Analysis of GAGE, NY-ESO-1 and SP17 cancer/testis antigen expression in early stage non-small cell lung carcinoma

Single-cell sequencing unveils extensive intratumoral heterogeneity of cancer/testis antigen expression in melanoma and lung cancer

Cancer/testis antigens (CTAs) are widely expressed in melanoma and lung cancer, emerging as promising targets for vaccination strategies and T-cell-based therapies in these malignancies. Despite recognizing the essential impact of intratumoral heterogeneity on clinical responses to immunotherapy, our understanding of intratumoral heterogeneity in CTA expression has remained limited. We employed single-cell mRNA sequencing to delineate the CTA expression profiles of cancer cells in clinically derived melanoma and lung cancer samples. Our findings reveal a high degree of intratumoral transcriptional heterogeneity in CTA expression. In melanoma, every cell expressed at least one CTA. However, most individual CTAs, including the widely used therapeutic targets NY-ESO-1 and MAGE, were confined to subpopulations of cells and were uncoordinated in their expression, resulting in mosaics of cancer cells with diverse CTA profiles. Coordinated expression was observed, however, mainly among highly structurally and evolutionarily related CTA genes. Importantly, a minor subset of CTAs, including PRAME and several members of the GAGE and MAGE-A families, were homogenously expressed in melanomas, highlighting their potential as therapeutic targets. Extensive heterogeneity in CTA expression was also observed in lung cancer. However, the frequency of CTA-positive cancer cells was notably lower and homogenously expressed CTAs were only identified in one of five tumors in this cancer type. Our findings underscore the need for careful CTA target selection in immunotherapy development and clinical testing and offer a rational framework for identifying the most promising candidates.

Recent advances and remaining challenges in lung cancer therapy

ABSTRACT

Lung cancer remains the most common cause of cancer death. Given the continued research into new drugs and combination therapies, outcomes in lung cancer have been improved, and clinical benefits have been expanded to a broader patient population. However, the overall cure and survival rates for lung cancer patients remain low, especially in metastatic cases. Among the available lung cancer treatment options, such as surgery, radiation therapy, chemotherapy, targeted therapies, and alternative therapies, immunotherapy has shown to be the most promising. The exponential progress in immuno-oncology research and recent advancements made in the field of immunotherapy will further increase the survival and quality of life for lung cancer patients. Substantial progress has been made in targeted therapies using tyrosine kinase inhibitors and monoclonal antibody immune checkpoint inhibitors with many US Food And Drug Administration (FDA)-approved drugs targeting the programmed cell death ligand-1 protein (e.g., durvalumab, atezolizumab), the programmed cell death-1 receptor (e.g., nivolumab, pembrolizumab), and cytotoxic T-lymphocyte-associated antigen 4 (e.g., tremelimumab, ipilimumab). Cytokines, cancer vaccines, adoptive T cell therapies, and Natural killer cell mono- and combinational therapies are rapidly being studied, yet to date, there are currently none that are FDA-approved for the treatment of lung cancer. In this review, we discuss the current lung cancer therapies with an emphasis on immunotherapy, including the challenges for future research and clinical applications.

Gene of the month: cancer testis antigen gene 1b (NY-ESO-1)

Cancer testis antigen gene 1B (CTAG1B) and its associated gene product; New York oesophageal squamous carcinoma 1 (NY-ESO-1), represent a unique and promising target for cancer immunotherapy. As a member of the cancer testis antigen family (CTA), the protein's restricted expression pattern and ability to elicit spontaneous humoural and cellular immune responses has resulted in a plethora of novel modalities and approaches attempting to harness its immunotherapeutic anti-cancer potential. Here, we discuss the structure and function of CTAG1B/NY-ESO-1 in both health and disease, immunohistochemical detection, as well as the most promising advances in the development of associated anti-cancer therapies. From cancer vaccines to engineered cellular therapy approaches, a multitude of immunotherapies targeting CTA's are coming to the forefront of oncology. Although the efficacy of such approaches have yet to provide convincing evidence of durable response, early phase clinical trial data has resulted in some exciting findings which will have significant potential to act as a platform for future practice changing technologies.

Sperm Autoantigenic Protein 17 Predicts the Prognosis and the Immunotherapy Response of Cancers: A Pan-Cancer Analysis

Background

Sperm autoantigen protein 17 (SPA17) is a highly conserved mammalian protein that participates in the acrosome reaction during fertilization and is a recently reported member of the cancer-testicular antigen (CTA) family. It has been reported that the SPA17 expression is limited in adult somatic tissues and re-expressed in tumor tissues. Recently, studies have found that SPA17 regulates the progression of various cancers, but its role in cancer immunotherapy is not clear.

