Immunosuppressive Tumor Microenvironment Research Articles

Biomimetic “nano-spears” for CAFs-targeting: splintered three “shields” with enhanced cisplatin anti-TNBC efficiency

The treatment dilemma of triple-negative breast cancer (TNBC) revolves around drug resistance and metastasis. Cancer-associated fibroblasts (CAFs) contribute to cisplatin (Cis) resistance and further metastasis in TNBC, making TNBC a difficult-to-treat disease. The dense stromal barrier which restricts drug delivery, invasive phenotype of tumor cells, and immunosuppressive tumor microenvironment (TME) induced by CAFs serve as three “shields” for TNBC against Cis therapy. Here, we designed a silybin-loaded biomimetic nanoparticle coated with anisamide-modified red blood cell membrane (ARm@SNP) as a “nanospear” for CAFs-targeting, which could shatter the “shields” and significantly exhibit inhibitory effect on 4T1 cells in combination with Cis both in vitro and in vivo. The ARm@SNP/Cis elicited 4T1 tumor growth arrest and destroyed three “shields” as follows: disintegrating the stromal barrier by inhibiting blood vessels growth and the expression of fibronectin; decreasing 4T1 cell invasion and metastasis by affecting the TGF-β/Twist/EMT pathway which impeded EMT activation; reversing the immunosuppressive microenvironment by increasing the activity and infiltration of immunocompetent cells. Based on CAFs-targeting, ARm@SNP reversed the resistance of Cis, remodeled the TME and inhibited invasion and metastasis while significantly improving the therapeutic effect of Cis on 4T1 tumor-bearing mice, providing a promising approach for treating intractable TNBC.

Challenges and opportunities for cancer stem cell-targeted immunotherapies include immune checkpoint inhibitor, cancer stem cell-dendritic cell vaccine, chimeric antigen receptor immune cells, and modified exosomes.

Cancer stem cells (CSCs) are associated with the tumor microenvironment (TME). CSCs induce tumorigenesis, tumor recurrence and progression, and resistance to standard therapies. Indeed, CSCs pose an increasing challenge to current cancer therapy due to their stemness or self-renewal properties. The molecular and cellular interactions between heterogeneous CSCs and surrounding TME components and tumor-supporting immune cells show synergistic effects toward treatment failure. In the immunosuppressive TME, CSCs express various immunoregulatory proteins, growth factors, metabolites and cytokines, and also produce exosomes, a type of extracellular vesicles, to protect themselves from host immune surveillance. Among these, the identification and application of CSC-derived exosomes could be considered for the development of therapeutic approaches to eliminate CSCs or cancer, in addition to targeting the modulators that remodel the composition of the TME, as reviewed in this study. Here, we introduce the role of CSCs and how their interaction with TME complicates immunotherapies, and then present the CSC-based immunotherapy and the limitation of these therapies. We describe the biology and role of tumor/CSC-derived exosomes that induce immune suppression in the TME, and finally, introduce their potentials for the development of CSC-based targeted immunotherapy in the future.

Neuroinflammation in Glioblastoma: The Role of the Microenvironment in Tumour Progression.

Glioblastoma (GBM) stands as the most aggressive and lethal among the main types of primary brain tumors. It exhibits malignant growth, infiltrating the brain tissue, and displaying resistance toward treatment. GBM is a complex disease characterized by high degrees of heterogeneity. During tumour growth, microglia and astrocytes, among other cells, infiltrate the tumour microenvironment and contribute extensively to gliomagenesis. Tumour-associated macrophages (TAMs), either of peripheral origin or representing brain-intrinsic microglia, are the most numerous nonneoplastic populations in the tumour microenvironment in GBM. The complex heterogeneous nature of GBM cells is facilitated by the local inflammatory tumour microenvironment, which mostly induces tumour aggressiveness and drug resistance. The immunosuppressive tumour microenvironment of GBM provides multiple pathways for tumour immune evasion, contributing to tumour progression. Additionally, TAMs and astrocytes can contribute to tumour progression through the release of cytokines and activation of signalling pathways. In this review, we summarize the role of the microenvironment in GBM progression, focusing on neuroinflammation. These recent advancements in research of the microenvironment hold the potential to offer a promising approach to the treatment of GBM in the coming times.

Overcoming resistance to immune checkpoint blockade in liver cancer - stronger together?

