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

The Evolving Landscape of Immunotherapy in Uterine Cancer: A Comprehensive Review

Endometrial cancer affects the uterus and is becoming increasingly common and deadly. Although surgery and adjuvant pelvic radiotherapy can often cure the disease when it is contained in the uterus, patients with metastatic or recurrent disease have limited response rates to chemotherapy, targeted agents, and hormonal therapy. To address this unmet clinical need, innovative treatment strategies are needed, and a growing focus on the immunomodulation of the tumor microenvironment has arisen. Current data suggest that active and/or passive immunotherapy may be promising for the treatment of endometrial cancer.

Clinicopathological Assessment of Cancer/Testis Antigens NY-ESO-1 and MAGE-A4 in Highly Aggressive Soft Tissue Sarcomas

We aimed to investigate the clinical significance of the expression of NY-ESO-1 and MAGE-A4 in soft tissue sarcoma (STS). Immunostaining for NY-ESO-1, MAGE-A4, and Ki67 was performed using pathological specimens harvested from 10 undifferentiated pleomorphic sarcoma (UPS), nine myxofibrosarcoma (MFS), and three malignant peripheral nerve sheath tumor (MPNST) patients treated at our hospital. We examined the correlation of NY-ESO-1 and MAGE-A4 expression levels with tumor size, histological grade, and SUVmax values. Positive cell rates of various markers were also compared between patients in remission and those who were not in remission. The rates of cases positive for NY-ESO, MAGE-A4, and Ki67 were 50%, 63.6%, and 90.9%, respectively. The average rates of cells positive for NY-ESO, MAGE-A4, and Ki67 in all STS types were 18.2%, 39.4%, and 16.8%, respectively. A positive correlation was observed between rates of cells positive for NY-ESO-1 and MAGE-A4 and between NY-ESO-1 and MAGE-A4 expression levels and clinical features. There was no significant difference in the positive cell rate of NY-ESO-1 or MAGE-A4 between remission and non-remission cases. Our results suggest that NY-ESO-1 and MAGE-A4 expression may be useful for the diagnosis and prognostication of UPS, MFS, and MPNST.

Investigating the Role of Telomere and Telomerase Associated Genes and Proteins in Endometrial Cancer

Endometrial cancer (EC) is the commonest gynaecological malignancy. Current prognostic markers are inadequate to accurately predict patient survival, necessitating novel prognostic markers, to improve treatment strategies. Telomerase has a unique role within the endometrium, whilst aberrant telomerase activity is a hallmark of many cancers. The aim of the current in silico study is to investigate the role of telomere and telomerase associated genes and proteins (TTAGPs) in EC to identify potential prognostic markers and therapeutic targets. Analysis of RNA-seq data from The Cancer Genome Atlas identified differentially expressed genes (DEGs) in EC (568 TTAGPs out of 3467) and ascertained DEGs associated with histological subtypes, higher grade endometrioid tumours and late stage EC. Functional analysis demonstrated that DEGs were predominantly involved in cell cycle regulation, while the survival analysis identified 69 DEGs associated with prognosis. The protein-protein interaction network constructed facilitated the identification of hub genes, enriched transcription factor binding sites and drugs that may target the network. Thus, our in silico methods distinguished many critical genes associated with telomere maintenance that were previously unknown to contribute to EC carcinogenesis and prognosis, including NOP56, WFS1, ANAPC4 and TUBB4A. Probing the prognostic and therapeutic utility of these novel TTAGP markers will form an exciting basis for future research.

