mRNA expression of MAGE-A3 gene in leukemia cells

Overexpression of BCL2, BCL6, VEGFR1 and TWIST1 in Circulating Tumor Cells Derived from Patients with DLBCL Decreases Event-Free Survival

Purpose

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous malignant lymphoid neoplasm and is the most common subtype of non-Hodgkin lymphoma in adults. More than half of patients with DLBCL can achieve remission with standard R-CHOP regimes; however, approximately 30-40% of patients are still failing this standard therapy, which remains as an important cause of progression and mortality of this disease. It is necessary to have diagnostic and monitoring tools that allow us to improve the accuracy of prognosis in these patients. Circulating tumor cells (CTCs) identification through molecular biomarkers is one of the novel strategies that have been used in other types of cancer, and we aim to use this tool to analyze the potential role in DLBCL.

Patients and Methods

We analyzed 138 blood samples of patients with DLBCL, of which CTCs were isolated by density gradient for subsequent detection and quantitation of molecular biomarkers using RT-qPCR with TaqMan probes. Survival analysis was performed using Kaplan-Meier curves.

Results

We found overexpression of ABCB1, αSMA, BCL2, BCL6 and VEGFR1 genes, as well as the presence of CK19, EpCAM, KI67, MAGE-A4, SNAIL and TWIST1 genes. CK19 and EpCAM expression were associated with a minor OS (85.7% vs 98.1%, p = 0.002). The overexpression of BCL2, BCL6, VEGFR1 and TWIST1 was related to a minor EFS (p = 0.001).

Conclusion

This study showed that in liquid biopsies analyzed, the presence of CTCs can be confirmed through molecular biomarkers, and it has an impact on OS and EFs, making this detection useful in the follow-up and prognosis of patients with DLBCL.

Acute Myeloid Leukemia: From Biology to Clinical Practices Through Development and Pre-Clinical Therapeutics

Recent studies have provided several insights into acute myeloid leukemia. Studies based on molecular biology have identified eight functional mutations involved in leukemogenesis, including driver and passenger mutations. Insight into Leukemia stem cells (LSCs) and assessment of cell surface markers have enabled characterization of LSCs from hematopoietic stem and progenitor cells. Clonal evolution has been described as having an effect similar to that of microenvironment alterations. Such biological findings have enabled the development of new targeted drugs, including drug inhibitors and monoclonal antibodies with blockage functions. Some recently approved targeted drugs have resulted in new therapeutic strategies that enhance standard intensive chemotherapy regimens as well as supportive care regimens. Besides the progress made in adoptive immunotherapy, since allogenic hematopoietic stem cell transplantation enabled the development of new T-cell transfer therapies, such as chimeric antigen receptor T-cell and transgenic TCR T-cell engineering, new promising strategies that are investigated.

Immunological and functional aspects of MAGEA3 cancer/testis antigen

Identification of ectopic gene activation in cancer cells serves as a basis for both gene signature-guided tumor targeting and unearthing of oncogenic mechanisms to expand the understanding of tumor biology/oncogenic process. Proteins expressed only in germ cells of testis and/or placenta (immunoprivileged organs) and in malignancies are called cancer testis antigens; they are antigenic because of the lack of antigen presentation by those specific cell types (germ cells), which limits the exposure of the proteins to the immune cells. Since the Cancer Testis Antigens (CTAs) are immunogenic and expressed in a wide variety of cancer types, CT antigens have become interesting target for immunotherapy against cancer. Among CT antigens MAGEA family is reported to have 12 members (MAGEA1 to MAGEA12). The current review highlights the studies on MAGEA3 which is a CT antigen and reported in almost all types of cancer. MAGEA3 is well tried for cancer immunotherapy. Recent advances on its functional and immunological aspect warranted much deliberation on effective therapeutic approach, thus making it a more interesting target for cancer therapy.

