Tumor Microenvironment Of Patients Research Articles

Iberdomide increases innate and adaptive immune cell subsets in the bone marrow of patients with relapsed/refractory multiple myeloma

Iberdomide is a potent cereblon E3 ligase modulator (CELMoD agent) with promising efficacy and safety as a monotherapy or in combination with other therapies in patients with relapsed/refractory multiple myeloma (RRMM). Using a custom mass cytometry panel designed for large-scale immunophenotyping of the bone marrow tumor microenvironment (TME), we demonstrate significant increases of effector T and natural killer (NK) cells in a cohort of 93 patients with multiple myeloma (MM) treated with iberdomide, correlating findings to disease characteristics, prior therapy, and a peripheral blood immune phenotype. Notably, changes are dose dependent, associated with objective response, and independent of prior refractoriness to MM therapies. This suggests that iberdomide broadly induces innate and adaptive immune activation in the TME, contributing to its antitumor efficacy. Our approach establishes a strategy to study treatment-induced changes in the TME of patients with MM and, more broadly, patients with cancer and establishes rational combination strategies for iberdomide with immune-enhancing therapies to treat MM.

The role of the tumor microenvironment in papillary thyroid microcarcinoma nodal metastasis.

The genetic alterations currently identified in papillary thyroid microcarcinomas (PTMCs) are insufficient for distinguishing tumors with aggressive features. We aimed to identify candidate markers associated with lateral lymph node metastasis (LLNM, N1sb disease) in patients with PTMC using transcriptomic analysis. RNA sequencing was performed on 26 matched tumor and normal thyroid tissue samples (N0, n = 14; N1b, n = 12), followed by functional enrichment analyses of differentially expressed genes (DEGs). EcoTyper was used to explore the distinct tumor microenvironment (TME). We identified 631 DEGs (213 upregulated and 418 downregulated) between N1b and N0 PTMCs. The most significantly upregulated genes in N1b were associated with tumorigenesis, adhesion, migration, and invasion. DEGs were mainly enriched in the pathways of idiopathic pulmonary fibrosis, TME, wound healing, and inhibition of matrix metalloproteases. We predicted the activation of these pathways in N1b PTMCs. N1b PTMCs had a unique TME with abundant fibroblasts and epithelial cells, associated with an increased risk of disease progression. Fibroblast marker genes, including POSTN, MMP11, TNFAIP6,and FN1, and epithelial cell marker genes, including NOX4, MFAP2, TGFVBI,and TNC, were selected. POSTN and FN1, fibroblast cell-specific genes, and NOX4 and TNC, epithelial cell-specific genes, were promising biomarkers for predicting LLNM development and recurrence in patients with PTMC. We delineated the cellular ecotypes within the TME of patients with N1b PTMC and revealed potential markers for predicting LLNM and the prognosis of PTMC. These findings provide valuable insights into the contributions of cancer-associated fibroblasts and epithelial cells to PTMC progression and metastasis.

FAT1 upregulation is correlated with an immunosuppressive tumor microenvironment and predicts unfavorable outcome of immune checkpoint therapy in non-small cell lung cancer

BackgroundPrevious studies found that FAT1 was recurrently mutated and aberrantly expressed in multiple cancers, and the loss function of FAT1 promoted the formation of cancer-initiating cells in several cancers. However, in some types of cancer, FAT1 upregulation could lead to epithelial-mesenchymal transition (EMT). The role of FAT1 in cancer progression, which appears to be cancer-type-specific, is largely unknown. MethodsQRT-PCR and immunochemistry were used to verify the expression of FAT1 in non-small cell lung cancer (NSCLC). QRT-PCR and Western blot were used to detect the influence of siFAT1 knockdown on the expression of potential targets of FAT1 in NSCLC cell lines. GEPIA, KM-plotter, CAMOIP, and ROC-Plotter were used to evaluate the association between FAT1 and clinical outcomes based on expression and clinical data from TCGA and immune checkpoint inhibitors (ICI) treated cohorts. ResultsWe found that FAT1 upregulation was associated with the activation of TGF-β and EMT signaling pathways in NSCLC. Patients with a high FAT1 expression level tend to have a poor prognosis and hard to benefit from ICI therapy. Genes involved in TGF-β/EMT signaling pathways (SERPINE1, TGFB1/2, and POSTN) were downregulated upon knockdown of FAT1. Genomic and immunologic analysis showed that high cancer-associated fibroblast (CAF) abundance, decreased CD8+ T cells infiltration, and low TMB/TNB were correlated with the upregulation of FAT1, thus promoting an immunosuppressive tumor microenvironment (TME) which influence the effect of ICI-therapy. ConclusionOur findings revealed the pattern of FAT1 upregulation in the TME of patients with NSCLC, and demonstrated its utility as a biomarker for unfavorable clinical outcomes, thereby providing a potential therapeutic target for NSCLC treatment.