Methods

The pan-cancer and normal tissue transcriptional data were acquired from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) datasets. We explored the SPA17 pan-cancer genomic alteration analysis in the cBioPortal webtool. The Human Protein Atlas (HPA) and ComPPI websites were used to mine the SPA17 protein information. We performed a western blotting assay to validate the upregulated SPA17 expression in clinical glioblastoma (GBM) samples. The univariate Cox regression and Kaplan-Meier method were used to assess the prognostic role of SPA17 in pan-cancer. Gene Set Enrichment Analysis (GSEA) was used to search the associated cancer hallmarks with SPA17 expression in each cancer type. TIMER2.0 was the main platform to investigate the immune cell infiltrations related to SPA17 in pan-cancer. The associations between SPA17 and immunotherapy biomarkers were performed by Spearman correlation analysis. The drug sensitivity information from the Connectivity Map (CMap) dataset was downloaded to perform SAP17-specific inhibitor sensitivity analysis.

Findings

SPA17 was aberrantly expressed in most cancer types and exhibited prognosis predictive ability in various cancers. In addition, our results also show that SPA17 was significantly correlated with immune-activated hallmarks (including pathways and biological processes), immune cell infiltrations, and immunoregulator expressions. The most exciting finding was that SPA17 could significantly predict anti-PDL1 and anti-PD1 therapy responses in cancer patients. Finally, specific inhibitors, like irinotecan and puromycin, which correlate with SPA17 expression in different cancer types, were also screened using Connectivity Map (CMap).

Conclusions

Our results reveal that SPA17 was abnormally expressed in cancer tissues, and this expression pattern could be associated with immune cell infiltrations in tumor microenvironments. Clinically, SPA17 not only acted as a potent prognostic factor to predict the clinical outcomes of cancer patients but was also a promising immunotherapy predictive biomarker for cancer patients treated with immune-checkpoint inhibitors (ICIs).

The role of autoantibody detection in the diagnosis and staging of lung cancer

Background

Previously, the clinical value of seven autoantibodies (p53, PGP9.5, SOX2, GAGE7, GBU4-5, MAGEA1, and CAGE) has been surveyed in our pilot observation and other published studies. Herein, we aimed to further investigate the role of these autoantibodies in the diagnosis and staging of LC.

Methods

We included a total of 135 individuals, who were divided into a Lung cancer (LC) group and a control group according to the final diagnosis. Seven autoantibody detection kits were used (ELISA method) for the expression measurement. The patients’ demographics information (e.g., age, gender, and smoking history) were also documented.

Results

Among the seven types of autoantibodies, only P53 and GBU4-5 were significantly increased in the LC group compared to the controls. Also, the P53 autoantibody was markedly different among the various subtype groups. Meanwhile, the GBU4-5 level was significantly higher in the small cell lung cancer (SCLC) patients compared to patients with adenocarcinoma (ADC). Autoantibodies against PGP9.5, SOX2, GBU4-5, and CAGE were found to be associated with stages. Their expressions were notably higher in the advanced stage (IV) versus early stages (I–II). Using logistic regression, the outcomes of LC prediction and stage prediction showed that the area under curve (AUCs) of the receiver operating characteristic (ROC) curves were 0.743 and 0.798, respectively.

Conclusions

In summary, our study confirmed the diagnostic value of tumor-associated autoantibodies, which may be useful as latent tumor markers to facilitate the detection of early LC. Single autoantibody testing is not yet sufficient in LC cancer screening, and the combined detection of autoantibodies can improve the sensitivity of detection compared with single antibody detection, especially for P53, PGP9.5, SOX2, GBU4-5, and CAGE autoantibodies.

Engineering Cancer Antigen-Specific T Cells to Overcome the Immunosuppressive Effects of TGF-β

Adoptive T cell therapy with T cells expressing affinity-enhanced TCRs has shown promising results in phase 1/2 clinical trials for solid and hematological tumors. However, depth and durability of responses to adoptive T cell therapy can suffer from an inhibitory tumor microenvironment. A common immune-suppressive agent is TGF-β, which is secreted by tumor cells and cells recruited to the tumor. We investigated whether human T cells could be engineered to be resistant to inhibition by TGF-β. Truncating the intracellular signaling domain from TGF-β receptor (TGFβR) II produces a dominant-negative receptor (dnTGFβRII) that dimerizes with endogenous TGFβRI to form a receptor that can bind TGF-β but cannot signal. We previously generated specific peptide enhanced affinity receptor TCRs recognizing the HLA-A*02-restricted peptides New York esophageal squamous cell carcinoma 1 (NY-ESO-1)_157-165/l-Ag family member-1A (TCR: GSK3377794, formerly NY-ESO-1^c259) and melanoma Ag gene A10_254-262 (TCR: ADP-A2M10, formerly melanoma Ag gene A10^c796). In this article, we show that exogenous TGF-β inhibited in vitro proliferation and effector functions of human T cells expressing these first-generation high-affinity TCRs, whereas inhibition was reduced or abolished in the case of second-generation TCRs coexpressed with dnTGFβRII (e.g., GSK3845097). TGF-β isoforms and a panel of TGF-β-associated genes are overexpressed in a range of cancer indications in which NY-ESO-1 is commonly expressed, particularly in synovial sarcoma. As an example, immunohistochemistry/RNAscope identified TGF-β-positive cells close to T cells in tumor nests and stroma, which had low frequencies of cells expressing IFN-γ in a non-small cell lung cancer setting. Coexpression of dnTGFβRII may therefore improve the efficacy of TCR-transduced T cells.