Primary liver cancer, represented mainly by hepatocellular carcinoma (HCC) and intrahepatic cholangiocellular carcinoma (CCA), is one of the most common and deadliest tumors worldwide. While surgical resection or liver transplantation are the best option in early disease stages, these tumors often present in advanced stages and systemic treatment is required to improve survival time. The emergence of immune checkpoint inhibitor therapy has had a positive impact especially on the treatment of advanced cancers, thereby establishing immunotherapy as part of first-line treatment in HCC and CCA. Nevertheless, low response rates reflect on the usually cold or immunosuppressed tumor microenvironment of primary liver cancer. In this review, we aim to summarize mechanisms of resistance leading to tumor immune escape with a special focus on the composition of tumor microenvironment in both HCC and CCA, also reflecting on recent important developments in ICI combination therapy. Furthermore, we discuss how combination of immune checkpoint inhibitors with established primary liver cancer treatments (e.g. multikinase inhibitors and chemotherapy) as well as more complex combinations with state-of-the-art therapeutic concepts may re-shape the tumor microenvironment, leading to higher response rates and long-lasting anti-tumor immunity for primary liver cancer patients.

Janus kinase inhibitor overcomes resistance to immune checkpoint inhibitor treatment in peritoneal dissemination of gastric cancer in C57BL/6J mice.

Cancer immunotherapy aims to unleash the immune system's potential against cancer cells, providing sustained relief for tumors responsive to immune checkpoint inhibitors (ICIs). While promising in gastric cancer (GC) trials, the efficacy of ICIs diminishes in the context of peritoneal dissemination. Our objective is to identify strategies to enhance the impact of ICI treatment specifically for cases involving peritoneal dissemination in GC. The therapeutic efficacy of anti-PD1, CTLA4 treatment alone, or in combination was assessed using the YTN16 peritoneal dissemination tumor model. Peritoneum and peritoneal exudate cells were collected for subsequent analysis. Immunohistochemical staining, flow cytometry, and bulk RNA-sequence analyses were conducted to evaluate the tumor microenvironment (TME). A Janus kinase inhibitor (JAKi) was introduced based on the pathway analysis results. Anti-PD1 and anti-CTLA4 combination treatment (dual ICI treatment) demonstrated therapeutic efficacy in certain mice, primarily mediated by CD8 + T cells. However, in mice resistant to dual ICI treatment, even with CD8 + T cell infiltration, most of the T cells exhibited anexhaustion phenotype. Notably, resistant tumors displayed abnormal activation of the Janus Kinase-Signal Transducer and Activator of Transcription (JAK-STAT) pathway compared to the untreated group, with observed infiltration of macrophages, neutrophils, and Tregs in the TME. The concurrent administration of JAKi rescued CD8 + T cells function and reshaped the immunosuppressive TME, resulting in enhanced efficacy of the dual ICI treatment. Dual ICI treatment exerts its anti-tumor effects by increasing tumor-specific CD8 + T cell infiltration, and the addition of JAKi further improves ICI resistance by reshaping the immunosuppressive TME.

In Situ Colonization of Trojan‐Yeast for Targeted Glucose Starvation and Reconstruction of Tumor Immune Environment

AbstractGlucose is an important energy source for living cells. Particularly, most tumor cells use glycolysis to harness energy for their fast growth, invasion and metastasis even under aerobic conditions. Thus, reduction of the glucose level in cancer can lead to suppression of tumor growth. Here, macrophage membrane dressed yeast, Trojan M‐yeast, is developed, via coating the surface of yeast with macrophage membrane, for targeted accumulation and suppression of tumor by glucose starvation. Due to the inflammatory homing effects of macrophage membrane, M‐yeast efficiently target and colonize in the inflammatory tumor site, where they compete with tumor cells for glucose consumption, thereby disrupting glycolysis of cancer cells, resulting in the reduction of lactate accumulation and reversal of the acidosis of tumor microenvironment. Subsequently, the apoptotic tumor cells and yeast promote dendritic cell maturation, increase tumor‐infiltrating cytotoxic T lymphocytes. Meanwhile, ethanol and acetaldehyde produced by yeast metabolism of glucose can re‐polarize tumor associated macrophages (TAMs) to the anti‐tumor phenotype (M1), thus reprogramming the tumor immunosuppressive microenvironment, leading to synergistic tumor suppression together with glucose starvation, which is different from traditional chemotherapy and immunotherapy. M‐yeast exhibits promising targeted cancer therapy with a decent safety profile. This work may provide new insights as well as a new paradigm for yeast‐based cancer therapy.

