Expression Of Inhibitory Immune Checkpoints Research Articles

Role of T Lymphocytes in Glioma Immune Microenvironment: Two Sides of a Coin.

Glioma is known for its immunosuppressive microenvironment, which makes it challenging to target through immunotherapies. Immune cells like macrophages, microglia, myeloid-derived suppressor cells, and T lymphocytes are known to infiltrate the glioma tumor microenvironment and regulate immune response distinctively. Among the variety of immune cells, T lymphocytes have highly complex and multifaceted roles in the glioma immune landscape. T lymphocytes, which include CD4+ helper and CD8+ cytotoxic T cells, are known for their pivotal roles in anti-tumor responses. However, these cells may behave differently in the highly dynamic glioma microenvironment, for example, via an immune invasion mechanism enforced by tumor cells. Therefore, T lymphocytes play dual roles in glioma immunity, firstly by their anti-tumor responses, and secondly by exploiting gliomas to promote immune invasion. As an immunosuppression strategy, glioma induces T-cell exhaustion and suppression of effector T cells by regulatory T cells (Tregs) or by altering their signaling pathways. Further, the expression of immune checkpoint inhibitors on the glioma cell surface leads to T cell anergy and dysfunction. Overall, this dynamic interplay between T lymphocytes and glioma is crucial for designing more effective immunotherapies. The current review provides detailed knowledge on the roles of T lymphocytes in the glioma immune microenvironment and helps to explore novel therapeutic approaches to reinvigorate T lymphocytes.

Identification of PANoptosis Subtypes to Assess the Prognosis and Immune Microenvironment of Lung Adenocarcinoma Patients: A Bioinformatics Combined Machine Learning Study.

PANoptosis, a novelty mechanism of cell death involving crosstalk between apoptosis, pyroptosis, and necroptosis, is strongly associated with tumor cell death and immunotherapy efficacy. However, its relevance in lung adenocarcinoma (LUAD) remains to be elucidated. In this study, we acquired 18 PANoptosis-related differentially expressed gene (PRDEG) of LUAD. Based on these genes, LUAD samples were identified with different sub-types by unsupervised clustering. Next, we compared the differences between the subtypes, including clinical features, immune microenvironment, and potentially sensitive drugs. Further-more, we used machine learning to identify hub prognostic PRDEGs, construct a risk score, and validate it on other external datasets. We incorporated the patient's clinical information and risk score into the proportional hazards model and lasso-cox models to find key prognostic features and constructed five prognostic models. The best model was identified via the area under the curve and validated on an external dataset. LUAD patients were divided into two clusters named C1 and C2, respectively. The C2 cluster exhibited shorter survival time, more advanced tumor stage, higher suppressive immune cell scores, such as dendritic cells, and higher expression of inhibitory immune checkpoints, such as LAG3 and CD86. TIMP1, CAV1, and CD69 were recognized as key prognostic factors, and risk scores predicted survival with significant differences in the external validation set. Risk score and N-stage were identified as critical prognostic features. The Coxph model outper-formed other machine learning clinical models. The 1-, 3-, and 5-year time-ROCs in the exter-nal validation set were 0.55, 0.59, and 0.60, respectively. We demonstrated the potential of PANoptosis-based molecular clustering and prognostic features in predicting the survival of patients with LUAD as well as the tumor mi-croenvironment.

Inhibition of the Rho/MRTF pathway improves the response of BRAF-resistant melanoma to PD1/PDL1 blockade.

Metastatic cutaneous melanoma is a fatal skin cancer. Resistance to targeted and immune therapies limits the benefits of current treatments. Identifying and adding anti-resistance agents to current treatment protocols can potentially improve clinical responses. Myocardin-related transcription factor (MRTF) is a transcriptional coactivator whose activity is indirectly regulated by actin and the Rho family of GTPases. We previously demonstrated that development of BRAF inhibitor (BRAFi) resistance frequently activates the Rho/MRTF pathway in human and mouse BRAFV600E melanomas. In clinical trials, pretreatment with BRAFi reduces the benefit of immune therapies. We aimed to test the efficacy of concurrent treatment with our MRTF pathway inhibitor CCG-257081 and anti-PD1 in vivo and to examine its effects on the melanoma immune microenvironment. Because MRTF pathway activation upregulates the expression of immune checkpoint inhibitor genes/proteins, we asked whether CCG-257081 can improve the response to immune checkpoint blockade. CCG-257081 reduced the expression of PDL1 in BRAFi-resistant melanoma cells and decreased surface PDL1 levels on both BRAFi-sensitive and -resistant melanoma cells. Using our recently described murine vemurafenib-resistant melanoma model, we found that CCG-257081, in combination with anti-PD1 immune therapy, reduced tumor growth and increased survival. Moreover, anti-PD1/CCG-257081 co-treatment increased infiltration of CD8+ T cells and B cells into the tumor microenvironment and reduced tumor-associated macrophages. Here, we propose CCG-257081 as an anti-resistance and immune therapy-enhancing anti-melanoma agent.

