Cancer-testis antigen expression in primary cutaneous melanoma has independent prognostic value comparable to that of Breslow thickness, ulceration and mitotic rate

Expression of the tumor antigens NY-ESO-1, tyrosinase, MAGE-A3, and TPTE in pediatric and adult melanoma: a retrospective case control study

Tumor-associated antigens (TAAs) are potential targets for T cell-based immunotherapy approaches in cutaneous melanoma. BNT111, an investigational lipoplex-formulated mRNA-based therapeutic cancer vaccine encoding melanoma TAAs NY-ESO-1, tyrosinase, MAGE-A3, and TPTE, is undergoing clinical testing in adults. Expression of these TAAs in pediatric melanoma is unclear but is a prerequisite for feasibility of this treatment approach in children with melanoma. Our main objective was to characterize expression of those TAAs in pediatric melanomas compared to control cohorts. In this retrospective case control study, protein and transcript expression of NY-ESO-1, tyrosinase, MAGE-A3, and TPTE were analyzed in a cohort of 25 pediatric melanomas, 31 melanomas of young adults, 29 adult melanomas, and 30 benign melanocytic nevi in children using immunohistochemical staining and digital pathology (QuPath) and reverse transcription quantitative PCR. Based on IHC analysis, pediatric melanomas expressed tyrosinase (100.0%), TPTE (44.0%), MAGE-A3 (12.0%), and NY-ESO-1 (8.0%). Young adult melanomas expressed tyrosinase (96.8%), NY-ESO-1 (19.4%), MAGE-A3 (19.4%), and TPTE (3.2%). Adult melanomas expressed tyrosinase (86.2%), MAGE-A3 (75.9%), NY-ESO-1 (48.3%), and TPTE (48.3%). Childhood melanocytic nevi only expressed tyrosinase (93.3%). Expression prevalence of individual TAAs did not differ between subtypes of pediatric melanoma, and no association with prognosis was found. All four TAAs were expressed in pediatric melanoma, albeit NY-ESO-1 and MAGE-A3 to a lesser extent than in adult melanoma. These data support the possibility of investigating vaccines targeting these TAAs for the treatment of pediatric melanoma.

Combinational expression of tumor testis antigens NY-ESO-1, MAGE-A3, and MAGE-A4 predicts response to immunotherapy in mucosal melanoma patients

PURPOSE

Immunotherapy using immune checkpoint inhibitors (ICI) has revolutionized cancer treatment in recent years, particularly in melanoma. While response to immunotherapy is associated with high tumor mutational burden (TMB), PD-L1 expression, and microsatellite instability in several cancers, tumors lacking these biomarkers can still respond to this treatment. Especially, mucosal melanoma, commonly exhibiting low TMB compared to cutaneous melanoma, may respond to immunotherapy with immune checkpoint inhibitors. Therefore, the aim of our study was to investigate novel biomarkers in mucosal melanoma that predict response to combined ipilimumab and nivolumab.

METHODS

We investigated 10 tumor samples from 10 patients (three responders, seven non-responders) before treatment and six tumor samples from five patients after progression using a targeted Next Generation Sequencing (NGS) gene expression panel. The findings were corroborated with an independent method (i.e., immunohistochemical staining) on the same 10 tumor samples before treatment and, to increase the cohort, in addition on three tumor samples before treatment of more recent patients (one responder, two non-responders).

RESULTS

With the targeted gene expression panel, we found the three tumor testis antigens CTAG1B (NY-ESO-1), MAGE-A3, and MAGE-A4 to be predominantly expressed in responding tumors. This marker panel was either not or not completely expressed in non-responders (p < 0.01). Using immunohistochemistry for all three markers, we could confirm the elevated expression in tumors responding to the ipilimumab/nivolumab combination therapy.

CONCLUSION

In conclusion, these three biomarkers await validation in a larger patient cohort and could be easily used in future routine diagnostics to predict the outcome of ipilimumab/nivolumab combination therapy in mucosal melanoma patients.

Chemical complementarity between tumor resident, T-cell receptor CDR3s and MAGEA3/6 correlates with increased melanoma survival: Potential relevance to MAGE vaccine auto-reactivity

Cancer testis antigens have been of interest as possible targets for cancer immunotherapies. To better understand the opportunities for the use of such immunotherapy targets, we used a chemical complementarity scoring algorithm and an original web tool to establish aspects of electrostatic complementarity of the CTAs, MAGEA3 and MAGEA6, with melanoma specimen resident, T-cell receptor (TCR) complementarity determining region 3 (CDR3) amino acid sequences. Greater electrostatic complementarity between T-cell receptor CDR3 and tumor CTAs MAGEA3/6 was associated with a greater probability of overall survival, for both the cancer genome atlas and Moffitt Cancer Center samples; and was associated with high levels of T-cell cytotoxicity-related gene expression. Most importantly, this approach allowed for the highly efficient screening of specific segments of the MAGEA3/6 antigens which indicated that certain MAGE segments would have either more or less risk of auto-reactivity. In sum, the chemical complementarity algorithm, and its efficient application via the web tool, adaptivematch.com, offers a convenient opportunity to identify likely parameters important for immunotherapy considerations and melanoma patient risk stratifications.

Multiomics analysis reveals CT83 is the most specific gene for triple negative breast cancer and its hypomethylation is oncogenic in breast cancer

Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer (BrC) subtype lacking effective therapeutic targets currently. The development of multi-omics databases facilities the identification of core genes for TNBC. Using TCGA-BRCA and METABRIC datasets, we identified CT83 as the most TNBC-specific gene. By further integrating FUSCC-TNBC, CCLE, TCGA pan-cancer, Expression Atlas, and Human Protein Atlas datasets, we found CT83 is frequently activated in TNBC and many other cancers, while it is always silenced in non-TNBC, 120 types of normal non-testis tissues, and 18 types of blood cells. Notably, according to the TCGA-BRCA methylation data, hypomethylation on chromosome X 116,463,019 to 116,463,039 is significantly correlated with the abnormal activation of CT83 in BrC. Using Kaplan-Meier Plotter, we demonstrated that activated CT83 is significantly associated with unfavorably overall survival in BrC and worse outcomes in some other cancers. Furthermore, GSEA suggested that the abnormal activation of CT83 in BrC is probably oncogenic by triggering the activation of cell cycle signaling. Meanwhile, we also noticed copy number variations and mutations of CT83 are quite rare in any cancer type, and its role in immune infiltration is not significant. In summary, we highlighted the significance of CT83 for TNBC and presented a comprehensive bioinformatics strategy for single-gene analysis in cancer.

Ropporin-1 and 1B Are Widely Expressed in Human Melanoma and Evoke Strong Humoral Immune Responses

Antibodies that block immune regulatory checkpoints (programmed cell death 1, PD-1 and cytotoxic T-lymphocyte-associated antigen 4, CTLA-4) to mobilise immunity have shown unprecedented clinical efficacy against cancer, demonstrating the importance of antigen-specific tumour recognition. Despite this, many patients still fail to benefit from these treatments and additional approaches are being sought. These include mechanisms that boost antigen-specific immunity either by vaccination or adoptive transfer of effector cells. Other than neoantigens, epigenetically regulated and shared antigens such as NY-ESO-1 are attractive targets; however, tissue expression is often heterogeneous and weak. Therefore, peptide-specific therapies combining multiple antigens rationally selected to give additive anti-cancer benefits are necessary to achieve optimal outcomes. Here, we show that Ropporin-1 (ROPN1) and 1B (ROPN1B), cancer restricted antigens, are highly expressed and immunogenic, inducing humoral immunity in patients with advanced metastatic melanoma. By multispectral immunohistochemistry, 88.5% of melanoma patients tested (n = 54/61) showed ROPN1B expression in at least 1 of 2/3 tumour cores in tissue microarrays. Antibody responses against ROPN1A and ROPN1B were detected in 71.2% of melanoma patients tested (n = 74/104), with increased reactivity seen with more advanced disease stages. Thus, ROPN1A and ROPN1B may indeed be viable targets for cancer immunotherapy, alone or in combination with other cancer antigens, and could be combined with additional therapies such as immune checkpoint blockade.