Bioconjugated Antibody-Trojan Immune Converter Enhance Cancer Immunotherapy with Minimized Toxicity by Programmed Two-Step Immunomodulation of Myeloid Cells.

Current immune checkpoint blockade therapy (ICBT) predominantly targets T cells to harness the antitumor effects of adaptive immune system. However, the effectiveness of ICBT is reduced by immunosuppressive innate myeloid cells in tumor microenvironments (TMEs). Toll-like receptor 7/8 agonists (TLR7/8a) are often used to address this problem because they can reprogram myeloid-derived suppressor cells (MDSCs) and tumor-associated M2 macrophages, and boost dendritic cell (DC)-based T-cell generation; however, the systemic toxicity of TLR7/8a limits its clinical translation. Here, to address this limitation and utilize the effectiveness of TLR7/8a, this work suggests a programmed two-step activation strategy via Antibody-Trojan Immune Converter Conjugates (ATICC) that specifically targets myeloid cells by anti-SIRPα followed by reactivation of transiently inactivated Trojan TLR7/8a after antibody-mediated endocytosis. ATICC blocks the CD47-SIRPα ("don't eat me" signal), enhances phagocytosis, reprograms M2 macrophages and MDSCs,and increases cross-presentation by DCs, resulting in antigen-specific CD8+ T-cell generation in tumor-draining lymph nodes and TME while minimizing systemic toxicity. The local or systemic administration of ATICC improves ICBT responsiveness through reprogramming of the immunosuppressive TME, increased infiltration of antigen-specific CD8+ T cells,and antibody-dependent cellular phagocytosis. These results highlight the programmed and target immunomodulation via ATICC could enhance cancer immunotherapy with minimized systemic toxicities.

Single-Cell RNA Sequencing Identifies Crucial Genes Influencing the Polarization of Tumor-Associated Macrophages in Liver Cancer

Background. In the context of hepatocellular carcinoma (HCC), tumor-associated macrophages (TAMs) are pivotal for the immunosuppressive nature of the tumor microenvironment (TME). This investigation delves into the functional transformations of TAMs within the TME by leveraging single-cell transcriptomics to pinpoint critical genes influencing TAM subset polarization. Methods. We procured single-cell and bulk transcriptomic data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA), implementing quality assurance, dimensional reduction, clustering, and annotation on the single-cell sequencing data. To examine cellular interactions, CellChat was utilized, while single-cell regulatory network inference and clustering (SCENIC) was applied to deduce transcription factors (TFs) and their associated targets. Through gene enrichment, survival, and immune infiltration correlation analyses, we sought to pinpoint and validate influential genes. A TAM model under HCC conditions was then established to confirm the expression levels of these key genes. Results. Our analysis encompassed 74,742 cells and 23,110 genes. Through postdimensional reduction and clustering, we identified seven distinct cell types and nine TAM subtypes. Analysis via CellChat highlighted a predominance of M2-phenotype-inclined TAM subsets within the tumor’s core. SCENIC pinpointed the transcription factor PRDM1 and its target genes as pivotal in this region. Further analysis indicated these genes’ involvement in macrophage polarization. Employing trajectory analysis, survival analysis, and immune infiltration correlation, we scrutinized and validated genes likely directing M2 polarization. Experimental validation confirmed PRDM1’s heightened expression in TAMs conditioned by HCC. Conclusions. Our findings suggest the PRDM1 gene is a key regulator of M2 macrophage polarization, contributing to the immunosuppressive TME in HCC.