Impaired Epithelial CD200L Tolerance Signaling in Irritable Bowel Syndrome Cases With Diarrhea May Be Associated With Recurrent Miscarriages.

There is a higher incidence of irritable bowel syndrome with miscarriages, and recurrent miscarriages of otherwise normal embryos have been linked to subnormal expression of the immune checkpoint inhibitor CD200L. We sought to determine if alterations in the expression of the CD200 immune checkpoint inhibitor occur in colonic tissue in IBS-D patients. Quantitative immunohistochemical staining of biopsies from proximal and distal colon or rectum for the inhibitory CD200L and CD200S molecules was done. CD56 cells were also enumerated as they play a role in recurrent miscarriages and may express CD200S. CD200L was decreased and CD200S was unchanged in epithelium but not stroma of 3 IBS-D cases. One case had an increase in both CD200L and CD200S. CD56 cells were also stained for CD200S. Degranulation was assessed by the percentage of extracellular CD200S that was increased as epithelial CD200L decreased. This pilot study was promising and warrants a larger sample to determine if a correlation between uterine implantation site CD200L and CD200S expression in normal and failing implantation sites is needed. Colonic epithelial CD200L may then provide useful information about the pathogenesis of the spontaneous miscarriage in individual cases.

Unveiling the Role of Endoplasmic Reticulum Stress Pathways in Canine Demodicosis.

Canine demodicosis is a prevalent skin disease caused by overpopulation of a commensal species of Demodex mite, yet its precise cause remains unknown. Research suggests that T-cell exhaustion, increased immunosuppressive cytokines, induction of regulatory T cells and increased expression of immune checkpoint inhibitors may contribute to its pathogenesis. This study aimed to gain a deeper understanding of the molecular changes occurring in canine demodicosis using mass spectrometry and pathway enrichment analysis. The results indicate that endoplasmic reticulum stress promotes canine demodicosis through regulation of three linked signalling pathways: eIF2, mTOR, and eIF4 and p70S6K. These pathways are involved in the modulation of Toll-like receptors, most notably TLR2, and have been shown to play a role in the pathogenesis of skin diseases in both dogs and humans. Moreover, these pathways are also implicated in the promotion of immunosuppressive M2 phenotype macrophages. Immunohistochemical analysis, utilising common markers of dendritic cells and macrophages, verified the presence of M2 macrophages in canine demodicosis. The proteomic analysis also identified immunological disease, organismal injury and abnormalities and inflammatory response as the most significant underlying diseases and disorders associated with canine demodicosis. This study demonstrates that Demodex mites, through ER stress, unfolded protein response and M2 macrophages contribute to an immunosuppressive microenvironment, thereby assisting in their proliferation.

Prognostic and immunological implications of paraptosis-related genes in lung adenocarcinoma: Comprehensive analysis and functional verification of hub gene.

Lung adenocarcinoma (LUAD) poses significant clinical challenges due to its inherent heterogeneity and variable response to treatment. Recent research has specifically focused on elucidating the role of Paraptosis-related genes (PRGs) in the progression of cancer and the prognosis of patients. We conducted a comprehensive analysis of the differential expression of PRGs in LUAD. Additionally, univariate Cox regression analysis was utilized to determine the prognostic significance of these genes. Furthermore, consensus clustering was employed to differentiate molecular subtypes within LUAD, while immune heterogeneity was assessed. To evaluate treatment outcomes, the expression of immune checkpoint inhibitors was examined, and the sensitivity of LUAD patients to chemotherapy drugs was assessed. Moreover, machine learning algorithms were employed to construct a Paraptosis-related risk score with prognostic and immunological indicators. Finally, to validate the findings, in vitro experiments were performed to verify the regulatory effect of key PRGs on Paraptosis. Our analysis identified 24 PRGs that exhibited differential expression, with CDKN3, TP53, and PHB emerging as the most prominently upregulated genes in tumor tissues. Among these genes, seven were identified as prognostic markers, with HSPB8 being the sole protective factor. Notably, our analysis also revealed the existence of two distinct molecular subtypes within LUAD, each characterized by unique prognoses and immune responses. Specifically, Subtype B displayed a poorer prognosis but demonstrated increased sensitivity to both chemotherapy and immunotherapy. In addition, our development of a Paraptosis-Associated Risk Score yielded a significant prognostic value in predicting patient outcomes. Furthermore, we found regulatory effect of CDKN3 on Paraptosis in two cell lines. Our study highlights the importance of PRGs in LUAD, particularly in prognosis and treatment response. The identified molecular subtypes and Paraptosis-Associated Risk Score offer valuable insights for personalized treatment strategies.

Molecular phenotypes behind patient stratification based on TP53 and HPV status and potential for treatment personalization with first single-cell RNA sequencing atlas of penile cancer.