Results of a randomized, double-blind phase II clinical trial of NY-ESO-1 vaccine with ISCOMATRIX adjuvant versus ISCOMATRIX alone in participants with high-risk resected melanoma

BACKGROUND

To compare the clinical efficacy of New York Esophageal squamous cell carcinoma-1 (NY-ESO-1) vaccine with ISCOMATRIX adjuvant versus ISCOMATRIX alone in a randomized, double-blind phase II study in participants with fully resected melanoma at high risk of recurrence.

METHODS

Participants with resected stage IIc, IIIb, IIIc and IV melanoma expressing NY-ESO-1 were randomized to treatment with three doses of NY-ESO-1/ISCOMATRIX or ISCOMATRIX adjuvant administered intramuscularly at 4-week intervals, followed by a further dose at 6 months. Primary endpoint was the proportion free of relapse at 18 months in the intention-to-treat (ITT) population and two per-protocol populations. Secondary endpoints included relapse-free survival (RFS) and overall survival (OS), safety and NY-ESO-1 immunity.

RESULTS

The ITT population comprised 110 participants, with 56 randomized to NY-ESO-1/ISCOMATRIX and 54 to ISCOMATRIX alone. No significant toxicities were observed. There were no differences between the study arms in relapses at 18 months or for median time to relapse; 139 vs 176 days (p=0.296), or relapse rate, 27 (48.2%) vs 26 (48.1%) (HR 0.913; 95% CI 0.402 to 2.231), respectively. RFS and OS were similar between the study arms. Vaccine recipients developed strong positive antibody responses to NY-ESO-1 (p≤0.0001) and NY-ESO-1-specific CD4+ and CD8+ responses. Biopsies following relapse did not demonstrate differences in NY-ESO-1 expression between the study populations although an exploratory study demonstrated reduced (NY-ESO-1)+/Human Leukocyte Antigen (HLA) class I+ double-positive cells in biopsies from vaccine recipients performed on relapse in 19 participants.

CONCLUSIONS

The vaccine was well tolerated, however, despite inducing antigen-specific immunity, it did not affect survival endpoints. Immune escape through the downregulation of NY-ESO-1 and/or HLA class I molecules on tumor may have contributed to relapse.

Expression of cancer/testis antigens in cutaneous melanoma: a systematic review

The cancer/testis antigen (CTA) family is a group of antigens whose expression is restricted to male germline cells of the testis and various malignancies. This expression pattern makes this group of antigens potential targets for immunotherapy. The aim of this study was to create an overview of CTA expressed by melanoma cells at mRNA and protein level. A systematic literature search was performed in Medline (PubMed) and Embase from inception up to and including February 2018. Studies were screened for eligibility by two independent reviewers. A total of 65 full-text articles were included in the final analysis. A total of 48 CTA have been studied in melanoma. Various CTA show different expression rates in primary and metastatic tumours. Of the 48 CTA, the most studied were MAGE-A3, MAGE-A1, NY-ESO-1, MAGE-A4, SSX2, MAGE-A2, MAGE-C1/CT7, SSX1, MAGE-C2/CT10 and MAGE-A12. On average, MAGE-A3 mRNA is present in 36% of primary tumours, whereas metastatic tumours have an expression rate of 55-81%. The same applies to the protein expression rate of MAGE-A3 in primary tumours, which is reported to be at 15-37%, whereas metastatic tumours have a higher expression rate of 25-70%. This trend of increased expression in metastases compared with primary tumours is observed with MAGE-A1, MAGE-A2, MAGE-A4, MAGE-A12 and NY-ESO-1. Many CTA are expressed on melanoma. This review provides an overview of the expression frequency of CTAs in melanoma and may aid in identifying CTA as the therapeutic target for immunotherapy.

The "-OMICS" facet of melanoma: Heterogeneity of genomic, proteomic and metabolomic biomarkers

In the recent decade, cutting edge molecular and proteomic analysis platforms revolutionized biomarkers discovery in cancers. Melanoma is the prototype with over 51,100 biomarkers discovered and investigated thus far. These biomarkers include tissue based tumor cell and tumor microenvironment biomarkers and circulating biomarkers including tumor DNA (cf-DNA), mir-RNA, proteins and metabolites. These biomarkers provide invaluable information for diagnosis, prognosis and play an important role in prediction of treatment response. In this review, we summarize the most recent discoveries in each of these biomarker categories. We will discuss the challenges in their implementation and standardization and conclude with some perspectives in melanoma biomarker research.

PD-L1 expression by tumor cell lines: A predictive marker in melanoma

Prognostic biomarkers for patients with melanoma after lymph node resection are of clinical relevance and could thus enable the identification of patients who therefore would most benefit from adjuvant treatment. The aim of this work was to determine, using an in vitro model, whether immune-related biomarkers, such as MHC-class I and II, melanoma-associated antigens, IDO1 and PD-L1, could also be relevant to predict the risk of relapse of patients with stage III melanoma after lymph node resection. We established tumor cell lines from metastatic lymph nodes of 50 patients with melanoma. The expression of investigated biomarkers was determined on untreated and IFN-γ treated melanoma cell lines using flow cytometry. Among the selected biomarkers, the IFN-γ-induced expression of PD-L1 and IDO1 was associated with an increased risk of relapse (P = .0001 and P = .013, respectively) and was also associated with death for IDO1 (P = .0005). In the future, this immunologic signature could permit the identification of patients at higher risk of relapse and justifying an adjuvant treatment using immunotherapy.

Melanoma: a prototype of cancer-testis antigen-expressing malignancies

Melanoma is the first malignancy in which expression and immunogenicity of cancer-testis antigens (CTAs) have been documented. Several CTAs have been shown to be expressed in melanoma samples especially those with metastatic potential. Many of them have been shown to exert oncogenic effects through modulation of essential pathways involved in melanoma. The crucial role of CTAs in the pathogenesis of melanoma, the high prevalence of expression of CTA panels in melanoma and the presence of spontaneous as well as inducible immune responses against CTAs in melanoma patients potentiate CTAs as immunotherapeutic targets. Numerous clinical trials are now ongoing to evaluate CTA-based immunotherapeutic effects in melanoma patient's survival. NY-ESO-1 and MAGE antigens have the most promising results up to now.

