Tumor Immune Suppression Research Articles

Intrahepatic IgA complex induces polarization of cancer-associated fibroblasts to matrix phenotypes in the tumor microenvironment of HCC.

Cancer-associated fibroblasts (CAFs) play key roles in the tumor microenvironment. IgA contributes to inflammation and dismantling antitumor immunity in the human liver. In this study, we aimed to elucidate the effects of the IgA complex on CAFs in Pil Soo Sung the tumor microenvironment of HCC. CAF dynamics in HCC tumor microenvironment were analyzed through single-cell RNA sequencing of HCC samples. CAFs isolated from 50 HCC samples were treated with mock or serum-derived IgA dimers in vitro. Progression-free survival of patients with advanced HCC treated with atezolizumab and bevacizumab was significantly longer in those with low serum IgA levels ( p <0.05). Single-cell analysis showed that subcluster proportions in the CAF-fibroblast activation protein-α matrix were significantly increased in patients with high serum IgA levels. Flow cytometry revealed a significant increase in the mean fluorescence intensity of fibroblast activation protein in the CD68 + cells from patients with high serum IgA levels ( p <0.001). We confirmed CD71 (IgA receptor) expression in CAFs, and IgA-treated CAFs exhibited higher programmed death-ligand 1 expression levels than those in mock-treated CAFs ( p <0.05). Coculture with CAFs attenuated the cytotoxic function of activated CD8 + T cells. Interestingly, activated CD8 + T cells cocultured with IgA-treated CAFs exhibited increased programmed death-1 expression levels than those cocultured with mock-treated CAFs ( p <0.05). Intrahepatic IgA induced polarization of HCC-CAFs into more malignant matrix phenotypes and attenuates cytotoxic T-cell function. Our study highlighted their potential roles in tumor progression and immune suppression.

Tumor-derived KLK8 predicts inferior survival and promotes an immune-suppressive tumor microenvironment in lung squamous cell carcinoma

Lung squamous cell carcinoma (LUSC) is the second most common lung cancer worldwide, leading to millions of deaths annually. Although immunotherapy has expanded the therapeutic choices for LUSC and achieved considerable efficacy in a subset of patients, many patients could not benefit, and resistance was pervasive. Therefore, it is significant to investigate the mechanisms leading to patients’ poor response to immunotherapies and explore novel therapeutic targets. Using multiple public LUSC datasets, we found that Kallikrein-8 (KLK8) expression was higher in tumor samples and was correlated with inferior survival. Using a LUSC cohort (n = 190) from our center, we validated the bioinformatic findings about KLK8 and identified high KLK8 expression as an independent risk factor for LUSC. Function enrichment showed that several immune signaling pathways were upregulated in the KLK8 low-expression group and downregulated in the KLK8 high-expression group. For patients with low KLK8 expression, they were with a more active TME, which was both observed in the TCGA database and immune marker immunohistochemistry, and they had extensive positive relations with immune cells with tumor-eliminating functions. This study identified KLK8 as a risk factor in LUSC and illustrated the associations between KLK8 and cancer immunity, suggesting the potentiality of KLK8 as a novel immune target in LUSC.

Preclinical evaluation of the gorilla-derived HAdV-B AdV-lumc007 oncolytic adenovirus 'GoraVir' for the treatment of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy which shows unparalleled therapeutic resistance due to its genetic and cellular heterogeneity, dense stromal tissue, and immune-suppressive tumour microenvironment. Oncolytic virotherapy has emerged as a new treatment modality which uses tumour-specific viruses to eliminate cancerous cells. Non-human primate adenoviruses of the human adenovirus B (HAdV-B) species have demonstrated considerable lytic potential in humancancer cells as well as limited preexisting neutralizing immunity in humans. Previously, we have generated a new oncolytic derivative of the gorilla-derived HAdV-B AdV-lumc007 named 'GoraVir'. Here, we show that GoraVir displays oncolytic efficacy in pancreatic cancer cells and pancreatic-cancer-associated fibroblasts. Moreover, it retains its lytic potential in monoculture and co-culture spheroids. In addition, we established the ubiquitously expressed complement receptor CD46 as the main entry receptor for GoraVir. Finally, a single intratumoural dose of GoraVir was shown to delay tumour growth in a BxPC-3 xenograft model at 10 days post-treatment. Collectively, these data demonstrate that the new gorilla-derived oncolytic adenovirus is a potent oncolytic vector candidate that targets both pancreatic cancer cells and tumour-adjacent stroma.