Simultaneous targeting of Tim3 and A2a receptors modulates MSLN-CAR T cell antitumor function in a human cervical tumor xenograft model

IntroductionChimeric antigen receptor (CAR) T cell therapy has transformed the treatment of hematological malignancies. However, its efficacy in solid tumors is limited by the immunosuppressive tumor microenvironment that compromises CAR T cell antitumor function in clinical settings. To overcome this challenge, researchers have investigated the potential of inhibiting specific immune checkpoint receptors, including A2aR (Adenosine A2 Receptor) and Tim3 (T cell immunoglobulin and mucin domain-containing protein 3), to enhance CAR T cell function. In this study, we evaluated the impact of genetic targeting of Tim3 and A2a receptors on the antitumor function of human mesothelin-specific CAR T cells (MSLN-CAR) in vitro and in vivo.MethodsSecond-generation anti-mesothelin CAR T cells were produced using standard cellular and molecular techniques. A2aR-knockdown and/or Tim3- knockdown anti-mesothelin-CAR T cells were generated using shRNA-mediated gene silencing. The antitumor function of CAR T cells was evaluated by measuring cytokine production, proliferation, and cytotoxicity in vitro through coculture with cervical cancer cells (HeLa cell line). To evaluate in vivo antitumor efficacy of manufactured CAR T cells, tumor growth and mouse survival were monitored in a human cervical cancer xenograft model.ResultsIn vitro experiments demonstrated that knockdown of A2aR alone or in combination with Tim3 significantly improved CAR T cell proliferation, cytokine production, and cytotoxicity in presence of tumor cells in an antigen-specific manner. Furthermore, in the humanized xenograft model, both double knockdown CAR T cells and control CAR T cells could effectively control tumor growth. However, single knockdown CAR T cells were associated with reduced survival in miceConclusionThese findings highlight the potential of concomitant genetic targeting of Tim3 and A2a receptors to augment the efficacy of CAR T cell therapy in solid tumors. Nevertheless, caution should be exercised in light of our observation of decreased survival in mice treated with single knockdown MSLN-CAR T cells, emphasizing the need for careful efficacy considerations.

Targeted Clearance of Senescent Cells via Engineered Extracellular Vesicles Reprograms Tumor Immunosuppressive Microenvironment.

Unravelling the mechanisms for the immunosuppressive tumor microenvironment and developing corresponding therapeutic strategies are of great importance to improve the cancer immunotherapy. In this study, we have revealed that there are abundant senescent cells accumulated in the colon cancer tissue, which contributes greatly to the immunosuppressive microenvironment. Oral delivery of Dasatinib and Quercetin (D+Q) eliminates the senescent cells with compromised efficiency due to the poor tumor penetration and short half-life. To improve the efficacy of senescent cell clearance, we have developed an extracellular vesicle (EV)-based senolytic strategy. The engineered senolytic EVs have anti-GPNMB (a senescent cell surface marker) displayed on the surface and D+Q loaded on the membrane. In a syngeneic mouse model, senolytic EVs efficiently and selectively eradicate the senescent cells and in turn unleashes the antitumor immunity. With the antitumor immunity boosted, cancer growth is inhibited and the survival is prolonged. In summary, we here have illuminated that senescent cells contribute to the immunosuppressive microenvironment in colon cancer and proposed a novel strategy to conquer the problem by EV-based senolytics. This article is protected by copyright. All rights reserved.

Current progress of CAR-T-cell therapy for patients with multiple myeloma.

Currently available chimeric antigen receptor (CAR)-engineered T-cell therapies targeting B-cell maturation antigen (BCMA), namely, idecabtagene vicleucel and ciltacabtagene autoleucel, have shown marked efficacy against relapsed and refractory multiple myeloma. However, further improvement in CAR-T-cell function is warranted as most patients treated with these products eventually relapse due to various mechanisms such as antigen loss and T-cell dysfunction or disappearance. Strategies for improving CAR-T-cell function include targeting of dual antigens, enhancing cell longevity through genetic modification, and eliminating the immunosuppressive tumor microenvironment. Serious side effects can also occur after CAR-T-cell infusions. Although understanding of the molecular pathogenesis of cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome is growing, the unique movement disorder caused by BCMA-targeted therapy is less understood, and its molecular mechanisms must be further elucidated to establish better management strategies. In this article, we will review the current status of BCMA-targeting CAR-T-cell therapy. We will also highlight progress in the development of CAR-T cells targeting other antigens, as well as universal allogeneic CAR-T cells and bispecific antibodies.

Multiple Synergistic Effects of the Microglia Membrane-Bionic Nanoplatform on Mediate Tumor Microenvironment Remodeling to Amplify Glioblastoma Immunotherapy.