NY-ESO-1 Based Immunotherapy of Cancer: Current Perspectives

NY-ESO-1 or New York esophageal squamous cell carcinoma 1 is a well-known cancer-testis antigen (CTAs) with re-expression in numerous cancer types. Its ability to elicit spontaneous humoral and cellular immune responses, together with its restricted expression pattern, have rendered it a good candidate target for cancer immunotherapy. In this review, we provide background information on NY-ESO-1 expression and function in normal and cancerous tissues. Furthermore, NY-ESO-1-specific immune responses have been observed in various cancer types; however, their utility as biomarkers are not well determined. Finally, we describe the immune-based therapeutic options targeting NY-ESO-1 that are currently in clinical trial. We will highlight the recent advancements made in NY-ESO-1 cancer vaccines, adoptive T cell therapy, and combinatorial treatment with checkpoint inhibitors and will discuss the current trends for future NY-ESO-1 based immunotherapy. Cancer treatment has been revolutionized over the last few decades with immunotherapy emerging at the forefront. Immune-based interventions have shown promising results, providing a new treatment avenue for durable clinical responses in various cancer types. The majority of successful immunotherapy studies have been reported in liquid cancers, whereas these approaches have met many challenges in solid cancers. Effective immunotherapy in solid cancers is hampered by the complex, dynamic tumor microenvironment that modulates the extent and phenotype of the antitumor immune response. Furthermore, many solid tumor-associated antigens are not private but can be found in normal somatic tissues, resulting in minor to detrimental off-target toxicities. Therefore, there is an ongoing effort to identify tumor-specific antigens to target using various immune-based modalities. CTAs are considered good candidate targets for immunotherapy as they are characterized by a restricted expression in normal somatic tissues concomitant with a re-expression in solid epithelial cancers. Moreover, several CTAs have been found to induce a spontaneous immune response, NY-ESO-1 being the most immunogenic among the family members. Hence, this review will focus on NY-ESO-1 and discuss the past and current NY-ESO-1 targeted immunotherapeutic strategies.

Inhibitor of vasculogenic mimicry restores sensitivity of resistant melanoma cells to DNA-damaging agents

The increasing incidence of melanoma makes this cancer an important public health problem. Therapeutic resistance is still a major obstacle to the therapy of patients with metastatic melanomas. The aim of this study was to develop the melanoma cell line resistant to DNA-alkylating agents and to elucidate the mechanisms involved in acquired drug resistance. We established a unique melanoma subline Mel MeR resistant to DNA-alkylating drug aranoza by continuous stepwise selection of the Mel Me/WT cell line with increasing concentrations of this drug. Mel MeR cells were also cross-resistant to streptozotocin or cisplatin. Here, we show that aranoza-resistant melanoma cells modulate the ABC transporter activity, upregulate the expression of PRAME, adopt a vascular-related phenotype and engage in vasculogenic mimicry. LCS1269, a vasculogenic mimicry low-molecular-weight inhibitor, reverses the sensitivity of resistant melanoma cells to DNA-damaging agents. In this study, we provide experimental evidence that LCS1269 might be considered as a new potential anticancer agent capable of overcoming multidrug resistance for DNA-damaging agents in melanoma.

The good, the (not so) bad and the ugly of immune homeostasis in melanoma

Within the immune system multiple mechanisms balance the need for efficient pathogen recognition and destruction with the prevention of tissue damage by excessive, inappropriate or even self-targeting (auto)immune reactions. This immune homeostasis is a tightly regulated system which fails during tumor development, often due to the hijacking of its essential self-regulatory mechanisms by cancer cells. It is facilitated not only by tumor intrinsic properties, but also by the microbiome, host genetics and other factors. In certain ways many cancers can therefore be considered a rare failure of immune control rather than an uncommon or rare disease of the tissue of origin, as the acquisition of potentially oncogenic traits through mutation occurs constantly in most tissues during proliferation. Normally, aberrant cells are well-controlled by cell intrinsic (repair or apoptosis) and extrinsic (immune) mechanisms. However, occasionally oncogenic cells survive and escape control. Melanoma is one of the first cancer types where treatments aimed at restoring and enhancing an immune response to regain control over the tumor have been used with various success rates. With the advent of "modern" immunotherapeutics such as anti-CTLA-4 or anti-PD-1 antibodies that both target negative immune-regulatory pathways on immune cells resulting in durable responses in a proportion of patients, the importance of the interplay between the immune system and cancer has been established beyond doubt.

Phase II trial of ipilimumab in melanoma patients with preexisting humoural immune response to NY-ESO-1

BACKGROUND

Immune checkpoint therapy has dramatically changed treatment options in patients with metastatic melanoma. However, a relevant part of patients still does not respond to treatment. Data regarding the prognostic or predictive significance of preexisting immune responses against tumour antigens are conflicting. Retrospective data suggested a higher clinical benefit of ipilimumab in melanoma patients with preexisting NY-ESO-1-specific immunity.

PATIENTS AND METHODS

Twenty-five patients with previously untreated or treated metastatic melanoma and preexisting humoural immune response against NY-ESO-1 received ipilimumab at a dose of 10 mg/kg in week 1, 4, 7, 10 followed by 3-month maintenance treatment for a maximum of 48 weeks. Primary endpoint was the disease control rate (irCR, irPR or irSD) according to immune-related response criteria (irRC). Secondary endpoints included the disease control rate according to RECIST criteria, progression-free survival and overall survival (OS). Humoural and cellular immune responses against NY-ESO-1 were analysed from blood samples.

RESULTS

Disease control rate according to irRC was 52%, irPR was observed in 36% of patients. Progression-free survival according to irRC was 7.8 months, according to RECIST criteria it was 2.9 months. Median OS was 22.7 months; the corresponding 1-year survival rate was 66.8%. Treatment-related grade 3 AEs occurred in 36% with no grade 4-5 AEs. No clear association was found between the presence of NY-ESO-1-specific cellular or humoural immune responses and clinical activity.

CONCLUSION

Ipilimumab demonstrated clinically relevant activity within this biomarker-defined population. NY-ESO-1 positivity, as a surrogate for a preexisting immune response against tumour antigens, might help identifying patients with a superior outcome from immune checkpoint blockade.

CLINICAL TRIAL INFORMATION

NCT01216696.

Prognostic factors for metastasis in cutaneous melanoma

BACKGROUND

Melanoma is a malignant neoplasia that shows high mortality when diagnosed in advanced stages. Early identification of high-risk patients for the development of melanoma metastases is the main strategy to reduce mortality.

OBJECTIVE

To assess the influence of eight epidemiological and histopathologic features on the development of metastases in patients diagnosed with primary cutaneous melanoma.

METHODS

Our historical cohort comprised patients with invasive primary cutaneous melanoma seen between 1995 and 2012 at a public university hospital and a private oncologic surgery institution in Southeastern Brazil. The following variables were analyzed: gender, age, family history of melanoma, site of the primary tumor, clinical and histologic subtype, Breslow thickness, histologic ulceration and the mitotic index. Kaplan-Meier univariate test and multivariate Cox proportional hazard analysis were used to assess factors associated with disease-free survival.

RESULTS

Five hundred and fourteen patients were enrolled. The univariate analysis identified the following significant risk factors: gender, age, site of the tumor, clinical and histologic subtype, Breslow thickness, histologic ulceration and mitotic index. Multivariate analysis included 244 patients and detected four significant prognostic factors: male gender, nodular clinical and histologic subtype, Breslow thickness > 4mm, and histologic ulceration. The mitotic index was not included in this analysis.

STUDY LIMITATIONS

Small number of patients in multivariate analysis.

CONCLUSIONS

The following prognostic factors to the development of melanoma metastasis were identified in the study: male gender, nodular histologic subtype, Breslow thickness > 4mm and ulceration.

