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

Detection of MAGE and SSX gene expressions by RT-nested PCR using common primers in head and neck cancer

Objectives

The melanoma antigen gene (MAGE) and synovial sarcoma on X chromosome (SSX) gene families are silent in most normal adult tissues, but are expressed in a variety of malignant lesions. Therefore, detection of MAGE and SSX transcription may be useful for the diagnosis of head and neck cancers. The aim of this study is to detect MAGE and SSX gene transcripts of head and neck cancers using the MAGE 1-6 assay and the SSX 1-9 assay.

Methods

The transcripts of MAGE 1-6 and SSX 1-9 genes were detected by the MAGE 1-6 assay and the SSX 1-9 assay respectively, in cancer cell lines, cancer tissue, and induced sputum specimens from head and neck cancer patients.

Results

The transcripts of MAGE 1-6 and SSX 1-9 genes were detected in 82.8% and 75.9% of head and neck cancer tissues (N=29) respectively, and 96.6% of cancer tissues expressed at least one of MAGE 1-6 or SSX 1-9 genes. In the induced sputum of head and neck cancer patients (N=18), the transcripts of MAGE 1-6 and SSX 1-9 genes were detected in 72.2% and 77.8%, respectively, and 94.4% of the sputum specimens were positive for either the MAGE 1-6 or the SSX 1-9 assay.

Conclusion

These results suggest that the combination of MAGE 1-6 and SSX 1-9 assays may be useful in the diagnosis of head and neck cancer.

Cancer-testis (CT) antigen expression in medulloblastoma

Medulloblastoma is the most common childhood malignant tumor of the central nervous system. Treatment of medulloblastoma requires harmful therapy and nevertheless carries a poor prognosis. Due to their presence in various cancers and their limited expression in normal tissues, CT antigens are ideal vaccine targets for tumor immunotherapy. CT antigens, such as MAGE and NY-ESO-1, have been employed in clinical trials in various malignancies but little is known about their presence in medulloblastoma. We analyzed 25 medulloblastomas for the expression of a panel of CT antigens by RT-PCR and immunohistochemistry. Messenger RNA expression in the samples was as follows: GAGE 64%, MAGEA3/6 56%, SYCP1 44%, SLCO6A1 32%, MAGEC1 28%, MAGEC2 28%, MAGEA4 28%, NY-ESO-1 20%, MAGEA1 16%, and TPTE 0%. All cases except one (96%) were positive for mRNA expression of at least one CT gene. However, CT antigen expression was scarce on a protein level. Immunoreaction to monoclonal antibody E978 (NY-ESO-1) was negative in all cases; MA454 (MAGEA1), 57B (MAGEA4), M3H67 (MAGEA3/6), CT10#5 (MAGEC2) and #23 (GAGE) were each positive in 1 case, while the highest incidence of positive immunostaining, albeit heterogeneous, was seen with CT7-33 (MAGEC1) in 3 out of the 25 cases. The absence of correlation between mRNA and protein expression in medulloblastoma has not been observed in other tumors and further studies addressing the biology of CT antigens are necessary to investigate the present discrepant results.

Efficient identification of a novel cancer/testis antigen for immunotherapy using three-step microarray analysis

Advanced technology in molecular biology has provided us powerful tools for the diagnosis and treatment for cancer. We herein adopted a new methodology to identify a novel cancer/testis (CT) antigen with high frequency of expression in colorectal cancer as follows: (a) combining laser microdissection and cDNA microarray was used to analyze the gene expression profile of colorectal cancer cells; (b) genes overexpressed in testis and underexpressed in normal colon epithelium were analyzed using cDNA microarray; and (c) the gene expression profile of colorectal cancer cells was compared with that of normal testis. Using this methodology, we selected 38 candidates for CT antigen. Among these genes, we identified a novel CT antigen, serine/threonine kinase 31 (STK31), which was previously reported as a gene expressed in spermatogonia. Reverse transcription-PCR analysis showed that STK31 gene expression levels in cancer samples were significantly higher (P < 0.0001) than those in normal samples. The STK31 gene was frequently expressed not only in colorectal cancer but also in gastric and esophageal cancer. Moreover, STK31 peptide was able to elicit specific CTLs and induced CTLs lysed either peptide-loading or endogenously STK31-expressing target cells. These results showed that the new methodology in this study facilitated identification of CT antigens and that STK31 may be a candidate for cancer immunotherapy against gastrointestinal cancer.

Breast cancer is a promising target for vaccination using cancer-testis antigens known to elicit immune responses

INTRODUCTION

Cancer-testis antigens (CTAGs) are expressed solely in germ cells and in malignant tissues. They are targets of immune responses mediated by cytotoxic T cells in some cancers, and there is much interest in developing vaccines that induce these responses. The purpose of the present study was to ascertain the frequency of expression of CTAGs in breast cancer.

METHODS

Breast tumours were collected sequentially in the Southampton Tumour Bank from donors who had given written informed consent. Stored samples where there was sufficient material were sampled in sequence. An initial series of 42 tumours was screened for expression of 17 different CTAGs. A second panel of 40 tumours was screened for the expression of those antigens present in the first panel.

RESULTS

Ninety-three per cent of tumours in the first series expressed at least one CTAG, and 62% expressed the single antigen CTAG1. Eighty per cent of tumours in the second series expressed at least one CTAG, 50% expressing CTAG1. Tumours exhibiting higher risk features tended to express more CTAGs.

CONCLUSION

More than two-thirds of breast cancers would be covered by a vaccine directed against just three CTAGs - CTAG1, BAGE1, and MAGEA10 - all of which are known to be targets of cytotoxic-T-lymphocyte responses.

Identification of a common HLA-A*0201-restricted epitope among SSX family members by mimicking altered peptide ligands strategy

The synovial sarcoma X breakpoint (SSX) gene family contains nine members. The SSX proteins are CT (cancer/testis) antigens and can be expressed in many tumor types. T cell immune response against SSX protein can be detected in tumor patients and mice expressing any SSX. Screening predominant protective epitopes might improve the low immunogenicity against these "self" CT antigens. Herein, we predicted HLA-A*0201-restricted epitopes for all nine SSX family members, followed by validation with epitope molecular modeling, peptide/HLA-A*0201 affinity, and binding stability assays. We obtained four highly homologous candidate epitopes with the high immunogenicity scores designated P1, P4, P5 and P6, from the nine SSX members. Each of the four candidates could elicit strong epitope-specific CTL immune responses, but P4 could evoke more interferon gamma (IFN-gamma)-producing T cells and more potent CTLs that could lyse more target cells. Importantly, almost all of the four epitopes induced CTLs could cross-lyse the mutual targets both in vitro in human PBMCs and HLA-A2.1/K(b) transgenic mice, but P4 showed superiority to other epitopes in term of cross-cytolysis. All of these results demonstrate that P4 can induce anti-tumor immunity in a fashion superior to other candidates, and may be the "common" CTL epitope among all SSX-expressing tumors. Due to its documented responses herein, P4 has potential application in peptide-mediated immunotherapy.