Abstract B082: Extinction of oncogenic Kras in genetic mouse models eradicates pancreatic cancer by inducing Fas-dependent apoptosis by CD8+ T cells

Abstract Oncogenic KrasG12D (Kras*) is critical for the initiation and maintenance of pancreatic ductal adenocarcinoma (PDAC), and a known repressor of tumor immunity. Conditional extinction of Kras* in genetic mouse models of PDAC leads to reactivation of Fas, CD8+ T cell mediated apoptosis, and complete eradication of tumors. Kras* extinction recruits CD4+ and CD8+ T cells, promotes the activation of putative antigen presenting CD11b−CD11c+ dendritic cells, and suppresses CD11b+ myeloid cell infiltration. Our findings shows that Kras* drives T cell suppression in PDAC. Mechanistically, Kras* mediated immune evasion involves epigenetic regulation of the death receptor Fas in cancer cells, via repression of its promoter region mediated by functional recruitment of DNA methyltransferase 1 (DNMT1), trimethylation of histone 3 at lysine 27 (H3K27me3), the histone methyltransferase EZH2, and suppression of acetylation of histone 3 at lysine 27 (H3K27ac). Further, analysis of human RNA sequencing reveals that Kras* expression levels inversely correlate with FAS expression and PDAC tumors with high KRAS demonstrate low CD8+ T cell infiltration, which is associated with shorter overall survival in PDAC patients. Given that specific and effective targeting of Kras* results in the CD8+ T cell mediated, Fas dependent apoptosis of cancer cells and eradication of PDAC in mice, this study highlights the direct role of Kras* in suppression of tumor immunity and supports a role for immunotherapy in combination with Kras* targeting strategies to control PDAC. Citation Format: Valerie S. LeBleu, Krishnan K. Mahadevan, Elena V. Ramirez, Yang Chen, Bingrui Li, Amari M. Sockwell, Mihai Gagea, Hikaru Sugimoto, Desiree Tampe, Michael Zeisberg, Haoqiang Ying, Abhinav K. Jain, Ronald A. DePinho, Aniban Maitra, Kathleen M. McAndrews, Raghu Kalluri. Extinction of oncogenic Kras in genetic mouse models eradicates pancreatic cancer by inducing Fas-dependent apoptosis by CD8+ T cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B082.

Abstract C002: Interleukin-1 receptor accessory protein (IL1RAP) overexpression is associated with worse prognosis in PDAC and is targetable by nadunolimab