Glioblastoma (GBM) is a lethal brain tumor with high levels of malignancy. Most chemotherapy agents show serious systemic cytotoxicity and restricted delivery effectiveness due to the impediments of the blood-brain barrier (BBB). Immunotherapy has developed great potential for aggressive tumor treatments. Disappointingly, its efficacy against GBM is hindered by the immunosuppressive tumor microenvironment (TME) and BBB. Herein, a multiple synergistic immunotherapeutic strategy against GBM was developed based on the nanomaterial-biology interaction. We have demonstrated that this BM@MnP-BSA-aPD-1 can transverse the BBB and target the TME, resulting in amplified synergetic effects of metalloimmunotherapy and photothermal immunotherapy (PTT). The journey of this nanoformulation within the TME contributed to the activation of the stimulator of the interferon gene pathway, the initiation of the immunogenic cell death effect, and the inhibition of the programmed cell death-1/programmed cell death ligand 1 (PD-1/PD-L1) signaling axis. This nanomedicine revitalizes the immunosuppressive TME and evokes the cascade effect of antitumor immunity. Therefore, the combination of BM@MnP-BSA-aPD-1 and PTT without chemotherapeutics presents favorable benefits in anti-GBM immunotherapy and exhibits immense potential for clinical translational applications.

Novel lactylation-related signature to predict prognosis for pancreatic adenocarcinoma

BACKGROUND Lactate, previously considered a metabolic byproduct, is pivotal in cancer progression and maintaining the immunosuppressive tumor microenvironment. Further investigations confirmed that lactate is a primary regulator, introducing recently described post-translational modifications of histone and non-histone proteins, termed lysine lactylation. Pancreatic adenocarcinomas are characterized by increased glycolysis and lactate accumulation. However, our understanding of lactylation-related genes in pancreatic adenocarcinomas remains limited. AIM To construct a novel lactylation-related gene signature to predict the survival of patients with pancreatic cancer. METHODS RNA-seq and clinical data of pancreatic adenocarcinoma (PDAC) were obtained from the GTEx (Genotype-Tissue Expression) and TCGA (The Cancer Genome Atlas) databases via Xena Explorer, and GSE62452 datasets from GEO. Data on lactylation-related genes were obtained from publicly available sources. Differential expressed genes (DEGs) were acquired by using R package “DESeq2” in R. Univariate COX regression analysis, LASSO Cox and multivariate Cox regressions were produced to construct the lactylation-related prognostic model. Further analyses, including functional enrichment, ESTIMATE, and CIBERSORT, were performed to analyze immune status and treatment responses in patients with pancreatic cancer. PDAC and normal human cell lines were subjected to western blot analysis under lactic acid intervention; two PDAC cell lines with the most pronounced lactylation were selected. Subsequently, RT-PCR was employed to assess the expression of LRGs genes; SLC16A1, which showed the highest expression, was selected for further investigation. SLC16A1-mediated lactylation was analyzed by immunofluorescence, lactate production analysis, colony formation, transwell, and wound healing assays to investigate its role in promoting the proliferation and migration of PDAC cells. In vivo validation was performed using an established tumor model. RESULTS In this study, we successfully identified 10 differentially expressed lactylation-related genes (LRGs) with prognostic value. Subsequently, a lactylation-related signature was developed based on five OS-related lactylation-related genes (SLC16A1, HLA-DRB1, KCNN4, KIF23, and HPDL ) using Lasso Cox hazard regression analysis. Subsequently, we evaluated the clinical significance of the lactylation-related genes in pancreatic adenocarcinoma. A comprehensive examination of infiltrating immune cells and tumor mutation burden was conducted across different subgroups. Furthermore, we demonstrated that SLC16A1 modulates lactylation in pancreatic cancer cells through lactate transport. Both in vivo and in vitro experiments showed that decreasing SLC16A1 Level and its lactylation significantly inhibited tumor progression, indicating the potential of targeting the SLC16A1/ Lactylation-associated signaling pathway as a therapeutic strategy against pancreatic adenocarcinoma. CONCLUSION We constructed a novel lactylation-related prognostic signature to predict OS, immune status, and treatment response of patients with pancreatic adenocarcinoma, providing new strategic directions and antitumor immunotherapies.