Molecular Basis of Tumor Heterogeneity in Endometrial Carcinosarcoma

Endometrial carcinosarcoma (ECS) represents one of the most extreme examples of tumor heterogeneity among human cancers. ECS is a clinically aggressive, high-grade, metaplastic carcinoma. At the morphological level, intratumor heterogeneity in ECS is due to an admixture of epithelial (carcinoma) and mesenchymal (sarcoma) components that can include heterologous tissues, such as skeletal muscle, cartilage, or bone. Most ECSs belong to the copy-number high serous-like molecular subtype of endometrial carcinoma, characterized by the TP53 mutation and the frequently accompanied by a large number of gene copy-number alterations, including the amplification of important oncogenes, such as CCNE1 and c-MYC. However, a proportion of cases (20%) probably represent the progression of tumors initially belonging to the copy-number low endometrioid-like molecular subtype (characterized by mutations in genes such as PTEN, PI3KCA, or ARID1A), after the acquisition of the TP53 mutations. Only a few ECS belong to the microsatellite-unstable hypermutated molecular type and the POLE-mutated, ultramutated molecular type. A common characteristic of all ECSs is the modulation of genes involved in the epithelial to mesenchymal process. Thus, the acquisition of a mesenchymal phenotype is associated with a switch from E- to N-cadherin, the up-regulation of transcriptional repressors of E-cadherin, such as Snail Family Transcriptional Repressor 1 and 2 (SNAI1 and SNAI2), Zinc Finger E-Box Binding Homeobox 1 and 2 (ZEB1 and ZEB2), and the down-regulation, among others, of members of the miR-200 family involved in the maintenance of an epithelial phenotype. Subsequent differentiation to different types of mesenchymal tissues increases tumor heterogeneity and probably modulates clinical behavior and therapy response.

MAGE-A4 and MAGE-A1 Immunohistochemical Expression in High-grade Endometrial Cancer

The aim was to investigate MAGE-A4 and MAGE-A1 protein expression in high-grade endometrial cancer and determine its correlation with histologic subtype, FIGO stage, presence of vascular invasion, disease free, and overall survival. Immunohistochemical staining was performed by using 77B (MAGE-A1) and 57B (MAGE-A4) monoclonal antibodies on paraffin-embedded sections from high-grade endometrial cancers diagnosed in University Hospital Split between 1998 and 2011 (n=77). Median follow-up time for survivors was 48 mo. MAGE-A4 was found to be expressed in 33% of endometrioid type endometrial cancers grade 3 and in 27% of serous and clear cell carcinomas. MAGE-A1 was found to be expressed in 93% endometrioid endometrial cancer grade 3 and 86% of serous and clear cell carcinomas. Univariate analysis showed that positive immunohistochemical staining for MAGE-A4 was associated with decreased disease free and overall survival in patients with high-grade endometrial cancer. Multivariate analysis showed an association between MAGE-A4 overexpression and decreased disease free but not overall survival in high-grade endometrial cancer. No correlation was found between MAGE-A1 immunohistochemical expression and patient survival. There was no significant correlation between MAGE-A4 and MAGE-A1 expression and histologic subtype, FIGO stage, lymph node metastasis, muscular infiltration, and lymphovascular invasion. MAGE-A4 immunohistochemical expression is associated with decreased disease free and overall survival in patients with high-grade endometrial cancer. Our findings suggest that MAGE-A1 may be expressed in the epithelial cells of the normal endometrium. MAGE-A1 is highly expressed in high-grade endometrial cancer, with no impact on survival.

Cancer-testis antigens are predominantly expressed in uterine leiomyosarcoma compared with non-uterine leiomyosarcoma

