[Pregnancy predictive factors in case of double embryo transfer during "Top Quality" attempts]

OBJECTIVES

To identify IVF±ICSI pregnancy predictive factors during "Top Quality" attempts in case of double embryo transfer.

PATIENTS AND METHODS

Three years retrospective study (2007, 2008 and 2009) on parameters and results obtained during IVF±ICSI defined as "Top Quality" attempts: first or second attempts on less than 35years old women (age inferior or equal to) with one or two "Top Quality" embryo transfer.

RESULTS

In case of double embryo transfer, pregnancy predictive factors are (OR [IC 95%], P): average endometrial thickness on start (4.6 [2.9-5.5], P<0.01), women smoking (4.2 [3.5-4.9], P<0.01), average stimulation duration (3.4 [2.7-3.9], P<0.01), average men age (2.2 [1.7-2.5], P<0.05), gonadotrophins total dose (2.1 [1.1-3.2], P<0.05) and first rank's attempts (1.6 [1.2-2.5], P<0.05).

DISCUSSION AND CONCLUSION

Age patient, rank attempts and quality embryo are criteria, which used to guide to a single embryo transfer. Our results incite us to consider other parameters, in particular men age and women smoking status.

[Professional Practice Evaluation: How to improve quality management in procreation centers?]

OBJECTIVES

The Professional Practice Evaluation (PPE) is at the heart of quality management in procreation centers. Hereby, we report 3 years of EPP in Cytogenetics and Reproduction laboratory in Amiens University Hospital.

PATIENTS AND METHODS

This PPE is based upon prospective analysis of in vitro fertilization techniques regarding two major parameters: clinically in improving embryo transfer and biologically by determining fecundation levels. Clinical pregnancies in "Top Quality" trial is chosen as a major indicator of our results.

RESULTS

Per transfer, there is an increase of 8% for clinical pregnancies and 31% in "Top quality" trials.

DISCUSSION AND CONCLUSION

The improvement in our results allowed us to propose, in favourable conditions, single embryo transfer.

[Premature ovarian failure: which protocols?]

This review shows the results of the various studies concerning the protocols applied to the women presenting a premature ovarian failure. Will be thus analyzed the natural cycles (or semi-natural), the increase in the dose of gonadotrophins, the clomiphene citrate and the anti-aromatases, the protocols with GnRH agonists long, short, stop or microdoses, the protocols with GnRH antagonists and the adjuvant treatments: aspirin, nitric oxyde, recombinant LH recombining, growth hormone and androgens. The interest of several protocols is to collect a sufficient number of oocytes (and thus of embryos to be transferred), making it possible to obtain reasonable rates of pregnancy. However, it arises that the rates of pregnancy observed among these women depend not only on their ovarian reserve and their age, but are also function of the type of infertility, of the cycle number and the uterus.

[Management of an ovarian stimulation in case of a Kallmann-De Morsier syndrome. The role of LH]

We report a case of ovarian stimulation in a woman with a Kallmann-De Morsier syndrome, which resulted in a triple pregnancy and childbirth by caesarean section at 36 weeks of amenorrhea of three girls weighing from 1,950 to 2,300 g. Starting from a literature review of Kallmann-De Morsier syndrome, we discuss the role of LH during the follicular phase and the monitoring of ovarian stimulation.

Electroporation of immature and mature dendritic cells: implications for dendritic cell-based vaccines

Until now, studies utilizing mRNA electroporation as a tool for the delivery of tumor antigens to human monocyte-derived dendritic cells (DC) have focused on DC electroporated in an immature state. Immature DC are considered to be specialized in antigen capture and processing, whereas mature DC present antigen and have an increased T-cell stimulatory capacity. Therefore, the consensus has been to electroporate DC before maturation. We show that the transfection efficiency of DC electroporated either before or after maturation was similarly high. Both immature and mature electroporated DC, matured in the presence of an inflammatory cytokine cocktail, expressed mature DC surface markers and preserved their capacity to secrete cytokines and chemokines upon CD40 ligation. In addition, both immature and mature DC can be efficiently cryopreserved before or after electroporation without deleterious effects on viability, phenotype or T-cell stimulatory capacity including in vitro antigen-specific T-cell activation. However, DC electroporated after maturation are more efficient in in vitro migration assays and at least as effective in antigen presentation as DC electroporated before maturation. These results are important for vaccination strategies where an optimal antigen presentation by DC after migration to the lymphoid organs is crucial.

Use of GNRH antagonists in reproductive medicine

Gonadotrophin-releasing hormone (GnRH) plays a key role in the secretion of gonadotrophins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which regulate steroidogenesis and folliculogenesis. Two GnRH antagonists, Cetrorelix and Ganirelix, deprived of histaminergic side-effects, have been introduced into ovarian stimulation protocols to prevent premature LH surges and proved their safety in clinical trials. At present, most of the published studies have not found significant differences in follicular recruitment, oocyte quality, and so on, except for a decrease in pregnancy and implantation rates in in vitro fertilization and embryo transfer (IVF-ET) cycles when the GnRH antagonist rather than the agonist was used. This decrease in pregnancy rates was in relation with a necessary learning curve of the physicians. Another possibility is the impact of the GnRH antagonist on endometrium through its GnRH receptor; this effect was cancelled after cryopreserved embryo transfers because the pregnancy rates were similar between GnRH antagonist and agonist in this case. GnRH antagonists were also interesting in poor responders and polycystic ovarian syndrome, where the agonists have not permitted to obtain the better results in IVF-ET cycles. Similarly, the GnRH antagonists could prevent the LH surge in the intrauterine insemination cycles.