CD24 is expressed in HNSCC and is correlated with a dampened immune response

Purpose:Recently, CD24 on tumor cells was identified as a phagocytic inhibitor contributing to an immunosuppressive tumor microenvironment via binding to Siglec-10 on macrophages. Head and neck squamous cell carcinoma (HNSCC) are highly immunogenic tumors, but little is known about the expression of CD24 in HNSCC. We aimed to evaluate the expression of CD24 and its binding partner Siglec-10 as well as the infiltration density of macrophages and CD8 positive T-cells. Material and methodsA previously described and characterized cohort of HNSCC (n = 156) was semiquantitatively analyzed by immunohistochemistry for CD24, Siglec-10, CD8, CD68, CD163 and CD80 expression. The expression data was correlated to clinico-pathological parameters. ResultsCD24 was expressed in 81.6 % of cases, showing an inverse correlation with the CD68 and CD8 infiltration density, indicating an immunosuppressive feature of CD24. Also, CD24 expression was higher in HNSCC with a negative HPV status. Nodal positive HNSCC showed significantly increased infiltration density of CD68+ cells. Furthermore, the cell density of CD68 and CD163 positive cells was associated with HPV/p16 positive HNSCC. ConclusionCD24 is commonly expressed in HNSCC and may contribute to an immunosuppressive tumor microenvironment in HNSCC. Its role as a putative therapy target should be clarified in further studies.

Synergistic antitumor immune response mediated by paclitaxel-conjugated nanohybrid oncolytic adenovirus with dendritic cell therapy

Dendritic cell (DC)-based vaccines have emerged as a promising strategy in cancer immunotherapy due to low toxicity. However, the therapeutic efficacy of DC as a monotherapy is insufficient due to highly immunosuppressive tumor environment. To address these limitations of DC as immunotherapeutic agent, we have developed a polymeric nanocomplex incorporating (1) oncolytic adenovirus (oAd) co-expressing interleukin (IL)-12 and granulocyte-macrophage colony-stimulating factor (GM-CSF) and (2) arginine-grafted bioreducible polymer with PEGylated paclitaxel (APP) to restore antitumor immune surveillance function in tumor milieu and potentiate immunostimulatory attributes of DC vaccine. Nanohybrid complex (oAd/APP) in combination with DC (oAd/APP+DC) induced superior expression level of antitumor cytokines (IL-12, GM-CSF, and interferon gamma) than either oAd/APP or DC monotherapy in tumor tissues, thus resulting in superior intratumoral infiltration of both endogenous and exogenous DCs. Furthermore, oAd/APP+DC treatment led superior migration of DC to secondary lymphoid organs, such as draining lymph nodes and spleen, in comparison with either monotherapy. Superior migration profile of DCs in oAd/APP+DC treatment group resulted in more prolific activation of tumor-specific T cells in these lymphoid organs and greater intratumoral infiltration of T cells. Additionally, oAd/APP+DC treatment led to lower subset of tumor infiltrating lymphocytes and splenocytes being immunosuppressive regulatory T cells than any other treatment groups. Collectively, oAd/APP+DC led to superior induction of antitumor immune response and amelioration of immunosuppressive tumor microenvironment to elicit potent tumor growth inhibition than either monotherapy.

The involvement and application potential of exosomes in breast cancer immunotherapy

Breast cancer has a high incidence and a heightened propensity for metastasis. The absence of precise targets for effective intervention makes it imperative to devise enhanced treatment strategies. Exosomes, characterized by a lipid bilayer and ranging in size from 30 to 150 nm, can be actively released by various cells, including those in tumors. Exosomes derived from distinct subsets of immune cells have been shown to modulate the immune microenvironment within tumors and influence breast cancer progression. In addition, tumor-derived exosomes have been shown to contribute to breast cancer development and progression and may become a new target for breast cancer immunotherapy. Tumor immunotherapy has become an option for managing tumors, and exosomes have become therapeutic vectors that can be used for various pathological conditions. Edited exosomes can be used as nanoscale drug delivery systems for breast cancer therapy, contributing to the remodeling of immunosuppressive tumor microenvironments and influencing the efficacy of immunotherapy. This review discusses the regulatory role of exosomes from different cells in breast cancer and the latest applications of exosomes as nanoscale drug delivery systems and immunotherapeutic agents in breast cancer, showing the development prospects of exosomes in the clinical treatment of breast cancer.

Inflammation-based lung adenocarcinoma molecular subtype identification and construction of an inflammation-related signature with bulk and single-cell RNA-seq data.