Leiomyosarcomas account for ~24% of all adult sarcomas, and develop predominantly either in the uterus [uterine leiomyosarcoma (ULMS)] or in deep soft tissue or the retroperitoneum [non-uterine leiomyosarcoma (NULMS)]. Leiomyosarcomas are relatively chemoresistant tumors, and the prognosis of patients with leiomyosarcomas is poor. Cancer-testis (CT) antigens are considered promising immunotherapeutic targets because of their restricted expression in normal tissue, except in the testis. Little is known about the expression of CT antigens in leiomyosarcomas. In the present study, the protein expression of the CT antigens MAGE family member A (MAGEA)1, MAGEA3, MAGEA4, G antigen 7 (GAGE7) and cancer/testis antigen 1 (NY-ESO-1) in ULMS and NULMS were investigated using immunohistochemistry (IHC), and their expression profiles compared. In ULMS and NULMS, positive expression was observed in 11/32 (31%) and 1/31 (3%; MAGEA1), 15/32 (47%) and 5/31 (16%; MAGEA3), 11/32 (34%) and 3/31 (10%; MAGEA4), 23/32 (72%) and 11/31 (35%; GAGE7) and 3/32 (9%) and 0/31 (0%; NY-ESO-1), respectively. The ULMSs demonstrated significantly higher positive expression of MAGEA1 (P=0.0034), MAGEA3 (P=0.0141), MAGEA4 (P=0.0319) and GAGE7 (P=0.0054) compared with the NULMSs. The ULMSs also had significantly higher IHC scores for MAGEA1 (P=0.0023), MAGEA3 (P=0.0474), MAGEA4 (P=0.011), GAGE7 (P=0.0319) and NY-ESO-1 (P=0.0437). The results of the present study support the potential utility of MAGEA1, MAGEA3, MAGEA4 and GAGE7 in ULMS and GAGE7 in NULMS as immunotherapeutic targets.

MAGEA4 expression in bone and soft tissue tumors: its utility as a target for immunotherapy and diagnostic marker combined with NY-ESO-1

Cancer-testis (CT) antigens have promise as targets for immunotherapy, because of their restricted expression in tumor or testis tissue. MAGEA4 is both a MAGE family member and a CT antigen, and has attracted attention as a potential immunotherapeutic target. We investigated MAGEA4 expression by immunohistochemistry in bone and soft tissue tumor specimens that consisted of 35 malignant or intermediate and 24 benign histological subtypes, in order to evaluate its possible utility as an immunotherapy target and its potential use as a diagnostic marker when combined with another CT antigen, NY-ESO-1. Among these tumors, MAGEA4 was detected in 82.2% of synovial sarcomas, 67.7% of myxoid liposarcomas, 43.8% of osteosarcomas, 41.4% of angiosarcomas, 24.6% of malignant peripheral nerve sheath tumors (MPNSTs), and 21.4% of chondrosarcomas. NY-ESO-1 expression was found in 88.2% of myxoid liposarcomas, 61.1% of synovial sarcomas, 31.3% of osteosarcomas, 21.4% of pleomorphic liposarcomas, 16.7% of desmoplastic small round cell tumors, and 14.3% of chondrosarcomas. Benign tumors and non-tumorous tissue, except for testis tissue, did not express MAGEA4 or NY-ESO-1. Combined use of MAGEA4 and NY-ESO-1 increased the sensitivity, specificity, positive predictive values, and negative predictive values for distinguishing synovial sarcoma from spindle cell tumors and other mimicking tumors, compared to individual use of MAGEA4 or NY-ESO-1. Our results support the immunotherapy targeting MAGEA4 or NY-ESO-1 can be an ancillary therapy in the above-mentioned tumors, and the potential utility of MAGEA4 as an ancillary diagnostic marker for synovial sarcoma combined with NY-ESO-1.

Overexpressed PRAME is a potential immunotherapy target in sarcoma subtypes

Background

PRAME (preferentially expressed antigen in melanoma), a member of the cancer-testis antigen family, has been shown to have increased expression in solid tumors, including sarcoma, and PRAME-specific therapies are currently in development for other cancers such as melanoma.

Methods

To map the landscape of PRAME expression in sarcoma, we used publicly available data from The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE) projects and determined which sarcoma subtypes and subsets are associated with increased PRAME expression. We also analyzed how PRAME expression correlates with survival and expression of markers related to antigen presentation and T cell function. Furthermore, tumor and normal tissue expression comparisons were performed using data from the genotype-tissue expression (GTEx) project.