High expression of MAGE-A9 is associated with unfavorable survival in esophageal squamous cell carcinoma

Melanoma-associated antigens (MAGEs) are a group of well-characterized members of the cancer/testis antigen family, which are expressed in a variety of malignant tumors. MAGE-A9, a subfamily of MAGE-As, has been studied in a number of types of cancer and have been associated with unfavorable survival outcome. However, the expression of MAGE-A9 in human esophageal squamous cell carcinoma (ESCC) and association of MAGE-A9 with the clinicopathological characteristics of ESCC, particularly prognostic characteristics, remains unknown. The present study aimed at determining the expression level of MAGE-A9 and at evaluating its clinical significance in human ESCC. Quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC) analyses were performed to characterize the expression of MAGE-A9 in ESCC tissues. Kaplan-Meier estimator survival and Coxs regression analyses were used to evaluate the prognosis of 103 patients with ESCC. The results of qPCR and IHC analysis revealed that the expression of MAGE-A9 was significantly increased in ESCC tissues, compared with that in healthy tissues. Furthermore, the expression level of MAGE-A9 protein in ESCC was significantly associated with the pathological grade (P=0.008), tumor size (P=0.027) and lymph node metastasis (P=0.009). Multivariate analysis using Coxs regression model identified that the expression level of MAGE-A9 and lymph node metastasis were independent prognostic factors for the overall survival rate of patients with ESCC (P=0.006 and P=0.001, respectively). The results of the present study are, to the best of our knowledge, the first to indicate that MAGE-A9 expression is a valuable prognostic biomarker for ESCC and that it may serve as a targeted therapy in the treatment of ESCC. Increased expression of MAGE-A9 indicated an unfavorable survival outcome in patients with ESCC.

Expression of novel cancer/testis antigen TMEM31 increases during metastatic melanoma progression

Cancer/testis (CT) antigens are promising targets for immunotherapy due to their restricted expression in the germ cells of the testis in healthy tissue and high immunogenicity. The aim of the present study was to determine whether transmembrane protein 31 (TMEM31) is a CT antigen and to investigate the pattern of TMEM31 expression during the progression of melanoma. The pattern of expression of human TMEM31 mRNA in multiple human tissues was determined through reverse transcription-polymerase chain reaction analysis. TMEM31 protein expression was analyzed in the human testis, in addition to 128 primary melanoma and 64 metastatic melanoma samples through immunohistochemistry analysis. TMEM31 was identified to be predominantly expressed in the testis and weakly expressed in the placenta. In addition, TMEM31 protein expression was detected in 120/190 (63.16%) melanoma samples (primary and metastatic). The intensity of TMEM31 staining in metastatic and primary melanomas was determined through semiquantitative integrated optical density (IOD) analysis, and identified to be significantly increased in metastatic melanoma compared with primary melanoma (0.24±0.03 vs. 0.09±0.01 IOD/area; P<0.001). The expression of TMEM31 protein was significantly increased in metastatic compared with primary melanoma samples (76.56 vs. 56.35%; P=0.017). The results of the present study suggest that TMEM31 is a novel CT antigen that serves an essential role in melanoma metastasis, in addition to being a potential immunotherapeutic target for the treatment of patients with melanoma.

Melanoma: tumor microenvironment and new treatments

In the recent past years, many discoveries in the tumor microenvironment have led to changes in the management of melanoma and it is rising up hopes, specially, to those in advanced stages. FDA approved seven new drugs from 2011 to 2014. They are: Vemurafenib, Dabrafenib and Trametinib, kinases inhibitors used for patients that have BRAFV600E mutation; Ipilimumab (anti-CTLA4), Pembrolizumab (anti-PD-1) and Nivolumab (anti-PD-1), monoclonal antibodies that stimulate the immune system; and Peginterferon alfa-2b, an anti-proliferative cytokine used as adjuvant therapy. In this article, we will review the molecular bases for these new metastatic melanoma therapeutic agents cited above and also analyze new molecular discoveries in melanoma study, as Cancer-Testis antigens (CT). They are capable of induce humoral and cellular immune responses in cancer patients and because of this immunogenicity and their restrict expression in normal tissues, they are considered an ideal candidate for vaccine development against cancer. Among CT antigens, NY-ESO-1 is the best characterized in terms of expression patterns and immunogenicity. It is expressed in 20-40% of all melanomas, more in metastatic lesions than in primary ones, and it is very heterogeneous inter and intratumoral. Breslow index is associate with NY-ESO-1 expression in primary cutaneous melanomas, but its relation to patient survival remains controversial.

Genetic variants in the integrin signaling pathway genes predict cutaneous melanoma survival

To identify genetic variants involved in prognosis of cutaneous melanoma (CM), we investigated associations of single nucleotide polymorphisms (SNPs) of genes in the integrin signaling pathway with CM survival by re-analyzing a published genome-wide association study (GWAS) from The University of Texas M.D. Anderson Cancer Center (MDACC) and then validated significant SNPs in another GWAS from Harvard University. In the MDACC study, 1,148 SNPs were significantly associated with CM-specific survival (CMSS) (p ≤ 0.050 and false-positive report probability ≤ 0.20), and nine SNPs were validated in the Harvard study (p ≤ 0.050). Among these, three independent SNPs (i.e., DOCK1 rs11018104 T > A, rs35748949 C > T and PAK2 rs1718404 C > T) showed a predictive role in CMSS, with an effect-allele attributed adjusted hazards ratio [adjHR of 1.50 (95% confidence interval (CI) = 1.18-1.90, p = 7.46E-04), 1.53 (1.18-1.97, 1.18E-03) and 0.58 (0.45-0.76, 5.60E-05), respectively]. Haplotype analysis revealed that a haplotype carrying two risk alleles A-T in DOCK1 was associated with the poorest survival in both MDACC (adjHR = 1.73, 95% CI = 1.19-2.50, p = 0.004) and Harvard (adjHR = 1.95, 95% CI = 1.14-3.33, p = 0.010) studies. In addition, patients with an increasing number of unfavorable genotypes (NUGs) for these three SNPs had a poorer survival. Incorporating NUGs with clinical variables showed a significantly improved ability to classify CMSS (AUC increased from 86.8% to 88.6%, p = 0.031). Genetic variants in the integrin signaling pathway may independently or jointly modulate the survival of CM patients. Further large, prospective studies are needed to validate these findings.

Transketolase-like 1 ectopic expression is associated with DNA hypomethylation and induces the Warburg effect in melanoma cells

BACKGROUND

The metabolism of cancer cells is often reprogrammed by dysregulation of metabolic enzymes. Transketolase-like 1 (TKTL1) is a homodimeric transketolase linking the pentose-phosphate pathway with the glycolytic pathway. It is generally silenced at a transcriptional level in somatic tissues. However, in human cancers its expression is associated with the acquisition of a glycolytic phenotype (the Warburg effect) by cancer cells that contributes to the progression of malignant tumors. In melanoma, defective promoter methylation results in the expression of genes and their products that can affect the tumor cell's phenotype including the modification of immune and functional characteristics. The present study evaluates the role of TKTL1 as a mediator of disease progression in melanoma associated with a defective methylation phenotype.

METHODS

The expression of TKTL1 in metastatic melanoma tumors and cell lines was analysed by qRT-PCR and immunohistochemistry. The promoter methylation status of TKTL1 in melanoma cells was evaluated by quantitative methylation specific PCR. Using qRT-PCR, the effect of a DNA demethylating agent 5-aza-2'-deoxycytidine (5aza) on the expression of TKTL1 was examined. Biochemical and molecular analyses such as glucose consumption, lactate production, invasion, proliferation and cell cycle progression together with ectopic expression and siRNA mediated knockdown were used to investigate the role of TKTL1 in melanoma cells.

