B7-H4 is increased in lung adenocarcinoma harboring EGFR-activating mutations and contributes to immunosuppression

The role of B7-H4 in ovarian cancer immunotherapy: current status, challenges, and perspectives

Immunotherapy stands as a critical and auspicious therapeutic approach in the fight against cancer nowadays. Immune checkpoint inhibitors, in particular, have garnered widespread employment and delivered groundbreaking therapeutic outcomes across various malignancies. However, the efficacy is unsatisfactory in the ovarian cancer. The pressing concerns of the substantial non-response rate require immediate attention. The pursuit of novel targets and the formulation of synergistic combination therapy approaches are imperative for addressing this challenge. B7-H4, a member of the B7 family of co-inhibitory molecules, exhibits high expression levels in ovarian cancer, correlating closely with tumor progression, drug resistance, and unfavorable prognosis. B7-H4 has the potential to serve as a valuable biomarker for evaluating the immune response of patients. Recent investigations and preclinical trials focusing on B7-H4 in the context of ovarian cancer immunotherapy highlight its emergence as a promising immunotherapeutic target. This review aims to discuss these findings and anticipate the future prospects of leveraging B7-H4 in ovarian cancer immunotherapy and targeted therapy.

The deubiquitinase USP2a promotes tumor immunosuppression by stabilizing immune checkpoint B7-H4 in lung adenocarcinoma harboring EGFR-activating mutants

B7-H4 is an immune checkpoint crucial for inhibiting CD8+ T-cell activity. A clinical trial is underway to investigate B7-H4 as a potential immunotherapeutic agent. However, the regulatory mechanism of B7-H4 degradation via the ubiquitin-proteasome pathway (UPP) remains poorly understood. In this study, we discovered that proteasome inhibitors effectively increased B7-H4 expression, while EGFR-activating mutants promoted B7-H4 expression through the UPP. We screened B7-H4 binding proteins by co-immunoprecipitation and mass spectrometry and found that USP2a acted as a deubiquitinase of B7-H4 by removing K48- and K63-linked ubiquitin chains from B7-H4, leading to a reduction in B7-H4 degradation. EGFR mutants enhanced B7-H4 stability by upregulating USP2a expression. We further investigated the role of USP2a in tumor growth in vivo. Depletion of USP2a in L858R/LLC cells inhibited tumor cell proliferation, consequently suppressing tumor growth in immune-deficient nude mice by destabilizing downstream molecules such as Cyclin D1. In an immune-competent C57BL/6 mouse tumor model, USP2a abrogation facilitated infiltration of CD95+CD8+ effector T cells and hindered infiltration of Tim-3+CD8+ and LAG-3+CD8+ exhausted T cells by destabilizing B7-H4. Clinical lung adenocarcinoma samples showed a significant correlation between B7-H4 abundance and USP2a expression, indicating the contribution of the EGFR/USP2a/B7-H4 axis to tumor immunosuppression. In summary, this study elucidates the dual effects of USP2a in tumor growth by stabilizing Cyclin D1, promoting tumor cell proliferation, and stabilizing B7-H4, contributing to tumor immunosuppression. Therefore, USP2a represents a potential target for tumor therapy.

EGFR-TKIs Combined with Allogeneic CD8+ NKT Cell Immunotherapy to Treat Patients with Advanced EGFR-Mutated Lung Cancer