MAGE-A genes are not expressed in human leukemias

Immunotherapy is promising to improve the prognosis of human leukemias, at least as adjuvant treatment. Tumor-associated antigens such as antigens encoded by MAGE-A1, -A2, -A3, -A4, -A6 and -A12 genes might provide tools in this field. We demonstrated recently that the presentation peptides encoded by MAGE-A genes might make leukemic blasts suitable targets to cytolytic T lymphocytes. We reported previously negative data of MAGE-A1 gene expression in hematological malignancies, but in further studies positive results of MAGE-A gene expression were published in some subtypes of hematological malignancies such as T leukemia, myeloma and Hodgkin's disease. This led us to enlarge the screening of MAGE-A gene expression in human leukemias. In the RT-PCR screening of a large panel including 154 patients, only weak signal were detected in a few samples. We conclude that MAGE-A genes are not expressed in human leukemias.

Expression of prostate-specific membrane antigen in transitional cell carcinoma of the bladder: prognostic value?

The expression of Prostate-specific membrane antigen (PSMA) mRNA was assessed in the normal bladder urothelium (n = 9), transitional cell carcinoma (TCC) specimens (n = 52), TCC-derived cell lines (n = 3), and preoperative blood samples from TCC patients (n = 27). Specific PSMA mRNA was found in 100% of normal and malignant tissues and two cell lines. PSMA protein was detected in normal (n = 3) and malignant tissues (n = 4). Using a PSMA-specific substrate, PSMA enzymatic activity was found in two bladder cell lines and correlated with immunostaining. Seven of the 27 TCC preoperative blood samples were positive by reverse transcription-PCR. These preliminary results, obtained on a nonrandomized cohort of patients, correlated with tumor invasion (positive RT-PCR: 0% for pT < or = 2 versus 41% for pT > or = 3) and 2-year survival rate (81% in the PSMA-negative group versus 29% in the PSMA-positive group). Although the clinical usefulness of this assay requires confirmation in larger prospective randomized trials, current preliminary results suggest that a blood-borne PSMA mRNA PCR assay may be a useful tool to predict a poor outcome in TCC patients.

Monoclonal antibody 57B stains tumor tissues that express gene MAGE-A4

Monoclonal antibody (Mab) 57B, which was raised against a recombinant MAGE-A3 protein, was tested for its ability to stain cells expressing various members of the MAGE-A gene family. COS-7 cells transfected with cDNAs encoding MAGE-A1, A2, A3, A4, A6, or A12 were stained, whereas those transfected with MAGE-A8, A9, A10, or A11 cDNAs were not. However, in tissue sections, we observed a different pattern of staining: the antibody effectively stained the tumors that expressed MAGE-A4 and only these tumors, regardless of the expression of the other MAGE-A genes. It seems, therefore, that at the level of MAGE gene expression found in tumors, a level clearly lower than that observed in transfected COS cells, only the MAGE-A4 protein can be reliably detected. We conclude that the 57B Mab should be useful for tumor diagnosis related to therapeutic vaccination involving MAGE-A4.

Expression of gene MAGE-A4 in Reed-Sternberg cells

Genes of the MAGE-A family are expressed in several types of solid tumors but are silent in normal tissues with the exception of male germline cells, which do not carry HLA molecules.Therefore, peptides encoded by MAGE-A genes are strictly tumor-specific antigens that can be recognized by CTL and constitute promising targets for immunotherapy. The expression of 6 genes of the MAGE-A family was tested with reverse transcriptase-polymerase chain reaction in lymphoma samples. Among 38 samples of non-Hodgkin lymphoma, 1 anaplastic large cell lymphoma expressed genes MAGE-A1, -A2, -A3, -A4, and -A12, and 1 lymphoepithelioid T-cell lymphoma expressed gene MAGE-A4. Five of 18 samples (28%) from patients with Hodgkin disease expressed gene MAGE-A4. In tissue sections, staining by a monoclonal antibody that recognizes the MAGE-A4 protein was observed in 11 of 53 samples (21%) from patients with Hodgkin disease. In the positive samples, the Reed-Sternberg cells were strongly stained whereas the surrounding cells were not. These results indicate that Hodgkin disease may be a target for specific immunotherapy involving MAGE-A4 antigens.

Cytolytic T lymphocytes raised against a human bladder carcinoma recognize an antigen encoded by gene MAGE-A12

Human bladder carcinoma line LB831-BLC expresses several distinct Ags that are recognized by different autologous CTL. Here, we show that one of these Ags is presented by HLA-Cw7 and encoded by gene MAGE-A12. This is the first time that CTL directed against a MAGE-encoded Ag have been derived from the lymphocytes of a patient with cancer other than melanoma. This new Ag was found to be nonapeptide VRIGHLYIL, corresponding to position 170-178 of the MAGE-A12 protein. Gene MAGE-A12 is silent in normal tissues except in male germline cells, which do not express HLA molecules. It is expressed in 26-62% of melanomas, infiltrating bladder carcinomas, lung carcinomas, esophageal carcinomas, and head and neck carcinomas. Because HLA-Cw7 is present in 43% of Caucasians, this new Ag is shared by many tumors and should be a useful target for cancer immunotherapy.

Processing of some antigens by the standard proteasome but not by the immunoproteasome results in poor presentation by dendritic cells

By stimulating human lymphocytes with an autologous renal carcinoma, we obtained CTL recognizing an antigen derived from a novel, ubiquitous protein. The CTL failed to lyse autologous EBV-transformed B cells, even though the latter express the protein. This is due to the presence in these cells of immunoproteasomes, which, unlike standard proteasomes, cannot produce the antigenic peptide. We show that dendritic cells also carry immunoproteasomes and fail to present this antigen. This may explain why the relevant CTL escape thymic deletion and are not regularly activated in the periphery. Lack of cleavage by the immunoproteasome was also observed for melanoma differentiation antigen Melan-A26-35/HLA-A2, currently used for antitumoral vaccination. For immunization with such antigens, proteins should be less suitable than peptides, which do not require proteasome digestion in dendritic cells.