The role of seven autoantibodies in lung cancer diagnosis

Background

To investigate the expression and diagnostic value of seven autoantibodies (P53, PGP9.5, SOX2, GAGE7, GBU4-5, MAGE, and CACE) in lung cancer patients.

Methods

A total of 370 patients were admitted to the Thoracic Surgery of the First Affiliated Hospital of Suzhou University from 2017 to 2019, including 305 patients with lung cancer and 65 patients with benign lesions. The concentrations of the seven autoantibodies were determined by enzyme linked immunosorbent assay (ELISA).The expression levels of each antibody were compared between the two groups, and the levels of each antibody between lung cancer patients with different pathological types were also compared. We aimed to analyze the diagnostic efficiency of single antibody detection combined with seven antibodies, and also to explore whether there were differences among the positive rates of each antibody in sex, age, smoking history, pathological classification, and clinical stages in the lung cancer group.

Results

The expression levels of seven autoantibodies in the lung cancer group were higher than those in the benign lesion group. In the lung cancer group, the expression levels of the seven autoantibodies did not vary statistically among different pathological types. The area under the curve of combined detection of the seven antibodies reached 0.735, and the Y-index reached 0.35, which was higher than that of single antibody detection. P53 exhibited the highest sensitivity and lowest specificity; meanwhile, PGP9.5, SOX2, GAGE7, GBU4-5, and MAGEA1 exhibited low sensitivity and high specificity. The sensitivity and specificity of the CAGE were approximately 60%, respectively. There was no statistical difference in the positive rate of each antibody in age, smoking history, and clinical stage. The positive rate of MAGEA1 and CAGE was statistically different in sex, and the positive rate of MAGEA1 was statistically different in pathological classification.

Conclusions

The seven autoantibodies of lung cancer can potentially be used as an auxiliary examination method for the early diagnosis of lung cancer.

Reverse Vaccinology Approach in Constructing a Multi-Epitope Vaccine Against Cancer-Testis Antigens Expressed in Non-Small Cell Lung Cancer

Background:

The 5-year survival rate of non-small cell lung cancer (NSCLC) patients has not significantly improved despite advancements in the currently applied treatments. Thus, efforts are put forth in developing novel immunotherapeutic agents targeting cancer-testis antigens (CTA) in NSCLC. This work utilized reverse vaccinology approach in designing a novel multi-epitope vaccine targeting melanoma-associated antigen 3 (MAGEA3), MAGEA4, New York esophageal squamous cell carcinoma-1 (NY-ESO-1), and Kita-Kyushu lung cancer antigen 1 (KK-LC1), being the most frequently expressed CTAs in NSCLC.

Methods:

Epitopes were mapped from the sequences of CTAs. The population coverage (PC) of identified CD4+ and CD8+ epitopes were estimated. Candidate linear B cell (BL), CD4+, and CD8+ epitopes were adjoined in a multi-epitope construct (Mvax) with flagellin domain as an adjuvant. Antigenicity, and cross-reactivity of Mvax were examined. The tertiary structure of Mvax was modelled, and validated. All epitopes included in the vaccine were docked with their human leukocyte antigen (HLA) binders. The immunogenicity of epitopes in Mvax was validated through molecular dynamics analysis.

Results:

Mvax contains 22 epitopes from MAGEA3, MAGEA4, NY-ESO-1, and KK-LC1. It is classified as antigenic, non-allergen, non-toxic, and possesses physicochemical stability. Epitopes have no significant hits with other human proteins, except for 2 other CTAs frequently expressed in NSCLC. The stretch of BL epitopes in Mvax confers flexibility, and accessibility emphasizing its antigenicity. The tertiary structure analysis showed that Mvax model has good structural quality. All epitopes included in the vaccine are highly immunogenic as indicated by favorable binding affinity, low binding energy, and acceptable root-mean-square deviation (RMSD). CD4+ and CD8+ epitopes have global PC of 81.81%, and 84.15%, respectively.

Conclusion:

Overall, in silico evaluations show that Mvax is a potential immunotherapeutic agent against NSCLC.