Background: To evaluate the efficacy and safety of allogenic CD8 + natural killer T (CD8+ NKT) immunotherapy combined with gefitinib in the treatment of advanced or metastatic EGFR mutant non-small cell lung cancer (NSCLC). Methods: This study is prospective. The NSCLC patients with exon 19 (Ex19del) or exon 21 L858R point mutations, and response to gefitinib treatment were enrolled into the trial to be randomly assigned into the gefitinib arm and the gefitinib/NKT arm. Allogenic CD8+ NKT cells were cultured in vitro and adaptive transferred into the patients via vein in the gefitinib/NKT arm. The primary endpoint was progression-free survival (PFS). Secondary endpoint analysis included time to disease progression (TTP), overall survival (OS), levels of serum tumour markers for carcinoembryonic antigen (CEA) and alanine aminotransferase (ALT) in the blood, the response rate and safety. From July 2017 to June 2021, 19 patients were randomly assigned to the gefitinib arm (n = 8) and the gefitinib/NKT arm (n = 11). Results: The estimated median survival PFS in the gefitinib/NKT arm was significantly longer than that of the gefitinib arm (12 months vs 7 months). Similar results were also observed for the median TTP. Moreover, the gefitinib/NKT arm had better CEA control than the gefitinib arm. Clinical grade 3 adverse reactions occurred in 64% and 39% of patients in the gefitinib/NKT arm and the gefitinib arm, respectively. The most common grade 3 adverse events in the gefitinib/NKT arm included abnormal liver function in 8 cases (73%) and diarrhoea in 1 case (9%), both of which resolved after drug intervention. Conclusion: The PFS of EGFR-mutated advanced NSCLC treated with allogenic CD8+ NKT cells combined with gefitinib was longer than that of gefitinib alone. No obvious serious adverse reactions occurred, and the patients compliance and survival status were good.

High DNA methylation age deceleration defines an aggressive phenotype with immunoexclusion environments in endometrial carcinoma

Like telomere shortening, global DNA hypomethylation occurs progressively with cellular divisions or in vivo aging and functions as a mitotic clock to restrain malignant transformation/progression. Several DNA-methylation (DNAm) age clocks have been established to precisely predict chronological age using normal tissues, but show DNAm age drift in tumors, which suggests disruption of this mitotic clock during carcinogenesis. Little is known about DNAm age alterations and biological/clinical implications in endometrial cancer (EC). Here we address these issues by analyzing TCGA and GSE67116 cohorts of ECs. Horvath clock analysis of these tumors unexpectedly revealed that almost 90% of them exhibited DNAm age deceleration (DNAmad) compared to patient chronological age. Combined with an additional clock named Phenoage, we identified a subset of tumors (82/429) with high DNAmad (hDNAmad+) as assessed by both clocks. Clinically, hDNAmad+ tumors were associated with advanced diseases and shorter patient survival, compared to hDNAmad- ones. Genetically, hDNAmad+ tumors were characterized by higher copy number alterations (CNAs) whereas lower tumor mutation burden. Functionally, hDNAmad+ tumors were enriched with cell cycle and DNA mismatch repair pathways. Increased PIK3CA alterations and downregulation of SCGB2A1, the inhibitor of PI3K kinase, in hDNAmad+ tumors, might promote tumor growth/proliferation and stemness. In addition, the inactivation of aging drivers/tumor suppressors (TP53, RB1, and CDKN2A) while enhanced telomere maintenance occurred more frequently in hDNAmad+ tumors, which supports sustained tumor growth. Prominently, hDNAmad+ tumors were featured with immunoexclusion microenvironments, accompanied by significantly higher levels of VTCN1 expression while lower PD-L1 and CTLA4 expression, which indicates their poor response to immune checkpoint inhibitor (ICI)-based immunotherapy. We further showed significantly higher levels of DNMT3A and 3B expression in hDNAmad+ than in hDNAmad- tumors. Thus, the tumor suppressive function of aging-like DNA hypomethylation is severely impaired in hDNAmad+ tumors, likely due to enhanced expression of DNMT3A/3B and dysregulated aging regulators. Our findings not only enrich biological knowledge of EC pathogenesis but also help improve EC risk stratification and precision ICI immunotherapy.