Quantitative evaluation of the expression of MAGE genes in tumors by limiting dilution of cDNA libraries

The MAGE-A genes are expressed in tumor cells but not in healthy tissues, except in male germ line cells and in placenta. They encode tumor-specific antigens recognized by autologous cytolytic T lymphocytes (CTLs). On the basis of semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assays, 6 of the 12 members of the MAGE-A family, including MAGE-A1, were previously reported to have a high level of expression in tumors, whereas 5 other members, including MAGE-A10, were expressed at a much lower level, deemed to be insufficient for CTL recognition. However, analysis with antibodies has shown that some melanoma cell lines contain equivalent amounts of MAGE-A1 and MAGE-A10 proteins. This discrepancy appeared to be due to the low efficacy of the primers that had been used for the previous MAGE-A10 RT-PCR assays. This led us to develop a method that is independent of the efficacy of the PCR primers to evaluate MAGE-A gene expression. cDNA libraries from tumor cell lines were introduced into bacteria, of which 200 pools of about 500 bacteria were maintained in microcultures. The frequencies of the MAGE-A cDNA clones in each library were evaluated by performing PCR assays on each of these pools. The abundance of MAGE-A10 cDNAs was found to be similar to that of MAGE-A1 in 3 of the libraries that were analyzed, including 2 with high expression (1/6,400), confirming that MAGE-A10 is expressed at a high level. MAGE-A2, A3, A4, A6 and A12 cDNAs were also confirmed often to be present at a frequency of more than 1/10,000, a level of expression that should suffice for recognition of antigenic peptides encoded by these genes by cytolytic T cells. The remaining MAGE genes are either not expressed in tumors or are expressed at a very low level, with the exception of MAGE-A8 and 11, which show high expression in a very small number of tumors. This method also allowed us to isolate 5 MAGE-A cDNAs that we had not obtained previously, enabling us to delineate the exons in the sequences of genes MAGE-A5, A8, A9, A10 and A11.

Quantitative evaluation of the expression of MAGE genes in tumors by limiting dilution of cDNA libraries

The MAGE-A genes are expressed in tumor cells but not in healthy tissues, except in male germ line cells and in placenta. They encode tumor-specific antigens recognized by autologous cytolytic T lymphocytes (CTLs). On the basis of semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assays, 6 of the 12 members of the MAGE-A family, including MAGE-A1, were previously reported to have a high level of expression in tumors, whereas 5 other members, including MAGE-A10, were expressed at a much lower level, deemed to be insufficient for CTL recognition. However, analysis with antibodies has shown that some melanoma cell lines contain equivalent amounts of MAGE-A1 and MAGE-A10 proteins. This discrepancy appeared to be due to the low efficacy of the primers that had been used for the previous MAGE-A10 RT-PCR assays. This led us to develop a method that is independent of the efficacy of the PCR primers to evaluate MAGE-A gene expression. cDNA libraries from tumor cell lines were introduced into bacteria, of which 200 pools of about 500 bacteria were maintained in microcultures. The frequencies of the MAGE-A cDNA clones in each library were evaluated by performing PCR assays on each of these pools. The abundance of MAGE-A10 cDNAs was found to be similar to that of MAGE-A1 in 3 of the libraries that were analyzed, including 2 with high expression (1/6,400), confirming that MAGE-A10 is expressed at a high level. MAGE-A2, A3, A4, A6 and A12 cDNAs were also confirmed often to be present at a frequency of more than 1/10,000, a level of expression that should suffice for recognition of antigenic peptides encoded by these genes by cytolytic T cells. The remaining MAGE genes are either not expressed in tumors or are expressed at a very low level, with the exception of MAGE-A8 and 11, which show high expression in a very small number of tumors. This method also allowed us to isolate 5 MAGE-A cDNAs that we had not obtained previously, enabling us to delineate the exons in the sequences of genes MAGE-A5, A8, A9, A10 and A11.

cDNA and protein characterization of human MAGE-10

MAGE genes are frequently expressed in several types of human malignancy and code for antigens recognized by cytotoxic T lymphocytes. We have previously described a monoclonal antibody (MAb), named 6C1, that recognizes the MAGE-1 protein and cross-reacts with a 72-kDa protein present in lysates of melanoma cells such as MZ2-MEL. To identify this protein, we have screened an expression library prepared from MZ2-MEL cells. Several clones that encoded a protein recognized by antibody 6C1 contained a sequence identical to that of MAGE-10, another member of the MAGE-A gene family. Full-length MAGE-10 cDNA clones, obtained after screening additional cDNA melanoma libraries, were found to be approximately 2.5 kb in length. In vitro translation and transient transfection experiments indicated that MAGE-10 codes for a protein of approximately 72 kDa. This product was recognized by MAb 6C1 as well as by a polyclonal serum raised against a MAGE-10 peptide, thus demonstrating its identity with MAGE-10. Analysis of MAGE-10 mRNA by RT-PCR confirmed its presence in testis and placenta but not in other normal tissues. Expression of MAGE-10 in melanoma tumors was found to parallel that of MAGE-1. Western blot analysis with the polyclonal anti-MAGE-10 antibody showed the presence of MAGE-10 in lysates of purified trophoblast cells. Immuno-cytochemistry of cultured melanoma cells indicated that MAGE-10 is a nuclear protein.

Genes encoding tumor-specific antigens are expressed in human myeloma cells

Genes of the MAGE, BAGE, GAGE, and LAGE-1/NY-ESO-1 families encode antigenic peptides that are presented by HLA class I molecules and that are recognized on human tumors by autologous cytolytic T lymphocytes. These genes are expressed in many solid tumor types but not in normal tissues, except male germline cells. Because the latter cells are devoid of HLA molecules, the derived antigens are strictly tumor-specific and should constitute safe immunogens for cancer immunotherapy. We detected a significant expression of these genes in a high proportion of bone marrow samples from patients with advanced multiple myeloma. This observation provides a basis for clinical trials aimed at inducing a cellular immune response directed at malignant plasma cells in advanced myeloma patients.