Expression of cancer testis antigens in thymic epithelial tumors

Cancer testis antigens (CTAs) are detected in cancer cells but not in healthy normal tissues, with the exception of gametogenic tissues. However, to our knowledge, expression of the antigens in thymic epithelial tumors has not been examined yet. We examined the immunohistochemical expression of five CTAs (MAGE-A, NY-ESO-1, MAGE-C1, SAGE and GAGE7) in 192 cases of thymic epithelial tumor. The CTAs were variably expressed in the thymic epithelial tumors. Type B component of type AB thymomas, type B1/B2/B3 thymomas, and thymic carcinomas showed a generally positive correlation between the malignancy grades and positive expression rates in four CTAs other than MAGE-C1. In thymic squamous cell carcinomas (SqCCs), four antigens except for MAGE-C1 showed high expression rates ranging from 23.1% to 43.6%. In the prognostic analysis, a positive expression of SAGE (P = 0.0485) and GAGE7 (P = 0.0289) were associated with a shorter overall survival in type B2/B3 thymomas, respectively. In thymic SqCC, a positive MAGE-A expression was significantly associated with an increased level of programmed death ligand in tumor-infiltrating lymphocytes (P = 0.0181). We showed (i) a frequent CTA expression, (ii) a general correlation of CTA expression with tumor malignancy grades and (iii) a prognostic impact in some of the CTAs.

Clinicopathological and prognostic significance of circRNAs in lung cancer: A systematic review and meta-analysis

BACKGROUND

Circular RNAs (circRNAs) regulate multiple pathways during lung cancer pathogenesis. Apart from functional significance, many circRNAs have been shown to be associated with clinicopathological characteristics and predict lung cancer prognosis. Our aim is to summarize the expanding knowledge of clinical roles of circRNAs in lung cancer.

METHODS

A thorough search of literature was conducted to identify articles about the correlation between circRNA expression and its prognostic and clinicopathological values. Biological mechanisms were summarized.

RESULTS

This study included 35 original articles and 32 circRNAs with prognostic roles for lung cancer. Increased expression of 25 circRNAs and decreased expression of 7 circRNAs predicted poor prognosis. For non-small cell lung cancer, changes of circRNAs were correlated with tumor size, lymph node metastasis, distant metastasis, tumor node metastasis (TNM) stage, and differentiation, indicating the major function of circRNAs is to promote lung cancer invasion and migration. Particularly, meta-analysis of ciRS-7, hsa_circ_0020123, hsa_circ_0067934 showed increase of the 3 circRNAs was associated with positive lymph node metastasis. Increase of ciRS-7 and hsa_circ_0067934 was also related with advanced TNM stage. The biological effects depend on the general function of circRNA as microRNA sponge.

CONCLUSIONS

CircRNAs have the potential to function as prognostic markers and are associated with lung cancer progression and metastasis.

The Cancer/Testis Antigen Gene VCX2 Is Rarely Expressed in Malignancies but Can Be Epigenetically Activated Using DNA Methyltransferase and Histone Deacetylase Inhibitors

Identification of novel tumor-specific targets is important for the future development of immunotherapeutic strategies using genetically engineered T cells or vaccines. In this study, we characterized the expression of VCX2, a member of the VCX/Y cancer/testis antigen family, in a large panel of normal tissues and tumors from multiple cancer types using immunohistochemical staining and RNA expression data. In normal tissues, VCX2 was detected in the germ cells of the testis at all stages of maturation but not in any somatic tissues. Among malignancies, VCX2 was only found in tumors of a small subset of melanoma patients and thus rarely expressed compared to other cancer/testis antigens such as GAGE and MAGE-A. The expression of VCX2 correlated with that of other VCX/Y genes. Importantly, we found that expression of VCX2 was inversely correlated with promoter methylation and could be activated by treatment with a DNA methyltransferase inhibitor in multiple breast cancer and melanoma cell lines and a breast cancer patient-derived xenograft. The effect could be further potentiated by combining the DNA methyltransferase inhibitor with a histone deacetylase inhibitor. Our results show that the expression of VCX2 can be epigenetically induced in cancer cells and therefore could be an attractive target for immunotherapy of cancer.

Expression and Prognostic Significance of Cancer/Testis Antigens, MAGE-E1, GAGE, and SOX-6, in Glioblastoma: An Immunohistochemistry Evaluation

Background & Objective:

Glioblastoma is the most common primary malignancy of the brain, the prognosis of which is poor. Immunotherapy with cancer/testis (CT) antigens is a novel therapeutic approach for glioblastoma. This study aimed to investigate the expression rate of MAGE-E1, GAGE, and SOX-6 in glioblastoma tumors using the method of immunohistochemistry (IHC).

Methods:

Expression of MAGE-E1, GAGE, and SOX-6 were determined by IHC in 50 paraffin blocks of glioblastoma. The results were compared between variables including age, gender, tumor location, and Karnofsky performance status (Kps) score. Survival analysis was also performed.