B7-H7: A potential target for cancer immunotherapy

Cancer immunotherapy enhances the body's immunity against tumors by mitigating immune escape. Compared with traditional chemotherapy, immunotherapy has the advantages of fewer drugs, a wider range of action and fewer side effects. B7-H7 (also known as HHLA2, B7y) is a member of the B7 family of costimulatory molecules that was discovered more than 20 years ago. B7-H7 is mostly expressed in organs such as the breast, intestine, gallbladder and placenta and is detected predominantly in monocytes/macrophages in the immune system. Its expression is upregulated after stimulation by inflammatory factors such as lipopolysaccharide and interferon-γ. B7-H7/transmembrane and immunoglobulin domain containing 2 (TMIGD2) and killer cell immunoglobulin-like receptor, three Ig domains and long cytoplasmic tail 3 (KIR3DL3)-B7-H7 are the two currently confirmed signaling pathways for B7-H7. An increasing number of studies have demonstrated that B7-H7 is widely present in a variety of human tumor tissues, especially in programmed cell death-1 (PD-L1)-negative human tumors. B7-H7 promotes tumor progression, disrupts T-cell-mediated antitumor immunity, and inhibits immune surveillance. B7-H7 also triggers tumor immune escape and is associated with clinical stage, depth of tumor infiltration, metastasis, prognosis, and survival related to different tumor types. Multiple studies have shown that B7-H7 is a promising immunotherapeutic target. Herein, review the current literature on the expression, regulation, receptors and function of B7-H7 and its regulation/function in tumors.

B7x in cancer immunity and immunotherapy

B7x (also called B7-H4) is a co-inhibitory molecule of B7 family that is highly expressed in non-inflamed or cold cancers, and its aberrant expression is contributed to cancer progression and poor outcomes. B7x preferentially expresses on antigen-presenting cells (APCs) and in tumor cells, and it acts as an alternative anti-inflammatory immune checkpoint for hampering peripheral immune responses. Augmented infiltration of immunosuppressive cells, reduced proliferation and effector function of CD4⁺ and CD8⁺ T cells, and increased generation of regulatory T cells (Tregs) are outcomes of increased B7x activity in cancer. Evaluation of B7x in sera can be exploited as an effective biomarker of response in cancer patients. B7x overexpression generally occurs in programmed death-ligand 1 (PD-L1)^- cancers and is involved in tumor resistance to anti-programmed death-1 (PD-1), anti-PD-L1 or anti-cytotoxic T lymphocyte associated antigen-4 (CTLA-4) therapy. Co-expression of B7x receptor with PD-1 on CD8⁺ T cells has made the anti-B7x a fruitful approach for reinvigoration of the functionality of exhausted T cells and is served as a complementary regimen in patients who are irresponsive to the common immune checkpoint inhibitor (ICI) therapy. An advance in the field is the development of bispecific antibodies against B7x with other regulatory molecules within tumor microenvironment (TME).

Ethacrynic acid suppresses B7-H4 expression involved in epithelial-mesenchymal transition of lung adenocarcinoma cells via inhibiting STAT3 pathway

Lung cancer is characterized by high incidence and mortality. 90% of cancer deaths are caused by metastases. The epithelial-mesenchymal transition (EMT) process in cancer cells is a prerequisite for the metastatic process. Ethacrynic acid (ECA) is a loop diuretic that inhibits the EMT process in lung cancer cells. EMT has been related to the tumour immunemicroenvironment. However, the effect of ECA on immune checkpoint molecules in the context of cancer has not been fully identified. In the present study, we found that sphingosylphosphorylcholine (SPC) and TGF-β1, awell-known EMT inducer, induced the expression of B7-H4 in lung cancer cells. We also investigated the involvement of B7-H4 in the SPC-induced EMT process. Knockdown of B7-H4 suppressed SPC-induced EMT, while B7-H4 overexpression enhanced EMT of lung cancer cells. ECA inhibited SPC/TGF-β1-induced B7-H4 expression via suppression of STAT3 activation. Moreover, ECA inhibits the colonization of mice lung by tail vein-injected LLC1 cells. ECA-treated mice increased the CD4-positive T cells in lung tumour tissues. In summary, these results suggested that ECA inhibits B7-H4 expression via STAT3 inhibition, leading to SPC/TGF-β1-induced EMT. Therefore, ECA might be an immune oncological drug for B7-H4-positive cancer, especially lung cancer.

Cancer immune evasion through KRAS and PD-L1 and potential therapeutic interventions

Oncogenic driver mutations have implications that extend beyond cancer cells themselves. Aberrant tumour cell signalling has various effects on the tumour microenvironment and anti-tumour immunity, with important consequences for therapy response and resistance. We provide an overview of how mutant RAS, one of the most prevalent oncogenic drivers in cancer, can instigate immune evasion programs at the tumour cell level and through remodelling interactions with the innate and adaptive immune cell compartments. Finally, we describe how immune evasion networks focused on RAS, and the immune checkpoint molecule PD-L1 can be disrupted through therapeutic intervention, and discuss potential strategies for combinatorial treatment. Video abstract.