A new MAGE gene with ubiquitous expression does not code for known MAGE antigens recognized by T cells

A number of genes of the MAGE family have been shown to code for antigens that are recognized on many human tumors by autologous CTLs. These antigens should be strictly tumor specific because the encoding MAGE genes are not expressed in normal adult cells, except for male germ-line cells, which lack HLA expression. Here, we report that a distant relative of the previously identified MAGE genes is expressed in many, if not all, normal tissues. This gene, which was named MAGE-D, is located in Xp11. Its exon-intron structure is completely different from that of the other MAGE genes. None of the 20 MAGE antigenic peptides presently known to be recognized by T lymphocytes is encoded by the new MAGE gene. It appears, therefore, that this new finding leaves intact the tumor specificity of the antigens encoded by the MAGE genes that are expressed only in tumor and germ-line cells.

Characterization of the GAGE genes that are expressed in various human cancers and in normal testis

The GAGE-1 gene was identified previously as a gene that codes for an antigenic peptide, YRPRPRRY, which was presented on a human melanoma by HLA-Cw6 molecules and recognized by a clone of CTLs derived from the patient bearing the tumor. By screening a cDNA library from this melanoma, we identified five additional, closely related genes named GAGE-2-6. We report here that further screening of this library led to the identification of two more genes, GAGE-7B and -8. GAGE-1, -2, and -8 code for peptide YRPRPRRY. Using another antitumor CTL clone isolated from the same melanoma patient, we identified antigenic peptide, YYWPRPRRY, which is encoded by GAGE-3, -4, -5, -6, and -7B and which is presented by HLA-A29 molecules. Genomic cloning of GAGE-7B showed that it is composed of five exons. Sequence alignment showed that an additional exon, which is present only in the mRNA of GAGE-1, has been disrupted in gene GAGE-7B by the insertion of a long interspersed repeated element retroposon. These GAGE genes are located in the p11.2-p11.4 region of chromosome X. They are not expressed in normal tissues, except in testis, but a large proportion of tumors of various histological origins express at least one of these genes. Treatment of normal and tumor cultured cells with a demethylating agent, azadeoxycytidine, resulted in the transcriptional activation of GAGE genes, suggesting that their expression in tumors results from a demethylation process.

Cytolytic T lymphocytes recognize an antigen encoded by MAGE-A10 on a human melanoma

From melanoma patient LB1751, cytolytic T lymphocytes (CTL) were generated that lysed specifically autologous tumor cells. To establish whether these CTL recognized one of the Ags that had previously been defined, a CTL clone was stimulated with cells expressing various MAGE genes. It produced TNF upon stimulation with target cells expressing MAGE-A10. The Ag was found to be nonapeptide GLYDGMEHL (codons 254-262), which is presented by HLA-A2.1. This is the first report on the generation of anti-MAGE CTL by autologous mixed lymphocyte-tumor cell culture (MLTC) from a melanoma patient other than patient MZ2, from whom the first MAGE gene was identified. MAGE genes are expressed in many tumors but not by normal tissues except male germline cells and placenta, which do not express HLA molecules. Therefore, the identification of an antigenic peptide derived from MAGE-A10 adds to the repertoire of tumor-specific shared Ags available for anti-tumoral vaccination trials.

HLA-G protein expression is not induced during malignant transformation

To evaluate the biological relevance of HLA-G expression during tumoral transformation, we analyzed its expression in different malignant cells and immune effector cells infiltrating solid tumors. Our analysis of 33 tumor cell lines and 53 tumoral biopsies demonstrated that: i) six tumor cell lines display HLA-G transcription with differential alternative splicing patterns and only Jeg3 choriocarcinoma and MCF-7 breast adenocarcinoma cell lines express HLA-G translated products; and ii) HLA-G antigens are not expressed in malignantly transformed cells derived from lung (n=18), liver (n=5), colon (n=5), breast (n=10), kidney (n=5), ovary (n=5), and larynx (n=5) tissues ex vivo. The healthy tissues surrounding these tumor tissues do not express HLA-G molecules either. On the other hand, surprisingly, HLA-G products were detected in activated macrophages and dendritic cells localized in tumoral biopsies of 5 out of 18 different lung carcinomas. No HLA-G labelling was observed in resident mononuclear phagocytes of surrounding healthy tissues. Our observations clearly demonstrate that HLA-G is not a marker of malignant cells but appears as a gene expressed in tumor-associated macrophages and dendritic cells, preferentially in those recruited in lung carcinomas. Our findings suggest that specific environmental factors around lung tumors could be involved in the induction of HLA-G protein expression.

Molecular expression of PSMA mRNA and protein in primary renal tumors

Human prostate-specific membrane antigen (PSMA), a 100-kDa integral transmembrane glycoprotein, is considered to be a highly specific marker of the prostate gland, and has successfully been used as a marker of circulating prostatic epithelial cells. Extended PSMA homology has been demonstrated with a cDNA found in rat cerebral and renal tissues. In this study, we aimed to evaluate the expression of PSMA mRNA in a variety of human renal cancer tissues (n = 20) and cell lines (n = 12). Using reverse transcriptase-polymerase chain reaction, DNA sequencing, blottings, and specific anti-PSMA labelling with CYT 351 antibody, we identified PSMA mRNA and protein in normal and in neoplastic renal tissue. The sequence of the polymerase-chain-reaction products is identical to that of PSMA cDNA derived from prostate tissue. Immunological staining with the CYT 351 reveals that PSMA is expressed mainly in tubular cells. Since PSMA does not appear to be restricted to prostatic tissue, this novel biomarker may prove useful in the staging of renal cancer and in the search for the hematogenous spread of renal cells.