Results:

The expression levels of SOX-6, MAGE-E1, and GAGE were 82%, 78%, and 76%, respectively. The relationship between CT antigens and age, gender, and tumor location was not significant, while the association between MAGE-E1 expression and age was statistically significant (P=0.002). High expression levels of SOX-6 and MAGE-E1 were associated with low Kps scores (P=0.034 and P<0.001, respectively). Survival analysis showed that age >40 and Kps score <80 were associated with significant relationship with shorter survival rate. (P=0.005 and P=0.018, respectively). Expression of MAGE-E1 and GAGE was negatively associated with overall 2-year survival rate (P=0.001 and P=0.021, respectively).

Conclusion:

The expression of all the three CT antigens, especially MAGE-E1 and SOX-6, was high in patients with glioblastoma. It can be concluded that these markers could be ideal targets for immunotherapy in such patients. MAGE-E1 and SOX-6 can be considered as important markers in determining the prognosis of glioblastoma.

NY-ESO-1 expression in solid tumors predicts prognosis: A systematic review and meta-analysis

BACKGROUND

New York esophageal squamous cell carcinoma 1 (NY-ESO-1) is a member of the cancer testis antigen family. NY-ESO-1 has documented potential as an effective target for cancer immunotherapy. The prognostic value of NY-ESO-1 expression in solid tumors, however, remains controversial because of inconclusive data.

METHODS

For this analysis, the Medline, Embase, and Cochrane Library databases were searched up to February 2018 for studies investigating NY-ESO-1 expression in solid tumors and overall survival (OS), progression-free survival (PFS), or disease-free survival (DFS). Hazard ratios (HRs) with 95% confidence intervals (CIs) were extracted from each study. Pooled HRs and CIs were calculated using the Mantel-Haenszel fixed effects or random effects model.

RESULTS

A total of 23 studies were included in the analysis. The combined HR (95% CI) estimates for OS, PFS, and DFS were 1.41 (95% CI: 1.24-1.61; I = 0%), 1.62 (95% CI: 1.42-1.84; I = 17%), and 0.95 (95% CI: 0.56-1.59; I = 57%), respectively.

CONCLUSIONS

NY-ESO-1 expression in solid tumors is associated with worse OS and PFS. Studies are still needed to provide more evidence.

A Computational Model of Neoadjuvant PD-1 Inhibition in Non-Small Cell Lung Cancer

Immunotherapy and immune checkpoint blocking antibodies such as anti-PD-1 are approved and significantly improve the survival of advanced non-small cell lung cancer (NSCLC) patients, but there has been little success in identifying biomarkers capable of separating the responders from non-responders before the onset of the therapy. In this study, we developed a quantitative system pharmacology (QSP) model to represent the anti-tumor immune response in human NSCLC that integrated our knowledge of tumor growth, antigen processing and presentation, T cell activation and distribution, antibody pharmacokinetics, and immune checkpoint dynamics. The model was calibrated with the available data and was used to identify potential biomarkers as well as patient-specific response based on the patient parameters. The model predicted that in addition to tumor mutational burden (TMB), a known biomarker for anti-PD-1 therapy in NSCLC, the number of effector T cells and regulatory T cells in the tumor and blood is a predictor of the responders. Furthermore, the model simulated a set of 12 patients with known TMB and MHC/antigen-binding affinity from a recent clinical trial (ClinicalTrials.gov number, NCT02259621) on neoadjuvant nivolumab therapy in resectable lung cancer and predicted an augmented durable response in patients with adjuvant nivolumab treatment in addition to the clinical trial protocol of neoadjuvant nivolumab treatment followed by resection. Overall, the model provides a valuable framework to model tumor immunity and response to immune checkpoint blockers to enhance biomarker discovery and performing virtual clinical trials to aid in design and interpretation of the current trials with fewer patients.

A phase I/IIa study of the mRNA-based cancer immunotherapy CV9201 in patients with stage IIIB/IV non-small cell lung cancer

CV9201 is an RNActive®-based cancer immunotherapy encoding five non-small cell lung cancer-antigens: New York esophageal squamous cell carcinoma-1, melanoma antigen family C1/C2, survivin, and trophoblast glycoprotein. In a phase I/IIa dose-escalation trial, 46 patients with locally advanced (n = 7) or metastatic (n = 39) NSCLC and at least stable disease after first-line treatment received five intradermal CV9201 injections (400-1600 µg of mRNA). The primary objective of the trial was to assess safety. Secondary objectives included assessment of antibody and ex vivo T cell responses against the five antigens, and changes in immune cell populations. All CV9201 dose levels were well-tolerated and the recommended dose for phase IIa was 1600 µg. Most AEs were mild-to-moderate injection site reactions and flu-like symptoms. Three (7%) patients had grade 3 related AEs. No related grade 4/5 or related serious AEs occurred. In phase IIa, antigen-specific immune responses against ≥ 1 antigen were detected in 63% of evaluable patients after treatment. The frequency of activated IgD+CD38hi B cells increased > twofold in 18/30 (60%) evaluable patients. 9/29 (31%) evaluable patients in phase IIa had stable disease and 20/29 (69%) had progressive disease. Median progression-free and overall survival were 5.0 months (95% CI 1.8-6.3) and 10.8 months (8.1-16.7) from first administration, respectively. Two- and 3-year survival rates were 26.7% and 20.7%, respectively. CV9201 was well-tolerated and immune responses could be detected after treatment supporting further clinical investigation.