Prognostic significance of epidermal growth factor receptor and programmed cell death-ligand 1 co-expression in esophageal squamous cell carcinoma

Our study aimed to observe the correlation between epidermal growth factor receptor (EGFR) and programmed cell death-ligand 1 (PD-L1) expression and evaluate prognostic potential of their co-expression in esophageal squamous cell carcinoma (ESCC) patients. EGFR and PD-L1 expression were evaluated by immunohistochemical analysis. We revealed that there was a positive correlation between EGFR and PD-L1 expression in ESCC (P = 0.004). According to the positive relationship between EGFR and PD-L1, all patients were divided into four groups: EGFR (+)/PD-L1 (+), EGFR (+)/PD-L1 (-), EGFR (-)/PD-L1 (+), and EGFR (-)/PD-L1 (-). In 57 ESCC patients without surgery, we found that EGFR and PD-L1 co-expression were statistically correlated with a lower objective response rate (ORR) (p = 0.029), overall survival (OS) (p = 0.018) and progression-free survival (PFS) (p = 0.045) than those with one or none positive protein. Furthermore, PD-L1 expression has a significant positive correlation with infiltration level of 19 immune cells, EGFR expression was significantly correlated with infiltration level of 12 immune cells. The infiltration level of CD8 T cell and B cell were negatively correlated with EGFR expression. On the contrary with EGFR, the infiltration level of CD8 T cell, and B cell were positively correlated with PD-L1 expression. In conclusion, EGFR and PD-L1 co-expression could predict poor ORR and survival in ESCC without surgery, indicating a subset of patients who may benefit from a combination of targeted therapy against EGFR and PD-L1, which may expand the population benefiting from immunotherapy and reduce the occurrence of hyper progressive diseases.

Role of B7 family members in glioma: Promising new targets for tumor immunotherapy

Glioma, is a representative type of intracranial tumor among adults, usually has a weak prognosis and limited treatment options. Traditional therapies, including surgery, chemotherapy, and radiotherapy, have had little impact on patient survival time. Immunotherapies designed to target the programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) signaling pathway have successfully treated various human cancers, informing the development of similar therapies for glioma. However, anti-PD-L1 response rates remain limited in glioma patients. Thus, exploring novel checkpoints targeting additional immunomodulatory pathways for activating durable antitumor immune responses and improving glioma outcomes is needed. Researchers have identified other B7 family checkpoint molecules, including PD-L2, B7-H2, B7-H3, B7-H4, and B7-H6. The current review article evaluates the expression of all 10 reported members of the B7 family in human glioma using The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) data, as well as summarizes studies evaluating the clinical meanings and functions of B7 family molecules in gliomas. B7 family checkpoints may contribute to different immunotherapeutic management options for glioma patients.

Novel considerations on EGFR-based therapy as a contributor to cancer cell death in NSCLC

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) represented by gefitinib and erlotinib are widely used in treating non-small cell lung cancer (NSCLC). However, acquired resistance to EGFR-TKI treatment remains a clinical challenge. In recent years, emerging research investigated in EGFR-TKI-based combination therapy regimens, and remarkable achievements have been reported. This article focuses on EGFR-TKI-based regimens, reviews the standard and novel application of EGFR targets, and summarizes the mechanisms of EGFR-TKI combinations including chemotherapy, anti-vascular endothelial growth factor monoclonal antibodies, and immunotherapy in the treatment of NSCLC. Additionally, we summarize clinical trials of EGFR-TKI-based combination therapy expanding indications to EGFR mutation-negative lung malignancies. Moreover, novel strategies are under research to explore new drugs with good biocompatibility. Nanoparticles encapsulating non-coding RNA and chemotherapy of new dosage forms drawn great attention and showed promising prospects in effective delivery and stable release. Overall, as the development of resistance to EGFR-TKIs treatment is inevitable in most of the cases, further research is needed to clarify the underlying mechanism of the resistance, and to evaluate and establish EGFR-TKI combination therapies to diversify the treatment landscape for NSCLC.