Tumor regressions observed in patients with metastatic melanoma treated with an antigenic peptide encoded by gene MAGE-3 and presented by HLA-A1

Thirty-nine tumor-bearing patients with metastatic melanoma were treated with 3 subcutaneous injections of the MAGE-3.A1 peptide at monthly intervals. No significant toxicity was observed. Of the 25 patients who received the complete treatment, 7 displayed significant tumor regressions. All but one of these regressions involved cutaneous metastases. Three regressions were complete and 2 of these led to a disease-free state, which persisted for more than 2 years after the beginning of treatment. No evidence for a cytolytic T lymphocyte (CTL) response was found in the blood of the 4 patients who were analyzed, including 2 who displayed complete tumor regression. Our results suggest that injection of the MAGE-3.A1 peptide induced tumor regression in a significant number of the patients, even though no massive CTL response was produced.

Expression of MAGE and GAGE in high-grade brain tumors: a potential target for specific immunotherapy and diagnostic markers

The mRNA expression of the tumor-associated antigens MAGE and GAGE was examined in 60 high-grade brain tumors. This analysis was performed by using reverse transcription-PCR, Southern blotting, and sequencing. It was demonstrated that, of the eight GAGE genes, GAGE-2 and -7 were expressed in five of seven normal brains. Four groups of tumors--adult glioblastoma multiforme (n = 20), pediatric glioblastoma multiforme (n = 9), medulloblastomas (n = 15), and ependymomas (n = 14)--were analyzed for mRNA expression. The following frequencies were observed: MAGE-1, 0, 0, 13, and 0%, respectively; MAGE-2, 5, 11, 60, and 57%; MAGE-3 & -6, 0, 0, 13, and 0%; GAGE-1, 65, 11, 13, and 43%; and GAGE-3-6 and -8: 75, 78, 47, and 93%, respectively. Two unclassified tumors expressed GAGE-3-6 and -8 only. The absence of GAGE-1 expression in normal brain, its relatively high frequency of expression in high-grade brain tumors, and its unique 3' sequence, suggest it may represent a useful target for specific immunotherapy. The detection method of reverse transcription-PCR and Southern blotting may also be useful for rapid screening of biopsy specimens both for diagnostic purposes and to determine a patient's eligibility for specific immunotherapy.

A human minor histocompatibility antigen specific for B cell acute lymphoblastic leukemia

Human minor histocompatibility antigens (mHags) play an important role in the induction of cytotoxic T lymphocyte (CTL) reactivity against leukemia after human histocompatibility leukocyte antigen (HLA)-identical allogeneic bone marrow transplantation (BMT). As most mHags are not leukemia specific but are also expressed by normal tissues, antileukemia reactivity is often associated with life-threatening graft-versus-host disease (GVHD). Here, we describe a novel mHag, HB-1, that elicits donor-derived CTL reactivity in a B cell acute lymphoblastic leukemia (B-ALL) patient treated by HLA-matched BMT. We identified the gene encoding the antigenic peptide recognized by HB-1-specific CTLs. Interestingly, expression of the HB-1 gene was only observed in B-ALL cells and Epstein-Barr virus-transformed B cells. The HB-1 gene-encoded peptide EEKRGSLHVW is recognized by the CTL in association with HLA-B44. Further analysis reveals that a polymorphism in the HB-1 gene generates a single amino acid exchange from His to Tyr at position 8 within this peptide. This amino acid substitution is critical for recognition by HB-1-specific CTLs. The restricted expression of the polymorphic HB-1 Ag by B-ALL cells and the ability to generate HB-1-specific CTLs in vitro using peptide-loaded dendritic cells offer novel opportunities to specifically target the immune system against B-ALL without the risk of evoking GVHD.

Tumor regressions observed in patients with metastatic melanoma treated with an antigenic peptide encoded by gene MAGE-3 and presented by HLA-A1

Thirty-nine tumor-bearing patients with metastatic melanoma were treated with 3 subcutaneous injections of the MAGE-3.A1 peptide at monthly intervals. No significant toxicity was observed. Of the 25 patients who received the complete treatment, 7 displayed significant tumor regressions. All but one of these regressions involved cutaneous metastases. Three regressions were complete and 2 of these led to a disease-free state, which persisted for more than 2 years after the beginning of treatment. No evidence for a cytolytic T lymphocyte (CTL) response was found in the blood of the 4 patients who were analyzed, including 2 who displayed complete tumor regression. Our results suggest that injection of the MAGE-3.A1 peptide induced tumor regression in a significant number of the patients, even though no massive CTL response was produced.

Mutations of the beta2-microglobulin gene result in a lack of HLA class I molecules on melanoma cells of two patients immunized with MAGE peptides

Mutations have been identified in the beta2-microglobulin gene of tumor cells of two metastatic melanoma patients who received immunizations with MAGE peptides. One mutation abolishes the start codon whereas the other introduces a premature stop codon. The second beta2-microglobulin allele of both tumors appears to be lost on the basis of sequence data and loss of microsatellite heterozygosity. The lack of beta2-microglobulin gene product results in the absence of HLA class I antigens on the surface of the tumor cells. This may explain why the tumors of both patients progressed despite the immunization treatment and shows the necessity of analyzing in depth the antigen presentation capability of the tumor cells for the interpretation of clinical trials involving anti-tumor vaccination.

An antigen recognized by autologous CTLs on a human bladder carcinoma

By stimulating blood lymphocytes with autologous bladder carcinoma cells that had been transfected with B7-1, we obtained a panel of CTL clones which lyse specifically the bladder tumor cells in an MHC class I-restricted fashion. Based on inhibition with anti-HLA Abs and the recognition of allogeneic tumor cells, we could distribute our clones in three groups that recognized three distinct Ags. We characterized one of these Ags by screening a cDNA library prepared with the RNA from this bladder tumor line. This new tumor Ag is a peptide presented by HLA-B4403 molecules. It is produced by a point mutation in a gene that is recorded in databases under the name KIAA0205, is ubiquitously expressed, and whose function is unknown. We also found this mutation in the tumor sample that was originally resected from this patient, but the mutation was not found in the 100 or more independent tumors of various histologic types that were tested. This report is the first to describe the isolation of CTL clones directed against human bladder cancer and the molecular characterization of a bladder tumor Ag.