RESULTS

Expression of TKTL1 was highly restricted in normal adult tissues and was overexpressed in a subset of metastatic melanoma tumors and derived cell lines. The TKTL1 promoter was activated by hypomethylation and treatment with 5aza induced TKTL1 expression in melanoma cells. Augmented expression of TKTL1 in melanoma cells was associated with a glycolytic phenotype. Loss and gain of function studies revealed that TKTL1 contributed to enhanced invasion of melanoma cells.

CONCLUSIONS

Our data provide evidence for an important role of TKTL1 in aerobic glycolysis and tumor promotion in melanoma that may result from defective promoter methylation. This epigenetic change may enable the natural selection of tumor cells with a metabolic phenotype and thereby provide a potential therapeutic target for a subset of melanoma tumors with elevated TKTL1 expression.

New York esophageal squamous cell carcinoma-1 and cancer immunotherapy

New York esophageal squamous cell carcinoma 1 (NY-ESO-1) is a known cancer testis gene with exceptional immunogenicity and prevalent expression in many cancer types. These characteristics have made it an appropriate vaccine candidate with the potential application against various malignancies. This article reviews recent knowledge about the NY-ESO-1 biology, function, immunogenicity and expression in cancers as well as and the results of clinical trials with this antigen.

The melanoma-associated antigen 1 (MAGEA1) protein stimulates the E3 ubiquitin-ligase activity of TRIM31 within a TRIM31-MAGEA1-NSE4 complex

The MAGE (Melanoma-associated antigen) protein family members are structurally related to each other by a MAGE-homology domain comprised of 2 winged helix motifs WH/A and WH/B. This family specifically evolved in placental mammals although single homologs designated NSE3 (non-SMC element) exist in most eukaryotes. NSE3, together with its partner proteins NSE1 and NSE4 form a tight subcomplex of the structural maintenance of chromosomes SMC5–6 complex. Previously, we showed that interactions of the WH/B motif of the MAGE proteins with their NSE4/EID partners are evolutionarily conserved (including the MAGEA1-NSE4 interaction). In contrast, the interaction of the WH/A motif of NSE3 with NSE1 diverged in the MAGE paralogs. We hypothesized that the MAGE paralogs acquired new RING-finger-containing partners through their evolution and form MAGE complexes reminiscent of NSE1-NSE3-NSE4 trimers. In this work, we employed the yeast 2-hybrid system to screen a human RING-finger protein library against several MAGE baits. We identified a number of potential MAGE-RING interactions and confirmed several of them (MDM4, PCGF6, RNF166, TRAF6, TRIM8, TRIM31, TRIM41) in co-immunoprecipitation experiments. Among these MAGE-RING pairs, we chose to examine MAGEA1-TRIM31 in detail and showed that both WH/A and WH/B motifs of MAGEA1 bind to the coiled-coil domain of TRIM31 and that MAGEA1 interaction stimulates TRIM31 ubiquitin-ligase activity. In addition, TRIM31 directly binds to NSE4, suggesting the existence of a TRIM31-MAGEA1-NSE4 complex reminiscent of the NSE1-NSE3-NSE4 trimer. These results suggest that MAGEA1 functions as a co-factor of TRIM31 ubiquitin-ligase and that the TRIM31-MAGEA1-NSE4 complex may have evolved from an ancestral NSE1-NSE3-NSE4 complex.

Increased NY-ESO-1 expression and reduced infiltrating CD3+ T cells in cutaneous melanoma

NY-ESO-1 is a cancer-testis antigen aberrantly expressed in melanomas, which may serve as a robust and specific target in immunotherapy. NY-ESO-1 antigen expression, tumor features, and the immune profile of tumor infiltrating lymphocytes were assessed in primary cutaneous melanoma. NY-ESO-1 protein was detected in 20% of invasive melanomas (16/79), rarely in in situ melanoma (1/10) and not in benign nevi (0/20). Marked intratumoral heterogeneity of NY-ESO-1 protein expression was observed. NY-ESO-1 expression was associated with increased primary tumor thickness (P = 0.007) and inversely correlated with superficial spreading melanoma (P < 0.02). NY-ESO-1 expression was also associated with reduced numbers and density of CD3+ tumor infiltrating lymphocytes (P = 0.017). When NY-ESO-1 protein was expressed, CD3+ T cells were less diffusely infiltrating the tumor and were more often arranged in small clusters (P = 0.010) or as isolated cells (P = 0.002) than in large clusters of more than five lymphocytes. No correlation of NY-ESO-1 expression with gender, age, tumor site, ulceration, lymph node sentinel status, or survival was observed. NY-ESO-1 expression in melanoma was associated with tumor progression, including increased tumor thickness, and with reduced tumor infiltrating lymphocytes.

NY-ESO-1 expression is tightly linked to TMPRSS2-ERG fusion in prostate cancer

BACKGROUND

NY-ESO-1 has been suggested as therapeutic cancer vaccine in prostate cancer. This study was undertaken to explore the relationship of NY-ESO-1 with tumor phenotype, biochemical recurrence, and molecular subgroups in hormone-naive prostate cancers.

METHODS

NY-ESO-1 immunohistochemistry was analyzed on a tissue microarray containing 11,152 prostate cancer samples. Results were compared to clinically follow-up data, ERG status, and deletions on PTEN, 3p13, 5q21, and 6q15.

RESULTS

NY-ESO-1 expression was absent in benign prostate glands. In prostate cancer, NY-ESO-1 positivity was found 8.8% of our 8,761 interpretable tumors including 5.8% with weak, 2.5% with moderate, and 0.5% with strong expression. There was a threefold higher rate of NY-ESO-1 expression in ERG fusion positive tumors than in ERG negative cancers (P < 0.0001). There was a significant association with early PSA recurrence, which was largely limited to ERG positive cancers. Within the ERG positive subgroup, high NY-ESO-1 expression was associated with early biochemical recurrence (P = 0.0002) and high Gleason grade (P < 0.0001). In ERG negative cancers, NY-ESO-1 expression was also linked to PTEN (P = 0.0012) and 6q15 deletions (P = 0.0005).

CONCLUSIONS

Our observations indicate a tight link of NY-ESO-1 expression to ERG activation and (to a lesser extent) PTEN- and 6q15-deletions in prostate cancer. The impact of these interactions on the likelihood of response to immunotherapy is unclear. The prognostic impact of NY-ESO-1 expression is little and not independent of histologic variables.

Tumor subtype-specific cancer-testis antigens as potential biomarkers and immunotherapeutic targets for cancers

Cancer-testis (CT) antigens are potential targets for cancer immunotherapy because of their restricted expression in immune-privileged germ cells and various malignancies. Current application of CT-based immunotherapy has been focused on CT expression-rich tumors such as melanoma and lung cancers. In this study, we surveyed CT expression using The Cancer Genome Atlas (TCGA) datasets for ten common cancer types. We show that CT expression is specific and enriched within certain cancer molecular subtypes. For example, HORMAD1, CXorf61, ACTL8, and PRAME are highly enriched in the basal subtype of breast cancer; MAGE and CSAG are most frequently activated in the magnoid subtype of lung adenocarcinoma; and PRAME is highly upregulated in the ccB subtype of clear cell renal cell carcinoma. Analysis of CT gene expression and DNA methylation indicates that some CTs are regulated epigenetically, whereas others are controlled primarily by tissue- and subtype-specific transcription factors. Our results suggest that although for some CT expression is associated with patient outcome, not many are independent prognostic markers. Thus, CTs with shared expression pattern are heterogeneous molecules with distinct activation modes and functional properties in different cancers and cancer subtypes. These data suggest a cancer subtype-orientated application of CT antigen as biomarkers and immunotherapeutic targets.