MAD-CT-2 identified as a novel melanoma cancer-testis antigen using phage immunoblot analysis

One focus in the field of tumor immunology is the identification of cancer-specific antigens that might be exploited as therapeutic targets or as immunologic diagnostic markers. Cancer-testis antigens (CTAs) are of particular interest as potential target antigens given that their expression is typically restricted to germ cells among normal tissues, but aberrantly expressed in multiple tumor types. In the current report, we sought to evaluate serum antibody immune responses to a defined panel of CTA from multiple antigen families to identify potential tumor-specific antigens that could potentially serve as candidate target antigens for immunotherapy or diagnostic purposes. This was conducted by screening sera from male patients with metastatic melanoma (n=44) and volunteer blood donors (n=50) against a panel of lambda phage-encoded CTA. We found that IgG antibody responses occurred in 39% of patients with melanoma to at least one of these antigens compared with 4% of controls (P<0.001). We found antibody responses to one antigen, MAD-CT-2, occurred in 27% of patients compared with 0/50 controls (P<0.0001). These findings, along with the demonstration that MAD-CT-2 is expressed in melanoma cell lines, identified MAD-CT-2 as a novel melanoma CTA.

Identification of a novel NY-ESO-1 promiscuous helper epitope presented by multiple MHC class II molecules found frequently in the Japanese population

NY-ESO-1 is a cancer-testis antigen that elicits strong cellular and humoral immune responses against NY-ESO-1-expressing tumors. Although CD4(+) T cells play a critical role in inducing antitumor immunity, little is known about MHC class II-restricted helper epitopes of the NY-ESO-1 antigen compared with MHC class I-restricted epitopes. Here, we searched for new NY-ESO-1 helper epitopes presented by MHC class II molecules, especially those found frequently in the Japanese population. We established five NY-ESO-1-specific helper T-cell lines from healthy Japanese donors using NY-ESO-1 recombinant protein and peptide. Using MHC class II-specific antibodies and a panel of Epstein-Barr virus-transformed B-cell lines, it was demonstrated that four out of the five T-cell lines recognized a region within NY-ESO-1(119-143) in the context of HLA-DRB1*0802, DRB1*0901, DRB1*1502 or DRB1*0405/*0410. In addition, using a set of overlapping 15-mer synthetic peptides, we found that NY-ESO-1(122-138) was a promiscuous region that bound to four distinct HLA-DR molecules found in the Japanese population. These findings expand the usefulness of NY-ESO-1 as a tool for tumor vaccine therapy in eliciting NY-ESO-1-specific helper T-cell responses, especially in Japanese cancer patients.

Detection of lung cancer using MAGE A1-6 and SSX4 RT-PCR expression profiles in the bronchial wash fluid

PURPOSE

Bronchial wash fluid may be a useful for detecting lung cancer. To increase the detection rates, we performed molecular analysis with using MAGE A1-6 and SSX4 RT-PCR on bronchial wash fluid specimens.

MATERIALS AND METHODS

We obtained 57 lung cancer tissue specimens by bronchoscopic biopsy and 131 bronchial washes from 96 patients with lung cancer and 35 patients with benign lung diseases. The MAGE A1-6 and SSX4 gene expressions were investigated in the cancer tissue specimens and bronchial wash fluids. We evaluated the positive detection rates of these methods according to the cytology results and the clinical findings.

RESULTS

For the cancer tissue specimens and the bronchial wash fluid, the positive detection rate of MAGE or SSX4 was 91.2% and 75.0%, respectively. Combined MAGE and SSX4 PCR and cytology tests showed an 83.3% detection rate for the bronchial wash fluid. From bronchial washes of patients with benign lung diseases, the positive rates of using MAGE or SSX4 was 11.4%. In the bronchial wash fluid of lung cancer patients, 66.7% of the peripheral cancers were detected by MAGE or SSX4, while examination with cytology did not detect any peripheral lung cancer.

CONCLUSION

The application of both MAGE and SSX4 showed high sensitivity and specificity for the detection of lung cancer. Thus, MAGE and SSX4 RT-PCR may be effectively utilized as additional methods to improve detection of lung cancer with using bronchial wash fluids.

Antibody response against NY-ESO-1 in CHP-NY-ESO-1 vaccinated patients

NY-ESO-1 specific humoral responses are frequently observed in patients with various types of NY-ESO-1 antigen expressing tumors. In a large proportion of NY-ESO-1 antibody-positive patients of NY-ESO-1-specific CD8 T-cells can also be detected suggesting that monitoring of the NY-ESO-1 specific humoral immune response may be a relevant and more practical surrogate for estimating the overall immune response against NY-ESO-1 in clinical vaccine studies. We have immunized 9 cancer patients with full length NY-ESO-1 protein formulated with cholesterol-bearing hydrophobized pullulan (CHP-NY-ESO-1) and investigated the humoral immune responses against NY-ESO-1. Seven patients were NY-ESO-1 antibody-negative and 2 patients were positive prior to vaccination. Vaccination with CHP-NY-ESO-1 resulted in the induction or increase of NY-ESO-1 antibody responses in all 9 patients immunized. Epitope analysis revealed 5 regions in the NY-ESO-1 protein molecule that were recognized by antibodies induced after vaccination. The 5 regions were also recognized by antibodies present in nonvaccinated, NY-ESO-1 antibody-positive cancer patients. A peptide spanning amino acids 91-108 was recognized in 6 out of 9 vaccinated patients and in 8 out of 9 nonvaccinated, sero-positive patients, being the most dominant antigenic epitope in NY-ESO-1 for antibody recognition in cancer patients. In conclusion, we showed that CHP-NY-ESO-1 protein vaccination had a potent activity for inducing humoral immune responses against NY-ESO-1 antigen in cancer patients. The antigenic epitopes recognized by antibodies in the vaccinated patients were similar to those recognized in cancer patients with spontaneous humoral immunity against NY-ESO-1.

CABYR Is a Novel Cancer-Testis Antigen in Lung Cancer

PURPOSE

Cancer-testis (CT) antigens are often expressed in a proportion of tumors of various types. Their restricted normal tissue expression and immunogenicity make them potential targets for immunotherapy. CABYR is a calcium-binding tyrosine phosphorylation-regulated fibrous sheath protein initially reported to be testis specific and subsequently shown to be present in brain tumors. This study was to determine whether CABYR is a novel CT antigen in lung cancer.

EXPERIMENTAL DESIGN

mRNA expression of CABYR-a/b (combination of CABYR-a and CABYR-b) and CABYR-c was examined in 36 lung cancer specimens, 14 cancer cell lines, and 1 normal cell line by conventional and real-time reverse transcription-PCR. Protein expression of CABYR was analyzed in 50 lung cancer tissues by immunohistochemistry. Antibodies specific to CABYR were analyzed in sera from 174 lung cancer patients and 60 healthy donors by ELISA and Western blot.

RESULTS

mRNA expression of CABYR-a/b and CABYR-c was observed, respectively, in 13 and 15 of 36 lung cancer tissues as well as in 3 and 5 of 14 cancer cell lines, whereas neither of them was observed in adjacent noncancerous tissues or the normal cell line. Protein expression of CABYR-a/b and CABYR-c was observed, respectively, in 20 and 19 of 50 lung cancer tissues. IgG antibodies specific to CABYR-a/b and CABYR-c were detected, respectively, in 11% and 9% of sera from lung cancer patients but not from the 60 healthy donors.

CONCLUSION

CABYR is a novel CT antigen in lung cancer and may be a promising target for immunotherapy for lung cancer patients.

Opa interacting protein 5 (OIP5) is a novel cancer-testis specific gene in gastric cancer

BACKGROUND

Identification of novel cancer-specific antigens is important for the advancement of immunotherapy. Our aim was to identify cancer-specific genes in gastric cancer.