Abstract 7533: PVRIG is uniquely expressed in tumor dendritic cells-rich niches on stem-like memory T cells and its blockade may induce immune infiltration and activation in non-inflamed tumors

Abstract Poorly immune infiltrated cancers pose a significant challenge, with current immunotherapies yielding limited clinical success. Stem-like memory T cells (TSCM) have been identified as a T cell subgroup which possess enhanced proliferative capacity that could expand and differentiate upon dendritic cells (DCs) priming. In this study we investigated the expression of the recently discovered inhibitory receptor PVRIG and its ligand, PVRL2, in the tumor microenvironment (TME). Leveraging single cell RNA sequencing (scRNAseq) data from diverse cancer indications, we found that in CD8+ T cells, PVRIG clusters with early differentiation/TSCM genes, unlike other immune checkpoints that cluster with genes related to T cells exhaustion. In agreement with the scRNAseq data, PVRIG protein expression was markedly increased on CD28+CD8+ early-memory T cells across cancer indications. PVRL2, was dominantly expressed on intratumoral DC subsets on both scRNA and protein levels. The observation that PVRIG is uniquely expressed by TSCM cells, and PVRL2 by DCs, led us to evaluate whether these cell populations physically co-localize in the TME, thus potentially allowing PVRIG/PVRL2 interaction. Employing spatial transcriptomic analysis in surgically resected CRC lesions we showed that while CTLA4, PD1, and TIM3 were mainly expressed by tumor infiltrating T cells, PVRIG and other genes of the DNAM-1 axis were intensely expressed by TSCM in specialized immune aggregates, as well as by T cells in tumor bed. High resolution spatial mapping of interacting immune and adjacent cells revealed pairs of activated LAMP3+PVRL2+ DCs interacting with CD28+PVRIG+ CD8 T cells in the intratumoral immune aggregates. Thus, PVRIG/PVRL2 interaction may limit TSCM priming by DCs and blocking this interaction may unleash potent TSCM proliferation, differentiation, and infiltration into the tumor regions. To gain a more comprehensive understanding on the intratumor effects induced by PVRIG blockade, we evaluated the immune response in the TME of patients with poorly immune infiltrated tumors, platinum resistant ovarian cancer and MSS-CRC, indications typically less responsive to immune checkpoint inhibitors. Treatment with COM701, anti-PVRIG antibody, as monotherapy or in combination with nivolumab resulted in an increased tumor T cell infiltration, accompanied by TCR clonality expansion, which were associated with clinical benefit. In summary, our study identifies PVRIG as uniquely expressed on TSCM in the TME, with its ligand PVRL2 expressed on activated DCs. Blockade of PVRIG/PVRL2 interaction by COM701 antibody emerges as a promising strategy to induce potent T cell responses, providing a novel approach overcoming resistance to immunotherapy in immune excluded tumors. Citation Format: Zoya Alteber, Gady Cojocaru, Roy Zvi Granit, Inbal Barbiro, Assaf Wool, Masha Frenkel, Amit Novik, Adi Shuchami, Yu Liang, Vered Daniel Carmi, Niv Sabath, Rob Foreman, Natalia Petrenko, Jiang He, Yossef Kliger, Henry Adewoye, Pierre Ferre, Zurit Levine, Eran Ophir. PVRIG is uniquely expressed in tumor dendritic cells-rich niches on stem-like memory T cells and its blockade may induce immune infiltration and activation in non-inflamed tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7533.

Abstract 5459: Inflammatory gene-based subtyping of osteosarcoma patients reveals the association of inflammation in tumor microenvironment with better survival

Abstract Introduction:Inflammation has a significant impact on the tumor microenvironment (TME) of osteosarcoma (OS). Nevertheless, due to the high heterogenecity and variable inflammatory characteristics among OS patients, it is still unclear which inflammatory factors or immune/stroma cell types are crucially associated with OS prognosis. Therefore, it is essential to explore the immune infiltration pattern and the related core inflammatory genes in OS. Method:We combined bulk RNA-seq data of 88 osteosarcoma (OS) patients from the TARGET database and single cell RNA-seq data in GSE152048 from the NCBI Gene Expression Omnibus. Firstly, we calculated the inflammatory gene expression matrix of bulk RNA-seq data by combining 80 inflammatory gene sets (3427 genes in total) from the MSigDB using the gene set variation analysis (GSVA). Secondly, consensus clustering was executed to evaluate the stability of clustering for the above matrix. Furthermore, the overall survival and differential expression analyses were used to screen for core inflammatory genes. Immune infiltration patterns among groups were profiled with CIBERSORT. Finally, we employed the scRNA-seq series to evaluate cell-level information to identify the survival-associated cell subpopulations using the Seurat package. The t-SNE was used for dimensionality reduction and cluster identification. Results:88 osteosarcoma (OS) patients were clustered into two distinct groups according to the consensus clustering of our formed GSVA inflammatory gene expression matrix. Group 1 (43 patients) exhibited evident inflammation features, while Group 2 (45 patients) displayed limited inflammation features. Patients from Group 1 had significantly better overall survival than those from Group 2. The difference in immune infiltration pattern of two groups were examined using bulk RNA-seq data. Group 1 showed a higher population of macrophages and CD8+ T cells compared to Group 2, implying high inflammatory features might lead to a better immune activation of TME in patients. To explore the factors and cell types that contributes to restricted immune infiltration and activation in OS TME, scRNA-seq data of 11 OS patient tissues were analyzed. Consistently with bulk RNA seq analysis, the 338 up-regulated genes from Group 1 were mainly expressed in immune cells including macrophages and myeloid cells. Interestingly, the 64 up-regulated genes from Group 2 were found nearly uniformly expressed in two type of non-immune cells: myoblasts and chondroblastic cells. Conclusion:Inflammatory gene-based subtyping of osteosarcoma (OS) patients reveals that the inflammation in TME led by myeloid-derived immune cells including macrophage is associated with better prognosis. Furthermore, myoblasts and chondroblastic cells might contribute to the limited inflammation response in OS TME. Citation Format: Liu Yang, Yalan Sheng, Shuangying Qiao, Desheng Hu, Debajyoti Chowdhury, Hiu Fung Yip, Zheng Chen, Yun He, Aiping Lu, Fangfei Li. Inflammatory gene-based subtyping of osteosarcoma patients reveals the association of inflammation in tumor microenvironment with better survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5459.