Development of a novel, quantitative protein microarray platform for the multiplexed serological analysis of autoantibodies to cancer-testis antigens

The cancer-testis antigens are a group of unrelated proteins aberrantly expressed in various cancers in adult somatic tissues. This aberrant expression can trigger spontaneous immune responses, a phenomenon exploited for the development of disease markers and therapeutic vaccines. However, expression levels often vary amongst patients presenting the same cancer type, and these antigens are therefore unlikely to be individually viable as diagnostic or prognostic markers. Nevertheless, patterns of antigen expression may provide correlates of specific cancer types and disease progression. Herein, we describe the development of a novel, readily customizable cancer-testis antigen microarray platform together with robust bioinformatics tools, with which to quantify anti-cancer testis antigen autoantibody profiles in patient sera. By exploiting the high affinity between autoantibodies and tumor antigens, we achieved linearity of response and an autoantibody quantitation limit in the pg/mL range-equating to a million-fold serum dilution. By using oriented attachment of folded, recombinant antigens and a polyethylene glycol microarray surface coating, we attained minimal non-specific antibody binding. Unlike other proteomics methods, which typically use lower affinity interactions between monoclonal antibodies and tumor antigens for detection, the high sensitivity and specificity realized using our autoantibody-based approach may facilitate the development of better cancer biomarkers, as well as potentially enabling pre-symptomatic diagnosis. We illustrated the usage of our platform by monitoring the response of a melanoma patient cohort to an experimental therapeutic NY-ESO-1-based cancer vaccine; inter alia, we found evidence of determinant spreading in individual patients, as well as differential CT antigen expression and epitope usage.

Tissue prognostic biomarkers in primary cutaneous melanoma

Cutaneous melanoma (CM) causes the greatest number of skin cancer-related deaths worldwide. Predicting CM prognosis is important to determine the need for further investigation, counseling of patients, to guide appropriate management (particularly the need for postoperative adjuvant therapy), and for assignment of risk status in groups of patients entering clinical trials. Since recurrence rate is largely independent from stages defined by morphological and morphometric criteria, there is a strong need for identification of additional robust prognostic factors to support decision-making processes. Most data on prognostic biomarkers in melanoma have been evaluated in tumor tissue samples by conventional morphology and immunohistochemistry (IHC) as well as DNA and RNA analyses. In the present review, we critically summarize main high-quality studies investigating IHC-based protein biomarkers of melanoma outcome according to Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK)-derived criteria. Pathways have been classified and conveyed in the "biologic road" previously described by Hanahan and Weinberg. Data derived from genomic and transcriptomic technologies have been critically reviewed to better understand if any of investigated proteins or gene signatures should be incorporated into clinical practice or still remain a field of melanoma research. Despite a wide body of research, no molecular prognostic biomarker has yet been translated into clinical practice. Conventional tissue biomarkers, such as Breslow thickness, ulceration, mitotic rate and lymph node positivity, remain the backbone prognostic indicators in melanoma.

Construction and analysis of multiparameter prognostic models for melanoma outcome

The outcome of Stage II melanoma is uncertain. Despite that 10-year melanoma-specific survival can approach 50 % following curative-intent wide local excision and negative sentinel lymph node biopsy, the adverse risk-benefit ratio of interferon-based adjuvant regimens precludes their use in most patients. The discovery and translation of protein-based prognostic biomarkers into the clinic offers the promise for residual risk stratification of Stage II melanoma patients beyond conventional clinicopathologic criteria to identify an additional subset of patients who, based upon tumor molecular profiles, might also derive benefit from adjuvant regimens. Despite incorporation of Ki-67 assays into clinical practice, systematic review of REMARK-compliant, immunostain-based prognostic biomarker assays in melanoma suggests that residual risk of recurrence might be best explained by a composite score derived from a small panel of proteins representing independent features of melanoma biology. Reflecting this trend, to date, five such multiparameter melanoma prognostic models have been published. Here, we review these five models and provide detailed protocols for discovering and validating multiparameter models including: appropriate cohort recruitment strategies, comprehensive laboratory protocols supporting fully quantitative chromogenic or fluorescent immunostaining platforms, statistical approaches to create composite prognostic indices recommended steps for model validation in independent cohorts.

Potential therapeutic value of dendritic cells loaded with NY‑ESO‑1 protein for the immunotherapy of advanced hepatocellular carcinoma

NY‑ESO‑1 is one of the most immunogenic cancer-testis (CT) antigens. Cancer vaccine trials based on NY‑ESO‑1 are currently ongoing. Dendritic cells (DCs) are the most potent antigen-presenting cells. The immune functions of DCs in a number of tumors have been identified; however, the potential therapeutic value of DCs pulsed with NY‑ESO‑1 in hepatocellular carcinoma (HCC) has not been extensively investigated. The objectives of the present study were to evaluate T cell response following stimulation with DCs pulsed with the recombinant NY‑ESO‑1 protein (rESO) and to establish a correlation between NY‑ESO‑1 expression and clinicopathological features in HCC patients. DCs were generated with granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL‑4) from human peripheral blood mononuclear cells. A mixed T cell reaction with DCs loaded with recombinant NY‑ESO‑1 protein (rESO-DCs) was evaluated by MTT assay. T cell responses against HCC cell lines were analyzed by measuring lactate dehydrogenase (LDH) activity. The protein levels of NY‑ESO‑1 were detected by immunohistochemistry (IHC) in a tissue microarray (TMA) containing 190 HCC samples. NY‑ESO‑1 transcript abundance was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) in 54 out of the 190 HCC samples. The results revealed that mature DCs were induced and that rESO‑DCs significantly stimulated T cell proliferation. The specific lysis of T cells stimulated with rESO‑DCs was significantly higher in the NY‑ESO‑1-positive HCC cells compared with the NY‑ESO‑1-negative cells and the other controls (p<0.01). NY‑ESO‑1 was expressed in 15.8% (30/190)of the HCC samples, as shown by IHC and in 24.1% (13/54) of the samples, as shown by RT-PCR. The frequency of NY‑ESO‑1 expression was significantly higher in HCC patients with portal vein tumor thrombosis (24.6%) compared with those without thrombosis (11.2%, p=0.013). Our data suggest that DCs loaded with NY‑ESO‑1 protein stimulate antigen-specific T cell responses against HCC cells in vitro. NY‑ESO‑1 may thus be used as a potential target for immunotherapy in advanced HCC.

Expression screening of cancer/testis genes in prostate cancer identifies NR6A1 as a novel marker of disease progression and aggressiveness

BACKGROUND

Cancer/Testis (CT) genes are expressed in male gonads, repressed in most healthy somatic tissues and de-repressed in various somatic malignancies including prostate cancers (PCa). Because of their specific expression signature and their associations with tumor aggressiveness and poor outcomes, CT genes are considered to be useful biomarkers and they are also targets for the development of new anti-cancer immunotherapies. The aim of this study was to identify novel CT genes associated with hormone-sensitive prostate cancer (HSPC), and castration-resistant prostate cancer (CRPC).