METHODS

Using cDNA microarray analysis, we detected genes overexpressed specifically in gastric cancer cells. The expression levels of selected genes, including OIP5, was confirmed by real time RT-PCR analysis in tumor/normal paired bulk samples of 58 clinical cases. The expression levels of selected genes in normal tissues were also determined with a human total RNA master panel. We also compared the expression status of OIP5 with that of the other known cancer-testis specific genes.

RESULTS

Twenty-two genes were determined to be upregulated in gastric cancer cells. Among these, three genes (CDC6, Exo1, and OIP5) were selected and confirmed to be upregulated in the tumor tissue compared to normal tissue. A human total RNA master panel demonstrated that OIP5, but not Exo1 or CDC6, showed high specificity in testis. Thus OIP5 may be considered a cancer-testis specific gene. In 58 clinical cases of gastric cancer examined, we found OIP5 gene expression in 27 cases (47%). Thirteen of these 27 cases showed no expression of the known cancer specific genes such as MAGE-1, MAGE-3 or NY-ESO-1.

CONCLUSIONS

Using a combination of LMD and microarray, we identified OIP5 as a cancer-testis specific gene. Further expression analysis in a set of clinical cases revealed that OIP5 may be a novel immunotherapy target for patients with gastric cancer.

Analysis of the mononuclear inflammatory cell infiltrate in the normal breast, benign proliferative breast disease, in situ and infiltrating ductal breast carcinomas: preliminary observations

BACKGROUND

Mammary carcinogenesis is a multistep process entailing the transition from normal breast to benign proliferative breast disease (ductal hyperplasia) to ductal carcinoma in situ to infiltrating ductal carcinoma.

HYPOTHESIS

These transitions are associated with changes in the mononuclear inflammatory cell infiltrate.

MATERIALS AND METHODS

A total of 53 mastectomy specimens of normal breast, benign proliferative breast disease, ductal carcinoma in situ and infiltrating ductal carcinoma were evaluated for mononuclear inflammatory cell infiltrate by using immunohistological methods and monoclonal antibodies including CD20, CD68, CD3 and granzyme B, histiocytes, T cells and cytotoxic T cells.

RESULTS

Transitions from normal breast to the subsequent tissue with lesions (normal skin v benign proliferative breast disease v ductal carcinoma in situ v infiltrating ductal carcinoma) were associated with significantly (p<0.01) increased mean (SD) density of mononuclear inflammatory cell infiltrate at the parenchyma (3.2 (1.0) v 26.4 (7.8) v 33.6 (7.9) v 39.1 (4.7) for CD20+ B cells; 2.8 (1.0) v 81.5 (14.0) v 84.0 (14.9) v103.7 (3.9) for CD3; 1.3 (2.0) v 3.8 (4.0) v 12.7 (23) v 22.1 (25.0) for CD68+ macrophages; 2.0 (1.0) v 58.3 (5.0) v 60.0 (10.0) v 74.1 (28.0) for granzyme B+ cytotoxic T cells) and at the stroma (0.7 (1.0) v 3.0 (5.0) v 13.3 (20) v 16.7 (30.0) for CD20+ B cells; 1.0 (2.06) v 4.0 (2.5) v 16.7 (5.0) v 21.7 (15) for CD68+ macrophages; 1.4 (0.6) v 4.2 (1.2) v 46.6 (16.7) v 77.0 (5.0) for CD3+ cells and 0 (0) v 0.5 (1.0) v 0.7 (1.0) v 0.7 (1.0) for granzyme B+ cytotoxic T cells).

CONCLUSIONS

The increased mononuclear inflammatory cell infiltrate during mammary carcinogenesis may reflect non-specific or specific immunological processes.

Regulation of clustered gene expression by cofactor of BRCA1 (COBRA1) in breast cancer cells

Eucaryotic genes that are coordinately expressed tend to be clustered. Furthermore, gene clusters across chromosomal regions are often upregulated in various tumors. However, relatively little is known about how gene clusters are coordinately expressed in physiological or pathological conditions. Cofactor of BRCA1 (COBRA1), a subunit of the human negative elongation factor, has been shown to repress estrogen-stimulated transcription of trefoil factor 1 (TFF1 or pS2) by stalling RNA polymerase II. Here, we carried out a genome-wide study to identify additional physiological target genes of COBRA1 in breast cancer cells. The study identified a total of 134 genes that were either activated or repressed upon small hairpin RNA-mediated reduction of COBRA1. Interestingly, many COBRA1-regulated genes reside as clusters on the chromosomes and have been previously implicated in cancer development. Detailed examination of two such clusters on chromosome 21 (21q22) and chromosome X (Xp11) reveals that COBRA1 is physically associated with a subset of its regulated genes in each cluster. In addition, COBRA1 was shown to regulate both estrogen-dependent and -independent transcription of the gene cluster at 21q22, which encompasses the previously identified COBRA1-regulated TFF1 (pS2) locus. Thus, COBRA1 plays a critical role in the regulation of clustered gene expression at preferred chromosomal domains in breast cancer cells.

NY-ESO-1: review of an immunogenic tumor antigen

In the 9 years since its discovery, cancer-testis antigen NY-ESO-1 has made one of the fastest transitions from molecular, cellular, and immunological description to vaccine and immunotherapy candidate, already tested in various formulations in more than 30 clinical trials worldwide. Its main characteristic resides in its capacity to elicit spontaneous antibody and T-cell responses in a proportion of cancer patients. An overview of immunological findings and immunotherapeutic approaches with NY-ESO-1, as well the role of regulation in NY-ESO-1 immunogenicity, is presented here.

Use of autoantibodies in breast cancer screening and diagnosis

Breast cancer is the most common cancer among women and accounts for 6% of all cancer deaths. Current screening modalities for breast cancer diagnosis include mammography, digital mammography and magnetic resonance imaging; however, there is still an urgent need to develop an alternative modality of screening for earlier diagnosis. Autoantibodies to tumor-associated autoantigens can be elicited in breast cancer patients. Tumor-associated antigens vary between cancers and can be the result of a number of different events, including mutation, overexpression or altered expression patterns. The inherent amplification of signals provided by the host's own immune system to low levels of tumor-associated antigens in early disease provides a potential route to the early diagnosis of cancer. In addition, autoantibody responses in breast cancer have been correlated with patient survival and their response to treatment.

Functional endogenous cytotoxic T lymphocytes are generated to multiple antigens co-expressed by progressing tumors; after intra-tumoral IL-2 therapy these effector cells eradicate established tumors

Tumors contain many antigens that may be recognized by the immune system. It is not known whether these antigens, and the epitopes within these antigens, can all be recognized by the anti-tumor immune response or if such responses are restricted to a few dominant epitopes. Effector function of endogenous cytotoxic T lymphocytes (CTL) generated during tumor progression has previously been assessed by indirect, ex vivo assays, which often focused on a single antigen. Therefore, we evaluated the endogenous in vivo CTL response to multiple neo tumor antigens using murine Lewis lung carcinoma tumor cells transfected with ovalbumin or a polyepitope construct. Both express multiple MHC class I-restricted epitopes. Ovalbumin contains a known hierarchy of epitopes for given MHC molecules, whilst the polyepitope expresses a number of dominant epitopes. We show that as tumors progress, potent effector CTL are generated in vivo that are restricted to dominant epitopes; we did not see the responses to subdominant or cryptic epitopes. Our data show that the CTL recognizing tumor antigens vary in their lytic capacity, as the CTL responding to two of the four epitopes were particularly potent killers. The presence of these effector CTLs did not prevent tumor growth. However, intra-tumoral IL-2 treatment altered the potency, but not the hierarchy, of these CTL such that they mediated tumor regression. These results have implications for immunotherapy protocols.