Impact of metronomic trabectedin combined with low-dose cyclophosphamide on sarcoma microenvironment and correlation with clinical outcome: results from the TARMIC study.

Soft tissue sarcomas (STS) are diverse mesenchymal tumors with few therapeutic options in advanced stages. Trabectedin has global approval for treating STS patients resistant to anthracycline-based regimens. Recent pre-clinical data suggest that trabectedin's antitumor activity extends beyond tumor cells to influencing the tumor microenvironment (TME), especially affecting tumor-associated macrophages and their pro-tumoral functions. We present the phase I/II results evaluating a combination of metronomic trabectedin and low-dose cyclophosphamide on the TME in patients with advanced sarcomas. 50 patients participated: 20 in phase I and 30 in phase II. Changes in the TME were assessed in 28 patients using sequential tumor samples at baseline and day two of the cycle. Treatment notably decreased CD68 + CD163 + macrophages in biopsies from tumor lesions compared to pre-treatment samples in 9 of the 28 patients after 4 weeks. Baseline CD8 + T cell presence increased in 11 of these patients. In summary, up to 57% of patients exhibited a positive immunological response marked by reduced M2 macrophages or increased CD8 + T cells post-treatment. This positive shift in the TME correlated with improved clinical benefit and progression-free survival. This study offers the first prospective evidence of trabectedin's immunological effect in advanced STS patients, highlighting a relationship between TME modulation and patient outcomes.This study was registered with ClinicalTrial.gov, number NCT02406781.

Adverse clinical outcomes and immunosuppressive microenvironment of RHO-GTPase activation pattern in hepatocellular carcinoma

BackgroundEmerging evidence suggests that Rho GTPases play a crucial role in tumorigenesis and metastasis, but their involvement in the tumor microenvironment (TME) and prognosis of hepatocellular carcinoma (HCC) is not well understood.MethodsWe aim to develop a tumor prognosis prediction system called the Rho GTPases-related gene score (RGPRG score) using Rho GTPase signaling genes and further bioinformatic analyses.ResultsOur work found that HCC patients with a high RGPRG score had significantly worse survival and increased immunosuppressive cell fractions compared to those with a low RGPRG score. Single-cell cohort analysis revealed an immune-active TME in patients with a low RGPRG score, with strengthened communication from T/NK cells to other cells through MIF signaling networks. Targeting these alterations in TME, the patients with high RGPRG score have worse immunotherapeutic outcomes and decreased survival time in the immunotherapy cohort. Moreover, the RGPRG score was found to be correlated with survival in 27 other cancers. In vitro experiments confirmed that knockdown of the key Rho GTPase-signaling biomarker SFN significantly inhibited HCC cell proliferation, invasion, and migration.ConclusionsThis study provides new insight into the TME features and clinical use of Rho GTPase gene pattern at the bulk-seq and single-cell level, which may contribute to guiding personalized treatment and improving clinical outcome in HCC.

Abstract A009: CD103+CD56+ innate lymphoid cells are associated with an immunosuppressive microenvironment in ovarian cancer

Abstract Background: Regulatory innate lymphoid cells (ILCregs) are an emerging heterogenous subset of innate lymphoid cells that suppress immunity in several healthy and diseased contexts, including cancer. Previously, we identified CD56+ ILCregs from in vitro expanded tumour-infiltrating lymphocyte (TIL) cultures in patients with epithelial ovarian carcinoma (EOC). However, lineage-defining surface markers or transcription factors that distinguishes these regulatory populations from other conventional NK cells have not been identified. The objective of this study is to characterize markers that define ILCregs directly from primary tumours and investigate its role within the tumour microenvironment (TME). Methods: Women with suspected abdominal mass were recruited and consented at Gynecology Cancer Clinic at Princess Margaret Hospital. Surgically resected EOC tumours were processed and analyzed by flow cytometry and single-cell RNA-sequencing. Suppression assays were performed by co-culture of tumour-infiltrating CD103+CD56+ ILCregs with autologous TILs for 4 days in vitro with soluble αCD3. Results: We found that CD103 expressing CD56+ ILCregs were associated with poor clinical prognosis in patients with ovarian carcinoma. CD103+CD56+ ILCregs displayed reduced expression of cytolytic related markers (i.e., GZMB, CD107a, CD16) compared to CD103-CD56+ NK cells and had a distinct transcriptomic profile from NK cells. Interestingly, CD103+CD56+ ILCregs displayed distinct surface markers (i.e., CD49a, CD69, GITR) and transcription factor networks that were associated with Treg development, differentiation, and suppressive function. Intratumoural CD103+CD56+ ILCregs suppressed autologous CD8+ T cells by downregulation of granzyme B in vitro. Concordantly, the abundance of CD103+CD56+ ILCregs in patient tumours were associated with reduced activated CD8+ T cells within the TME. Conclusion: This study identified CD103+CD56+ ILCregs in the TME of patients with EOC that are associated with poor clinical prognosis and plays a key role in regulating T cells. Further investigations into underlying immunoregulatory networks, including ILCregs, within the TME may provide novel targets to improve prognosis for patients with EOC. Citation Format: Douglas C Chung, Jehan Vakharia, Kathrin Warner, Nicolas Jacquelot, Azin Sayad, SeongJun Han, Maryam Ghaedi, Carlos R Garcia-Batres, Alisha Elford, Ben X Wang, Linh T Nguyen, Patricia A Shaw, Blaise A Clarke, Marcus Q Bernardini, Sarah E Ferguson, Pamela S Ohashi. CD103+CD56+ innate lymphoid cells are associated with an immunosuppressive microenvironment in ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2023 Oct 1-4; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Immunol Res 2023;11(12 Suppl):Abstract nr A009.