Abstract Introduction: The pancreatic tumor microenvironment (TME) is a major driver of tumor progression, chemoresistance and immune suppression, and the IL-1 axis has been implicated in tumor-promoting signaling networks. The IL1RAP-IL1R1 receptor complex is required for both IL-1α and IL-1β signaling and is expressed on tumor and stromal/immune cells. Nadunolimab is a fully humanized, ADCC-enhanced IgG1 antibody that targets IL1RAP and disrupts both IL-1α/IL-1β signaling. In the phase 1/2a trial CANFOUR (NCT03267316) in which 73 PDAC patients with previously untreated, locally advanced or metastatic PDAC received nadunolimab with gemcitabine/nab-paclitaxel (GN), encouraging preliminary data show median iPFS of 7.2 mo, median OS of 12.9 mo and 1-year survival of 58%. The present analyses investigated the correlation between IL1RAP expression and disease severity as well as therapeutic efficacy of nadunolimab/GN. Methods: Evaluable screening biopsies from 46 CANFOUR PDAC patients were stained for IL1RAP by immunohistochemistry. mRNA data was obtained from the GTEx, TCGA and Pancreatic Cancer Action Network’s Know Your Tumor (KYT) databases and correlated to patient data (TCGA, KYT) and mutational data (KYT). Results: IL1RAP expression was detected on tumor cells, fibroblasts, and infiltrating immune cells in tumor biopsies. Notably, all tumor cells expressed IL1RAP and stratification of evaluable samples into high or low tumor cell expression of IL1RAP revealed significantly prolonged median OS on nadunolimab/GN in IL1RAP high compared to IL1RAP low patients (14.2 vs 10.6 mo, p=0.017). This was also reflected in longer iPFS (8.0 vs 5.8 mo), 1-year survival (69 vs 40%) and iORR (52 vs 32%). Although varying in intensity, IL1RAP expression on stromal cells did not correlate significantly with treatment efficacy. In interrogating bulk RNA seq data from the GTEx, TCGA and KYT databases, IL1RAP was overexpressed in pancreatic cancer compared to normal tissue, with higher expression in advanced stage disease. Moreover, as KRAS mutations promote tumor inflammation and KRASG12D has been implicated in activating the IL-1 axis, we observed that KRASG12D tumors had a higher expression of IL1RAP and IL-1α, but not IL-1β, compared to KRAS-wildtype tumors. In both early and late-stage PDAC, high levels of IL1RAP strongly correlated with poor survival (both p&amp;lt;0.0001). Patients responding to GN tended to have lower IL1RAP levels than patients with progressive or stable disease, in stark contrast to the results with nadunolimab/GN. To understand the effects of nadunolimab/GN in the TME, spatial transcriptomics in screening and on-treatment biopsies are being analyzed with Nanostring GeoMx. Conclusion: IL1RAP is upregulated in pancreatic cancer, its expression correlates with oncogenic KRAS driver mutations and is strongly associated with poor survival. The IL1RAP-targeting antibody nadunolimab has shown promising target-dependent efficacy in combination with 1st line chemotherapy, indicating that IL1RAP is a both highly relevant and targetable protein in PDAC. Citation Format: Eric Van Cutsem, Kawther Abdilleh, Jashodeep Datta, Manuel Hidalgo, Camilla Rydberg Millrud, Petter Skoog, Annika Sanfridson, Dominique Tersago, David Liberg. Interleukin-1 receptor accessory protein (IL1RAP) overexpression is associated with worse prognosis in PDAC and is targetable by nadunolimab [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr C002.

Abstract C017: The anti-fungal itraconazole improves immunotherapy efficacy in pancreatic ductal adenocarcinoma by reversing the immune-suppressive tumor microenvironment

Abstract Pancreatic cancer (PC) has 5-year survival rates of 11% and is projected to become the second leading cause of cancer-related deaths by 2030. Poor outcomes result from early metastasis and a lack of effectual therapies for advanced disease. Our previous large-scale genomics studies revealed PC is molecularly highly varied (1). This heterogeneity, lack of effective therapies and high mortality rate make PC a prime arena to advance personalised medicine strategies, where individual cancers are selected for optimal therapy depending on molecular subtype. Utilising our significant experience of molecular-guided anti-cancer therapies (2-6) and stromal biology expertise (2,6,7), we are taking drug-repurposing approaches to test agents with effects on stromal biology in combination with standard-of-care chemotherapies and immunotherapy, to improve clinical outcomes. Itraconazole is an FDA-approved anti-fungal with potential anti-cancer effects, although its efficacy in PC remains relatively unexplored. Preliminary in vivo findings indicate that itraconazole, in combination with standard-of-care chemotherapy gemcitabine/nab-paclitaxel, significantly delays disease progression in both mouse and patient-derived xenograft models of PC. Single cell RNA-seq analyses of tumors from the KPC orthotopic model of PC suggest itraconazole treatment can inhibit immunosuppressive aspects of the stroma and pro-tumorigenic, pro-metastatic signalling. Excitingly, combining itraconazole with anti-PD1/-CTLA4 immunotherapy provides significant survival advantages in the KPC orthotopic model of PC. Finally, using a model of metastatic PC, we show that itraconazole hinders metastatic colonisation in the liver. This work aims to identify subtypes of PC responsive to itraconazole allowing optimisation and translation of tailored therapies combining itraconazole and the latest clinically-utilised chemotherapies and immunotherapies.