METHODS

To identify novel CT genes we screened genes for which transcripts were detected by RNA profiling specifically in normal testis and in either HSPC or CRPC as compared to normal prostate and 44 other healthy tissues using GeneChips. The expression and clinicopathological significance of a promising candidate--NR6A1--was examined in HSPC, CRPC, and metastatic site samples using tissue microarrays.

RESULTS

We report the identification of 98 genes detected in CRPC, HSPC and testicular samples but not in the normal controls. Among them, cellular levels of NR6A1 were found to be higher in HSPC compared to normal prostate and further increased in metastatic lesions and CRPC. Furthermore, increased NR6A1 immunoreactivity was significantly associated with a high Gleason score, advanced pT stage and cancer cell proliferation.

CONCLUSIONS

Our results show that cellular levels of NR6A1 are correlated with disease progression in PCa. We suggest that this essential orphan nuclear receptor is a potential therapeutic target as well as a biomarker of PCa aggressiveness.

Potential role of meiosis proteins in melanoma chromosomal instability

Melanomas demonstrate chromosomal instability (CIN). In fact, CIN can be used to differentiate melanoma from benign nevi. The exact molecular mechanisms that drive CIN in melanoma have yet to be fully elucidated. Cancer/testis antigens are a unique group of germ cell proteins that are found to be primarily expressed in melanoma as compared to benign nevi. The abnormal expression of these germ cell proteins, normally expected only in the testis and ovaries, in somatic cells may lead to interference with normal cellular pathways. Germ cell proteins that may be particularly critical in CIN are meiosis proteins. Here, we review pathways unique to meiosis with a focus on how the aberrant expression of meiosis proteins in normal mitotic cells “meiomitosis” could impact chromosomal instability in melanoma and other cancers.

Peripheral CD8(+) T cell proliferation is prognostic for patients with advanced thoracic malignancies

There is a complex interplay between the immune system and a developing tumor that is manifest in the way that the balance of T cell subsets in the local tumor environment reflects clinical outcome. Tumor infiltration by CD8(+) T cells and regulatory T cells (Treg) is associated with improved and reduced survival, respectively, in many cancer types. However, little is known of the prognostic value of immunological parameters measured in peripheral blood. In this study, peripheral CD8(+) T cells and Treg from 43 patients with malignant mesothelioma or advanced non-small-cell lung cancer scheduled to commence palliative chemotherapy were assessed by flow cytometry and evaluated for association with patient survival. Patients had a higher proportion of peripheral Treg, proliferating CD8(+) T cells and CD8(+) T cells with an activated effector phenotype compared with age-matched healthy controls. Higher proportions of Treg and proliferating CD8(+) T cells were both associated with poor survival in univariate analyses (hazard ratio [HR] 3.81, 95 % CI 1.69-8.57; p < 0.01 and HR 2.86, 95 % CI 1.26-6.50; p < 0.05, respectively). CD8(+) T cell proliferation was independently predictive of reduced survival in multivariate analysis (HR 2.58, 95 % CI 1.01-6.61; p < 0.05). These findings suggest that peripheral CD8(+) T cell proliferation can be a useful prognostic marker in patients with thoracic malignancies planned for palliative chemotherapy.

Germ cell proteins in melanoma: prognosis, diagnosis, treatment, and theories on expression

Germ cell protein expression in melanoma has been shown to correlate with malignancy, severity of disease and to serve as an immunologic target for therapy. However, very little is known about the role that germ cell proteins play in cancer development. Unique germ cell pathways include those involved in immortalization, genetic evolution, and energy metabolism. There is an ever increasing recognition that within tumors there is a subpopulation of cells with stem-cell-like characteristics that play a role in driving tumorgenesis. Stem cell and germ cell biology is intertwined. Given the enormous potential and known expression of germ cell proteins in melanoma, it is possible that they represent a largely untapped resource that may play a fundamental role in tumor development and progression. The purpose of this paper is to provide an update on the current value of germ cell protein expression in melanoma diagnosis, prognosis, and therapy, as well as to review critical germ cell pathways and discuss the potential roles these pathways may play in malignant transformation.

Prognostic value of melanoma-associated antigen A9 in renal cell carcinoma

OBJECTIVE

The aim of this study was to evaluate the prognostic relevance of melanoma-associated antigen (MAGE) A9 in renal cell carcinoma (RCC).

MATERIAL AND METHODS

Immunohistochemical staining for MAGE A9 was evaluated in a tissue microarray containing 587 RCC tumour tissue samples. Nuclear MAGE A9 expression was reviewed using a semiquantitative score. Follow-up has been surveyed since 1990 in a prospectively conducted tumour database. The effect of MAGE A9 expression on cancer-specific survival (CSS) was assessed by univariate and multivariate Cox regression analyses. Subgroup analyses were performed for non-metastatic and metastatic disease.

RESULTS

Median age in all patients was 63.2 years, 354 patients were male and 233 female, and 108 patients had metastatic disease. Median follow-up was 5.6 years for all patients and 9.0 years for patients still alive (range 0-19.9 years). High nuclear MAGE A9 expression was present in 326 tumour specimens (55.5%). In multivariate analyses high nuclear MAGE A9 expression was associated with poor CSS (p = 0.0027). Furthermore, tumour stage, lymph-node and distant metastasis, Fuhrman grade G3/4, Karnofsky index < 80% and male gender were associated with poor CSS. In subgroup analyses, results were concordant for patients with non-metastatic disease. In patients with metastatic disease, only Karnofsky index > 80% was a significant predictor for CSS; MAGE A9 expression could not be shown to be associated with CSS (p = 0.161).

CONCLUSIONS

High nuclear MAGE A9 expression is independently associated with poor CSS in patients with non-metastatic RCC. The assessment of MAGE A9 expression can provide additional prognostic information and should be used in decision-making regarding adjuvant therapy in patients with non-metastatic disease.

MAGE-C2 promotes growth and tumorigenicity of melanoma cells, phosphorylation of KAP1, and DNA damage repair

Melanoma-associated antigen-encoding (MAGE) genes are expressed in melanoma and other cancers but not in normal somatic cells. MAGE expression is associated with aggressive tumor growth, poor clinical outcome, and resistance to chemotherapy, but the mechanisms have not been completely elucidated. In this study, we show that downregulation of MAGE-C2 in A375 melanoma cells and low-passage cultures from human metastatic melanomas (MRA cells) results in increased apoptosis and decreased growth of tumor xenografts in athymic nude mice. Previously, we showed that MAGE-C2 binds KAP1, a scaffolding protein that regulates DNA repair. Phosphorylation of KAP1-Serine 824 (Ser824) by ataxia-telangiectasia-mutated (ATM) kinase is necessary for repair of DNA double-strand breaks (DSBs); now we show that MAGE-C2 knockdown reduces, whereas MAGE-C2 overexpression increases, ATM kinase-dependent phosphorylation of KAP1-Ser824. We demonstrate that MAGE-C2 increases co-precipitation of KAP1 with ATM and that binding of MAGE-C2 to KAP1 is necessary for increased KAP1-Ser824 phosphorylation. Furthermore, ectopic expression of MAGE-C2 enhances repair of I-SceI endonuclease-induced DSBs in U-2OS cells. As phosphorylation of KAP1-Ser824 facilitates relaxation of heterochromatin, which is necessary for DNA repair and cellular proliferation, our results suggest that MAGE-C2 can promote tumor growth by phosphorylation of KAP1-Ser824 and by enhancement of DNA damage repair.