Abstract PR001: Interpretation of patient-specific ex vivo immunotherapy response for ovarian cancer

Abstract Background: Immunotherapies have shown great benefits, including durable clinical responses. However, the overall response rate remains low and it is challenging to select sensitive patients upfront. Patient-derived ex vivo tumor tissues with preserved tumor microenvironment (TME) represent the ideal model for patient-specific testing of immunotherapy sensitivities. This study aims to confirm that patient-specific ex vivo immunotherapy responses are matched by the presence of relevant immune components. Material & Methods: Ascites of 84 patients with predominantly primary high grade ovarian carcinoma was collected between 2019 and 2023 in the Netherlands (IRB P18.032). Fresh tumor clusters with TME were seeded and exposed to six immunotherapies and the superantigen Staphylococcus aureus (SEA) as positive control. Tumor killing and immune cell proliferation were measured using 3D imaging. Ex vivo tumor sensitivity was classified on percentage and statistical significance of tumor killing. Immunohistochemical staining (IHC) for immune cell markers (CD3, CD68) (n=40) and proteomics analyses (n=26) were performed prior to drug exposure. Results: SEA response was observed in 52% (44/84). Differential patient response profiles were observed, with 30% of the patients tissues displaying highly significant sensitivity for at least one of the therapies tested. Clustering the patients based on pathology scores uncovered four distinct groups: 1) CD68-/CD3-, 2) CD3-/CD68+, 3) CD3+/CD68+ and 4) CD3++/CD68++. Clustering and regression analysis demonstrated a significant correlation of increased CD3 and CD68 expression to ex vivo SEA sensitivity (p-value < 0.05). Protein biomarker analysis supported these results, reporting significantly higher levels of chemokines and interleukins in SEA responders. Finally, different immune checkpoint inhibitors demonstrated distinct protein abundance profiles consistent with their mode of action. Conclusion: This study reports classification and characterization of patient-specific sensitivity to 6 immunotherapies in 84 ovarian cancer patients enabled by a robust image-based ex vivo 3D tumor testing platform. The results demonstrate a positive relationship between the ex vivo sensitivity to immune-stimulatory compounds and the presence of functional immune components in the patient's TME. This confirms the interpretability of 3D ex vivo tumor testing for classification of patient-specific immune responses. Discussion: We previously demonstrated the predictive value of the platform by correlation of ex vivo sensitivity to clinical chemotherapy responses of ovarian cancer patients. Assay feasibility was also established for NSCLC, mesothelioma and bladder cancer. The two-week timeline enables its application in clinical practice. Quantifying ex vivo immunotherapy sensitivity will facilitate improved patient stratification for standard of care and novel treatments. Clinical trials are currently ongoing to establish the correlation of the assay with patients' response to immunotherapy. Citation Format: Lieke Ceton, Esmee Koedoot, Timothy Sijsenaar, Marta Montero Garcia, Fanny Grillet, Jurrian van der Valk, Klaus Weber, Roman Schoenauer, Katrin Hufnagel, Ronny Schmidt, Nadine Stroh, Henning Boekhoff, Cor de Kroon, Anne van Altena, Dieudonné van der Meer, Willemijn Vader, Nelleke Ottevanger, Judith Kroep. Interpretation of patient-specific ex vivo immunotherapy response for ovarian cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr PR001.

EFHD1 expression is correlated with tumor-infiltrating neutrophils and predicts prognosis in gastric cancer

BackgroundGastric cancer (GC) ranks third in terms of mortality worldwide. The tumor microenvironment is critical for the progression of gastric cancer. This study investigated the association between EF-hand domain containing 1 (EFHD1) expression and its clinical significance in the tumor microenvironment (TME) of gastric cancer. MethodsWe used bioinformatic analyses to assess the relevance of EFHD1 mRNA in the TME of gastric carcinoma tissues and its relationship with clinical features. Therefore, we performed multiplex immunohistochemistry analyses to determine the potential role of the EFHD1 protein in the TME of gastric cancer. ResultsEFHD1 expression increased dramatically in gastric cancer tissues compared to levels in non-cancerous tissue samples (t = 6.246, P < 0.001). The EFHD1 protein presentation was associated with invasion depth (χ2 = 19.120, P < 0.001) and TNM stages (χ2 = 14.468, P = 0.002). Notably, EFHD1 protein expression was significantly related to CD66b + neutrophil infiltration of the intratumoral (r = 0.420, P < 0.001) and stromal (r = 0.367, P < 0.001) TME in gastric cancer. Additionally, Cox regression analysis revealed that EFHD1 was an independent prognostic predictor (hazard ratio [HR] = 2.262, P < 0.001) in patients with gastric cancer. ConclusionsOur study revealed the pattern of EFHD1 overexpression in the TME of patients with gastric cancer and demonstrated its utility as a biomarker for unfavorable clinical outcomes, thereby providing a potential immunotherapy target.