Acidic tumor microenvironment-activated MRI nanoprobes for modulation and visualization of anti-PD-L1 immunotherapy

Tumor acidity has emerged as a pivotal regulator of immune checkpoint blockade (ICB). However, acidity-based therapy presents challenges of low efficiency and lack of reliable imaging technology for assessing the immune response. Here we report a magnetic resonance imaging (MRI)-guided ICB therapy (MRGIT) strategy to modulate and visualize the efficacy of anti-PD-L1 in pancreatic ductal adenocarcinoma (PDAC). MRGIT was achieved by a pH responsive nanoprobe (APPAM@U-104) composed of ultrasmall iron oxide nanoparticles (USIONs) and a tumor pH regulator (U-104). Notably, the nanoprobes exhibited a T1 “ON” MR signal in acidic tumors but switched to a T2 “ON” MR signal in a neutralized tumor microenvironment, resulting in a switchable MR signal from T1 to T2 during real-time MRI monitoring. Moreover, the switch of MR signals can serve as an indicator for alleviating tumor immune suppression, thus guiding the timing of anti-PD-L1 therapy. Our results revealed that the MRGIT strategy can potentiate the antitumor efficacy of anti-PD-L1 against pancreatic tumors. Collectively, this strategy sensitively regulates and recognizes tumor acidosis, thus paving the way for the modulation and noninvasive monitoring of anti-PD-L1 efficacy in PDAC.

Photo-Driven InSitu Solidification of Whole Cells through Inhibition of Trogocytosis for Immunotherapy.

Achieving antitumor immunotherapy based on hybridization of multiple types of inactivated cells has attracted a lot of attention. However, the hybridized cells of disordered structure could result in the shedding of antigens and their transfer to immune cells, which suppresses tumor immunity through trogocytosis. Here, we report a strategy for in situ solidification of tumor whole cell by biomineralization for sustained stimulation of antitumor immunity. The near-infrared light was used to accelerate the breaking of Au=P bonds in auranofin, and the exposed Au atoms biomineralize at the secondary structure (β-corner) of the protein to form Au nanocrystals with insitu protein coronas in tumor cells. Au nanocrystals are anchored to the tumor cells through protein coronas, which fixes the morphology and antigens of whole tumor cells, rendering them physiologically inactive. Interestingly, this solidified tumor cell prevents immune cells from undergoing trogocytosis, which inhibits proximal and distal tumor growth. Thus, this study presents the strategy of solidified cells and its potential application in tumor immunotherapy.

Nanoparticles targeting the adenosine pathway for cancer immunotherapy.

Cancer immunotherapy, as an emerging approach to cancer treatment, has tremendous potential for application. Compared to traditional methods such as surgery, chemotherapy, and radiation therapy, it has the ability to restore the patient's immune system, leading to long-term immune memory with less damage to normal tissues. However, immunotherapy has its limitations, including limited therapeutic efficacy, restricted patient populations, and inconsistent treatment responses. Finding effective immunotherapeutic approaches has become a key focus of its clinical application. The adenosine pathway is a recently discovered tumor immune regulatory signaling pathway. It can influence the metabolism and growth of tumor cells by acting through key enzymes in the adenosine pathway, thereby affecting the development of tumors. Therefore, inhibiting the adenosine pathway is an effective cancer immunotherapy. Common adenosine pathway inhibitors include small molecules and antibody proteins, and extensive preclinical trials have demonstrated their effectiveness in inhibiting tumor growth. The short half-life, low bioavailability, and single administration route of adenosine pathway inhibitors limit their clinical application. With the advent of nanotechnology, nano-delivery of adenosine pathway inhibitors has addressed these issues. Compared to traditional drugs, nano-drugs extend the drug's circulation time and improve its distribution within the body. They also offer targeting capabilities and have low toxic side effects, making them very promising for future applications. In this review, we discuss the mechanism of the adenosine pathway in tumor immune suppression, the clinical applications of adenosine pathway inhibitors, and nano-delivery based on adenosine pathway inhibitors. In the final part of this article, we also briefly discuss the technical issues and challenges currently present in nano-delivery of adenosine pathway inhibitors, with the hope of advancing the progress of adenosine inhibitor nano-drugs in clinical treatment.