8 Background: TP53 mutations and Human papillomavirus (HPV) have been suggested to impact penile squamous cell carcinoma (pSCC) prognosis and may predict treatment outcomes. Insights in differences in tumor micro-environment at single cell resolution may benefit personalized therapeutic development and are currently unavailable. Methods: We performed single cell RNA sequencing and targeted next generation sequencing (for TP53 loss-of-function mutations; p53LOF) on primary HPV-associated and HPV-independent (HPV+/-) pSCC lesions or healthy control samples of the coronal sulcus skin. Cell clusters were annotated based on known marker genes. Gene Set Enrichment Analysis (GSEA) and slingshot trajectory analysis was performed using R/Seurat package. Results: Twenty-two samples were analyzed: 4 tumors harbored p53LOF mutations (1 HPV+ p53LOF, 3 HPV- p53LOF), 6 HPV- p53WT, 6 HPV+ p53WT and 6 healthy controls. A total of 84.394 cells was annotated and we identified 68 distinct cell subtypes in pSCC. In epithelial cells, two distinct pseudotime trajectories stemming from the basal cells were identified characterized by either signals of partial epithelial-mesenchymal transition (pEMT; TGFB, ZEB2, SNAI2) or cornification ( ELF3, KRT19, PPL). Whilst the pEMT trajectory was enriched in p53LOF samples, cornification was enriched in HPV+ p53WT. HPV- p53WT samples displayed increase in metabolic changes and stemness hallmarks ( SOX2, HEY1, ZEB1). GSEA confirmed these findings and showed upregulation of pEMT gene sets in p53LOF; fatty acid metabolism and xenobiotic metabolism in HPV- p53WT, and cornification in HPV+ p53WT. We observed an immune suppressive environment in p53LOF patients with higher regulatory T-cell abundancy, and this correlated with abundancy in the epithelial pEMT clusters. Pseudo-bulk analysis on all T-cell subsets demonstrated a higher expression of inhibitory immune checkpoints ( PD-1, CTLA4, TIM3 and LAG3) in p53LOF and HPV- p53WT while HPV+ p53WT patients displayed higher abundancy of immunomodulatory and cytotoxic natural killer (NK) cells. Conclusions: We established the first comprehensive pSCC transcriptomic atlas at single cell resolution and illustrate differences in molecular phenotypes of pSCC according to TP53 mutation- and HPV status. p53LOF tumors are characterized by pEMT, which is a known driver of invasiveness, therapy resistance and metastasis. HPV- p53WT display hallmarks of stemness, which is related to and may explain chemotherapy-resistance often observed in these patients. p53LOF and HPV- p53WT display immune-evasion and exhaustion, while HPV+ p53WT are characterized by abundant cytotoxic innate-like lymphocytes. These observations provide deeper insights into cancer biology that will help advancing pSCC diagnosis and therapy.

Spatial profiling of the placental chorioamniotic membranes reveals upregulation of immune checkpoint proteins during Group B Streptococcus infection in a nonhuman primate model.

Preterm birth is a leading cause of neonatal mortality, which is often complicated by intrauterine infection and inflammation. We have established a nonhuman primate model of Group B Streptococcus (GBS, Streptococcus agalactiae) infection-associated preterm birth. Immune checkpoints are modulators of the immune response by activating or suppressing leukocyte function and are understudied in preterm birth. The objective of this study was to spatially profile changes in immune protein expression at the maternal-fetal interface during a GBS infection with a focus on immune checkpoints. Twelve nonhuman primates (pigtail macaques, Macaca nemestrina) received a choriodecidual inoculation of either: 1) 1-5 X 108 colony forming units (CFU) of hyperhemolytic/hypervirulent GBS (GBSΔcovR, N=4); 2) an isogenic/nonpigmented strain (GBS ΔcovRΔcylE, N=4); or, 3) saline (N=4). A Cesarean section was performed at preterm labor or 3 days after GBS infection or 7 days after saline inoculation. Nanostring GeoMx® Digital Spatial Profiling technology was used to segment protein expression within the amnion, chorion, and maternal decidua at the inoculation site using an immuno-oncology panel targeting 56 immunoproteins enriched in stimulatory and inhibitory immune checkpoint proteins or their protein ligands. Statistical analysis included R studio, Kruskal-Wallis, Pearson and Spearman tests. Both inhibitory and stimulatory immune checkpoint proteins were significantly upregulated within the chorioamniotic membranes and decidua (VISTA, LAG3, PD-1, CD40, GITR), as well as their ligands (PD-L1, PD-L2, CD40L; all p<0.05). Immunostaining for VISTA revealed positive (VISTA+) cells, predominantly in the chorion and decidua. There were strong correlations between VISTA and amniotic fluid concentrations of IL-1β, IL-6, IL-8, and TNF-α (all p<0.05), as well as maternal placental histopathology scores (p<0.05). Differential regulation of multiple immune checkpoint proteins in the decidua at the site of a GBS infection indicates a major perturbation in immunologic homeostasis that could benefit the host by restricting immune-driven pathologies or the pathogen by limiting immune surveillance. Protein expression of VISTA, an inhibitory immune checkpoint, was upregulated in the chorion and decidua after GBS infection. Investigating the impact of innate immune cell expression of inhibitory immune checkpoints may reveal new insights into placental host-pathogen interactions at the maternal-fetal interface.