High PD-L1 Expression Correlates with an Immunosuppressive Tumour Immune Microenvironment and Worse Prognosis in ALK-Rearranged Non-Small Cell Lung Cancer.

High tumour programmed cell death-ligand 1 (PD-L1) expression is associated with poor progression-free survival (PFS) after tyrosine kinase inhibitor (TKI) therapy in ALK-rearranged non-small cell lung cancer (NSCLC). However, the characteristics of the tumour microenvironment (TME) and their prognostic values in ALK-rearranged NSCLC are unknown. Here, we collected tumour tissues from pretreated ALK-rearranged NSCLC patients, immunohistochemical staining was used to assess PD-L1 expression, and tumour-infiltrating immune cells were determined via multiplex immunofluorescence staining (mIF). Our data showed that the median values of PFS for the high PD-L1 group and low PD-L1 group who received ALK-TKI treatment were 4.4 and 16.4 months, respectively (p = 0.008). The median overall survival (OS) of the two groups was 24.0 months and not reached, respectively (p = 0.021). Via univariate and multivariate analyses, a high PD-L1 expression and a worse ECOG PS were determined to be independent prognostic factors of OS (HR = 3.35, 95% CI: 1.23-9.11, p = 0.018; HR = 6.42, 95% CI: 1.45-28.44, p = 0.014, respectively). In addition, the high PD-L1 group had increased Tregs and exhausted CD8+ T cells in both the tumour and stroma (all p < 0.05). High PD-L1 expression was an adverse predictive and prognostic biomarker for ALK-rearranged NSCLC. The characteristics of the TME in patients with high PD-L1 expression were shown to have an immunosuppressive status.

Distribution characteristics and clinical significance of infiltrating Tcells in the tumor microenvironment of pancreatic cancer.

Tumor-infiltrating lymphocytes (TILs) are important components of the tumor microenvironment (TME). However, the distribution characteristics of TILs and their significance in pancreatic cancer (PC) remain largely unexplored. The levels of TILs, including the total number of T cells, cluster of differentiation (CD)4+ T cells, CD8+ cytotoxic T lymphocytes (CTLs), regulatory T-cells (Tregs), programmed cell death protein 1+ T cells and programmed cell death ligand 1 (PD-L1)+ T cells, in the TME of patients with PC were detected using multiple fluorescence immunohistochemistry. The associations between the number of TILs and the clinicopathological characteristics were investigated using χ2 tests. In addition, Kaplan-Meier survival and Cox regression analyses were used to assess the prognostic value of these TIL types. Compared with paracancerous tissues, in PC tissues, the proportions of total T cells, CD4+ T cells and CD8+ CTLs were markedly decreased, while those of Tregs and PD-L1+ T cells were significantly increased. The levels of CD4+ T cell and CD8+ CTL infiltrates were inversely associated with tumor differentiation. Higher infiltrates of Tregs and PD-L1+ T cells were closely associated with advanced N and TNM stages. It is important to note that the infiltrates of total T cells, CD4+ T cells, Tregs and PD-L1+ T cells in the TME were independent risk factors for the prognosis of PC. PC was characterized by an immunosuppressive TME with a decrease in the number of CD4+ T cells and CD8+ CTLs, and an increase in the number of Tregs and PD-L1+ T cells. Overall, the number of total T cells, CD4+ T cells, Tregs and PD-L1+ T cells in the TME was a potential predictive marker for the prognosis of PC.

A novel population of CD103-expressing CD56 +regulatory ILCs suppresses intratumoural T cells and are associated with poor prognosis in patients with ovarian carcinoma

Abstract Regulatory innate lymphoid cells (ILCregs) are an emerging family of immunoregulatory cells that suppress innate and adaptive immunity in the context of diseases, including cancer. However, there is currently a lack of lineage-defining surface markers or transcription factors (TFs) that distinguishes ILCregs from other subsets of ILCs. Moreover, the functional role of ILCregs within the tumour microenvironment (TME) has not been well established. In this study, we uncovered a novel population of CD103-expressing CD56 +ILCregs within the TME that correlated with poor recurrent-free survival (RFS) in patients with epithelial ovarian carcinoma (EOC). CD103 +ILCregs expressed distinct surface markers and TFs that distinguishes them from canonical CD56 +natural killer (NK) cells. Moreover, intratumoural CD103 +ILCregs expressed markers (i.e., CD39, CD69, CD101, TIGIT) and transcriptomic profiles that are shared with Tregs, suggesting that they may have immunoregulatory properties. We found that ascites-derived TGF-β drives NK cell conversion into CD103 +ILCs that can suppress autologous CD4 +T cells in vitro. Furthermore, intratumoural CD103 +ILCregs suppressed autologous CD8 +T cells in vitro. Finally, we found that the abundance of CD103 +ILCregs in the TME were associated with reduced levels of both activated CD4 +T cells and CD8 +T cells. Overall, we have identified CD103 +ILCregs as distinct immunoregulatory cells that suppresses T cells within the TME of patients with EOC. Further untangling of the complex networks of immune regulation, including ILCregs, may give rise to novel therapeutic targets to enhance anti-tumour immunity and improve clinical response rates to immunotherapies. This work was supported by a CIHR foundation award (CIHR FDN #143220), a TRANSCAN CIHR grant (CIHR – TRN #184713), a TRI grant from the Ontario Institute for Cancer Research (TRI OICR GCS #108796), and the Terry Fox Research Institute (TFRI-iTNT #1060). This project was also generously funded in memory of Mr. JIM JoTak under the Canadian Cancer Society (CCSRI #706152).