T cells targeting multiple tumor-associated antigens as a postremission treatment to prevent or delay relapse in acute myeloid leukemia

Background

Relapse is a major problem in acute myeloid leukemia (AML) and adversely affects survival. Tumor-associated antigen-specific cytotoxic T lymphocyte (TAA-CTLs)-based therapy was introduced and increasingly used clinically to kill tumor cells via tumor antigen activation.

Method

In this study, we expanded autologous lymphocytes reactive to five TAA (NY-ESO-1, MAGE-A3, WT1, Survivin, and PRAME) and evaluated its safety and efficacy in 9 patients with AML at high risk of relapse.

Results

Before first TAA-CTL infusion, 5 patients were minimal residual disease (MRD) positive, whereas 4 were MRD negative. Patients received TAA-CTL infusion for 1–3 times. None of them had obvious adverse reactions during or post the infusion. Of the 4 MRD-negative patients who were infused with TAA-CTLs, one developed relapsed disease. Among 5 MRD+ patients, there was a demonstrable antileukemic effect of the TAA-CTLs alone without any concomitant chemotherapy in 2 patients, as demonstrated by the negative of MRD in bone marrow after TAA-CTL infusion.

Conclusions

In summary, we have observed preliminary indications of activity and safety after administration of autologous TAA-CTLs in patients with AML. The ultimate question of clinical efficacy, however, will need to be addressed in a larger trial with larger homogeneous patient population.

Checkpoint inhibitors and acute myelogenous leukemia: promises and challenges

INTRODUCTION

Immunity, for treatment of acute myelogenous leukemia (AML), has been leveraged historically in the form of allogeneic stem cell transplantation. Checkpoint inhibitors (CPI) as positive modulators of immune response have been recent major breakthroughs in solid tumors. Areas covered: Emerging concepts and clinical data with CPIs in acute Myeloid Leukemia - the focus of this review- will be discussed. CPIs can potentially be effective in absence of 'actionable' mutations and are expected to be effective against poor-risk AML. Immune inhibitory checkpoint molecules are upregulated in both de novo and relapsed AML. Similar data also suggest role of checkpoint molecules in mediating resistance particularly to hypomethylating agent (HMA) therapy, which can potentially be reversed by using checkpoint inhibitors. Expert commentary: Ongoing clinical trials in combination with HMAs are showing early promise, with doubling of response than that seen in historic controls. The optimal combinations of CPIs and the optimal space that they will fit in the continuum of AML therapies need lot of in depth work.

Leukemia Associated Antigens: Their Dual Role as Biomarkers and Immunotherapeutic Targets for Acute Myeloid Leukemia

Leukemia associated antigens (LAAs) are being increasingly identified by methods such as cytotoxic T-lymphocyte (CTL) cloning, serological analysis of recombinant cDNA expression libraries (SEREX) and mass spectrometry (MS). In additional, large scale screening techniques such as microarray, single nucleotide polymorphisms (SNPs), serial analysis of gene expression (SAGE) and 2-dimensional gel electrophoresis (2-DE) have expanded our understanding of the role that tumor antigens play in the biological processes which are perturbed in acute myeloid leukemia (AML). It has become increasingly apparent that these antigens play a dual role, not only as targets for immunotherapy, but also as biomarkers of disease state, stage, response to treatment and survival. We need biomarkers to enable the identification of the patients who are most likely to benefit from specific treatments (conventional and/or novel) and to help clinicians and scientists improve clinical end points and treatment design. Here we describe the LAAs identified in AML, to date, which have already been shown to play a dual role as biomarkers of AML disease.