Reliability of reverse transcription-polymerase chain reaction (RT-PCR)-based assays for the detection of circulating tumour cells: a quality-assurance initiative of the EORTC Melanoma Cooperative Group

Reverse transcription-polymerase chain reaction (RT-PCR)-based assays detecting occult neoplastic cells are increasingly being used for the study of tumour dissemination and minimal residual disease. However, different methods are employed by various research groups and the results are heterogenous. We prospectively assessed the results from nine laboratories performing tyrosinase RT-PCR assays for the detection of melanoma cells on a series of blind samples. After complete analysis, the results were compared for sensitivity and specificity. All laboratories reported correct results for cDNA standards. Five laboratories attained acceptable specificity and a sensitivity detecting 10 cells in 10 ml of whole blood. Four laboratories had unacceptable specificity and/or sensitivity. This blind study highlights the difficulty of RT-PCR data interpretation and the need for quality assurance between laboratories. Measures to increase the reliability of RT-PCR assays are proposed, which have to be prospectively evaluated in future studies.

Genes coding for melanoma antigens recognised by cytolytic T lymphocytes

It is now well established that human melanoma cells express antigens that are recognised by cytolytic T lymphocytes derived from the tumour-bearing patient. The molecular definition of these antigens is progressing at an accelerated pace. The currently characterised melanoma antigens can be classified into three categories: differentiation antigens, antigens encoded by genes that are specifically expressed in tumours, and antigens encoded by mutated genes. Several of these antigens are sufficiently tumour-specific to qualify them as candidate anti-cancer vaccines in melanoma patients.

Identification of human testis-specific transcripts and analysis of their expression in tumor cells

Tumor-specific antigens recognized by autologous T lymphocytes are encoded by genes, including those of the MAGE, BAGE, and GAGE gene families, that are expressed in a significant fraction of tumors of various types, but not in normal adult tissues, except for testis where they appear to be expressed in germ cells. Because male germ cells are known to express many genes that are not expressed in other normal adult tissues, we wished to determine whether most of these genes are occasionally activated in tumor cells. Representational difference analysis was used to obtain testis-specific transcripts. The expression of 15 testis-specific cDNA sequences was tested by RT-PCR in a series of tumor cell lines. Only one cDNA sequence showed a significant level of expression in some tumor cell lines. Remarkably, this cDNA clone proved to be a new gene of the MAGE family. These results suggest that MAGE, BAGE, and GAGE genes belong to a minor subset of testis-specific genes that is often activated in tumors of various types, whereas most testis-specific genes are either never or very rarely activated in tumors.

Two members of the human MAGEB gene family located in Xp21.3 are expressed in tumors of various histological origins

Genes of the MAGE family direct the expression of tumor antigens recognized on a human melanoma by autologous cytolytic T lymphocytes. Twelve closely related MAGE genes are located in the Xq28 region. These genes share 60-98% nucleotide identity in their coding region. The presence of homologous genes in a region of Xp21.3 has been reported previously. We obtained the complete sequence of a 42-kb stretch of this region. It contains four MAGE-related genes, which we propose to name MAGE-B1, B2, B3, and B4 (HGMW-approved symbols MAGEB1, MAGEB2, MAGEB3, and MAGEB4). The coding regions of these genes share 66-81% nucleotide identity and show 45-63% identity with those of the MAGE genes located in Xq28. Like the MAGE genes located in Xq28, the MAGE-B genes are silent in normal tissues with the exception of testis. Like MAGE-1, 2, 3, 4, 6 and 12 (HGMW-approved symbols MAGEA1, 2, 3, 4, 6, and 12), genes MAGE-B1 and MAGE-B2 are expressed in a significant fraction of tumors of various histological types. The transcription of MAGE-B1 and MAGE-B2 can be induced by 5-aza-2'-deoxycytidine, suggesting that the activation of these genes in tumors results from a demethylation process.

A CASP-8 mutation recognized by cytolytic T lymphocytes on a human head and neck carcinoma

Of the antigens recognized on human tumors by autologous cytolytic T lymphocytes, all those defined thus far have been identified on melanoma or renal cell carcinoma. We report here the identification of an antigen recognized by autologous cytolytic T lymphocytes on a human squamous cell carcinoma of the oral cavity. The antigen is encoded by a mutated form of the CASP-8 gene. This gene, also named FLICE or MACH, codes for protease caspase-8, which is required for induction of apoptosis through the Fas receptor and tumor necrosis factor receptor-1. The mutation, which was found in the tumor cells but not in the normal cells of the patient, modifies the stop codon and adds an Alu repeat to the coding region, thereby lengthening the protein by 88 amino acids. The ability of the altered protein to trigger apoptosis appears to be reduced relative to the normal caspase-8. The antigenic peptide is a nonamer presented by HLA-B*3503. The five last amino acids are encoded by the extension of the reading frame caused by the mutation. This, together with previous observations of CDK4 and beta-catenin mutations, suggests that a significant fraction of the point mutations generating a tumor antigen also play a role in the tumoral transformation or progression.