Treatment of metastatic non-small cell lung cancer with NY-ESO-1 specific TCR engineered-T cells in a phase I clinical trial: A case report

This article presented a case of a human leukocyte antigen (HLA)-A2-positive patient with advanced cancer/testis antigen New York esophageal squamous cell carcinoma-1 (NY-ESO-1) expressing lung adenocarcinoma (LADC) who received adoptive cell therapy of T cell receptor engineered-T cells (TCR-T cells) targeting the cancer-testis antigen NY-ESO-1. The appropriate clinical and laboratory assessments were conducted to investigate the safety and efficacy of this therapy for this lung cancer patient. The patient had a clinical response to and was well-tolerated with this therapy in the clinical trial. In addition, a preliminary evaluation of the safety of NY-ESO-1 TCR-T cell therapy was performed in four patients with non-small cell lung cancer (NSCLC) enrolled in a clinical trial. It was well-tolerated and did not observe any serious adverse events post-infusion. Fever, anemia, and a decrease in white blood cell count were common adverse events, which were likely due to the TCR-T cell therapy. Two patients had clinical responses to NY-ESO-1 TCR-T cell therapy, including the 44-year-old female patient with LADC, who achieved a short-term partial response for 4 months, improved in Karnofsky performance status, and had a recovery of drug sensitivity. This suggests that TCR-T cell therapy targeting NY-ESO-1 antigen may be beneficial for HLA-A2-positive late-stage patients with NY-ESO-1-expressing NSCLC.

Establishment of cancer/testis antigen profiling based on clinicopathological characteristics in resected pathological stage III non-small cell lung cancer

Background

Cancer/testis antigen (CTA) expression was found to be highly heterogeneous in previous studies. We aimed to establish a precision CTA profiling in resected stage III non-small cell lung cancer (NSCLC) and demonstrate the best CTA combination covering the widest range of NSCLC cases.

Materials and methods

The expression of 10 CTAs was evaluated in 200 resected stage III NSCLC tissue specimens at protein level. Hierarchical clustering and python programming language analyses was used to demonstrate CTA expression and coverage.

Results

The most commonly expressed CTAs for total cases were MAGEA1 (60.0%), MAGEA10 (50.0%), and KK-LC-1 (47.5%). CTA expression was histology dependent, and concurrent expression was common. The best 2, 3, and 4 CTA combination covered 72.0%, 76.5%, and 79.5% of total cases, respectively. Stratified analysis based on variable clinicopathological characteristics achieved the maximum coverage of 92.3% with only 2 CTA combination in patients with features of male sex, positive smoking history, and adenocarcinoma, compared with a 85.0% coverage when 10 CTAs were assessed. Selected CTA expression was correlated with prognosis based on subgroup analysis. No significant difference was found between CTA expression and epidermal growth factor receptor mutant status.

Conclusion

We established an individualized CTA profiling in resected stage III NSCLC based on 10 CTA expression. With the help of computer programming language, the goal of the maximum CTA expression coverage was reached by using the least CTA combination based on sex, smoking history, and histology. These results were significant for the further study of CTA-specific T-cell immunotherapy.

The cancer-testis antigens SPANX-A/C/D and CTAG2 promote breast cancer invasion

Genes that are normally biased towards expression in the testis are often induced in tumor cells. These gametogenic genes, known as cancer-testis antigens (CTAs), have been extenstively investigated as targets for immunotherapy. However, despite their frequent detection, the degree to which CTAs support neoplastic invasion is poorly understood. Here, we find that the CTA genes SPANX-A/C/D and CTAG2 are coordinately induced in breast cancer cells and regulate distinct features of invasive behavior. Our functional analysis revealed that CTAG2 interacts with Pericentrin at the centrosome and is necessary for directional migration. Conversely, SPANX-A/C/D interacts with Lamin A/C at the inner nuclear membrane and is required for the formation of actin-rich cellular protrusions that reorganize the extracellular matrix. Importantly, SPANX-A/C/D was required for breast cancer cells to spontaneously metastasize to the lung, demonstrating that CTA reactivation can be critical for invasion dependent phenotypes in vivo. Moreover, elevated SPANX-A/C/D expression in breast cancer patient tumors correlated with poor outcome. Together, our results suggest that distinct CTAs promote tumor progression by regulating complementary cellular functions that are integrated together to induce invasive behavior.