CD8+ TIL recruitment may revert the association of MAGE A3 with aggressive features in thyroid tumors

Background. We aimed to investigate a possible role of MAGE A3 and its associations with infiltrated immune cells in thyroid malignancy, analyzing their utility as a diagnostic and prognostic marker. Materials and Methods. We studied 195 malignant tissues: 154 PTCs and 41 FTCs; 102 benign tissues: 51 follicular adenomas and 51 goiter and 17 normal thyroid tissues. MAGE A3 and immune cell markers (CD4 and CD8) were evaluated using immunohistochemistry and compared with clinical pathological features. Results. The semiquantitative analysis and ACIS III analysis showed similar results. MAGE A3 was expressed in more malignant than in benign lesions (P < 0.0001), also helping to discriminate follicular-patterned lesions. It was also higher in tumors in which there was extrathyroidal invasion (P = 0.0206) and in patients with stage II disease (P = 0.0107). MAGE A3+ tumors were more likely to present CD8+ TIL (P = 0.0346), and these tumors were associated with less aggressive features, that is, extrathyroidal invasion and small size. There was a trend of MAGE A3+ CD8+ tumors to evolve free of disease. Conclusion. We demonstrated that MAGE A3 and CD8+ TIL infiltration may play an important role in malignant thyroid nodules, presenting an interesting perspective for new researches on DTC immunotherapy.

Immunomodulatory action of SGI-110, a hypomethylating agent, in acute myeloid leukemia cells and xenografts

The mechanism of clinical action for the FDA approved hypomethylating drugs azacitidine and decitabine remains unresolved and in this context the potential immunomodulatory effect of these agents on leukemic cells is an area of active investigation. Induced expression of methylated Cancer Testis Antigen (CTA) genes has been demonstrated in leukemic cell lines following exposure to hypomethylating drugs in vitro. SGI-110 is a novel hypomethylating dinucleotide with prolonged in vivo exposure and clinical activity in patients with MDS and AML. We demonstrate that this agent, like decitabine, produces robust re-expression of the CTAs NY-ESO-1 and MAGE-A, both in vitro and in leukemia-bearing AML xenografts. Upregulation of these genes in vitro was sufficient to induce cytotoxicity by HLA-compatible CD8+ T-cells specific for NY-ESO-1, a well-recognized and immunogenic CTA. Additionally, exposure to SGI-110 enhances MHC class I and co-stimulatory molecule expression, potentially contributing to recognition of CTAs. SGI-110, like the parent compound decitabine, induces expression of CTAs and might modulate immune recognition of myeloid malignancy.

Generation of tumor antigen-specific T cell lines from pediatric patients with acute lymphoblastic leukemia--implications for immunotherapy

PURPOSE

Although modern cure rates for childhood acute lymphoblastic leukemia (ALL) exceed 80%, the outlook remains poor in patients with high-risk disease and those who relapse, especially when allogeneic hematopoietic stem cell transplantation is not feasible. Strategies to improve outcome and prevent relapse are therefore required. Immunotherapy with antigen-specific T cells can have antileukemic activity without the toxicities seen with intensive chemotherapy, and therefore represents an attractive strategy to improve the outcome of high-risk patients with ALL. We explored the feasibility of generating tumor antigen-specific T cells ex vivo from the peripheral blood of 50 patients with ALL [26 National Cancer Institute (NCI) high-risk and 24 standard-risk] receiving maintenance therapy.

EXPERIMENTAL DESIGN

Peripheral blood mononuclear cells were stimulated with autologous dendritic cells pulsed with complete peptide libraries of WT1, Survivin, MAGE-A3, and PRAME, antigens frequently expressed on ALL blasts.

RESULTS

T-cell lines were successfully expanded from all patients, despite low lymphocyte counts and irrespective of NCI risk group. Antigen-specificity was observed in more than 50% of patients after the initial stimulation and increased to more than 90% after three stimulations as assessed in IFN-γ-enzyme-linked immunospot (ELISpot) and (51)Cr-release assays. Moreover, tumor-specific responses were observed by reduction of autologous leukemia blasts in short- and long-term coculture experiments.

CONCLUSION

This study supports the use of immunotherapy with adoptively transferred autologous tumor antigen-specific T cells to prevent relapse and improve the prognosis of patients with high-risk ALL.