MAGE-1 expression threshold for the lysis of melanoma cell lines by a specific cytotoxic T lymphocyte

Human gene MAGE-1 codes for an antigen that is recognized on a melanoma by an autologous cytotoxic T lymphocyte (CTL). Because MAGE-1 is expressed on a significant proportion of tumours of various histological types and not on normal tissues, the encoded antigen may serve as a target for cancer immunotherapy. Evaluation of the expression of the gene by reverse transcription polymerase chain reaction (RT-PCR) in various tumour samples and tumour cell lines has suggested great variability in the level of expression. It was therefore important to evaluate the minimal level of expression required for lysis by CTL. We tested a number of melanoma cell lines by a quantitative RT-PCR assay to correlate their level of MAGE-1 expression and recognition by the relevant CTL clone. We found that only cell lines expressing more than 10% of the MAGE-1 messenger RNA (mRNA) level of reference cell line MZ2-MEL.3.0 (i.e. more than three mRNA molecules per cell) were lysed by the CTL or induced significant tumour necrosis factor release.

Expression of MAGE genes in esophageal squamous-cell carcinoma

The genes MAGE-1, -2, -3 and -4 are expressed in tumors of different histological types, but not in normal tissues, with the exception of testis and placenta. Short peptides derived from MAGE-1 and MAGE-3 gene products are recognized by cytolytic T lymphocytes when presented by HLA-class-I molecules, and represent potential targets for specific immunotherapy. We have determined whether esophageal carcinoma patients should be eligible for MAGE-peptide-based vaccine therapies. The expression of genes MAGE-1, -2, -3 and -4 in tumor samples was assessed by reverse-transcription and polymerase-chain-reaction amplification. Out of the 49 esophageal squa-mous-cell carcinomas studied, 53% expressed MAGE-1, 49% MAGE-2, 47% MAGE-3 and 71% MAGE-4. Eighty-four percent of the tumors expressed one or more of the four MAGE genes. Owing to the high incidence of MAGE gene expression in esophageal squamous-cell carcinoma, a large proportion of patients could be suitable candidates for immune therapies involving tumor-specific antigens encoded by MAGE genes.

The activation of human gene MAGE-1 in tumor cells is correlated with genome-wide demethylation

Human gene MAGE-1 encodes tumor-specific antigens that are recognized on melanoma cells by autologous cytolytic T lymphocytes. This gene is expressed in a significant proportion of tumors of various histological types, but not in normal tissues except male germ-line cells. We reported previously that reporter genes driven by the MAGE-1 promoter are active not only in the tumor cell lines that express MAGE-1 but also in those that do not. This suggests that the critical factor causing the activation of MAGE-1 in certain tumors is not the presence of the appropriate transcription factors. The two major MAGE-1 promoter elements have an Ets binding site, which contains a CpG dinucleotide. We report here that these CpG are demethylated in the tumor cell lines that express MAGE-1, and are methylated in those that do not express the gene. Methylation of these CpG inhibits the binding of transcription factors, as seen by mobility shift assay. Treatment with the demethylating agent 5-aza-2'-deoxycytidine activated gene MAGE-1 not only in tumor cell lines but also in primary fibroblasts. Finally, the overall level of CpG methylation was evaluated in 20 different tumor cell lines. It was inversely correlated with the expression of MAGE-1. We conclude that the activation of MAGE-1 in cancer cells is due to the demethylation of the promoter. This appears to be a consequence of a genome-wide demethylation process that occurs in many cancers and is correlated with tumor progression.

Infrequent expression of the MAGE gene family in uveal melanomas

It has previously been reported that MAGE-1, -2, -3 and -4 genes are expressed in human cancers including cutaneous melanoma. MAGE-1 and MAGE-3 represent targets for specific immunotherapy because they encode peptide antigens which are recognised by cytotoxic T lymphocytes (CTL) when presented by HLA class I molecules, and pilot clinical trials with these peptides are currently in progress. It is likely that other members of the MAGE gene family may also encode antigens recognised by CTL. Uveal melanomas, like cutaneous melanomas, arise from melanocytes that are derived from the neural crest. To determine if uveal melanoma patients would be suitable for MAGE-peptide immunotherapy, the expression of MAGE-1, -2, -3 and -4 genes was assessed by reverse transcription followed by polymerase chain reaction (RT-PCR) amplification and ethidium bromide staining. Expression of MAGE genes was not detected in any of 27 primary tumours. Either MAGE-1 or MAGE-4 was expressed in only 2 of 26 metastatic samples, but expression of MAGE-2 or -3 was not detected. Our data suggest that, unlike cutaneous melanomas, uveal melanomas may not be suitable candidates for MAGE-peptide immunotherapy.

A mutated HLA-A2 molecule recognized by autologous cytotoxic T lymphocytes on a human renal cell carcinoma

Many human tumor cells have been shown to express antigens that are recognized by autologous cytotoxic T lymphocytes (CTL) and the molecular nature of a number of melanoma antigens has been defined recently. Here we describe the characterization of an antigen recognized on a renal cell carcinoma by autologous CTL clones. This antigen is encoded by the HLA-A2 gene present in the tumor cells. The sequence of this gene differs from the HLA-A2 sequence found in autologous peripheral blood lymphocytes by a point mutation that results in an arginine to isoleucine exchange at residue 170, which is located on the alpha-helix of the alpha 2 domain. Transfection experiments with the normal and mutated HLA-A2 cDNA demonstrated that this amino acid replacement was responsible for the recognition of the HLA-A2 molecule expressed on the tumor cells. The mutant HLA-A2 gene was also detected in the original tumor tissue from the patient, excluding the possibility that the mutation had appeared in vitro. Thus, HLA class I molecules carrying a tumor-specific mutation can be involved in the recognition of tumor cells by autologous CTL.