Potential impact of cuproptosis-related genes on tumor immunity in esophageal carcinoma.

Cuproptosis involves a direct interaction with the tricarboxylic acid (TCA) lipid acylation components. This process intricately intersects with post-transcriptional lipid acylation (LA) and is linked to mitochondrial respiration and LA metabolism. Copper ions form direct bonds with acylated DLAT, promoting DLAT oligomerization, reducing Fe-S cluster proteins, and inducing a protein-triggered toxic stress response that culminates in cell demise. Simultaneously, the importance of immune contexture in cancer progression and treatment has significantly increased. We assessed the expression of cuproptosis-related genes (CRGs) across TCGA and validated our findings using the GEO data. Consensus clustering divided esophageal cancer (ESCA) patients into two clusters based on the expression of 7 CRGs. We evaluated the expression of immune checkpoint inhibitor (ICI) targets and calculated the elevated tumor mutational burden (TMB). Weighted gene co-expression network analysis (WGCNA) identified genes associated with the expression of CRGs and immunity. Cluster 1 exhibited increased immune infiltration, higher expression of ICI targets, higher TMB, and a higher incidence of deficiency in mismatch repair-microsatellite instability-high status. WGCNA analysis identified 14 genes associated with the expression of CRGs and immune scores. ROC analysis revealed specific hub genes with strong predictive capabilities. The expression levels of SLC6A3, MITD1, and PDHA1 varied across different pathological stages; CCS, LIPT2, PDHB, and PDHA1 showed variation in response to radiation therapy; MITD1 and PDHA1 exhibited differences related to the pathological M stages of ESCA. CRGs influence the immune contexture and can potentially transform cold tumors into hot tumors in ESCA patients.

Cholinergic signaling influences the expression of immune checkpoint inhibitors, PD-L1 and PD-L2, and tumor hallmarks in human colorectal cancer tissues and cell lines

BackgroundCancer cells express immunosuppressive molecules, such as programmed death ligands (PD-L)1 and PD-L2, enabling evasion from the host’s immune system. Cancer cells synthesize and secrete acetylcholine (ACh), acting as an autocrine or paracrine hormone to promote their proliferation, differentiation, and migration.MethodsWe correlated the expression of PD-L1, PD-L2, cholinergic muscarinic receptor 3 (M3R), alpha 7 nicotinic receptor (α7nAChR), and choline acetyltransferase (ChAT) in colorectal cancer (CRC) tissues with the stage of disease, gender, age, risk, and patient survival. The effects of a muscarinic receptor blocker, atropine, and a selective M3R blocker, 4-DAMP, on the expression of immunosuppressive and cholinergic markers were evaluated in human CRC (LIM-2405, HT-29) cells.ResultsIncreased expression of PD-L1, M3R, and ChAT at stages III-IV was associated with a high risk of CRC and poor survival outcomes independent of patients’ gender and age. α7nAChR and PD-L2 were not changed at any CRC stages. Atropine and 4-DAMP suppressed the proliferation and migration of human CRC cells, induced apoptosis, and decreased PD-L1, PD-L2, and M3R expression in CRC cells via inhibition of EGFR and phosphorylation of ERK.ConclusionsThe expression of immunosuppressive and cholinergic markers may increase the risk of recurrence of CRC. These markers might be used in determining prognosis and treatment regimens for CRC patients. Blocking cholinergic signaling may be a potential therapeutic for CRC through anti-proliferation and anti-migration via inhibition of EGFR and phosphorylation of ERK. These effects allow the immune system to recognize and eliminate cancer cells.

GSK-3 Inhibitor Elraglusib Enhances Tumor-Infiltrating Immune Cell Activation in Tumor Biopsies and Synergizes with Anti-PD-L1 in a Murine Model of Colorectal Cancer.

Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that has been implicated in numerous oncogenic processes. GSK-3 inhibitor elraglusib (9-ING-41) has shown promising preclinical and clinical antitumor activity across multiple tumor types. Despite promising early-phase clinical trial results, there have been limited efforts to characterize the potential immunomodulatory properties of elraglusib. We report that elraglusib promotes immune cell-mediated tumor cell killing of microsatellite stable colorectal cancer (CRC) cells. Mechanistically, elraglusib sensitized CRC cells to immune-mediated cytotoxicity and enhanced immune cell effector function. Using western blots, we found that elraglusib decreased CRC cell expression of NF-κB p65 and several survival proteins. Using microarrays, we discovered that elraglusib upregulated the expression of proapoptotic and antiproliferative genes and downregulated the expression of cell proliferation, cell cycle progression, metastasis, TGFβ signaling, and anti-apoptotic genes in CRC cells. Elraglusib reduced CRC cell production of immunosuppressive molecules such as VEGF, GDF-15, and sPD-L1. Elraglusib increased immune cell IFN-γ secretion, which upregulated CRC cell gasdermin B expression to potentially enhance pyroptosis. Elraglusib enhanced immune effector function resulting in augmented granzyme B, IFN-γ, TNF-α, and TRAIL production. Using a syngeneic, immunocompetent murine model of microsatellite stable CRC, we evaluated elraglusib as a single agent or combined with immune checkpoint blockade (anti-PD-1/L1) and observed improved survival in the elraglusib and anti-PD-L1 group. Murine responders had increased tumor-infiltrating T cells, augmented granzyme B expression, and fewer regulatory T cells. Murine responders had reduced immunosuppressive (VEGF, VEGFR2) and elevated immunostimulatory (GM-CSF, IL-12p70) cytokine plasma concentrations. To determine the clinical significance, we then utilized elraglusib-treated patient plasma samples and found that reduced VEGF and BAFF and elevated IL-1 beta, CCL22, and CCL4 concentrations correlated with improved survival. Using paired tumor biopsies, we found that tumor-infiltrating immune cells had a reduced expression of inhibitory immune checkpoints (VISTA, PD-1, PD-L2) and an elevated expression of T-cell activation markers (CTLA-4, OX40L) after elraglusib treatment. These results address a significant gap in knowledge concerning the immunomodulatory mechanisms of GSK-3 inhibitor elraglusib, provide a rationale for the clinical evaluation of elraglusib in combination with immune checkpoint blockade, and are expected to have an impact on additional tumor types, besides CRC.

A signature of cuproptosis-related lncRNAs predicts prognosis and provides basis for future anti-tumor drug development in breast cancer.

Breast cancer is the most prevalent malignancy worldwide and the leading culprit for women's death. Cuproptosis is a novel and promising modality of tumor cell death and the relationship with long non-coding RNAs (lncRNAs) remains shrouded in a veil. Studies in cuproptosis-related lncRNAs can aid in the clinical management of breast cancer and provide a basis for anti-tumor drug development. RNA-Seq data, somatic mutation data, and clinical information were downloaded from The Cancer Genome Atlas (TCGA). Patients were divided into high- and low-risk groups according to the risk score. Cox regression and least absolute shrinkage and selection operator (LASSO) regression analyses were used to select prognostic lncRNAs to construct a risk score system. Its' prognostic value was confirmed in the training and validation cohorts subsequently. Functional analysis regarding cuproptosis-related lncRNAs was performed. Eighteen cuproptosis-related lncRNAs were identified and 11 of them including AL023882.1, AC091588.1, AC138028.2, AC027514.1, AL592301.1, LRRC8C-DT, MFF-DT, NIFK-AS1, MECOM-AS1, OTUD6B-AS1 and RNF32-AS1 were selected for risk score system construction. The risk score was confirmed as an independent prognostic factor and patients in the high-risk group had a worse prognosis. A nomogram based on the independent prognostic factors was constructed for clinical decision aids. Further analyses revealed that patients in the high-risk group faced a heavier tumor mutational burden (TMB) and suppressed anti-tumor immunity. Besides, cuproptosis-related lncRNAs were associated with the expression of immune checkpoint inhibitors, N6-adenylate methylation (m6a), and drug sensitivity in breast cancer. A prognostic risk score system with satisfactory predictive accuracy was constructed. Besides, cuproptosis-related lncRNAs can influence the immune microenvironment, TMB, m6a, and drug sensitivity in breast cancer, which may provide a basis for future anti-tumor drug development.

GSK-3 inhibitor elraglusib (9-ING-41) to enhance tumor-infiltrating immune cell activation in tumor biopsies and synergize with anti-PD-L1 in a murine model of colorectal cancer.