Results

We found that uterine carcinosarcoma highly overexpresses the PRAME antigen, and synovial sarcomas and multifocal leiomyosarcomas also show high expressions suggesting that PRAME may be an effective target of immunotherapies of these tumors. However, we also discovered that PRAME expression negatively correlates with genes involved in antigen presentation, and in synovial sarcoma MHC class I antigen presentation deficiencies are also present, potentially limiting the efficacy of immunotherapies of this malignancy.

Conclusions

We determined that uterine carcinosarcoma, synovial sarcoma, and leiomyosarcoma patients would potentially benefit from PRAME-specific immunotherapies. Tumor escape through loss of antigen presentation needs to be further studied.

Time-dependent transition of the immunoglobulin G subclass and immunoglobulin E response in cancer patients vaccinated with cholesteryl pullulan-melanoma antigen gene-A4 nanogel

A phase I+II clinical trial of vaccination with MAGE-A4 protein complexed with cholesteryl pullulan melanoma antigen gene-A4 nanogel (CHP-MAGE-A4) is currently underway in patients with MAGE-A4-expressing cancer. In the present study, the primary phase I endpoint was to test the safety of the administration of 300 µg CHP-MAGE-A4 with and without OK-432. Another aim of the study was to clarify the details of the specific humoral immune response to vaccination. The 9 patients enrolled for phase I were vaccinated 6 times, once every 2 weeks: 3 patients with 100 µg and 3 patients with 300 µg CHP-MAGE-A4, and 3 patients with 300 µg CHP-MAGE-A4 plus 0.5 clinical units of OK-432. Toxicities were assessed using Common Terminology Criteria for Adverse Events v3.0. Clinical response was evaluated by modified Response Evaluation Criteria in Solid Tumours. Immunological monitoring of anti-MAGE-A4-specific antibodies was performed by ELISA of pre- and post-vaccination patient sera. The 6 vaccinations produced no severe adverse events. Stable disease was assessed in 4/9 patients. Anti-MAGE-A4 total immunoglobulin (Ig)G titers increased in 7/9 patients. Efficacious anti-MAGE-A4 IgG1, 2 and 3 antibody responses were observed in 7/9 patients. Among them, positive conversions to T helper 2 (Th2)-type antibody responses (IgG4 and IgE) were observed after frequent vaccination in 4/7 patients. The Th2 conversion was possibly associated with undesirable clinical observations, including progressive disease and the appearance of a new relapse lesion. The present study suggested that frequent vaccinations activated a Th2-dominant status in the cancer patients. The identification of a time-dependent IgG subclass and IgE antibody production during vaccination protocols may be a useful surrogate marker indicating a potentially undesirable change of the immunological environment for an effective antitumor immune response in cancer patients.

Immunotherapy in endometrial cancer - an evolving therapeutic paradigm

Endometrial cancer is the only gynecologic malignancy with a rising incidence and mortality. While cure is routinely achieved with surgery alone or in combination with adjuvant pelvic radiotherapy when disease is confined to the uterus, patients with metastatic or recurrent disease exhibit limited response rates to cytotoxic chemotherapy, targeted agents, or hormonal therapy. Given the unmet clinical need in this patient population, exploration of novel therapeutic approaches is warranted, and attention is turning to immunomodulation of the tumor microenvironment. Existing evidence suggests that endometrial cancer is sufficiently immunogenic to be a reasonable candidate for active and/or passive immunotherapy. In this review, we critically examine what is known about the microenvironment in endometrial cancer and what has been learned from preliminary immunotherapy trials that enrolled endometrial cancer patients, encouraging further attempts at immunomodulation in the treatment of aggressive forms of this disease.

miR-888: A Novel Cancer-Testis Antigen that Targets the Progesterone Receptor in Endometrial Cancer