Expression of cancer/testis antigens MAGE-A, MAGE-C1, GAGE and CTAG1B in benign and malignant thyroid diseases

Despite considerable advances in the understanding of thyroid gland biology, correctly diagnosing thyroid nodules and treating high-grade thyroid carcinoma remains challenging. Cancer/testis (CT) antigens have emerged as potential diagnostic tools as well as targets of potential cancer vaccinations. In the present study, a total of 117 patients who underwent surgical therapy for thyroid disease were available for analysis. The expression levels of melanoma-associated antigen (MAGE) A, MAGE-C1/CT7, cancer/testis antigen 1B (CTAG1B) and G antigen (GAGE) were analyzed by immunohistochemistry. None of the CT antigens were expressed in the normal thyroid or goiter. In papillary and follicular carcinoma, MAGE-A was present in 8.1% of cases, GAGE in 10.8% and CT/7MAGE-C1 and CTAG1B in 2.7% each. In medullary carcinoma, CT antigen expression was as follows: MAGE-A in 42.9% of patients; MAGE-C1/CT7 in 46.5%; GAGE in 92.9%; and CTAG1B in 3.6%. A statistically significant association was observed between the expression of G MAGE-C1/CT7 and patient gender as well as patient clinical stage (P=0.029 and 0.031, respectively). In poorly differentiated and anaplastic carcinoma cases, CT antigen expression was as follows: MAGE-A in 61.8% of cases; MAGE-C1 in 57.1%; GAGE in 66.7%; and CTAG1B in 14.4%. There was a statistically significant association between expression of GAGE and gender (P=0.043). However, there was no association between CT antigen expression and patient survival in any of the tumor entities analyzed. The current study identified a distinct expression pattern of CT antigens in malignant thyroid tumors indicating that CT antigens have the potential to outperform existing thyroid cancer biomarkers. The prevalence of CT antigens in high-grade carcinomas suggests that they serve an important biological role within malignant tumors.

Exosomal proteins as prognostic biomarkers in non-small cell lung cancer

Background

Use of exosomes as biomarkers in non‐small cell lung cancer (NSCLC) is an intriguing approach in the liquid‐biopsy era. Exosomes are nano‐sized vesicles with membrane‐bound proteins that reflect their originating cell. Prognostic biomarkers are needed to improve patient selection for optimal treatment. We here evaluate exosomes by protein phenotyping as a prognostic biomarker in NSCLC.

Methods

Exosomes from plasma of 276 NSCLC patients were phenotyped using the Extracellular Vesicle Array; 49 antibodies captured the proteins on the exosomes, and a cocktail of biotin‐conjugated antibodies binding the general exosome markers CD9, CD81 and CD63 was used to visualise the captured exosomes. For each individual membrane‐bound protein, results were analysed based on presence, in a concentration‐dependent manner, and correlated to overall survival (OS).

Results

The 49 proteins attached to the exosomal membrane were evaluated. NY‐ESO‐1, EGFR, PLAP, EpCam and Alix had a significant concentration‐dependent impact on inferior OS. Due to multiple testing, NY‐ESO‐1 was the only marker that maintained a significant impact on inferior survival (hazard rate (HR) 1.78 95% (1.78–2.44); p = 0.0001) after Bonferroni correction. Results were adjusted for clinico‐pathological characteristics, stage, histology, age, sex and performance status.

Conclusion

We illustrate the promising aspects associated with the use of exosomal membrane‐bound proteins as a biomarker and demonstrate that they are a strong prognostic biomarker in NSCLC.

In NSCLC, exosomal membrane‐bound protein profiling is feasible in liquid biopsies.

Nine exosomal proteins showed potential as prognostic markers in NSCLC.

Exosomal NY‐ESO‐1 was a strong prognostic biomarkers in NSCLC.

Endogenous, very small embryonic-like stem cells: critical review, therapeutic potential and a look ahead

BACKGROUND

Both pluripotent very small embryonic-like stem cells (VSELs) and induced pluripotent stem (iPS) cells were reported in 2006. In 2012, a Nobel Prize was awarded for iPS technology whereas even today the very existence of VSELs is not well accepted. The underlying reason is that VSELs exist in low numbers, remain dormant under homeostatic conditions, are very small in size and do not pellet down at 250-280g. The VSELs maintain life-long tissue homeostasis, serve as a backup pool for adult stem cells and are mobilized under stress conditions. An imbalance in VSELs function (uncontrolled proliferation) may result in cancer.

SEARCH METHODS

The electronic database 'Medline/Pubmed' was systematically searched with the subject heading term 'very small embryonic-like stem cells'.

