Expression of cancer-testis antigens in the immune microenvironment of non-small cell lung cancer

Melanoma-associated antigen A4: A cancer/testis antigen as a target for adoptive T-cell receptor T-cell therapy

T-cell receptor (TCR) T-cell therapies are adoptive cell therapies in which patient cells are engineered to express TCRs targeting specific cancer antigens and infused back into the patient. Since TCR recognition depends on antigen presentation by the human leukocyte antigen system, TCRs can respond to intracellular antigens. Cancer/testis antigens (CTAs) are a large family of proteins, many of which are only expressed in cancerous tissue and immune-privileged germline sites. Melanoma-associated antigen A4 (MAGE-A4) is an intracellular CTA expressed in healthy testis and placenta, and in a range of cancers, including esophageal, head and neck, gastric, ovarian, colorectal, lung, endometrial, cervical, bladder, breast and prostate cancers; soft tissue sarcomas; urothelial and hepatocellular carcinomas; osteosarcoma; and melanoma. This expression pattern, along with the immunogenicity and potential role in tumorigenesis of MAGE-A4 make it a prime target for TCR T-cell therapy. We outline the preclinical and clinical development of TCR T-cell therapies targeting CTAs for treatment of solid tumors, highlighting the need for extensive preclinical characterization of putative off-target, and potential on-target but off-tumor, effects. We identified ten clinical trials assessing TCR T-cell therapies targeting MAGE-A4. Overall, manageable safety profiles and signals of efficacy have been observed, especially in patients with advanced synovial sarcoma, myxoid/round cell liposarcoma, ovarian, head and neck, and urothelial cancers, with one TCR T-cell therapy approved by the US Food and Drug Administration in August 2024. We also review the limitations, and strategies to enhance efficacy and improve safety, of these therapies, and summarize related immunotherapies targeting MAGE-A4.

MAGE-A4 induces non-small cell lung cancer and tumor-promoting plasma cell accumulation

Adaptive immunity is critical in eliminating tumors, but cancer-intrinsic factors can subvert this function. Melanoma antigen-A4 (MAGE-A4), a cancer-testis antigen, is expressed in solid tumors and correlates with poor survival, but its role in tumorigenesis and antitumor immunity remains unclear. We found that expression of MAGE-A4 was highly associated with the loss of PTEN, a tumor suppressor, in human non-small cell lung cancers (NSCLC). Here, we show that constitutive expression of human MAGE-A4 with Pten loss in mouse airway epithelia results in metastatic adenocarcinoma. Tumors showed distinct enrichment in IgA+ CD138+ CXCR4+ plasma cells (PCs) and increased expression of CXCL12 in endothelial cells. Consistently, human NSCLC expressing MAGE-A4 showed increased CD138+ IgA+ PCs surrounding tumors. Abrogation of PCs decreased tumor burden, increased activated T cell infiltration, and reduced CD163+CD206+ macrophages in the MAGE-A4-induced lung tumors. These findings suggest MAGE-A4 promotes NSCLC tumorigenesis, in part, through the recruitment and retention of IgA+ PCs in the lungs.

Exploring the role and mechanisms of MAGEA4 in tumorigenesis, regulation, and immunotherapy

MAGEA4 is a member of the Melanoma-Associated Antigen (MAGE) family, characterized by high expression in various tumor tissues but low expression in normal tissues, with the exception of testis and placenta. Its expression is associated with poor prognosis in cancer. This review summarizes the mechanisms of action, regulatory functions, and immunotherapeutic applications of MAGEA4 in cancer.MAGEA4 promotes tumor initiation and progression through multiple pathways, including ubiquitination and degradation of the tumor suppressor P53, regulation of cell cycle and apoptosis, modulation of DNA damage repair, and enhancement of cancer cell survival. By forming a complex with TRIM28, MAGEA4 accelerates tumor development via P53 degradation. Factors such as TWIST1 and BORIS can upregulate MAGEA4 expression. MAGEA4 interacts with proteins including Miz-1, p53, and RAD18, participating in gene transcription regulation and DNA damage repair. By stabilizing RAD18, MAGEA4 facilitates the recruitment of Y-family DNA polymerases, enabling cells to continue replication under DNA damage conditions and thus supporting cancer cell survival. MAGEA4-based TCR-T cell therapy and cancer vaccines show clinical potential. This article comprehensively reviews the structure and function of MAGEA4, as well as recent research progress in solid tumors, providing a theoretical foundation for the clinical translation of MAGEA4 and its application in immunotherapy.

ATAD2 is a potential immunotherapy target for patients with small cell lung cancer harboring HLA-A∗0201

BACKGROUND

Small cell lung cancer (SCLC) represents a highly aggressive neuroendocrine tumour with a dismal prognosis. Currently, the identification of a specific tumour antigen that can facilitate immune-based therapies for SCLC remains elusive.

METHODS

We employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to analyse cancer/testis antigens (CTAs) in SCLC cell lines and human tumour specimens. Immunohistochemistry of clinical specimens was performed to compare protein expression in SCLC, non-small cell lung cancer (NSCLC), and matched normal-adjacent tissues. Additionally, publicly available RNA sequencing databases were interrogated to identify gene expression patterns in different SCLC subtypes and in different disease stages.