Characteristics of immune-infiltrating cells in the tumor microenvironment of appendiceal cancer with peritoneal disease.

217 Background: Appendiceal cancers (AC) are rare, associated with peritoneal metastases, and respond poorly to current systemic treatments. There are limited studies on the characteristics and prognostic impact of infiltrating immune cells within the tumour microenvironment (TME) of AC with peritoneal metastases. Infiltrating immune cells are associated with survival outcomes and predict the effectiveness of immunotherapies in solid tumours. Different definitions have been developed to describe infiltrating immune cells and associated structures such as tertiary lymphoid aggregates (TLS). The aim of our study was to describe the immune TME in patients with AC peritoneal metastases to understand mechanisms of sensitivity and resistance to chemoimmunotherapies. Methods: Fresh tissue was collected during cytoreductive surgery from consenting patients with AC with peritoneal disease (Jul 2020-Feb 2022). Uncultured Day 0 tissues were fixed in formalin prior to paraffin embedding (FFPE). Haematoxylin and eosin (H&amp;E) staining was performed on sections of FFPE tissue. Sections were evaluated by light microscopy for the presence of immune cells based on morphological appearance. Patterns of infiltrating immune cells were classified based on location (peritumoural, intratumoural, perimucinous, stromal), and aggregation (none, immature, mature). Immune cells forming aggregates were counted and the diameter of aggregates measured using QuPath. Results: We evaluated 25 patients with AC peritoneal disease during the study period. Immune cells were detected in tissues from all except 3 patients; 16 cases (78 immune areas) were low grade (LG) disease of primary appendiceal mucinous neoplasms, and 6 cases (29 immune areas) were high grade (HG) from primary appendiceal adenocarcinomas (Table). Immune cell aggregates had a median diameter of 209 mm (75-491) and median cell count of 892 cells (46-6490). Conclusions: This study represents the first formal description and characterisation of infiltrating immune cells in appendiceal cancer peritoneal metastases. Perimucinous immune cells were not observed in HG disease despite presence of mucin. Intratumoural immune cells were not observed in LG disease, consistent with these tumours being more resistant to chemotherapy. We plan ongoing work correlating the immune features with clinical outcomes alongside immunohistochemical and transcriptomic characterisation of the aggregates. [Table: see text]

A bioinformatic analysis of the role of TP53 status on the infiltration of CD8+ T cells into the tumor microenvironment.

CD8+ T cells play basic roles in the immune system in a tumor microenvironment (TME) to fight cancer. Several reports have suggested signs of the involvement of tumor protein p53 (TP53) in a complex immune system network. Moreover, our previous research indicated that TP53 orchestrates the polarization and infiltration of macrophages into the TME. In the present study, the clinical function of TP53 status (wild/mutant) in CD8+ T cell infiltration was assessed using more than 10,000 The Cancer Genome Atlas (TCGA) samples from 30 cancer types through Tumor Immune Estimation (TIMER). Our investigation revealed that CD8+ T cell infiltration was higher in head and neck squamous cell carcinoma (HNSC) and uterine corpus endometrial carcinoma (UCEC) patients with wild-type TP53 than in those with mutant TP53. Wild-type TP53 conferred a good prognosis for HNSC and UCEC (P<0.05). In contrast, CD8+ T cell infiltration in lung adenocarcinoma (LUAD) patients with wild-type TP53 was much lower than in those with mutant TP53. Notably, clinical outcomes for LUAD with wild-type TP53 were poor (P<0.05). This study was the first to provide insights into the novel association of TP53 with CD8+ T cells infiltration in the TME in patients with HNSC, LUAD, and UCEC. Therefore, TP53 status acts as a prognostic marker, and this can be used as a basis to further study the effect of targeting TP53 in these patients. Furthermore, our study found that TP53 status was a reliable predictive factor and therapeutic target in patients with HNSC and UCEC.

The crosstalk within the breast tumor microenvironment in type II diabetes: Implications for cancer disparities.

Obesity-driven (type 2) diabetes (T2D), the most common metabolic disorder, both increases the incidence of all molecular subtypes of breast cancer and decreases survival in postmenopausal women. Despite this clear link, T2D and the associated dysfunction of diverse tissues is often not considered during the standard of care practices in oncology and, moreover, is treated as exclusion criteria for many emerging clinical trials. These guidelines have caused the biological mechanisms that associate T2D and breast cancer to be understudied. Recently, it has been illustrated that the breast tumor microenvironment (TME) composition and architecture, specifically the surrounding cellular and extracellular structures, dictate tumor progression and are directly relevant for clinical outcomes. In addition to the epithelial cancer cell fraction, the breast TME is predominantly made up of cancer-associated fibroblasts, adipocytes, and is often infiltrated by immune cells. During T2D, signal transduction among these cell types is aberrant, resulting in a dysfunctional breast TME that communicates with nearby cancer cells to promote oncogenic processes, cancer stem-like cell formation, pro-metastatic behavior and increase the risk of recurrence. As these cells are non-malignant, despite their signaling abnormalities, data concerning their function is never captured in DNA mutational databases, thus we have limited insight into mechanism from publicly available datasets. We suggest that abnormal adipocyte and immune cell exhaustion within the breast TME in patients with obesity and metabolic disease may elicit greater transcriptional plasticity and cellular heterogeneity within the expanding population of malignant epithelial cells, compared to the breast TME of a non-obese, metabolically normal patient. These challenges are particularly relevant to cancer disparities settings where the fraction of patients seen within the breast medical oncology practice also present with co-morbid obesity and metabolic disease. Within this review, we characterize the changes to the breast TME during T2D and raise urgent molecular, cellular and translational questions that warrant further study, considering the growing prevalence of T2D worldwide.