Potential contribution of SIM2 and ETS2 functional polymorphisms in Down syndrome associated malignancies

Background

Proper expression and functioning of transcription factors (TFs) are essential for regulation of different traits and thus could be crucial for the development of complex diseases. Subjects with Down syndrome (DS) have a higher incidence of acute lymphoblastic leukemia (ALL) while solid tumors, like breast cancer (BC) and oral cancer (OC), show rare incidences. Triplication of the human chromosome 21 in DS is associated with altered genetic dosage of different TFs. V-ets erythroblastosis virus E26 oncogene homolog 2 (ETS2) and Single Minded 2 (SIM2) are two such TFs that regulate several downstream genes involved in developmental and neurological pathways. Here we studied functional genetic polymorphisms (fSNP) in ETS2 and SIM2 encoding genes in a group of patients and control subjects to better understand association of these variants with DS phenotypes.

Methods

We employed an in silico approach to identify potential target pathways of ETS2 and SIM2. fSNPs in genes encoding for these two TFs were identified using available databases. Selected sites were genotyped in individuals with DS, their parents, ALL, BC, OC as well as ethnically matched control individuals. We further analyzed these data by population-based statistical methods.

Results

Allelic/genotypic association analysis showed significant (P < 0.03) differences of rs2070530, rs1051476, rs11254, rs711 for DS subjects compared to control. rs711 also exhibited significantly different genotypic distribution pattern in parents of DS probands (P < 0.02) and BC patients (P < 0.02). Interaction analysis revealed independent main effect of rs711 in all the groups, while rs11254 exhibited independent main effect in DS subjects only. High entropy values were noticed for rs461155 in the solid tumor groups. Significant interactive effects of rs2070531 with rs1051475, rs1051476, rs11254 were observed in all the groups except DS.

Conclusions

We infer from the present investigation that the difference in frequencies of fSNPs and their independent as well as interactive effects may be the cause for altered expression of SIM2 and ETS2 in DS and malignant groups, which affects different downstream biological pathways. Thus, altered expression of SIM2 and ETS2 could be one of the reasons for variable occurrence of different malignant conditions in DS.

Leukemia-associated antigens and their relevance to the immunotherapy of acute myeloid leukemia

The graft-versus-leukemia effect of allogeneic hematopoietic stem cell transplantation (HSCT) has shown that the immune system is capable of eradicating acute myeloid leukemia (AML). This knowledge, along with the identification of the target antigens against which antileukemia immune responses are directed, has provided a strong impetus for the development of antigen-targeted immunotherapy of AML. The success of any antigen-specific immunotherapeutic strategy depends critically on the choice of target antigen. Ideal molecules for immune targeting in AML are those that are: (1) leukemia-specific; (2) expressed in most leukemic blasts including leukemic stem cells; (3) important for the leukemic phenotype; (4) immunogenic; and (5) clinically effective. In this review, we provide a comprehensive overview on AML-related tumor antigens and assess their applicability for immunotherapy against the five criteria outlined above. In this way, we aim to facilitate the selection of appropriate target antigens, a task that has become increasingly challenging given the large number of antigens identified and the rapid pace at which new targets are being discovered. The information provided in this review is intended to guide the rational design of future antigen-specific immunotherapy trials, which will hopefully lead to new antileukemia therapies with more selectivity and higher efficacy.

MAGE-A3 expression is an adverse prognostic factor in diffuse large B-cell lymphoma

This study evaluates the prognostic value of MAGE-A3 expression in 28 diffuse large B-cell lymphoma (DLBCL) patients. A significant association was observed between MAGE-A3 expressions, assessed by quantitative real-time RT-polymerase chain reaction (PCR), with advanced stages of disease (P < 0.05). Elevated serum lactate dehydrogenase (LDH) levels and International Prognostic Index (IPI) score were significantly higher in MAGE-A3-positive patients (P = 0.025 and P = 0.004, respectively). Expression of MAGE-A3 was associated with poor response to treatment and a significantly shorter overall survival (P < 0.001). Our data address new information in the association of MAGE-A3 expression and poor prognosis in DLBCL patients.