FINDINGS

Distinct numbers and types of CTAs were identified across SCLC subtypes, with significantly higher expression levels of ATPase family AAA domain-containing protein 2 (ATAD2) observed in SCLC compared to normal adjacent tissues and NSCLC tissues. A dynamic expression pattern of ATAD2 was found throughout the clinical course of SCLC and exhibited a positive correlation with achaete-scute family bHLH transcription factor 1 (ASCL1) expression in SCLC. Immunopeptidomics analysis identified the YSDDDVPSV sequence derived from the HLA-A∗02:01 restriction epitope of ATAD2 as a highly promising tumour antigen candidate for potential immunotherapy applications. YSDDDVPSV immunopeptides were confirmed to be present in SCLC-A and SCLC-N with HLA-A∗02:01 restriction. Notably, HLA-A∗02:01 T cells exhibited a robust response upon stimulation with YSDDDVPSV immunopeptide pulsed by T2 cells.

INTERPRETATION

Our findings highlight the potential of targeting the ATAD2 YSDDDVPSV immunopeptide for SCLC immunotherapy, thereby offering a promising avenue for the development of adoptive T cell therapies to effectively treat ASCL1-positive or NEUROD1-positive SCLC carrying HLA-A∗02:01.

FUNDING

This study was supported by the National key R&D program of China (2022YFC2505000); National Natural Science Foundation of China (NSFC) general program (82272796) NSFC special program (82241229); CAMS Innovation Fund for Medical Sciences (CIFMS 2022-I2M-1-009); CAMS Key Laboratory of Translational Research on Lung Cancer (2018PT31035); Aiyou foundation (KY201701). National key R&D program of China (2022YFC2505004). NSFC general program (81972905). Medical Oncology Key Foundation of Cancer Hospital Chinese Academy of Medical Sciences (CICAMS-MOCP2022012).

EZHIP's role in diffuse midline glioma: echoes of oncohistones?

The enhancer of zeste inhibitory protein (EZHIP) is typically expressed during germ cell development and has been classified as a cancer-testis antigen (CTA) in various cancers. In 2020, 4% of diffuse midline gliomas (DMGs) were shown to aberrantly express EZHIP, mirroring the DMG hallmark histone H3 K27M (H3K27M) oncohistone mutation. Similar to H3K27M, EZHIP is a negative regulator of polycomb repressive complex 2 (PRC2), leading to global epigenomic remodeling. In this opinion, we explore the similarities and disparities between H3K27M- and EZHIP-DMGs with a focus on their shared functional hallmark of PRC2 inhibition, their genetic and epigenomic landscapes, plausible differences in the cell of origin, and therapeutic avenues. Upcoming research on EZHIP will help better understand its role in gliomagenesis and DMG therapy.

Landscape of targeted therapies for lung squamous cell carcinoma

Lung cancer, a common type of malignant neoplasm, has seen significant advancements in the treatment of lung adenocarcinoma (LUAD). However, the management of lung squamous cell carcinoma (LSCC) continues to pose challenges. Traditional treatment methods for LSCC encompass surgical resection, chemotherapy, and radiotherapy. The introduction of targeted therapy and immunotherapy has greatly benefited LSCC patients, but issues such as limited immune response rates and adverse reactions persist. Therefore, gaining a deeper comprehension of the underlying mechanisms holds immense importance. This review provides an in-depth overview of classical signaling pathways and therapeutic targets, including the PI3K signaling pathway, CDK4/6 pathway, FGFR1 pathway and EGFR pathway. Additionally, we delve into alternative signaling pathways and potential targets that could offer new therapeutic avenues for LSCC. Lastly, we summarize the latest advancements in targeted therapy combined with immune checkpoint blockade (ICB) therapy for LSCC and discuss the prospects and challenges in this field.

MAGE-A4-Responsive Plasma Cells Promote Non-Small Cell Lung Cancer

Adaptive immunity is critical to eliminate malignant cells, while multiple tumor-intrinsic factors can alter this protective function. Melanoma antigen-A4 (MAGE-A4), a cancer-testis antigen, is expressed in several solid tumors and correlates with poor survival in non-small cell lung cancer (NSCLC), but its role in altering antitumor immunity remains unclear. We found that expression of MAGE-A4 was highly associated with the loss of PTEN , a tumor suppressor, in human NSCLC. Here we show that constitutive expression of human MAGE-A4 combined with the loss of Pten in mouse airway epithelial cells results in metastatic adenocarcinoma enriched in CD138 + CXCR4 + plasma cells, predominantly expressing IgA. Consistently, human NSCLC expressing MAGE-A4 showed increased CD138 + IgA + plasma cell density surrounding tumors. The abrogation of MAGE-A4-responsive plasma cells (MARPs) decreased tumor burden, increased T cell infiltration and activation, and reduced CD163 + CD206 + macrophages in mouse lungs. These findings suggest MAGE-A4 promotes NSCLC tumorigenesis, in part, through the recruitment and retention of IgA + MARPs in the lungs.

Melanoma Antigen Family A (MAGE A) as Promising Biomarkers and Therapeutic Targets in Bladder Cancer

The Melanoma Antigen Gene (MAGE) is a large family of highly conserved proteins that share a common MAGE homology domain. Interestingly, many MAGE family members exhibit restricted expression in reproductive tissues but are abnormally expressed in various human malignancies, including bladder cancer, which is a common urinary malignancy associated with high morbidity and mortality rates. The recent literature suggests a more prominent role for MAGEA family members in driving bladder tumorigenesis. This review highlights the role of MAGEA proteins, the potential for them to serve as diagnostic or prognostic biomarker(s), and as therapeutic targets for bladder cancer.