The role of inflammation is increasingly understood to have a central influence on therapeutic outcomes and prognosis in lung adenocarcinoma (LUAD). However, the detailed molecular divisions involved in inflammatory responses are yet to be fully elucidated. Our study identified two main inflammation-oriented LUAD grades: the inflammation-low (INF-low) and the inflammation-high (INF-high) subtypes. Both presented with unique clinicopathological features, implications for prognosis, and distinctive tumor microenvironment profiles. Broadly, the INF-low grade, marked by its dominant immunosuppressive tumor microenvironment, was accompanied by less favorable prognostic outcomes and a heightened prevalence of oncogenic mutations. In contrast, the INF-high grade exhibited more optimistic clinical trajectories, underscored by its immune-active environment. In addition, our efforts led to the conceptualization and empirical validation of an inflammation-centric predictive model with considerable predictive potency. Our study paves the way for a refined inflammation-centric LUAD classification and fosters a deeper understanding of tumor microenvironment intricacies.

Facile Synthesis of a Multifunctional Porous Organic Polymer Nanosonosensitizer (mHM@HMME) for Enhanced Cancer Sonodynamic Therapy.

Sonodynamic therapy (SDT), which involves the activation of sonosensitizers to generate cytotoxic reactive oxygen species under ultrasound irradiation, is a promising noninvasive modality for cancer treatment. However, the clinical translational application of SDT is impeded by the lack of efficient sonosensitizers, the inefficient accumulation of sonosensitizers at tumor sites, and the complicated immunosuppressive tumor microenvironment. Herein, we developed a facilely synthesized multifunctional porous organic polymer nanosonosensitizer (mHM@HMME) for enhanced SDT. Specifically, mHM@HMME nanosonosensitizers were prepared by incorporating chemotherapeutic mitoxantrone into the one-step synthesis process of disulfide bond containing porous organic polymers, followed by loading with organic sonosensitizer (HMME) and camouflaging with a cancer cell membrane. Due to the cancer cell membrane camouflage, this multifunctional mHM@HMME nanosonosensitizer showed prolonged blood circulation and tumor targeting aggregation. Under ultrasound irradiation, the mHM@HMME nanosonosensitizer exhibited a satisfactory SDT performance both in vitro and in vivo. Moreover, the potent SDT combined with glutathione-responsive drug release in tumor cells induced robust immunogenic cell death to enhance the antitumor effect of SDT in turn. Overall, this facilely synthesized multifunctional mHM@HMME nanosonosensitizer shows great potential application in enhanced SDT.

Abstract B007: Urinary cytokine profiles reflect rationale for treatment with gemcitabine and Bacillus Calmette-Guérin (BCG) in BCG-exposed high-risk non-muscle invasive bladder cancer (NMIBC)