Integrated single-cell and transcriptome sequencing analyses determines a chromatin regulator-based signature for evaluating prognosis in lung adenocarcinoma

BACKGROUND

Accumulating evidence has highlighted the significance of chromatin regulator (CR) in pathogenesis and progression of cancer. However, the prognostic role of CRs in LUAD remains obscure. We aim to detect the prognostic value of CRs in LUAD and create favorable signature for assessing prognosis and clinical value of LUAD patients.

METHODS

The mRNA sequencing data and clinical information were obtained from TCGA and GEO databases. Gene consensus clustering analysis was utilized to determine the molecular subtype of LUAD. Cox regression methods were employed to set up the CRs-based signature (CRBS) for evaluating survival rate in LUAD. Biological function and signaling pathways were identified by KEGG and GSEA analyses. In addition, we calculated the infiltration level of immunocyte by CIBERSORT algorithm. The expressions of model hub genes were detected in LUAD cell lines by real-time polymerase chain reaction (PCR).

RESULTS

KEGG analysis suggested the CRs were mainly involved in histone modification, nuclear division and DNA modification. Consensus clustering analysis identified a novel CRs-associated subtype which divided the combined LUAD cohort into two clusters (C1 = 217 and C2 = 296). We noticed that a remarkable discrepancy in survival rate among two clusters. Then, a total of 120 differentially expressed CRs were enrolled into stepwise Cox analyses. Four hub CRs (CBX7, HMGA2, NPAS2 and PRC1) were selected to create a risk signature which could accurately forecast patient outcomes and differentiate patient risk. GSEA unearthed that mTORC1 pathway, PI3K/Akt/mTOR and p53 pathway were greatly enriched in CRBS-high cohort. Moreover, the infiltration percentages of macrophage M0, macrophage M2, resting NK cells, memory B cells, dendritic cells and mast cells were statistically significantly different in the two groups. PCR assay confirmed the differential expression of four model biomarkers.

CONCLUSIONS

Altogether, our project developed a robust risk signature based on CRs and offered novel insights into individualized treatment for LUAD cases.

Clinical, Pathologic, and Molecular Prognostic Factors in Patients with Early-Stage EGFR-Mutant NSCLC

PURPOSE

In early-stage, EGFR mutation-positive (EGFR-M+) non-small cell lung cancer (NSCLC), surgery remains the primary treatment, without personalized adjuvant treatments. We aimed to identify risk factors for recurrence-free survival (RFS) to suggest personalized adjuvant strategies in resected early-stage EGFR-M+ NSCLC.

EXPERIMENTAL DESIGN

From January 2008 to August 2020, a total of 2,340 patients with pathologic stage (pStage) IB-IIIA, non-squamous NSCLC underwent curative surgery. To identify clinicopathologic risk factors, 1,181 patients with pStage IB-IIIA, common EGFR-M+ NSCLC who underwent surgical resection were analyzed. To identify molecular risk factors, comprehensive genomic analysis was conducted in 56 patients with matched case-controls (pStage II and IIIA and type of EGFR mutation).

RESULTS

Median follow-up duration was 38.8 months (0.5-156.2). Among 1,181 patients, pStage IB, II, and IIIA comprised 577 (48.9%), 331 (28.0%), and 273 (23.1%) subjects, respectively. Median RFS was 73.5 months [95% confidence interval (CI), 62.1-84.9], 48.7 months (95% CI, 41.2-56.3), and 22.7 months (95% CI, 19.4-26.0) for pStage IB, II, and IIIA, respectively (P < 0.001). In multivariate analysis of clinicopathologic risk factors, pStage, micropapillary subtype, vascular invasion, and pleural invasion, and pathologic classification by cell of origin (type II pneumocyte-like tumor cell vs. bronchial surface epithelial cell-like tumor cell) were associated with RFS. As molecular risk factors, the non-terminal respiratory unit (non-TRU) of the RNA subtype (HR, 3.49; 95% CI, 1.72-7.09; P < 0.01) and TP53 mutation (HR, 2.50; 95% CI, 1.24-5.04; P = 0.01) were associated with poor RFS independent of pStage II or IIIA. Among the patients with recurrence, progression-free survival of EGFR-tyrosine kinase inhibitor (TKI) in those with the Apolipoprotein B mRNA Editing Catalytic Polypeptide-like (APOBEC) mutation signature was inferior compared with that of patients without this signature (8.6 vs. 28.8 months; HR, 4.16; 95% CI, 1.28-13.46; P = 0.02).