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.

Expression of cancer-testis antigen (CTA) in tumor tissues and peripheral blood of Chinese patients with hepatocellular carcinoma

To investigate the expression of cancer-testis antigen (CTA) in Chinese patients with hepatocellular carcinoma (HCC), and the relationship between CTA gene expression and clinical indexes, we used one-step reverse transcription polymerase chain reaction (RT-PCR). The expression of the CTA mRNA was investigated in the tissues of HCC and corresponding peripheral blood of 37 patients with HCC. Fifteen samples of cirrhotic tissues and 15 normal tissues were examined with the same method. Two kinds of CTA (SSX-2 and SSX-5) showed high-specific and high-frequent expression in HCC tissues, but neither of them could be detected in adjacent non-HCC tissues. In corresponding peripheral blood of HCC tissues, the positive expression rate of the SSX-2 and SSX-5 mRNA was not very high. No relationship was found between the expression of CTA and clinical indicators such as age, sex, tumor size, TNM staging, serum AFP level and infection with hepatitis virus. In 15 patients with cirrhosis and 15 other non-tumor patients, none of the SSX-2 and SSX-5 mRNA was detected in liver tissue or peripheral blood. High frequency and specificity of CTAs in HCC indicates that their products may be new potential promising targets for antigen-specific immunotherapy of HCC. High frequent co-expression of the two genes in HCC provides a possibility of polyvalent vaccinations for HCC. Specific expression of CTAs was observed in AFP-negative HCC, suggested applying their mRNA as tumor markers to detect circulating HCC cells as adjuvant diagnostic tool and as indicators of recurrence and prognosis.

Prospective study on the expression of cancer testis genes and antibody responses in 100 consecutive patients with primary breast cancer

To determine the expression of cancer testis (CT) genes and antibody responses in a nonselected population of patients with primary breast cancer, we investigated the composite expression of 11 CT genes by RT-PCR in fresh biopsies of 100 consecutive cases of primary breast carcinoma and by immunohistology in selected RT-PCR-positive cases. Antibody responses against 7 CT antigens were analyzed using recombinant antigen expression on yeast surface. In 98 evaluable cases, SCP-1 and SSX-4 were expressed most frequently (both 65%), followed by HOM-TES-85/CT-8 (47%), GAGE (26%), SSX-1 (20%), NY-ESO-1 (13%), MAGE-3 (11%), SSX-2 (8%), CT-10 (7%), MAGE-4 (4%) and CT-7 (1%). One CT gene was expressed by 90% of the cases; 79% expressed > or =2, 48% > or =3, 29% > or =4, 12% > or =5, 6% > or =6, 3% > or =7, 2% > or =8 and one case coexpressed 9 antigens. Of 100 serum samples screened for CT antigen-specific antibodies, antibodies against NY-ESO-1 were detected in 4 patients, against SCP-1 in 6 patients and against SSX-2 in 1 patient, while no antibodies were detected against MAGE-3, CT-7 and CT-10. Expression of CT genes or antibody responses was not correlated with clinical parameters (menopausal status, tumor size, nodal involvement, grading, histology and estrogen receptor status) or the demonstration of CT gene expression at the protein level, by immunohistology. Our results show that breast carcinomas are among the tumors with the most frequent expression of CT antigens, rendering many patients potential candidates for vaccine trials.

Expression and possible prognostic role of MAGE-A4, NY-ESO-1, and HER-2 antigens in women with relapsing invasive ductal breast cancer: retrospective immunohistochemical study

AIM

To evaluate the possible prognostic role of the expression of MAGE-A4 and NY-ESO-1 cancer/testis antigens in women diagnosed with invasive ductal breast cancer and determine the expression of HER-2 antigen.

METHODS

The expression of MAGE-A4, NY-ESO-1, and HER-2 antigens was evaluated immunohistochemically on archival paraffin-embedded samples of breast cancer tissue from 81 patients. All patients had T1 to T3, N0 to N1, M0 tumors and underwent postoperative radiotherapy and, if indicated, systemic therapy (chemotherapy and hormonal therapy). The antigen expression in women who were disease-free for 5 years of follow up (n=23) was compared with that in women with either locoregional relapse (n=30) or bone metastases (n=28). Patient survival after 10 years of follow up was assessed.

RESULTS

The three groups of women were comparable in terms of age, type of operation, tumor size, tumor grade, number of metastatically involved axillary lymph nodes, Nottingham prognostic index (NPI), progesterone receptor (PR) status, and adjuvant hormonal therapy. Estrogen receptors (ER) were positive in 13 women in the 5-year relapse-free group vs 8 in locoregional relapse and 7 in bone metastases group (P=0.032). There were significantly fewer women who received adjuvant chemotherapy in the 5-year relapse-free group than in other two groups (7 vs 23 with locoregional relapse and 25 with bone metastases; P<0.001). This group also had a significantly better 10-year survival (14 women vs 1 with locoregional relapse and 1 with bone metastases; P<0.001). The three groups did not differ in the NY-ESO-1 or HER-2 expression, but the number of patients expressing MAGE-A4 antigen was significantly lower in the group with locoregional relapse (P=0.014). In all groups, MAGE-A4 antigen expression was associated with the NY-ESO-1 antigen expression (P=0.006), but not with tumor size and grade, number of metastatically involved axillary lymph nodes, or the ER and PR status. MAGE-A4-positive patients had a significantly longer survival than the MAGE-A4-negative patients (P=0.046). This was not observed with NY-ESO-1 and HER-2 antigens.

CONCLUSION

Our results suggest that the MAGE-A4 antigen may be used as a tumor marker of potential prognostic relevance.

Serological immune response to cancer testis antigens in patients with pancreatic cancer

Serological screening approaches have allowed for the identification of a large number of potentially relevant tumor antigens in cancer patients. Within this group, cancer testis antigens represent promising targets for cancer immunotherapy, since they are widely expressed in a variety of human cancer entities. In pancreatic cancer, however, there are only few data available about the expression pattern and serological response to cancer testis antigens and other serological-defined tumor antigens. Therefore, we investigated the IgG antibody response against 11 cancer testis antigens (SCP-1, GAGE, LAGE-1a,-1b, CT-7, NY-ESO-1, SSX-1-5) recombinantly expressed on yeast surface (RAYS) in patients with pancreatic cancer (n = 96), chronic pancreatitis (n = 18) and healthy donors (n = 48). We found in 14% of all patients antibody responses to SCP-1, but not to other cancer testis antigens (GAGE, LAGE-1a,-1b, CT-7, NY-ESO-1, SSX-1-5). Antibody response correlated with the expression of SCP-1 in the primary tumor of the respective patient as shown by RT-PCR, immunohistochemistry and Western blot. In contrast, no serological response to cancer testis antigens was observed in healthy donors. The humoral immune response against SCP-1 was associated with the size of tumor, but not with other clinico-pathological parameters such as histology, stage, presence of lymph node metastases, grading, age, gender or gemcitabine treatment. In conclusion, antibody response to cancer testis antigen SCP-1 is found in a proportion of pancreatic carcinoma patients. These results indicate that identification of additional tumor antigens by serological screening of tumor cDNA expression libraries by RAYS is a promising goal in pancreatic cancer.