Abstract Background: Bacillus Calmette-Guérin (BCG) remains the most efficacious and widely studied intravesical therapy for NMIBC, but less than 50% of BCG-exposed patients will respond to a second course of BCG. One mechanism of resistance to BCG is an immunosuppressive tumor microenvironment with myeloid-derived suppressor cells (MDSCs), tumor associated macrophages (TAMs), and Tregs that abrogate the anti-tumor immune response. IL-6 is associated with MDSCs and BCG resistance. Gemcitabine (Gem), however, has been shown to selectively inhibit MDSCs, TAMs, and Tregs. This observation served as the biologic rationale for our recently completed Phase I trial of combination chemoimmunotherapy with intravesical Gem and BCG for BCG-exposed high-grade (HG) NMIBC (NCT04179162) that demonstrated excellent tolerability and preliminary efficacy (96% complete response at 6-month follow-up). We sought to evaluate immune modulation with the addition of Gem to BCG as determined by changes in urinary cytokine/chemokine levels. Methods: Patients with BCG-exposed papillary HG NMIBC (Ta/T1) +/- carcinoma in situ recurring within 24 months of BCG therapy were treated with intravesical Gem twice weekly (weeks 1,4,7,10; 8 total doses) and intravesical TICE BCG weekly (weeks 2,3,5,6,8,9; 6 total doses) followed by SWOG maintenance BCG for responders. Urine specimens were collected prior to treatment and on weeks 4, 8, 12, 24, and 52 weeks after on-trial treatment initiation. Urinary cytokines present in the supernatant were evaluated using a 96-plex immuno-oncology proximity extension assay (Olink®). Cytokines with < 75% of values below the lower limit of detection of the assay were not evaluated. We performed an exploratory analysis of select pre-specified cytokines using a linear mixed model. Mean changes and 95% confidence intervals (CI) are presented with global p-values testing for a change in cytokine levels at any timepoint. Results: Urine samples were available for all 25 patients in the Phase I study. A total of 25 proteins on the panel were excluded due to low detection. Chemokines associated with T-cell trafficking (CXCL9, CXCL10, CXCL11) increased during induction treatment through 3 months of follow up and then returned to baseline after the completion of treatment (p<0.001 for each cytokine). IL-6 decreased after initiation of treatment and remained low through 12 months of follow up (-2.7, 95% CI -3.8, -1.7; p<0.001). Notably, the one patient who had a recurrence also had a rise in IL-6 after an initial decline while on treatment. Conclusion: We found evidence that the addition of intravesical gemcitabine to BCG favorably augments the tumor microenvironment based on changes in urinary cytokine/chemokine profiles. Additional tumor and urinary correlatives are ongoing. Based on the the robust preliminary efficacy demonstrated in the ongoing phase I/II trial (NCT04179162), a prospective randomized controlled trial comparing GemBCG to BCG alone for BCG-exposed NMIBC is planned through the National Clinical Trial Network (Alliance A032303). Citation Format: Christopher D. Gaffney, Syed M. Alam, Jessica A. Lavery, Merve Basar, Neeta D'Souza, Christian Hernandez, Melissa McCarter, Patricia Moran, Kristen Stasi, Kara Worth, Daniel Sjoberg, Guido Dalbagni, Timothy Donahue, Sherri Donat, Dean Bajorin, Bernard H. Bochner, Alvin Goh, Judy Sarungbam, Hikmat Al-Ahmadie, Eugene J. Pietzak. Urinary cytokine profiles reflect rationale for treatment with gemcitabine and Bacillus Calmette-Guérin (BCG) in BCG-exposed high-risk non-muscle invasive bladder cancer (NMIBC) [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B007.

Spatial Heterogeneity of Immune Drivers Coordinates the Organisation of Antitumor Immunity in Pancreatic Cancer, Affecting Patient Outcome

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is considered low immunogenic with “cold” tumor microenvironment (TME) and is mostly unresponsive to immune checkpoint blockade therapies. Aims We aim to decipher the impact of intratumoral heterogeneity of immune determinants on antitumor response. Methods 130PDAC specimens were classified according to overall survival in long-term survivors (LTSs, n=29, OS≥60 months) and short-term survivors (STSs, n=101, OS<60 months). Spatial compartment masks were defined by immunofluorescence imaging (tumor cells: Pancytokeratin+CD45-, leukocytes: CD45+Pancytokeratin-, stroma cells: PanCK-CD45-). 4regions of interest from tumor center (TC) and the invasive front (IF) were examined by transcriptomic and proteomic analysis using the Nanostring platform for immune pathway targets. Results of NGS and morphological features were integrated. 20samples underwent immunophenotypic analysis by multiplex immunofluorescence. Results LTSs displayed mostly homogeneous morphology with extended glandular differentiation and immunogenic TME both at TC and IF, with increasing gradient towards the IF. There was higher presence of immune checkpoint-associated and immunogenic genes and proteins at the IF as compared to the TC, including CD40, CD3, CD8, CD4, GZMB and PD-L1. In contrast, STSs were characterized by morphologic heterogeneity, including areas with reduced glandular differentiation and high tumor budding, and a mostly immunosuppressive TME with negative gradient towards the IF. Moreover, there was reduced gene expression and protein abundance at the IF as compared to the TC, including CD3, CD8, CXCL10, GZMB, IFNG, HLA-DR and CD40. Conclusion LTSs display a highly immunogenic TME, underscoring their effective antitumor immunity, especially at the area of IF compared with STSs. A significant intratumoral heterogeneity between TC and IF exists with regards to immune determinants in both, LTSs and STSs, which might explain the different antitumor immune responses, affecting patient outcome. The differential expression of immune drivers may help selecting patients for combination therapies to improve antitumor immunity and harness the responsiveness to immune checkpoint inhibitors in PDAC.