Cancer-testis (CT) antigens are a large family of genes that are selectively expressed in human testis germ cells, overexpressed in a variety of tumors and predominantly located on the X chromosome. To date, all known CT antigens are protein-coding genes. Here, we identify miR-888 as the first miRNA with features characteristic of a CT antigen. In a panel of 21 normal human tissues, miR-888 expression was high in testes and minimal or absent in all other examined tissues. In situ hybridization localized miR-888 expression specifically to the early stages of sperm development within the testes. Using The Cancer Genome Atlas database, we discovered that miR-888 was predominately expressed in endometrial tumors, with a significant association to high-grade tumors and increased percent invasion. In a separate panel of endometrial tumor specimens, we validated overexpression of miR-888 by real-time polymerase chain reaction. In addition, miR-888 expression was highest in endometrial carcinosarcoma, a rare and aggressive type of endometrial tumor. Moreover, we identified the progesterone receptor (PR), a potent endometrial tumor suppressor, as a direct target of miR-888. These data define miR-888 as the first miRNA CT antigen and a potential mediator of an aggressive endometrial tumor phenotype through down-regulation of PR.

The biology of uterine sarcomas: A review and update

Uterine sarcoma is a rare neoplasm, accounting for only 5% of uterine malignancies. The pathogenesis of uterine sarcoma remains largely unknown, although recent basic science and pre-clinical animal models have provided a better understanding of tumor biology. The aim of this study was to review the clinical features, imaging characteristics, genetic aberrations and therapeutic approaches in uterine sarcoma. This study reviewed the English-language literature on clinical and basic studies on uterine sarcoma. The common variants of uterine sarcoma are carcinosarcoma, leiomyosarcoma and endometrial stromal sarcoma (ESS). Genetic profiling efforts have identified amplification, overexpression and mutation, while the molecular mechanisms of tumorigenesis driven by these genomic and genetic aberrations have yet to be fully elucidated yet. Recent genome-wide studies have also identified complex chromosomal rearrangements as oncogenic mechanisms. The cell cycle regulators, p16 and p53, are frequently over-expressed and appear to be involved in key modifications of sarcomagenesis. Molecular-targeted therapy has now been evaluated in clinical trials for certain subtypes. In conclusion, aberrations of cell cycle control would be a critical step in the development of uterine sarcoma. This review has provided new areas of study targeting molecular and genetic pathways.

Immune effects of trastuzumab

Trastuzumab's targeted therapy has become a stronghold for human epidermal growth factor receptor 2 positive breast cancer patients. This humanized monoclonal antibody binds to the extracellular juxta-membrane domain of HER2 and inhibits the proliferation and survival of HER2 dependent cancer cells. The ways by which this molecule exerts its action have been partially elucidated but several new mechanisms are being constantly identified. Several new agents are being introduced that interfere with HER2. Several new immunotherapy strategies are being introduced in order to direct the immune system against cells and tissues that aberrantly overexpressed HER2. We review the strategies currently adopted and those suggested against HER2 expressing tumors.

Immunomodulation in endometrial cancer

Endometrial cancer is the most frequent gynecological cancer and the fourth most common cancer in women in the developed world. Over the last decade, immunotherapy has been the focus of intense investigation as a form of cancer treatment whereby the treatment initiates a host immune response ultimately eradicating the tumor. It has been suggested that in endometrial cancer and many other forms of cancer, immunosuppression poses a significant obstacle at inducing antitumor immunity by immunotherapy. This review will look at the different studies that have identified immunomodulation of T cells, cytokines and macrophages, and regulation of apoptotic and angiogenic factors in endometrial cancer patients that may contribute to the inefficiency of immunotherapy.

Global expression analysis of cancer/testis genes in uterine cancers reveals a high incidence of BORIS expression

PURPOSE

Cancer/testis (CT) genes predominantly expressed in the testis (germ cells) and generally not in other normal tissues are aberrantly expressed in human cancers. This highly restricted expression provides a unique opportunity to use these CT genes for diagnostics, immunotherapeutic, or other targeted therapies. The purpose of this study was to identify those CT genes with the greatest incidence of expression in uterine cancers.