OBJECTIVE AND RATIONALE

The most primitive stem cells that undergo asymmetric cell divisions to self-renew and give rise to progenitors still remain elusive in the hematopoietic system and testes, while the presence of stem cells in ovary is still being debated. We propose to review the available literature on VSELs, the methods of their isolation and characterization, their ontogeny, how they compare with embryonic stem (ES) cells, primordial germ cells (PGCs) and iPS cells, and their role in maintaining tissue homeostasis. The review includes a look ahead on how VSELs will result in paradigm shifts in basic reproductive biology.

OUTCOMES

Adult tissue-specific stem cells including hematopoietic, spermatogonial, ovarian and mesenchymal stem cells have good proliferation potential and are indeed committed progenitors (with cytoplasmic OCT-4), which arise by asymmetric cell divisions of pluripotent VSELs (with nuclear OCT-4). VSELs are the most primitive stem cells and postulated to be an overlapping population with the PGCs. Rather than migrating only to the gonads, PGCs migrate and survive in various adult body organs throughout life as VSELs. VSELs express both pluripotent and PGC-specific markers and are epigenetically and developmentally more mature compared with ES cells obtained from the inner cell mass of a blastocyst-stage embryo. As a result, VSELs readily differentiate into three embryonic germ layers and spontaneously give rise to both sperm and oocytes in vitro. Like PGCs, VSELs do not divide readily in culture, nor produce teratoma or integrate in the developing embryo. But this property of being relatively quiescent allows endogenous VSELs to survive various kinds of toxic insults. VSELs that survive oncotherapy can be targeted to induce endogenous regeneration of non-functional gonads. Transplanting healthy niche (mesenchymal) cells have resulted in improved gonadal function and live births.

WIDER IMPLICATIONS

Being quiescent, VSELs possibly do not accumulate genomic (nuclear or mitochondrial) mutations and thus may be ideal endogenous, pluripotent stem cell candidates for regenerative and reproductive medicine. The presence of VSELs in adult gonads and the fact that they survive oncotherapy may obviate the need to bank gonadal tissue for fertility preservation prior to oncotherapy. VSELs and their ability to undergo spermatogenesis/neo-oogenesis in the presence of a healthy niche will help identify newer strategies toward fertility restoration in cancer survivors, delaying menopause and also enabling aged mothers to have better quality eggs.

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.

Lack of ADAM2, CALR3 and SAGE1 Cancer/Testis Antigen Expression in Lung and Breast Cancer

Immunotherapy is emerging as a supplement to conventional cancer treatment, and identifying antigen targets for specific types of cancer is critical to optimizing therapeutic efficacy. Cancer/testis antigens are highly promising targets for immunotherapy due to their cancer-specific expression and antigenic properties, but the expression patterns of most of the more than 200 identified cancer/testis antigens in various cancers remain largely uncharacterized. In this study, we investigated the expression of the cancer/testis antigens ADAM2, CALR3 and SAGE1 in lung and breast cancer, the two most frequent human cancers, with the purpose of providing novel therapeutic targets for these diseases. We used a set of previously uncharacterized antibodies against the cancer/testis antigens ADAM2, CALR3 and SAGE1 to investigate their expression in a large panel of normal tissues as well as breast and lung cancers. Staining for the well-characterized MAGE-A proteins was included for comparison. Immunohistochemical staining confirmed previous mRNA analysis demonstrating that ADAM2, CALR3 and SAGE1 proteins are confined to testis in normal individuals. Negative tissues included plancenta, which express many other CT antigens, such as MAGE-A proteins. Surprisingly, we detected no ADAM2, CALR3 and SAGE1 in the 67 lung cancers (mainly non-small lung cancer) and 189 breast cancers, while MAGE-A proteins were present in 15% and 7–16% of these tumor types, respectively. Treatment with DNA methyltransferase inhibitors has been proposed as an attractive strategy to increase the expression of cancer/testis antigens in tumors before immunotargeting; however, neither ADAM2, CALR3 nor SAGE1 could be significantly induced in lung and breast cancer cell lines using this strategy. Our results suggest that ADAM2, CALR3 and SAGE1 cancer/testis antigens are not promising targets for immunotherapy of breast and lung cancer.

SSX2-4 expression in early-stage non-small cell lung cancer

The expression of cancer/testis antigens SSX2, SSX3, and SSX4 in non-small cell lung cancers (NSCLC) was examined, since they are considered promising targets for cancer immunotherapy due to their immunogenicity and testis-restricted normal tissue expression. We characterized three SSX antibodies and performed immunohistochemical staining of 25 different normal tissues and 143 NSCLCs. The antibodies differed in binding to two distinctive splice variants of SSX2 that exhibited different subcellular staining patterns, suggesting that the two splice variants display different functions. SSX2-4 expression was only detected in 5 of 143 early-stage NSCLCs, which is rare compared to other cancer/testis antigens (e.g. MAGE-A and GAGE). However, further studies are needed to determine whether SSX can be used as a prognostic or predictive biomarker in NSCLC.