The melanoma-associated antigen MAGE-D2 suppresses TRAIL receptor 2 and protects against TRAIL-induced apoptosis in human melanoma cells

Emerging evidence has pointed to biological roles of melanoma-associated antigens (MAGEs) in cancer development, progression and resistance to treatment. However, the mechanisms involved remain to be fully elucidated. In this report, we show that one of the MAGE proteins, MAGE-D2, suppresses the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) death receptor 2 (TRAIL-R2) and plays an important role in protecting melanoma cells from apoptosis induced by TRAIL. MAGE-D2 was commonly expressed at increased levels in melanoma cells compared with melanocytes. Although its inhibition by small interfering RNA (siRNA) did not cause cell death, it rendered melanoma cells more sensitive to TRAIL-induced apoptosis. This was associated with enhanced formation of TRAIL death-inducing signaling complex and up-regulation of TRAIL-R2, and was blocked by a recombinant TRAIL-R2/Fc chimeric protein or siRNA knockdown of TRAIL-R2. Regulation of TRAIL-R2 by MAGE-D2 appeared to be mediated by p53, in that knockdown MAGE-D2 did not up-regulate TRAIL-R2 in p53-null or mutant p53 melanoma cells. In addition, inhibition of MAGE-D2 did not result in up-regulation of TRAIL-R2 in wild-type p53 cell lines with p53 inhibited by short hairpin RNA. Indeed, knockdown of MAGE-D2 led to up-regulation of p53 due to a transcriptional increase. The regulatory effect of MAGE-D2 on TRAIL-R2 expression and TRAIL-induced apoptosis was recapitulated in studies on fresh melanoma isolates. Taken together, these results identify the expression of MAGE-D2 as an important mechanism that inhibit TRAIL-induced apoptosis and suggest that targeting MAGE-D2 may be a useful strategy in improving the therapeutic efficacy of TRAIL in melanoma.

NY-ESO-1 expression in hepatocellular carcinoma: A potential new marker for early recurrence after surgery

NY-ESO-1 belongs to the cancer testis antigens (CTA) family, and is identified in a variety of tumors. Certain studies have demonstrated that NY-ESO-1 predicts tumor recurrence and treatment response. No reports are currently available regarding the correlation between NY-ESO-1 and the recurrence of hepatocellular carcinoma (HCC) following surgery. The purpose of the present study was to evaluate the association between NY-ESO-1 and relapse of HCC and to explore the possible mechanisms for this correlation. A total of 120 HCC patients were analyzed for the expression of NY-ESO-1 by immunohistochemistry (IHC). A stable NY-ESO-1 over-expressed HepG2 cell line (ESO-HepG2) was established to determine the biological effects of NY-ESO-1 on cell proliferation, cell cycle and migration by using the xCELLigence DP system, flow cytometry and xCELLigence SP system. NY-ESO-1 was positive in 28 of 120 (23.3%) HCC tumor tissues. NY-ESO-1 was not detectable in adjacent normal liver tissues. A close correlation was found between NY-ESO-1 expression and the recurrence of HCC following surgery (P=0.007). Kaplan-Meier analysis showed a shorter recurrence-free survival (RFS) for patients positive for NY-ESO-1 (log-rank test, P=0.003). The Cox regression model demonstrated that NY-ESO-1 expression was a significant independent predictor for the recurrence of HCC following curative surgery (P=0.022). Compared with HepG2 cells, ESO-HepG2 cells have increased migration but not proliferation ability. In conclusion, NY-ESO-1 expression is associated with worse HCC outcome following surgery, and the mechanism for this finding may be that NY-ESO-1 increases tumor cell migration.

Melanoma update: diagnostic and prognostic factors that can effectively shape and personalize management

Routine light microscopy remains a powerful tool to diagnose, stage and prognose melanoma. Although it is very economical and efficient, it requires a significant level of expertise and, in difficult cases the final diagnosis is affected by subjective interpretation. Fortunately, new insights into the genomic aberrations characteristic of melanoma, coupled with ancillary studies, are further refining evaluation and management allowing for more confident diagnosis, more accurate staging and the selection of targeted therapy. In this article, we review the standard of care and new updates including four probe FISH, the 2009 American Joint Commission on Cancer staging of melanoma and mutant testing of melanoma, which will be crucial for targeted therapy of metastatic melanoma.

Cancer/Testis Antigens as potential predictors of biochemical recurrence of prostate cancer following radical prostatectomy

Background

The Cancer/Testis Antigens (CTAs) are an important group of proteins that are typically restricted to the testis in the normal adult but are aberrantly expressed in several types of cancers. As a result of their restricted expression patterns, the CTAs could serve as unique biomarkers for cancer diagnosis/prognosis. The aim of this study was to identify promising CTAs that are associated with prostate cancer (PCa) recurrence following radical prostatectomy (RP).

Methods

The expression of 5 CTAs was measured by quantitative multiplex real-time PCR using prostate tissue samples obtained from 72 patients with apparently clinically localized PCa with a median of two years follow-up (range, 1 to 14 years).

Results

The expression of CTAs namely, CEP55, NUF2, PBK and TTK were significantly higher while PAGE4 was significantly lower in patients with recurrent disease. All CTAs with the exception of TTK were significantly correlated with the prostatectomy Gleason score, but none were correlated with age, stage, or preoperative PSA levels. In univariate proportional hazards models, CEP55 (HR = 3.59, 95% CI: 1.50-8.60), p = 0.004; NUF2 (HR = 2.28, 95% CI: 1.11-4.67), p = 0.024; and PAGE4 (HR = 0.44, 95% CI: 0.21-0.93), p = 0.031 were significantly associated with the risk of PCa recurrence. However, the results were no longer significant after adjustment for prostatectomy Gleason score.

Conclusions

To our knowledge, this is the first study to identify CTAs as biomarkers that can differentiate patients with recurrent and non-recurrent disease following RP and underscores its potential impact on PCa prognosis and treatment.

Improving T-cell therapy for relapsed EBV-negative Hodgkin lymphoma by targeting upregulated MAGE-A4

PURPOSE

Patients with Hodgkin lymphoma (HL) relapsing after hematopoietic stem cell transplant have limited options for long-term cure. We have shown that infused cytotoxic T cells (CTL) targeting Epstein Barr virus (EBV)-derived proteins induced complete remissions in EBV(+) HL patients. A limitation of this approach is that up to 70% of relapsed HL tumors are EBV-negative. For these patients, an alternative is to target the cancer/testis antigen MAGE-A4 present in EBV antigen-negative HL tumors. Furthermore, epigenetic modification by clinically available demethylating agents can enhance MAGE-A4 expression in previously MAGE-negative tumors.

EXPERIMENTAL DESIGN

We explored the feasibility of combining adoptive T cell therapy with epigenetic modification of tumor antigen expression. We further characterized MAGE-A4-specific T-cell phenotype and function, and examined the effects of the epigenetic modifying drug decitabine on these T cells.

RESULTS

Cytotoxic T cells were generated specifically recognizing MAGE-A4 expressed by autologous HL targets and tumor cell lines. Decitabine-previously shown to increase tumor antigen expression in HL-did not compromise MAGE-A4-specific T-cell phenotype and function. In patients treated with decitabine, expanded MAGE-A4-specific T cells had a broader antitumor T cell repertoire, consistent with increased antigen stimulation in vivo.

CONCLUSIONS

Adoptive transfer of MAGE-A4-specific T cells, combined with epigenetic modifying drugs to increase expression of the protein, may improve treatment of relapsed HL.