EXPERIMENTAL DESIGN

We queried the expression of known and putative CT gene transcripts (representing 79 gene loci) using whole genome gene expression arrays. Specifically, the global gene expressions of uterine cancers (n = 122) and normal uteri (n = 10) were determined using expression data from the Affymetrix HG-U133A and HG-U133B chips. Additionally, we also examined the brother of the regulator of imprinted sites (BORIS) transcript by reverse transcription-PCR and quantitative PCR because its transcript was not represented on the array.

RESULTS

Global microarray analysis detected many CT genes expressed in various uterine cancers; however, no individual CT gene was expressed in more than 25% of all cancers. The expression of the two most commonly expressed CT genes on the arrays, MAGEA9 (24 of 122 cancers and 0 of 10 normal tissues) and Down syndrome critical region 8 (DSCR8)/MMA1 (16 if 122 cancers and 0 of 10 normal tissues), was confirmed by reverse transcription-PCR methods, validating the array screening approach. In contrast to the relatively low incidence of expression of the other CT genes, BORIS expression was detected in 73 of 95 (77%) endometrial cancers and 24 of 31 (77%) uterine mixed mesodermal tumors.

CONCLUSIONS

These data provide the first extensive survey of multiple CT genes in uterine cancers. Importantly, we detected a high frequency of BORIS expression in uterine cancers, suggesting its potential as an immunologic or diagnostic target for these cancers. Given the high incidence of BORIS expression and its possible regulatory role, an examination of BORIS function in the etiology of these cancers is warranted.

Cancer/testis antigen MAGE-A4 expression pattern differs in epithelial skin tumors of organ-transplant recipients and immunocompetent patients

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.

Directions in the immune targeting of cancer: lessons learned from the cancer-testis Ag NY-ESO-1

Since the early 1990s, numerous cancer Ag have been defined and for a handful of these there is now some clinical experience, which has made it possible to assess their value as targets for cancer immunotherapy. The cancer-testis Ag have been particularly attractive because their expression is limited to cancer and virtually no non-malignant cells apart from germ cells and trophoblast. Among these, NY-ESO-1 has been the focus of our attention. The exceptional immunogenicity of this Ag coupled with its widespread distribution among many cancer types make it a very good vaccine candidate, with the potential to be used in vaccines against many types of malignancies. This article reviews emerging knowledge about the biology of NY-ESO-1 and experience with the early clinical development of vaccines directed against NY-ESO-1. These early studies have yielded a wealth of information about the immunology of NY-ESO-1 and set the scene for future clinical strategies for immune targeting of cancer.

Frequent Immune Responses to a Cancer/Testis Antigen, CAGE, in Patients with Microsatellite instability–Positive Endometrial Cancer

PURPOSE

Identification of cancer/testis antigens useful for diagnosis or immunotherapy of cancers was attempted by cDNA expression cloning with patients' sera (SEREX).

EXPERIMENTAL DESIGN

cDNA expression libraries made from testis or endometrial cancer cell lines were screened using sera from patients with endometrial cancer or melanoma patients immunized with dendritic cells pulsed with autologous tum or lysates. Tissue-specific expression by RT-PCR and immunogenicity by Western blotting of the bacterial recombinant antigen with sera from cancer patients were evaluated.

RESULTS

A cancer/testis antigen, CAGE, was isolated by two independently performed SEREX. CAGE was expressed in various cancer cell lines including endometrial cancer, colon cancer, and melanoma in 7 of 10 endometrial cancer tissues and in 1 of 3 atypical endometrial hyperplasia, but not in normal tissues including the endometrium and testis. The protein expression on cancer cells was confirmed by Western blot analysis with the recombinant CAGE protein, anti-CAGE IgG antibody was detected in sera from 5 of 45 endometrial cancer, 2 of 24 melanoma, and 2 of 33 colon cancer patients, but not in sera from healthy individuals. By ELISA analysis, anti-CAGE antibody was detected in 12 of 45 endometrial cancer, 2 of 20 melanoma, and 4 of 33 colon cancer patients. Intriguingly, anti-CAGE antibody was highly positive in 7 of the 13 (53.8%) microsatellite instability (MSI)-H patients with endometrial cancer, but negative in 20 non-MSI-H patients (P = 0.001).