Heterogeneous expression of GAGE, NY-ESO-1, MAGE-A and SSX proteins in esophageal cancer: Implications for immunotherapy

Cancer/testis antigens (CTAs) elicit immune response in cancer patients and are therefore targets of immunotherapy. Current information on CTA expression is primarily based on mRNA assays and little is known about their expression at the protein level. The objectives of our study are to analyze GAGE, NY-ESO-1, MAGE-A and SSX protein expression in esophageal cancer and to correlate their expression patterns with clinicopathologic parameters and survival. We examined CTA protein expression in 213 patients with esophageal cancer by immunohistochemistry. Antigen-positive tumors were evaluated once and antigen-negative tumors were evaluated 3 times by examining different parts of the cancer specimen. GAGE, NY-ESO-1 and MAGE-A were heterogeneously expressed in 42 (20%), 44 (21%) and 111 (52%) tumors, respectively, whereas SSX expression was not detected. Of the 126 (59%) patients expressing CTAs, 70 (33%) expressed 1, 41 (19%) expressed 2 and 15 (7%) expressed 3 antigens. The expression of MAGE-A was correlated with those of GAGE (p = 0.001) and NY-ESO-1 (p = 0.002), and the expression of GAGE was correlated with that of NY-ESO-1 (p = 0.002). One hundred fifty-six (79%) sections were positively stained in the first evaluation, whereas 37 (19%) and 4 (2%) positive sections were identified in the second and third evaluations, respectively. Particularly, MAGE and GAGE expression showed overlaps. GAGE, NY-ESO-1 and MAGE-A protein expression was not correlated with the disease progression, TNM factors or survival. The detection of immunonegative cells in every specimen suggests addition of other drugs such as 5-aza-2'-deoxycytidine to increase the therapeutic effect of CTA-specific cancer vaccines.

Cancer-Testis Genes Are Coordinately Expressed and Are Markers of Poor Outcome in Non–Small Cell Lung Cancer

PURPOSE

Cancer-testis genes mapping to the X chromosome have common expression patterns and show similar responses to modulators of epigenetic mechanisms. We asked whether cancer-testis gene expression occurred coordinately, and whether it correlated with variables of disease and clinical outcome of non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Tumors from 523 NSCLC patients undergoing surgery were evaluated for the expression of nine cancer-testis genes (NY-ESO-1, LAGE-1, MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, CT7/MAGE-C1, SSX2, and SSX4) by semiquantitative PCR. Clinical data available for 447 patients were used to correlate cancer-testis expression to variables of disease and clinical outcome.

RESULTS

At least one cancer-testis gene was expressed by 90% of squamous carcinoma, 62% of bronchioloalveolar cancer, and 67% of adenocarcinoma samples. Statistically significant coexpression was observed for 34 of the 36 possible cancer-testis combinations. Cancer-testis gene expression, either cumulatively or individually, showed significant associations with male sex, smoking history, advanced tumor, nodal and pathologic stages, pleural invasion, and the absence of ground glass opacity. Cox regression analysis revealed the expression of NY-ESO-1 and MAGE-A3 as markers of poor prognosis, independent of confounding variables for adenocarcinoma of the lung.

CONCLUSIONS

Cancer-testis genes are coordinately expressed in NSCLC, and their expression is associated with advanced disease and poor outcome.

NY-ESO-1/LAGE-1 coexpression with MAGE-A cancer/testis antigens: a tissue microarray study

The characterization of the expression pattern of different families of cancer/testis (C/T) antigens in different tumors, at the protein level, might be of relevance in the development of multiantigen vaccine preparations for active specific immunotherapy. We have used tissue microarray (TMA) technology to explore in large numbers of tumor specimens the expression of NY-ESO-1/LAGE-1 C/T antigens and its correlation with MAGE-A expression by using D8.38 and 57B monoclonal antibodies (MAb). The epitopes recognized by these reagents in C/T antigens were identified by molecular mapping by using a bacterial expression system. Out of 2,052 samples, 119 (5.8%) scored positive upon staining with D8.38 NY-ESO-1/LAGE-1-specific MAb. Expression in >10% of cases was detectable in melanoma and basalioma (31.6 and 18.2%, respectively), large cell carcinomas and adenocarcinomas of the lung (17.8 and 10.5%, respectively), stomach adenocarcinomas of the intestinal type (13.2%), pT2-4 bladder TCC (18.2%), nonseminomatous carcinomas of the testis (10.4%) and liposarcomas (15.4%). Simultaneous expression of NY-ESO-1/LAGE-1 and MAGE-A C/T antigens was then addressed in a TMA where 101/845 and 73/845 samples (12 and 8.6%, respectively) showed evidence of MAGE-A or NY-ESO-1/LAGE-1 specific staining, respectively. In 35/845 specimens (4.1%) concomitant expression of MAGE-A and NY-ESO-1/LAGE-1 was observed (p = 0.0002). Discrepancies in the expression of NY-ESO-1/LAGE-1 and MAGE-A were conspicuously detectable in squamous cell carcinomas of the skin (MAGE-A positive but NY-ESO-1/LAGE-1 negative) and in liposarcomas (NY-ESO-1/LAGE-1 positive, but MAGE-A negative). Taken together, these data suggest novel areas of application of C/T antigens targeted active specific immunotherapy possibly based on multiantigen vaccine preparations.

CD4+ T cell responses to SSX-4 in melanoma patients

Genes of the synovial sarcoma X breakpoint (SSX) family are expressed in different human tumors, including melanomas, but not in adult somatic tissues. Because of their specific expression at the tumor site, SSX-encoded Ags are potential targets for anticancer immunotherapy. In this study, we have analyzed CD4+ T cell responses directed against the Ag encoded by SSX-4. Upon in vitro stimulation of PBMC from four melanoma patients bearing Ag-expressing tumors with a pool of long peptides spanning the protein sequence, we detected and isolated SSX-4-specific CD4+ T cells recognizing several distinct antigenic sequences, mostly restricted by frequently expressed HLA class II alleles. The majority of the identified sequences were located within the Krüppel-associated box domain in the N-terminal region of the protein, indicating a high potential immunogenicity of this region. Together our data document the existence of CD4+ T cells specific for multiple SSX-4 derived sequences in circulating lymphocytes from melanoma patients and encourage further studies to assess the impact of SSX-4-specific T cell responses on disease evolution in cancer patients.

Expression of cancer/testis (CT) antigens in Chinese hepatocellular carcinoma and its correlation with clinical parameters

For investigating the expression of cancer/testis (CT) antigens in patients with hepatocellular carcinoma (HCC) in China, and evaluating the correlations between the expression of these CT antigens and clinical parameters, we collected tumors and adjacent non-cancerous tissues of 43 HCC patients from Beijing and 30 HCC patients from Guangxi province. Expression of the mRNA of 14 CT antigens was evaluated by reverse transcription PCR (RT-PCR). The correlation between CT antigen expression and clinical parameters was statistically analyzed. The mRNA expression frequencies of CT antigens in tumor tissue were: MAGE-A1, 69.9%; MAGE-A3, 47.9%; MAGE-A4, 20.0%; MAGE-A10, 36.7%; SSX-1, 67.4%; SSX-2, 35.6%; SSX-4, 48.8%; SSX-5, 30.2%; NY-ESO-1, 42.5%; MAGE-B1, 52.0%; MAGE-B2, 60.0%; MAGE-C1, 48.0%; MAGE-C2, 68.0%; and SCP-1, 33.3%. However, in adjacent tissues, no CT antigen mRNA expression was detected, except SSX-1 in 9.3% patients. In each HCC tissue, the expression of a minimum of one, two, or three CT antigens was in the range of 80-90, 70-80 or 50-70%, respectively. MAGE-A3 mRNA expression differed between the HCC patients in Beijing and Guangxi (P=0.002). The average age of the HCC patients bearing CT antigen positive tumors was higher than that of the HCC patients bearing CT antigen negative tumors. The expression of MAGE-A3, SSX-1, SSX-2, SSX-4, MAGE-B2, MAGE-C1, and MAGE-C2 correlated significantly with older age (P<0.05). Moreover, the expressions of MAGE-A4 and SCP-1 were related to alpha-fetoprotein abnormality (P<0.05), and the expression of NY-ESO-1 was related to early tumor stage (P<0.05). There was no correlation observed between the expression of CT antigens and the sex, HBV infection or tumor size.