Antigens in chronic myeloid leukemia: implications for vaccine development

Treatment with imatinib mesylate and other tyrosine kinase inhibitors (TKI) revolutionized the therapy of chronic myeloid leukemia (CML). However, it alone does not cure this disease. Moreover, some patients develop resistance or adverse effects to this therapy. As successful treatment of a portion of CML patients by hematopoietic stem cell transplantation (HSCT) suggests the importance of immune mechanisms in the elimination of leukemic cells, including leukemia stem cells, TKI administration or HSCT might be combined with vaccination to cure CML patients. However, antigens implicated in the immune responses have not yet been sufficiently identified. Therefore, in this report, we compiled and characterized a list of 165 antigens associated with CML (CML-Ag165) and analyzed the expression of the corresponding genes in CML phases, subpopulations of leukemic cells, and CML-derived cell lines using available datasets from microarray transcriptional-profiling studies. From the CML-Ag165 list, we selected antigens most suitable for vaccine development and evaluated their appropriate characteristics.

Cancer-testis antigen expression and its epigenetic modulation in acute myeloid leukemia

Cancer-testis antigens (CTA) represent attractive targets for tumor immunotherapy. However, a broad picture of CTA expression in acute myeloid leukemia (AML) is missing. CTA expression was analyzed in normal bone marrow (BM) as well as in AML cell lines before and after treatment with demethylating agents and/or histone acetylase inhibitors. Presence of selected CTA with a strictly tumor-restricted expression was then determined in samples of patients with AML before and after demethylating therapy. Screening AML cell lines for the expression of 20 CTA, we identified six genes (MAGE-A3, PRAME, ROPN1, SCP-1, SLLP1, and SPO11) with an AML-restricted expression. Analyzing the expression of these CTA in blast-containing samples from AML patients (N = 64), we found all samples to be negative for MAGE-A3 and SPO11 while a minority of patients expressed ROPN1 (1.6%), SCP-1 (3.1%), or SLLP1 (9.4%). The only CTA expressed in substantial proportion of patients (53.1%) was PRAME. Following demethylating treatment with 5'-aza-2'-deoxycytidine, we observed an increased or de novo expression of CTA, in particular of SSX-2, in AML cell lines. In AML patients, we detected increased expression of PRAME and induction of SSX-2 after demethylating therapy with 5-azacytidine. With the exception of PRAME, CTA are mostly absent from AML blasts. However, demethylating treatment induces strong expression of CTA, particularly of SSX-2, in vitro and in vivo. Therefore, we propose that CTA-specific immunotherapy for AML should preferentially target PRAME and/or should be combined with the application of demethylating agents opening the perspective for alternative targets like CTA SSX-2.

The melanoma-associated antigen-A3, -A4 genes: relation to the risk and clinicopathological parameters in breast cancer patients

This study aimed to evaluate the clinical reliability and accuracy of two MAGE transcripts (MAGE-A3, MAGE-A4 mRNA) in the peripheral blood (PB) of patients with breast cancer (BC), and to evaluate their potential limits and utility to detect BC. We aimed also to analyze their relation to clinicopathological characteristics of the tumor. This study is a prospective, controlled, double-blinded study conducted on 100 BC women and 100 age-matched control women. There were 52 patients with localized breast mass with no evidence of nodal affection or distant metastases and 48 patients suffering from metastatic BC. MAGE-A3 and MAGE-A4 mRNA in the PB were assayed using reverse transcriptase-polymerase chain reaction (RT-PCR). None of the control women was positive for either MAGE-A3, MAGE-A4. In BC women, positivity for MAGE-A3 in PB was observed in 37 patients (37%), and MAGE-A4 positivity was observed in 11 patients (11%); with 100% specificity for both transcripts. The presence of MAGE-A3 was significantly associated with nodal status (P = 0.009), tumor size (P = 0.009), and American Joint Committee on Cancer stage (P = 0.009), whereas MAGE-A4 positivity was significantly associated with histological grade (P = 0.020). RT-PCR assays of MAGE-A3 and MAGE-A4 in the PB of BC patients may have prognostic and predictive implications, and they are promising specific tumor markers of BC.