CONCLUSION

CAGE may be useful for immunotherapy and diagnosis of various cancers particularly MSI-positive endometrial cancer.

NY-ESO-1 expression and immunogenicity in esophageal cancer

PURPOSE

Although NY-ESO-1 was isolated from an esophageal carcinoma patient, its expression in this type of cancer and its immunogenicity in esophageal cancer patients have not yet been fully elucidated. We report here the frequency of NY-ESO-1 mRNA and protein expression in esophageal cancer and the presence of NY-ESO-1-specific immune response in patients.

EXPERIMENTAL DESIGN

One hundred twenty three esophageal squamous cell carcinoma specimens were analyzed for the expression of NY-ESO-1 mRNA by conventional and real-time reverse transcription-PCR and the expression of protein by immunohistochemistry and Western blot. Sera and peripheral blood lymphocytes from 51 patients were analyzed for the NY-ESO-1 antibody production by enzyme-linked immunosorbent assay and NY-ESO-1 T cell response by enzyme-linked immunospot assay. Survival analyses were also performed.

RESULTS

NY-ESO-1 mRNA was expressed in 41 of 123 (33%) esophageal squamous cell carcinoma specimens, and its expression was found at higher frequency in well-differentiated and moderately differentiated type of cancer. No mRNA copy was detected in any of the adjacent normal tissues. Twenty-one of 24 (87.5%) NY-ESO-1 mRNA-positive tumors were stained positively by immunohistochemistry. Correlation between the level of NY-ESO-1 mRNA expression and the degree of immunohistochemistry positivity was observed. Antibody production was observed in 2 patients with tumors that showed protein expression. Furthermore, a CD8 T-cell response against NY-ESO-1 was observed in 1 of the 2 seropositive patients.

CONCLUSIONS

The high expression frequency of NY-ESO-1 mRNA and protein indicates NY-ESO-1 as a feasible vaccine target in esophageal cancer.

Intratumoral CD8+ T lymphocytes as a prognostic factor of survival in endometrial carcinoma

PURPOSE

CTLs are a prominent immune component infiltrating many solid tumors. These cells are considered to be a manifestation of host-immune response to the tumor; however, their prognostic significance remains a subject of considerable debate. The objective of this study was to evaluate the distribution pattern and prognostic value of CD8(+) T cells in endometrial carcinoma.

EXPERIMENTAL DESIGN

We studied 90 cases of endometrial carcinoma, including 75 endometrioid and 15 papillary serous carcinomas. Immunohistochemical staining for CD8 and granzyme B was performed on paraffin-embedded sections. The number of immunohistochemically staining CD8(+) T cells was enumerated in the following four regions: lymphocytes infiltrating the tumor epithelium at the invasive border, within the underlying tumor stroma, within the superficial tumor epithelium, and in the perivascular areas of the myometrium.

RESULTS

Patients with >10 CD8(+) T lymphocytes/high-power field within the tumor epithelium at the invasive border displayed improved overall survival compared with patients with fewer intraepithelial CD8(+) T lymphocytes (87 and 50%, respectively; P = 0.027). Multivariate analysis revealed that stage, vascular invasion, grade, and the number of intraepithelial CD8(+) T lymphocytes at the invasive border were the only independent predictors of survival (P < 0.0001, P = 0.001, P = 0.011, and P = 0.025, respectively). Granzyme B(+) cytoplasmatic granules were detected in a high proportion of CTLs, confirming their activated cytotoxic phenotype.

CONCLUSIONS

Our study demonstrates for the first time that increased numbers of CTLs at the invasive border may be a reliable independent prognostic factor of survival in patients with endometrial carcinoma.