e15138 Background: Glycogen synthase kinase 3 (GSK-3) is a serine/threonine kinase with key roles in myriad biological processes such as tumor progression, and inhibition of GSK-3 using a novel small-molecule elraglusib has shown promising preclinical antitumor activity in multiple tumor types. Methods: We characterize the effects of elraglusib in vitro on tumor and immune cells including cell killing and cytokine profiling , in vivo in combination with checkpoint inhibitors in a syngeneic murine colon carcinoma BALB/c model using MSS cell line CT-26, and in human tumor biopsies and plasma samples from patients with refractory solid tumors of multiple tissue origins enrolled in a Phase 1 clinical trial investigating elraglusib ( NCT03678883 ).We used human plasma samples from patients treated with elraglusib, paired pre- and post-treatment tumor biopsies and performed digital spatial proteomics. Results: Elraglusib promoted immune cell-mediated tumor cell killing, enhanced tumor cell pyroptosis, decreased tumor cell NF-κB-regulated survival protein expression, and increased immune cell effector molecule secretion. Synergy was observed between elraglusib and anti-PD-L1 in an immunocompetent murine model of colorectal cancer. Murine responders had more tumor-infiltrating T-cells, fewer tumor-infiltrating Tregs, lower tumorigenic circulating cytokine concentrations, and higher immunostimulatory circulating cytokine concentrations. Murine responders had lower serum concentrations of BAFF, CCL7, CCL12, VEGF, VEGFR2, and CCL21, and higher serum concentrations of CCL4, TWEAK, GM-CSF, CCL22, and IL-12p70 as compared to non-responders. We utilized human plasma samples from patients treated with elraglusib and correlated cytokine profiles with survival. Elevated baseline plasma levels of proteins such as IL-1 β and reduced levels of proteins such as VEGF correlated with improved PFS and OS. PFS was also found to be positively correlated with elevated plasma levels of immunostimulatory analytes such as Granzyme B, IFN-γ, and IL-2 at 24 hours post-treatment with elraglusib. Several of these secreted proteins correlated with results from the in vivo study where expression of proteins such as IL-1 β, CCL22, CCL4, and TWEAK was positively correlated with improved response to therapy while expression of proteins such as BAFF and VEGF negatively correlated with response to therapy. Using paired tumor biopsies, we found that CD45+ tumor-infiltrating immune cells had lower expression of inhibitory immune checkpoints and higher expression of T-cell activation markers in post-elraglusib patient biopsies. Conclusions: These results introduce several immunomodulatory mechanisms of GSK-3 inhibition using elraglusib, providing a rationale for the clinical evaluation of elraglusib in combination with immunotherapy.

ARHGAP11A Is a Novel Prognostic and Predictive Biomarker Correlated with Immunosuppressive Microenvironment in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is a highly immunogenic tumor and immune dysfunction is associated with ccRCC poor prognosis. The RhoGTPase-activating proteins (RhoGAPs) family was reported to affect ccRCC development, but its role in immunity and prognosis prediction for ccRCC remain unknown. In the current study, we found ARHGAP11A was the only independent risk factor among 33 RhoGAPs (hazard ratio [HR] 1.949, 95% confidence interval [CI] 1.364-2.785). High ARHGAP11A level was associated with shorter overall survival (OS, HR 2.040, 95% CI 1.646-3.417) and ARHGAP11A is a prognostic biomarker for ccRCC. ARHGAP11A knockdown suppressed renal cell carcinoma (RCC) cell proliferation, colony formation, and migration, suggesting the promoting role of ARHGAP11A on RCC development. Mechanistically, ARHGAP11A might contribute to the suppressive tumor immune microenvironment (TIME). High ARHGAP11A level was correlated with infiltration of immunosuppressive cells (including T helper 2 (Th2) cells, regulatory T (Treg) cells, myeloid derived suppressor cells (MDSC), and M2 macrophage cells), activation of immunosuppressive pathways (IL6-JAK-STAT3 signaling and IFNγ response), and expression of inhibitory immune checkpoints (ICs). ARHGAP11A could promote T cell exhaustion and induce immune escape. ccRCC patients with low ARHGAP11A level were more suitable for immune checkpoint inhibitors (ICIs) therapy, while those with high ARHGAP11A level might benefit from a combination of ARHGAP11A blockade and ICIs. In all, ARHGAP11A might serve as a novel prognostic marker, therapeutic target, and predictor in the clinical response to ICIs therapy for ccRCC.

Abstract 2982: TriTCE CPI, next generation trispecific T cell engagers with integrated checkpoint inhibition (CPI) for the treatment of solid tumors