CD8(+) T-cell immunity against cancer-testis antigens develops following allogeneic stem cell transplantation and reveals a potential mechanism for the graft-versus-leukemia effect

BACKGROUND

Allogeneic stem cell transplantation is associated with a powerful 'graft-versus-leukemia' effect that is generally considered to result from an alloreactive T-cell immune response. However, disease remission can also be observed after syngeneic transplantation and we investigated whether a T-cell immune response to cancer-testis antigens can be detected in patients in the post-transplant period.

DESIGN AND METHODS

The T-cell immune response against cancer-testis antigens was studied in a cohort of 41 patients who underwent allogeneic stem cell transplantation for the management of acute myeloid leukemia or multiple myeloma. The cytokine secretion assay was combined with magnetic selection to allow detection of an interferon-gamma-secreting T-cell response to a panel of cancer-testis antigen peptides.

RESULTS

A cancer-testis antigen-specific CD8(+) T-cell immune response was observed in the peripheral blood of five patients with an average magnitude of 0.045% of the CD8(+) T-cell repertoire. Four of these patients had undergone reduced intensity conditioning transplantation with alemtuzumab for the treatment of acute myeloid leukemia and three remain in long-term remission. T-cell immunity was focused against peptides derived from MAGE proteins and was markedly increased within the bone marrow.

CONCLUSIONS

Functional cancer-testis antigen-specific CD8(+) T-cell immune responses develop in the early period following reduced intensity allogeneic stem cell transplantation and are preferentially localized to bone marrow. These immune responses are likely to contribute to the cellular basis of the graft-versus-leukemia effect.

Detection of circulating lymphoma cells in patients with non-Hodgkin lymphoma using MAGE-A3 gene expression in peripheral blood

BACKGROUND/AIMS

Lymphoma-specific gene expression in peripheral blood reflects the presence of circulating lymphoma cells (CLCs). MAGE-A3 is widely expressed in solid tumors and is a potent candidate for immunotherapy. To determine whether MAGE-A3 expression would be a useful marker for CLCs in non-Hodgkin lymphoma (NHL), we assessed MAGE-A3 mRNA expression in the peripheral blood of NHL patients and controls.

METHODS

We measured MAGE-A3 gene expression in ten lymphoma cell lines (Farage, RL, SU-DHL, Toledo, WSU-NHL, BJA-B, Daudi, Raji, Granta-519 and Jurkat) using nested RT-PCR, and determined detection sensitivity using mixtures of MAGE-A3-positive and -negative cells over a range of 1/10(6) to 10(6)/10(6) cells. MAGE-A3 expression was determined in buffy coat samples of 40 controls and 95 NHL patients prior to treatment. Clinical characteristics (e.g., cell lineage) and international prognostic indices, including age, performance, LDH, stage and extra-nodal involvement, were evaluated and related to MAGE-A3 expression. Hazard ratios, reflecting risk for overall survival and progression-free survival, were also evaluated. Follow-up MAGE-A3 expression was evaluated at two time points: after 3-4 cycles of chemotherapy (80 patients) and after 6-8 cycles of chemotherapy (74 patients).

RESULTS

MAGE-A3 mRNA was detected in four lymphoma cell lines - RL, Farage, Toledo and Raji - and was present in 45 of 95 (47.3%) patients with NHL, but in none of the 40 controls. The detection sensitivity was 1 in 1000 cells. MAGE-A3 expression prior to treatment was not associated with clinical features or patient survival. During follow-up, only six patients (7.5%) were positive for MAGE-A3 after 3-4 cycles of chemotherapy and three (4.1%) were positive after 6-8 cycles.

CONCLUSIONS

The results showed that MAGE-A3 gene expression was frequent in NHL patients and decreased after effective chemotherapy, suggesting that MAGE-A3 can be used as a tumor marker for CLCs in patients with NHL. However, MAGE-A3 expression showed no prognostic value in this group of patients.