A peptide recognized by human cytolytic T lymphocytes on HLA-A2 melanomas is encoded by an intron sequence of the N-acetylglucosaminyltransferase V gene

A cytolytic T lymphocyte (CTL) clone that lyses many HLA-A2 melanomas was derived from a population of tumor-infiltrating lymphocytes of an HLA-A2 melanoma patient. The gene coding for the antigen recognized by this CTL was identified by transfection of a cDNA library. It is the gene which has been reported to code for N-acetylglucosaminyltransferase V (GnT-V). Remarkably, the antigenic peptide recognized by the CTL is encoded by a sequence located in an intron. In contrast to the fully spliced GnT-V mRNA, which was found in a wide range of normal and tumoral tissues, the mRNA containing the intron region coding for the antigen was not found at a significant level in normal tissues. This mRNA was observed to be present in about 50% of melanomas. Our results suggest that a promoter located near the end of the relevant intron is activated in melanoma cells, resulting in the production of an mRNA coding for the antigen.

Expression of MAGE genes in primary and metastatic cutaneous melanoma

Human genes MAGE-1 and MAGE-3 code for antigens that are recognized on melanoma cells by autologous cytolytic T lymphocytes. These antigens may constitute useful targets for specific anti-tumor immunization of cancer patients, since genes MAGE-1 and MAGE-3 are expressed in a number of tumors of different histological types, but are not expressed in normal adult tissues other than testis. This also applies to genes MAGE-2 and MAGE-4, which are closely related to MAGE-1 and MAGE-3. We have analyzed the expression of these 4 MAGE genes in cutaneous melanoma. Sixteen of 100 primary tumors vs. 69 (48%) of 145 metastases from individual patients expressed MAGE-1. Similar differences in the frequency of gene expression between primary and metastatic tumor samples were observed for MAGE-2, MAGE-3, and MAGE-4. MAGE expression in primary tumors was correlated with tumor thickness: there was a significantly increased frequency in the expression of MAGE-1, -2 and -3 in tumors of greater thickness. Benign and dysplastic nevi, as well as in situ melanomas, did not express any of the 4 MAGE genes.

Expression of MAGE genes in transitional-cell carcinomas of the urinary bladder

Human genes MAGE-1 and MAGE-3 code for distinct antigens, which are recognized on melanoma cells by autologous cytolytic T lymphocytes (CTL). These antigens may constitute useful targets for anti-cancer immunotherapy, since no expression of MAGE genes has been observed in normal tissues other than testis. Out of 57 samples of primary transitional-cell carcinomas of the bladder, 12 (21%) expressed MAGE-1 and 20 (35%) expressed MAGE-3. All but one of the tumors expressing MAGE-1 also expressed MAGE-3. Genes MAGE-2 and MAGE-4, which are closely related to MAGE-1 and MAGE-3, were expressed by 30% and 33% of the tumors respectively. MAGE expression was more frequent in advanced tumor stages: 61% of the invasive tumors (stage > or = T2) were positive for expression of at least one of the four genes, whereas only 28% of the superficial tumors (stages Ta and T1) expressed these genes.

Structure, chromosomal localization, and expression of 12 genes of the MAGE family

We reported previously that human gene MAGE-1 directs the expression of a tumor antigen recognized on a melanoma by autologous cytolytic T lymphocytes. Probing cosmid libraries with a MAGE-1 sequence, we identified 11 closely related genes. The analysis of hamster-human somatic cell hybrids indicated that the 12 MAGE genes are located in the q terminal region of chromosome X. Like MAGE-1, the 11 additional MAGE genes have their entire coding sequence located in the last exon, which shows 64%-85% identity with that of MAGE-1. The coding sequences of the MAGE genes predict the same main structural features for all MAGE proteins. In contrast, the promoters and first exons of the 12 MAGE genes show considerable variability, suggesting that the existence of this gene family enables the same function to be expressed under different transcriptional controls. The expression of each MAGE gene was evaluated by reverse transcription and polymerase chain reaction amplification. Six genes of the MAGE family including MAGE-1 were found to be expressed at a high level in a number of tumors of various histological types. None was expressed in a large panel of healthy tissues, with the exception of testis and placenta.

Expression of mage genes by non-small-cell lung carcinomas

Human gene MAGE-I codes for an antigen that is recognized on melanoma cells by autologous cytolytic T lymphocytes (CTL). This antigen is potentially useful as a target for cancer immunotherapy because gene MAGE-I is not expressed in any normal tissues except the testis. We tested 46 surgical samples of non-small-cell lung carcinomas and observed MAGE-I expression in 16 of them (35%). Genes MAGE-2 and 3, which are closely related to MAGE-I, were expressed by a similar proportion of these tumors. Some small-cell lung tumors also express MAGE genes. The proportion of tumors expressing MAGE-I suggests that lung tumor patients may constitute the largest group of patients potentially eligible for pilot studies involving MAGE-I immunization.

Human gene MAGE-3 codes for an antigen recognized on a melanoma by autologous cytolytic T lymphocytes

Human melanoma cell line MZ2-MEL expresses several antigens recognized by autologous cytolytic T lymphocyte (CTL) clones. We reported previously the identification of a gene, named MAGE-1, that codes for one of these antigens named MZ2-E. We show here that antigen MZ2-D, which is present on the same tumor, is encoded by another member of the MAGE gene family named MAGE-3. Like MAGE-1, MAGE-3 is composed of three exons and the large open reading frame is entirely located in the third exon. Its sequence shows 73% identity with MAGE-1. Like MZ2-E, antigen MZ2-D is presented by HLA-A1. The antigenic peptide of MZ2-D is a nonapeptide that is encoded by the sequence of MAGE-3 that is homologous to the MAGE-1 sequence coding for the MZ2-E peptide. Competition experiments using single Ala-substituted peptides indicated that amino acid residues Asp in position 3 and Tyr in position 9 were essential for binding of the MAGE-1 peptide to HLA-A1. Gene MAGE-3 is expressed in many tumors of several types, such as melanoma, head and neck squamous cell carcinoma, lung carcinoma and breast carcinoma, but not in normal tissues except for testes. It is expressed in a larger proportion of melanoma samples than MAGE-1. MAGE-3 encoded antigens may therefore have a wide applicability for specific immunotherapy of melanoma patients.