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.

Expression Profile of Cancer-Testis Genes in 121 Human Colorectal Cancer Tissue and Adjacent Normal Tissue

PURPOSE

Among tumor antigens identified to date, cancer-testis (CT) antigens, which are coded by CT genes, are identified as a group of highly attractive targets for cancer vaccines. This study is the first to analyze the mRNA expression and possible correlation with pathologic characteristics of multiple CT genes in a large cohort of colorectal cancer (CRC) patients.

EXPERIMENTAL DESIGN

The expression of 10 individual CT genes in 121 CRC and adjacent tissues were analyzed by RT-PCR method. The presence of autologous antibodies against NY-ESO-1 was examined in serum samples by ELISA. To confirm the protein expression, immunohistochemistry was done for detecting the NY-ESO-1 antigen in mRNA-positive CRC tissues.

RESULTS

The CT genes were detected with various frequencies in CRC tissue, SCP-1, 1.7%; SSX-2, 2.5%; SSX-4, 2.5%; SSX-1, 5.0%; CT10, 6.6%; NY-ESO-1, 9.9%; MAGE-1, 11.6%; LAGE-1, 15.7%; MAGE-4, 22.3%; and MAGE-3, 27.3%. In 56.2% of tumor tissues examined in this study, at least one CT gene was detected. In contrast, no CT gene expression was found in cancer adjacent tissues. Among 10 CT genes investigated, NY-ESO-1 and LAGE-1 are of particular interest because their mRNA expression in CRC was rarely reported before. In our study, NY-ESO-1 mRNA was found to express in 9.9% of the samples, and also correlated significantly with stages (P = 0.041) and local lymph node metastasis (P = 0.002). In addition, we also identified one NY-ESO-1 antibody-positive serum sample. MAGE-4 mRNA was expressed at a high frequency in tumor tissues with vessel emboli samples (P = 0.025).

CONCLUSIONS

These results suggested that CT genes, especially NY-ESO-1 and LAGE-1, do express in CRC. More than 50% of the CRC patients in this study express at least one CT gene, making them eligible for CT vaccination. NY-ESO-1 gene may serve as a marker for local metastasis and advanced disease. MAGE-4 gene is significantly associated with the vessel emboli.

Expression of cancer-testis antigen (CTA) genes in intrahepatic cholangiocarcinoma

BACKGROUND

Cancer-testis antigens (CTA), such as MAGE, are selectively expressed in various types of human neoplasms but not in normal tissues other than testis. This characteristic feature of CTA makes them promising antigens for cancer-specific immunotherapy.

METHODS

We investigated the expression of five genes, including MAGE-1, MAGE-3, NY-ESO-1, SCP-1, and SSX-4, in 20 surgical samples of intrahepatic cholangiocarcinomas (IHCC) using reverse transcription-polymerase chain reaction. To visualize the localization of MAGE proteins, we performed immunohistochemical studies. Furthermore, the correlation between the CTA expression and DNA methylation status was studied in three bile duct cancer cell lines.

RESULTS

Expression of MAGE-1, MAGE-3, NY-ESO-1, SCP-1, and SSX-4 was recognized in 4, 4, 2, 6, and 3 of all 20 cases, respectively. In contrast, the expressions of five genes were not recognized at all in the corresponding normal tissues. In 10 cases (50%), the tumors expressed at least one of the five CTA. An immunohistochemical analysis of MAGE proteins demonstrated homogenous or focal distributions in cytoplasm of the IHCC. Using a demethylating agent, MAGE-1, NY-ESO-1, SCP-1, and SSX-4 were induced in two of three cell lines, whereas MAGE-3 was not.

CONCLUSIONS

Half of the tumor tissues of IHCC expressed at least one of the CTA. Some of the patients with IHCC, therefore, should be candidates for potentially useful cancer-specific immunotherapy.

Novel molecular targeted therapy for esophageal cancer

Esophageal cancers are highly lethal neoplasms which are generally refractory to conventional multidisciplinary interventions. Recent elucidation of the mechanisms of esophageal carcinogenesis, as well as preclinical studies utilizing chromatin remodeling agents and inhibitors of oncogene signaling in conjunction with conventional chemotherapeutic agents provide new opportunities for the development of potentially efficacious molecular targeted therapies for these malignancies.

Identification of multiple antigens recognized by tumor-infiltrating lymphocytes from a single patient: tumor escape by antigen loss and loss of MHC expression

The authors describe a patient who experienced recurrence of metastatic melanoma after an initial dramatic response to immunotherapy using peptides derived from gp100, MART-1, and tyrosinase emulsified in incomplete Freund's adjuvant, and present data to support the hypothesis that the progression of disease in this patient was due to in vivo immunoselection for immunoresistant tumor variants. The authors previously demonstrated the existence of T-cell clones in this patient's peripheral blood and tumor-infiltrating lymphocytes (TILs) reactive against multiple antigens, including gp100, the tyrosinase-related protein (TRP)-2, a novel TRP-2 isoform-TRP-2-6b, SOX10, and the melanoma antigen NY-ESO-1. In addition to the multiple HLA-A2 restricted T-cell clones, the authors have now identified additional HLA-B/C-restricted as well as class II (HLA-DP)-restricted anti-melanoma antigen T-cell clones from this patient's TIL. One recurrent tumor showed loss of expression of multiple tumor antigens but retention of HLA class I expression. The other recurrent lesion showed total loss of HLA class I expression even though the tumor cells still expressed many melanoma antigens. This paper thus provides evidence for both the effectiveness of the immune destruction of cancer as well as problems associated with antigen-loss tumor escape mechanisms.

Expression of MAGE-A3 in intrahepatic cholangiocarcinoma and its precursor lesions

MAGE-A3 antigen is known to be neo-expressed in a large proportion of tumors but not detectable in normal tissues, and could be a target antigen recognized by autologous cytotoxic T lymphocytes. In the present study, the expression of MAGE-A3 at protein and mRNA levels was examined in intrahepatic cholangiocarcinoma (ICC) and its precursor lesions. Carcinomatous and dysplastic biliary cells expressed MAGE-A3 in their cytoplasm diffusely, although there was no MAGE-A3 expression in normal and hyperplastic biliary cells. MAGE-A3 was expressed in one of 10 cases (10%) of low-grade dysplasia, four of 13 (31%) cases of high-grade dysplasia/in situ carcinoma, and 32 of 68 invasive ICC cases (47%), respectively. The MAGE-A3 mRNA expression pattern was similar to that of MAGE-A3 protein. The incidence and intensity of MAGE-A3 expression increased along the progression of biliary neoplasia (P < 0.05). There was no correlation between MAGE-3 expression and histological differentiation or anatomical locations of invasive ICC. MAGE-A3 is a promising target molecule for the specific immunotherapy of ICC.