Characteristics of the immune microenvironment and their clinical significance in non-small cell lung cancer patients with ALK-rearranged mutation.

BackgroundAlthough immune checkpoint inhibitors (ICIs) are one of the most important treatments for advanced-stage non-small-cell lung cancer (NSCLC), NSCLC patients with ALK-rearranged usually don’t obtain a clinical benefit. The reason may be related to the unique tumor microenvironment (TME). We evaluated the characteristics of immune biomarkers of the TME and their prognostic value in ALK-rearranged NSCLC.MethodsTumor samples from patients with ALK-rearranged (N = 39) and EGFR- (N = 40)/KRAS- (N = 30) mutated NSCLC were collected. Immunohistochemistry (IHC) was used to assess the expression of 9 tumor immune markers as well as 6 immune markers of tumor-infiltrating cells. To research the TME of ALK-rearranged NSCLC, EGFR/KRAS-positive patients were used as controls. Furthermore, the correlation between the efficacy and prognosis of patients with advanced-stage (IIIC-IV) ALK rearrangements treated with targeted drugs was analyzed in terms of the TME.ResultsThe proportion of PD-L1+ tumors was lower in ALK-positive NSCLC than in KRAS-positive NSCLC. Besides, the proportion of T cells expressing TIM-3-CD8+ (15.38%), CTLA4-CD8+ (12.82%), LAG3-CD8+ (33.33%) and PD-1-CD8+ (2.56%) in ALK-positive NSCLC was lower than that in EGFR/KRAS-positive NSCLC. The expression of CD3, CD8 T cells and CD20 B cells was lower in ALK-positive NSCLC than in KRAS-positive NSCLC (p < 0.0001, < 0.005, and < 0.001, respectively). Nevertheless, the level of CD4 helper T cells was higher in ALK-positive NSCLC than in EGFR/KRAS-positive NSCLC (p < 0.0001 and p < 0.05, respectively). The repression of TIM3 was higher in ALK-positive NSCLC than in KRAS-positive NSCLC (p < 0.001). In addition, our data showed that high expression of PD-L1 (HR = 0.177, 95% CI 0.038–0.852, p = 0.027) and CTLA4 (HR = 0.196, 95% CI 0.041–0.947, p = 0.043) was related to lower OS in advanced-stage ALK- rearranged NSCLC patients treated with ALK tyrosine kinase inhibitors (TKIs).ConclusionsImmunosuppressive status was characteristic of the TME in patients with ALK-positive NSCLC compared with EGFR/KRAS-positive NSCLC. High expression of PD-L1 and CTLA4 was an adverse prognostic factor in advanced-stage ALK-rearranged NSCLC patients treated with ALK-TKIs. Immunotherapy for ALK-rearranged patients requires further exploration and validation by clinical trials.

Identification of a Prognostic Microenvironment-Related Gene Signature in Glioblastoma Patients Treated with Carmustine Wafers.

Simple SummaryCarmustine wafer (CW) implantation into the resection cavity of patients operated for glioblastoma (GBM) was approved as an adjuvant treatment before the Stupp Protocol. Although contrasting clinical results limited its use, our retrospective study on 116 GBM treated with CW showed a significant benefit in terms of OS in a subgroup of patients. Since GBM growth, progression, and drug resistance are supported by the surrounding environment, and since the tumor microenvironment (TME) is the source of druggable targets, we hypothesized that the TME of patients who benefited from CW could have different characteristics compared to patients who did not show any advantage. Exploiting a human in vitro model of glioma microenvironment and a transcriptomic approach, we found a different gene signature suggesting the importance of developing in vitro models that mimic the properties of human cancers and that can help to study individual patient characteristics at the cellular and molecular level.Despite the state-of-the-art treatment, patients diagnosed with glioblastoma (GBM) have a median overall survival (OS) of 14 months. The insertion of carmustine wafers (CWs) into the resection cavity as adjuvant treatment represents a promising option, although its use has been limited due to contrasting clinical results. Our retrospective evaluation of CW efficacy showed a significant improvement in terms of OS in a subgroup of patients. Given the crucial role of the tumor microenvironment (TME) in GBM progression and response to therapy, we hypothesized that the TME of patients who benefited from CW could have different properties compared to that of patients who did not show any advantage. Using an in vitro model of the glioma microenvironment, represented by glioma-associated-stem cells (GASC), we performed a transcriptomic analysis of GASC isolated from tumors of patients responsive and not responsive to CW to identify differentially expressed genes. We found different transcriptomic profiles, and we identified four genes, specifically down-regulated in GASC isolated from long-term survivors, correlated with clinical data deposited in the TCGA–GBM dataset. Our results highlight that studying the in vitro properties of patient-specific glioma microenvironments can help to identify molecular determinants potentially prognostic for patients treated with CW.

