T cell response to a recently identified CTL epitope derived from an alternative ORF product of gene LAGE-1 (named CAMEL), and the highly homologous gene NY-ESO-1 in melanoma patients. Using MHC/peptide tetramers we detected CAMEL(1-11)-specific CD8(+) T cells in peptide-stimulated PBMC as well as among tumor-infiltrated lymph node cells from several patients. Sorting and expansion of tetramer(+) CD8(+) T cells allowed the isolation of tetramer(bright) and tetramer(dull) populations that specifically recognized the peptide Ag with high and low avidity, respectively. Remarkably, only high avidity CAMEL-specific CTL were able to recognize Ag-expressing tumor cells. A large series of HLA-A2-positive melanoma cell lines was characterized for the expression of LAGE-1 and NY-ESO-1 mRNA and protein and tested for recognition by CAMEL-specific CTL as well as CTL that recognize a peptide (NY-ESO-1(157-165)) encoded by the primary ORF products of the LAGE-1 and NY-ESO-1 genes. This analysis revealed that tumor-associated CD8(+) T cell epitopes are simultaneously and efficiently generated from both primary and nonprimary ORF products of LAGE-1 and NY-ESO-1 genes and, importantly, that this occurs in the majority of melanoma tumors. These findings underscore the in vivo immunological relevance of CTL epitopes derived from nonprimary ORF products and support their use as candidate vaccines for inducing tumor specific cell-mediated immunity against cancer.