Identification of HLA-A24-restricted CTL epitope from cancer-testis antigen, NY-ESO-1, and induction of a specific antitumor immune response

PURPOSE

For the development of peptide-based, cancer-specific immunotherapy, the identification of CTL epitopes from additional tumor antigens is very important. NY-ESO-1, a cancer-testis antigen, is considered to be a promising target of tumor-specific immunotherapy. Because HLA-A24-expressing individuals cover >60% in the population of Japan, we aim at identifying NY-ESO-1-encoded peptide presented by HLA-A24.

EXPERIMENTAL DESIGN

In our study, a HLA-A24-restricted CTL epitope was identified by using the following four-step procedure: (a) computer-based epitope prediction from the amino acid sequence of NY-ESO-1 antigen; (b) peptide-binding assay to determine the affinity of the predicted peptide with HLA-A24 molecule; (c) stimulation of primary T-cell response against the predicted peptides in vitro; and (d) testing of the induced CTLs toward various carcinoma cells expressing NY-ESO-1 antigen and HLA-A24.

RESULTS

Of the tested peptides, effectors induced by a peptide of NY-ESO-1 at residue position 158-166 lysed three kinds of carcinoma cells expressing both NY-ESO-1 and HLA-A24. Our results indicate that peptide NY-ESO-1 (158-166) (LLMWITQCF) is a new HLA-A24-restricted CTL epitope capable of inducing NY-ESO-1-specific CTLs in vitro mediating HLA class I-restricted manner.

CONCLUSIONS

We identified a novel HLA-A24-restricted NY-ESO-1-derived epitope peptide (LLMWITQCF) that could induce specific CTLs from the peripheral blood mononuclear cells of HLA-A24(+) healthy donors. This peptide would be useful in further evaluating the clinical utility of peptide-based, cancer-specific immunotherapy against various histological tumors.

Expression of cancer-testis antigens in hepatocellular carcinoma

AIM: To investigate the expression of cancer-testis (CT) antigens MAGE-1, SSX-1 ,CTp11 and HCA587 genes in hepatocellular carcinoma (HCC) and the possibility of applying these antigens as targets for specific immunotherapy for HCC.

METHODS: Expression levels of MAGE-1, SSX-1, CTp11 and HCA587 mRNA were detected with reverse transcription polymerase chain reaction (RT-PCR) in HCC tissues and corresponding adjacent non-cancerous tissues from 105 HCC patients, 40 samples of cirrhosis and normal liver tissues. Genes of five samples with positive PCR results were sequenced.

RESULTS: Of 105 HCC tissues, MAGE1, SSX-1 ,CTp11 and HCA587 mRNA expressions were detectable in 75.2% (79/105), 72.4% (76/105), 62.9% (66/105) and 56.2% (59/105) of HCC samples, respectively. About 93.3% (98/105), 72.4% (76/105), 48.6% (51/105) and 37.1% (39/105) of HCC tissues positively expressed at least one, two, three, and four members of CT antigens, respectively. Conversely, only SSX-1 could be detectable in 2.9% (3/105) of the corresponding adjacent non-HCC tissues in which no metastatic lesion was found. Of the latter 3 patients, biopsy samples far from tumor were obtained in 2 patients and RT-PCR indicated no expression of SSX-1 mRNA in these two samples. In addition, none of 40 samples of cirrhotic and normal liver tissues expressed CT antigen gene mRNA. DNA sequences confirmed that the RT-PCR products were true target cDNA. No relationship was found between expression of CT antigens and clinico pathological indicators such as age, gender, tumor size, degree of tumor differentiation, serum α-fetoprotein level and infection of hepatitis B virus or hepatitis C virus (P > 0.05).

CONCLUSION: CT antigens genes (MAGE-1, SSX-1, CTp11 and HCA587) are expressed with high percentage and specificity in HCC and their products are promising targets for antigen-specific immunotherapy of HCC. High frequent co-expression of multiple members of CT antigens in HCC provides possibility of polyvalent vaccinations for HCC.

NY-ESO-1 expression and its serum immunoreactivity in esophageal cancer

PURPOSE

NY-ESO-1, a member of the cancer/testis antigen (CTA) family, elicits humoral and cellular immune responses in patients with advanced cancer. Unresectable or metastatic esophageal carcinoma patients do not benefit from the present multimodality treatment regimens in terms of survival. The objectives of this study were to analyze the antibody response to NY-ESO-1 antigen in patients with esophageal cancer and to determine the potential of NY-ESO-1 for use in tumor-specific immunotherapy.

METHODS

Serum from 69 patients with esophageal cancer was investigated for antibody production against NY-ESO-1 by Western blot analysis. Also analyzed by immunohistochemistry were 56 tissue samples from these patients for NY-ESO-1 protein expression.

RESULTS

NY-ESO-1 protein expression was found in 18 of 56 (32%) esophageal carcinomas. Serum immunoreactivity specific for NY-ESO-1 was found in 9 patients (13%) of whom 8 were in the advanced stage (stages III and IV). There was no relationship between clinicopathologic features and serum immunoreactivity for NY-ESO-1. NY-ESO-1 protein expression was detected in three of five antibody-positive patients whose tissue was available for analysis. Survival analysis showed no significant difference between antibody-positive and antibody-negative patient groups.

CONCLUSIONS

A humoral immune response to NY-ESO-1 antigen was established in patients with advanced esophageal cancer. NY-ESO-1 is a good candidate for vaccine-based immunotherapy for advanced esophageal carcinoma.

Expression of cancer testis antigens in pancreatic carcinoma cell lines, pancreatic adenocarcinoma and chronic pancreatitis

In order to define antigens that might be suitable as vaccines for pancreatic carcinoma, we investigated the composite expression of 10 cancer testis (CT) antigens (SCP-1, NY-ESO-1, SSX-1, SSX-2, SSX-4, GAGE, MAGE-3, MAGE-4, CT-7 and CT-8) by Reverse Transcriptase-PCR (RT-PCR) in fresh biopsies of human pancreatic adenocarcinoma, chronic pancreatitis and pancreatic carcinoma cell lines. While all CT genes were frequently expressed in cell lines derived from pancreatic cancer, no expression of MAGE-3, SSX-1, SSX-2, NY-ESO-1 and CT-7 was detected in fresh tumor biopsies, and MAGE-4 (1/52), SSX-4 (1/39) and CT-8 (2/41) were only rarely expressed. In contrast, HOM-TES-14/SCP-1 was expressed in 48% (29/61) and GAGE in 21% (13/61) of cases, respectively. One CT gene was expressed by 59% (75% in male, 46% in female patients; p = 0.05) and 2 or more CT genes by 15% of the samples. SCP-1 protein expression correlated well with mRNA expression. While SCP-1 and GAGE were absent in normal pancreas, they were found in 2/8 (SCP-1) and 1/8 (GAGE) samples of chronic pancreatitis, respectively, supporting the concept of chronic pancreatitis as a premalignant condition. SCP-1 and GAGE represent promising candidates for vaccine development in pancreatic carcinoma. Whether SCP-1 and GAGE expression identify cases of chronic pancreatitis with a high risk of malignant transformation remains to be shown.