Abstract 2814: Anti-CAIX Immune Restoring (IR) CAR-T cells display superior antitumor activity and reverse immunosuppressive TME in a humanized ccRCC orthotopic mouse model

Abstract Chimeric Antigen Receptor (CAR) T cell therapy is a new type of “living drug” that has proven to be a powerful, clinically translatable immunotherapy for hematologic malignancies. To date, there are five CAR-T products approved by FDA, four CD19 targeted CAR-T cells, and one targeting B-cell maturation antigen (BCMA). However, this success has not yet been transferred to solid tumors. A major challenge is the immunosuppressive tumor microenvironment (TME). Development of immunotherapies has traditionally been hampered by discrepancies observed between in vitro and in vivo studies and actual clinical trial outcomes. The lack of clinically relevant mouse models for human immunotherapy testing is often seen as the primary cause. Existing clear cell renal cell carcinoma (ccRCC) in vivo models poorly recapitulate the tumor microenvironment (TME). Here we report a ccRCC orthotopic humanized NSG-SGM3 mouse model (ccRCC-hNSG-SGM3) with reconstituted human lymphocytes and bearing human ccRCC skrc-59 cells under the kidney capsule. Human leukocyte antigen (HLA) matched CD34+ human stem cells were used for the humanization to reduce T cell alloreactivity against skrc-59 human ccRCC cells. Tumors were harvested, sorted for CD45+ tumor infiltrating leukocytes (TILs) and single cell RNA sequencing (scRNAseq) was performed to profile the TME in ccRCC-hNSG-SGM3. By comparing to patient data from prospective clinical trials of the anti-PD-1 monoclonal antibody (mAb) nivolumab in advanced ccRCC, the results demonstrated that CD45+ TILs from ccRCC-hNSG-SGM3 reconstitute most CD45+ cell types, including dendritic cells, exhausted CD8 T cells, and regulatory T cells (Tregs), that are observed in advanced ccRCC patient TME. Furthermore, we generated HLA matched Immune Restoring (IR) CAR-T cells which can secrete anti-PD-L1 monoclonal antibody (mAb) locally to restore active antitumor immunity, and we assessed the efficacy and safety of IR CAR-T cells in this model. Anti-CAIX CAR-T cells armored with anti-PD-L1 mAb showed superior efficacy in tumor regression and significantly decreased TIL exhaustion compared to irrelevant CAR or irrelevant payload in this model. In addition, in situ hybridization (ISH) results showed CAR-T cells infiltration in tumor but no CAR-T cells were observed in normal tissues. In summary, the ccRCC-hNSG-SGM3 system is able to model the advanced ccRCC TME and provides a powerful tool for ccRCC TME study and immunotherapy assessment. IR CAR-T cells exhibited superior tumor regression and reversed immunosuppressive TME in humanized mice. Citation Format: Yufei Wang, Alicia Buck, Marion Grimaud, Aedin Culhane, David Braun, Sreekumar Kodangattil, Cecile Razimbaud, Matthew Chang, Atef Fayed, Audrey Apollon, Gabriella Kastrunes, Luann Zerefa, Brandon Piel, Elena Ivanova, Dennis Bonal, Kristen Jones, Quang-De Nguyen, Zhu Zhu, Kevin Wei, Nicholas Hayden, Madison O'Donnell, Ying Huang, Rebecca Jenning, Miriam Ficial, Maura Aliezah Sticco-Ivins, Sabina Signoretti, Catherine Wu, Toni Choueiri, Jon Wee, Cloud Paweletz, David A. Barbie, Gordon Freeman, Wayne A. Marasco. Anti-CAIX Immune Restoring (IR) CAR-T cells display superior antitumor activity and reverse immunosuppressive TME in a humanized ccRCC orthotopic mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2814.

Analysis of the Heterogeneity of the Tumor Microenvironment and the Prognosis and Immunotherapy Response of Different Immune Subtypes in Hepatocellular Carcinoma.

Purpose The current clinical classification of hepatocellular carcinoma (HCC) cannot well predict the patient's possible response to the treatment plan, nor can it predict the patient's prognosis. We use the gene expression patterns of patients with hepatocellular carcinoma to reveal the heterogeneity of hepatocellular carcinoma and analyze the differences in prognosis and immunotherapy response of different immune subtypes. Methods Firstly, using the hepatocellular carcinoma expression profile data of TCGA, combined with the single sample gene set enrichment analysis (ssGSEA) algorithm, the immune enrichment of the patient's tumor microenvironment was analyzed. Subsequently, the spectral clustering algorithm was used to extract different classifications, and the cohort of hepatocellular carcinoma was divided into 3 subtypes, and the correlation between immune subtypes and clinical characteristics and survival prognosis was established. The patient's risk index is obtained through the prognostic prediction model, suggesting the correlation between the risk index and various types of immune cells. Results We can divide the liver cancer cohort into three subtypes: stromal cell activated immune-enriched type (A-IS), general immune-enriched type (N-IS), and non-immune-enriched type (non-IS). The 3-year survival rate of TCGA's A-IS is higher than that of N-IS and non-IS, and the three components are significantly different (p = 0.017). The 3-year survival rates of ICGC's A-IS and N-IS groups were higher than those of the non-IS group. The analysis of the correlation between the risk index and immune cells showed that the patient's disease risk was significantly positively correlated with cancer-associated fibroblast (CAF) stimulated cell, activated stroma cell, and anti-PD-1 resistant cell. Conclusion The tumor gene expression characteristics of patients with hepatocellular carcinoma can be used as a basis for clinical patient classification. Different immune subtypes are closely related to survival prognosis. Different immune cell states of patients may lead to different disease risk levels. All these provide important references for the clinical identification and prognosis prediction of hepatocellular carcinoma.