CONCLUSIONS

The low-risk group with TRU subtype and TP53 wild-type without clinicopathologic risk factors might not need adjuvant EGFR-TKIs. In the high-risk group, with non-TRU subtype and/or TP 53 mutation, or clinicopathologic risk factors, a novel adjuvant strategy of EGFR-TKI with others, e.g., chemotherapy or antiangiogenic agents needs to be investigated. Given the poor outcome to EGFR-TKIs after recurrence in patients with the APOBEC mutation signature, an alternative adjuvant strategy might be needed.

Combination of Tumor Mutational Burden and DNA Damage Repair Gene Mutations with Stromal/Immune Scores Improved Prognosis Stratification in Patients with Lung Adenocarcinoma

Background

Both the tumor environment and the genomic landscape of lung cancer may shape patient responses to treatments, including immunotherapy, but their joint impacts on lung adenocarcinoma (LUAD) prognosis are underexplored.

Methods

RNA sequencing data and whole-exome sequencing results were downloaded from the TCGA database, and only LUAD-related data were included in this study. Based on gene expression data, the ESTIMATE algorithm was used to estimate stromal and immune scores, and CIBERSORT analysis was used for quantification of the relative abundances of immune cells. Somatic mutations were used for calculating tumor mutation burden (TMB). Specific mutations in genes involved in DNA damage repair (DDR) pathways were identified. The individual and joint associations of stromal and immune score, TMB, and DDR gene mutations with 5-year survival were analyzed by the Kaplan–Meier method and multivariate Cox model.

Results

LUAD patients with a high (>highest 25%) stromal or immune score had prolonged survival as compared to those with a low (<lowest 25%) score (log-rank P=0.05 and 0.035, respectively). Patients with both high stromal and immune scores had the most favorable survival. Although the survival differences between patients with high (>highest 25%) and low (<lowest 25%) TMB, or between patients with mutant- and wild-type DDR genes were not statistically significant, a survival benefit from high TMB or DDR gene mutations was observed in patients with high stromal or immune scores.

Conclusion

A comprehensive evaluation of transcriptomic signatures and genomic biomarkers may provide a novel avenue for improving prognosis stratification in LUAD.

The expression pattern of Immune checkpoints after chemo/radiotherapy in the tumor microenvironment

As a disease with the highest disease-associated burden worldwide, cancer has been the main subject of a considerable proportion of medical research in recent years, intending to find more effective therapeutic approaches with fewer side effects. Combining conventional methods with newer biologically based treatments such as immunotherapy can be a promising approach to treating different tumors. The concept of "cancer immunoediting" that occurs in the field of the tumor microenvironment (TME) is the aspect of cancer therapy that has not been at the center of attention. One group of the role players of the so-called immunoediting process are the immune checkpoint molecules that exert either co-stimulatory or co-inhibitory effects in the anti-tumor immunity of the host. It involves alterations in a wide variety of immunologic pathways. Recent studies have proven that conventional cancer therapies, such as chemotherapy, radiotherapy, or a combination of them, i.e., chemoradiotherapy, alter the "immune compartment" of the TME. The mentioned changes encompass a wide range of variations, including the changes in the density and immunologic type of the tumor-infiltrating lymphocytes (TILs) and the alterations in the expression patterns of the different immune checkpoints. These rearrangements can have either anti-tumor immunity empowering or immune attenuating sequels. Thus, recognizing the consequences of various chemo(radio)therapeutic regimens in the TME seems to be of great significance in the evolution of therapeutic approaches. Therefore, the present review intends to summarize how chemo(radio)therapy affects the TME and specifically some of the most important, well-known immune checkpoints' expressions according to the recent studies in this field.