Expression of cancer-testis antigens in endometrial carcinomas using a tissue microarray

Cancer-testis (CT) antigens are expressed in a variety of malignant tumors, but in normal adult tissue, they are only expressed in testicular germ cells. Owing to this tumor-associated expression pattern, these antigens are of major interest as potential targets for immunotherapy and possibly for diagnostic purposes. This study was performed to analyze the expression of four CT antigens, NY-ESO-1, MAGE-A3, MAGE-A4, and CT7/MAGE-C1, in endometrial carcinoma using immunohistochemistry, and to correlate expression with histologic subtypes, grade, and expression of WT1 and p53. Formalin-fixed paraffin-embedded tissues of 130 endometrial carcinomas of the following types and grades were analyzed using a tissue microarray: 85 endometrioid carcinomas (FIGO grade 1, 39; grade 2, 11; and grade 3, 35), 18 papillary serous carcinomas, 12 clear cell carcinomas, 13 malignant mixed mullerian tumors, one mucinous adenocarcinoma, and one undifferentiated carcinoma. The following anti-CT monoclonal antibodies/antigens were studied by immunohistochemistry: monoclonal antibody ES121/NY-ESO-1, monoclonal antibody M3H67/MAGE-A3, monoclonal antibody 57B/MAGE-A4, and monoclonal antibody CT7-33/CT7. The CT expression data were compared to WT1 and p53 protein expression as analyzed in a previous study. Positive staining with anti-CT monoclonal antibodies was graded as follows: focal, <5% positive cells; 1+, 5-25% cells; 2+, 26-50% cells; 3+, 51-75%; and 4+, >75% cells. The 3+ and 4+ staining patterns were considered homogeneous patterns of potential clinical significance and were scored positive for statistical analysis. In low-grade tumors, the most immunoreactivity was seen with mAb M3H67 but little labeling was observed with the other monoclonal antibodies. In high-grade tumors, monoclonal antibodies M3H67 (25%), 57B (23%), and CT7-33 (20%) showed the highest reactivity, while ES121 showed the lowest immunoreactivity (6%). The staining pattern was mostly heterogeneous. Statistical significance was found solely for the correlation of monoclonal antibody 57B staining and p53 expression. No correlation was found for any anti-CT monoclonal antibody staining and clinical stage or for anti-CT staining and WT1 expression. CT antigens CT7, MAGE-A3 and MAGE-A4, but not NY-ESO-1, are expressed in high-grade endometrial carcinomas, and expression of MAGE-A4 is correlated with the presence of overexpressed p53.

The anti-MAGE antibody B57 as a diagnostic marker in melanocytic lesions

The differentiation of melanoma from certain benign melanocytic lesions on histologic grounds alone may sometimes be difficult. The anti-MAGE antibody 57B was suggested to be a useful adjunct in differentiating melanoma from nevi. Our aim was to study MAGE immunoreactivity with B57 in benign melanocytic lesions that have not been investigated to this end so far. One hundred six benign melanocytic lesions were stained with the monoclonal antibody 57B. They included deep-penetrating nevus (n = 6), desmoplastic nevus (n = 9), halo nevus (n = 10), persistent melanocytic nevus (n = 12), common blue nevus (n = 17), cellular blue nevus (n = 8), cellular blue nevus with microalveolar pattern (n = 3), desmoplastic cellular blue nevus (n = 6), epithelioid blue nevus (n = 2), sclerotic blue nevus (n = 3), and clonal nevus (n = 30). Fifty-two lesions (49%) demonstrated various patterns of MAGE immunoreactivity, with clonal nevi and deep-penetrating nevi showing the most consistent staining. In conclusion, MAGE immunoreactivity detected by the monoclonal antibody 57B in formalin-fixed, paraffin-embedded tissue can be observed in benign melanocytic lesions, and therefore this antibody cannot be used in the differential diagnosis between melanoma and nevi.