Abstract CD3-bispecific T cell engager (TCE) therapies have exhibited clinical utility against hematological malignancies, but successes in solid tumor indications have been limited. Compared to heme malignancies, treatment of solid tumors is hindered by immunosuppressed microenvironments that can be refractory to traditional CD3-bispecific TCEs. Immunosuppression in the tumor microenvironment limits treatment responses in part due to the expression of inhibitory immune checkpoints, such as PD-1 on exhausted T cells and PD-L1 on tumor cells. To improve T cell responses and anti-tumor activity in immunosuppressed solid tumors, we generated trispecific TCE antibodies (Abs) that target a tumor associated antigen (TAA), CD3 and PD-L1 (via a PD1 moiety) to stimulate tumor-directed T cell killing and checkpoint blockade at the tumor site. In this engineering approach we harnessed the flexibility of our AzymetricTM technology to screen multiple antibody formats, geometries, paratopes, and PD-1 domain affinities in parallel. We screened the TriTCE CPI antibodies, targeting different TAAs, for tumor-directed T cell cytotoxicity and CPI activity on TAA+PD-L1+ and TAA-PD-L1+ tumor cells. We identified multiple TriTCE CPI Abs that induced potent TAA-dependent T cell killing of TAA+PD-L1+, but not TAA-PD-L1+, tumor cells. Evaluation of CPI using a PD-1/PD-L1 checkpoint reporter gene assay identified antibody formats that stimulated simultaneous TAA dependent T cell engagement and enhanced checkpoint inhibition superior to bispecific Ab plus anti-PD-L1 Ab combination treatments. Additionally, in a human PBMC-engrafted xenograft model, TriTCE CPI Abs showed increased anti-tumor activity compared to a bispecific Ab control +/- anti-PD-L1 Ab treatment. Furthermore, the benefits of increased anti-tumor activity and CPI was observed across multiple TriTCE CPI Abs targeting different TAAs. We generated multiple TriTCE CPI Abs that combine tumor-dependent T cell cytotoxicity with checkpoint blockade, which may translate to improved T cell responses in immunosuppressed solid tumors. The evaluation of multiple Ab formats, geometries and paratope affinities allowed for optimization of TAA-dependent cytotoxicity and CPI to identify Abs with enhanced anti-tumor activity and superior site-specific CPI, key factors that may contribute to a wide therapeutic index and improved clinical outcomes. Citation Format: Maya C. Poffenberger, Meghan M. Verstraete, Anna Von Rossum, Patricia Zwierzchowski, Matteo Zago, Veronica Luu, Sifa Arrafi, Siran Cao, Harsh Pratap, Chayne L. Piscitelli, Nina E. Weisser, Thomas Spreter von Kreudenstein. TriTCE CPI, next generation trispecific T cell engagers with integrated checkpoint inhibition (CPI) for the treatment of solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2982.

Abstract P2-20-07: Immunotherapy becomes a treatment option in cryoablated Luminal A breast cancers

Abstract Background: Most breast cancers are not inherently immunogenic, and as a result are difficult to treat with immunotherapy. However, recent research has shown that triple-negative breast cancer (TNBC) and HER-2 positive (HER2) breast cancers can stimulate some level of an immune response. In contrast, the most common form of breast cancer, the luminal A (hormone receptor-positive (HR+)/HER-2 negative), has shown low involvement of tumor-infiltrating lymphocytes (TILs) and low expression of immune checkpoint inhibitors specifically programmed death-ligand-1 (PD-L1). Cryoablation, the destruction of cells using ultra-low temperatures, has been used as a primary treatment method for benign breast tumors and is in clinical trials to evaluate its use for invasive breast cancer. A secondary effect of cryoablation is the release of cellular proteins that can function as neoantigens and are in their native folded state We hypothesize that release of these native neoantigens might trigger an immune response capable of preventing/reducing metastasis and local relapse. In this pilot study, we evaluated biopsy material, cryoablated specimens and sentinel lymph nodes (SLN) from patients enrolled in the ACOSOG Z1072 trial at Lankenau Medical Center (LMC) [N=18] with cancers &amp;lt; 2 cm. Responses were compared to patients treated with surgical resection. Methods: After obtaining IRB approval for retrospective analyses of specimens from the ACOSOG Z1072 trial, these samples were evaluated with immunohistochemistry (IHC) using commercially available antibodies and standard techniques to determine changes in CD4, CD8, CD20, CD21, CD1c levels, as well as the immune checkpoint regulators PD-1, PD-L1 and CTLA-4, and the immune modulator IDO1. Patient samples included biopsy, surgical material, and SLN collected from the patients and were compared with patients of similar age, tumor characteristics and time to surgery. Per the ACOSOG trial protocol, tumors had to be surgically removed within 28 days of cryoablation, but the exact time was left to the surgeon’s discretion. Participating surgeons at LMC preferred to remove tumors on average 24.7 days after ablation resulting in an average time from diagnosis to surgical removal of 43.3 days. Results: Cryoablation of the tumors resulted in coagulative necrosis presenting as a gelatinous mass surrounded by a fibrous capsule. The ACOSOG trial demonstrated effective cryoablation-induced destruction of ER+ invasive ductal carcinoma lesions in 92% of patients (N=86). On IHC staining of the cryoablated samples, more CD8+ lymphocytes were identified compared to CD4+, which was consistent with pattern among non-cryoablated tumors, albeit to a lesser degree. Though no difference in percentage of PD-1 positive cells were observed between treatment modalities, positive cells in cryoablated tumors had mostly moderate-to-strong staining. We observed a 20% increase in cells positive for PD-L1 after cryoablation with predominantly strong staining. Though IDO1 had fewer positive cells in the tumor mass, the expression in SLN was higher with nearly all cells exhibiting strong staining. Compared to the patients who were treated with surgery alone, the SLNs of cryo patients had higher levels of CD20+ B cells as well as CD21+ follicular dendritic cells. CTLA-4 was seen sporadically, but with a slight preference for the surgery patients. Conclusion: We show that cryoablation of breast cancer lesions in vivo can induce an immune response in HR+ tumors, turning an immunogenically cold tumor into an immunogenically hot, tumor potentially responsive to check-point inhibitors and immune modulators. Possibly providing less toxic treatment options for elderly patients and/or patients with comorbidities All local cryo patients in the clinical trial are currently disease-free (F/U 5 - 13years), while 1 surgical patient is alive with late recurrence (11 years post-surgery). Citation Format: Zachary Aukers, Jonah Klein, Vincent Ciocca, Vlasta Zemba-Palko, Jennifer Sabol, Robin Ciocca, Laura Mandik-Nayak, Ned Carp, Margaretha Wallon. Immunotherapy becomes a treatment option in cryoablated Luminal A breast cancers [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-20-07.