NY-ESO-1 expression and immunogenicity in malignant and benign breast tumors

NY-ESO-1 is a cancer/testis antigen expressed in normal adult tissues solely in the testicular germ cells of normal adults and in various cancers. It induces specific humoral and cellular immunity in patients with NY-ESO-1-expressing cancer. The aim of this study was to determine the frequency of NY-ESO-1 mRNA and protein expression in malignant and benign breast tumors. NY-ESO-1 mRNA expression was detected by conventional reverse transcription-PCR and real-time PCR, and that of the protein expression by immunohistochemistry and Western blot analysis. Expression of NY-ESO-1 mRNA was detected in 37 of 88 (42%) cancer specimens, whereas that of the NY-ESO-1 protein was detected only in 1 mRNA-positive specimen. In the latter case, expression level of NY-ESO-1 mRNA relative to that in the testis was relatively high (75% of testicular expression) and to the other among breast cancer specimens. In benign breast lesions, 21 of 31 (68%) specimens expressed low levels of NY-ESO-1 mRNA. In 1 case of fibroadenoma, NY-ESO-1 mRNA was 8% of the testicular level, and protein was detected by Western blot analysis. Only 1 breast cancer patient had detectable antibody at time of surgery, which disappeared within 2 years. Tumor specimen from this patient was both NY-ESO-1 mRNA and protein positive, and NY-ESO-1-specific CD8 T cells were detected in this patient by IFN-gamma enzyme-linked immunospot assay using NY-ESO-1 recombinant adeno and vaccinia virus. A higher rate of NY-ESO-1 expression was noted in breast cancer with high histological grade and negative hormone receptor status, suggesting NY-ESO-1 as a potential tumor antigen for immunotherapy in patients with breast cancer and poor prognosis.

Epigenetic targets for immune intervention in human malignancies

Emerging evidences suggest that epigenetic events associated with tumor development and progression, such as deregulated methylation of CpG dinucleotides and aberrant histone acetylation, may impair the immunogenic potential of cancer cells. In fact, DNA hypermethylation and/or histone deacetylation contribute to the absent or downregulated expression of different components of the 'tumor recognition complex' (i.e., HLA class I antigens, cancer/testis antigens and accessory/costimulatory molecules) in solid and hemopoietic human malignancies. However, pharmacologic agents that induce DNA hypomethylation or inhibit histone deacetylation can modify these epigenetic phenomena, restoring the defective expression of selected components of the 'tumor recognition complex' in cancer cells. These antigenic modifications positively modulate the immunogenicity and the immune recognition of cancer cells, making epigenetic drugs attractive agents to design new combined chemoimmunotherapeutic strategies for the treatment of cancer patients.

Transcriptional gene expression profile of human esophageal squamous cell carcinoma

To identify the genes involved in esophageal carcinogenesis, we compared gene expression profiles in esophageal squamous cell carcinoma (ESCC) and matched normal esophageal epithelial tissues. Differential display analysis revealed significant changes in the expression of 26 genes; 21 genes were upregulated and 5 genes were downregulated. The differentially expressed genes included those associated with cellular metabolism, cell structure, transcription, proliferation, apoptosis, signal transduction, complement pathway, and cell-cell adhesion. The differential expression of these genes was confirmed by reverse Northern blot analysis. Reverse transcription PCR analysis of ESCC and matched normal esophageal tissues provided the first evidence that melanoma metastasis clone D (MEMD), a gene similar to oncostatin M receptor beta, and KIAA0471 gene products are upregulated in ESCCs. Intriguingly, KIAA0471, a novel gene product, is upregulated in esophageal tumors showing nodal invasion. Identification of these differentially expressed genes in esophageal tumors adds to the repertoire of genes associated with esophageal carcinogenesis and they may thus serve as potential novel molecular targets for diagnosis and therapy. Further characterization of known and unknown differentially expressed cDNAs identified in this study may provide significant clues for understanding the molecular mechanisms underlying esophageal tumorigenesis.

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 antigens: an expanding family of targets for cancer immunotherapy

Cancer/testis (CT) antigens are a category of tumor antigens with normal expression restricted to male germ cells in the testis but not in adult somatic tissues. In some cases, CT antigens are also expressed in ovary and in trophoblast. In malignancy, this gene regulation is disrupted, resulting in CT antigen expression in a proportion of tumors of various types. Since their initial identification by T-cell epitope cloning, the list of CT antigens has been greatly expanded through serological expression cloning (SEREX) and differential mRNA expression analysis, and approximately 20 CT antigens or antigen families have been identified to date. Characteristics commonly shared by CT antigens, aside from the highly tissue-restricted expression profile, include existence as multigene families, frequent mapping to chromosome X, heterogeneous protein expression in cancer, likely correlation with tumor progression, induction of expression by hypomethylation and/or histone acetylation, and immunogenicity in cancer patients. Spontaneous humoral and cell-mediated immune responses have been demonstrated against several CT antigens, including NY-ESO-1, MAGE-A, and SSX antigens. Since CT antigens are immunogenic and highly restricted to tumors, their discovery has led directly to the development of antigen-specific cancer vaccines, and clinical trials with MAGE-A and NY-ESO-1 are in progress.

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.

Polytope vaccines for the codelivery of multiple CD8 T-cell epitopes

Vaccines against a number of diseases, including HIV, Epstein Barr virus, malaria and several cancers, are believed to require the coinduction of multiple alphabeta CD8+ cytotoxic T-lymphocyte responses that are directed towards a number of different target antigens. The difficulties associated with making large recombinant vaccines that contain numerous antigens has led to the development of alphabeta CD8+ cytotoxic T-lymphocyte polyepitope or polytope vaccine approach, where multiple (usually 8-10 amino acids long) alphabeta CD8+ cytotoxic T-lymphocyte epitopes, derived from several antigens are conjoined into single artificial constructs. Such polytope constructs can be delivered using a number of different vaccine vector modalities with each epitope in the construct emerging as individually immunogenic.

Cancer-testis antigens: promising targets for antigen directed antineoplastic immunotherapy

During the last decade, the aberrant expression of normal testicular proteins in neoplastically transformed cells became common knowledge. Cancer-testis antigens (CTAs) represent a novel family of immunogenic proteins. The genes MAGE, BAGE, GAGE, LAGE and NY-ESO-1 code for antigens that are recognised on various neoplastically transformed cells by autologous, cytolytic CD8 ( + ) T lymphocytes. The MAGE genes were initially analysed from melanomas and turned out to have an almost exclusively neoplasm specific expression pattern. In normal adult tissues, most 23 human MAGE genes are expressed only in the testis, with expression patterns suggesting that this gene family is involved in germ cell development. The SSX (synovial sarcoma on X chromosome) gene family, located on the X chromosome, encode a family of highly homologous nuclear proteins. A number of observations confirmed that all five SSX genes were expressed in normal testis. The newly detected CTA, NY-ESO-1, is regarded as one of the most immunogenic antigens ever isolated, inducing spontaneous host immune responses in 50% of patients with NY-ESO-1-expressing neoplasms. The identification of neoplasm-associated markers recognised by cellular or humoral effectors of the immune system has opened new perspectives for antigen directed, individualised antineoplastic immunotherapy. In preparation for this new era of targeted immunotherapy, a number of neoplasm-associated antigen families have been identified as targets for CD8+, cytolytic T lymphocytes in vitro and in vivo : (1) CTAs expressed in various neoplasms and in normal testis, restricted to male germ cells; (2) melanocyte differentiation antigens; (3) point mutations of normal genes; (4) antigens overexpressed in neoplastic tissues; and (5) viral antigens. Immunotherapeutic protocols directed against the CTAs have already been initiated to analyse the induction of antigen-specific cellular and humoral immune responses in vivo.