Unlocking molecular mechanisms and identifying druggable targets in matched-paired brain metastasis of breast and lung cancers.

The incidence of brain metastases in cancer patients is increasing, with lung and breast cancer being the most common sources. Despite advancements in targeted therapies, the prognosis remains poor, highlighting the importance to investigate the underlying mechanisms in brain metastases. The aim of this study was to investigate the differences in the molecular mechanisms involved in brain metastasis of breast and lung cancers. In addition, we aimed to identify cancer lineage-specific druggable targets in the brain metastasis. To that aim, a cohort of 44 FFPE tissue samples, including 22 breast cancer and 22 lung adenocarcinoma (LUAD) and their matched-paired brain metastases were collected. Targeted gene expression profiles of primary tumors were compared to their matched-paired brain metastases samples using nCounter PanCancer IO 360™ Panel of NanoString technologies. Pathway analysis was performed using gene set analysis (GSA) and gene set enrichment analysis (GSEA). The validation was performed by using Immunohistochemistry (IHC) to confirm the expression of immune checkpoint inhibitors. Our results revealed the significant upregulation of cancer-related genes in primary tumors compared to their matched-paired brain metastases (adj. p ≤ 0.05). We found that upregulated differentially expressed genes in breast cancer brain metastasis (BM-BC) and brain metastasis from lung adenocarcinoma (BM-LUAD) were associated with the metabolic stress pathway, particularly related to the glycolysis. Additionally, we found that the upregulated genes in BM-BC and BM-LUAD played roles in immune response regulation, tumor growth, and proliferation. Importantly, we identified high expression of the immune checkpoint VTCN1 in BM-BC, and VISTA, IDO1, NT5E, and HDAC3 in BM-LUAD. Validation using immunohistochemistry further supported these findings. In conclusion, the findings highlight the significance of using matched-paired samples to identify cancer lineage-specific therapies that may improve brain metastasis patients outcomes.

Molecular underpinnings of exceptional response in primary malignant melanoma of the esophagus to anti-PD-1 monotherapy

BackgroundAccumulating data suggest that mucosal melanoma, well known for its poor response to immune checkpoint blockade (ICB) and abysmal prognosis, is a heterogeneous subtype of melanoma with distinct genomic and...

Potential impact of WTAP and YTHDF2 on tumor immunity in lung adenocarcinoma.

WTAP and N6-methyladenosine (m6A) reader proteins (YTHDF2) are N6-methyladenosine (m6A) methyltransferase and m6A reading proteins, respectively. In recent years, the tumor immune environment has received more and more attention in the progress and treatment of cancer. The aim of this study was to investigate the relationship between N6-methyladenosine (m6A) methyltransferase (WTAP)/YTHDF2 and the immunological characteristics of lung adenocarcinoma (LUAD). Based on the expression of WTAP and YTHDF2 in the cancer genome atlas (TCGA) and gene expression omnibus (GEO) database, LUAD patients were divided into 2 clusters by coherently clustering method, and performed gene set enrichment analysis (GSEA) to identify the functional differences. Immunoinvasion analysis was performed using ESTIMATE, CIBERSORT, and single-sample GSEA (ssGSEA), and expression of immune checkpoint inhibitors (ICIs) targets was assessed, while tumor mutation burden (TMB) was calculated in tumor samples. Weighted gene co-expression network analysis (WGCNA) was used to identify the genes related to both WTAP/YTHDF2 expression and immunity. The immunological characteristics between the 2 clusters were externally verified based on GSE39582. The expression of WTAP was higher in cluster 1 and YTHDF2 was lower, but it was opposite in cluster 2. Cluster 1 had stronger immune infiltration, more ICIs target expression, more TMB. In addition, WGCNA identified 22 genes associated with WTAP/YTHDF2 expression and immune score, including TIM3 (HAVCR2) and CD86. WTAP and YTHDF2 influence immune contexture and may be novel prognostic and druggable targets associated with the immune system of LUAD.

Pan-cancer analysis revealing DAAM1 as a novel predictive biomarker for PD-1/PD-L1 blockade in clear cell renal cell carcinoma.

Pan-cancer analysis revealing DAAM1 as a novel predictive biomarker for PD-1/PD-L1 blockade in clear cell renal cell carcinoma.