Emerging drug delivery systems to alter tumor immunosuppressive microenvironment: Overcoming the challenges in immunotherapy for glioblastoma.

Glioblastoma (GBM) is a highly proliferative, lethal cancer of the brain. The median survival at eight months is ca. 6.8%. Resistance towards the anti-glioblastoma drug temozolomide (TMZ), recurrence of cancer cells, blood-tumor brain barrier (BTBB), blood-brain barrier (BBB), and tumor immunosuppression are major challenges in treating GBM. Drug delivery systems employing TMZ and other anti-cancer drugs and combination therapy (temozolomide with immunotherapeutics) are under pre-clinical and clinical studies, respectively. Immunotherapeutics have emerged as a dominant mechanism to silence tumor development and dissemination. Paradoxically, immunotherapy has witnessed failure in treating GBM. This is due to the unique immunosuppressive microenvironment in GBM. Future immunotherapeutics with inherent tumor environment-modulating properties have to be identified. In this review, we discuss recent delivery systems and devices engineered to deliver immunotherapeutics with the ability to alter/silence tumor immune suppression.

Current applications of tumor local ablation (TLA) combined with immune checkpoint inhibitors in breast cancer treatment.

Breast cancer is one of the most common cancers in women globally, posing significant challenges to treatment because of the diverse and complex pathological and molecular subtypes. The emergence of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of breast cancer, particularly for triple-negative breast cancer (TNBC), significantly improving patient outcomes. However, the overall tumor response rate remains suboptimal due to drug resistance to ICIs. This resistance is primarily due to the immune-suppressive tumor microenvironment (TME), tumor cells' ability to evade immune surveillance, and other complex immune regulatory mechanisms. To address these challenges, clinical researchers are actively exploring combinatorial therapeutic strategies with ICIs. Tumor local ablation (TLA) technology is anticipated to overcome resistance to ICIs and enhance therapeutic efficacy by ablating tumor tissue, releasing tumor antigens, remodeling the TME, and stimulating local and systemic immune responses. Combination therapy with TLA and ICIs has demonstrated promising results in preclinical breast cancer studies, underscoring the feasibility and importance of addressing drug resistance mechanisms in breast cancer. This provides novel strategies for breast cancer treatment and is expected to drive further advancements in the field.

Harnessing endoscopic ultrasound-guided radiofrequency ablation to reshape the pancreatic ductal adenocarcinoma microenvironment and elicit systemic immunomodulation.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by poor prognostics and substantial therapeutic challenges, with dismal survival rates. Tumor resistance in PDAC is primarily attributed to its fibrotic, hypoxic, and immune-suppressive tumor microenvironment (TME). Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA), an Food and Drug Administration (FDA)-approved minimally invasive technique for treating pancreatic cancer, disrupts tumors with heat and induces coagulative necrosis, releasing tumor antigens that may trigger a systemic immune response-the abscopal effect. We aim to elucidate the roles of EUS-RFA-mediated thermal and mechanical stress in enhancing anti-tumor immunity in PDAC. A comprehensive literature review focused on radiofrequency immunomodulation and immunotherapy in pancreatic tumors to understand the pathophysiological mechanisms of RFA and its effect on the TME, which could prevent recurrence and resistance. We reviewed clinical, preclinical, and in vitro studies on RFA mechanisms in pancreatic adenocarcinoma, discussing the unique immunomodulatory effects of EUS-RFA. Recent findings suggest that combining RFA with immune adjuvants enhances responses in pancreatic adenocarcinoma. EUS-RFA offers a dual benefit against PDAC by directly reducing tumor viability and indirectly enhancing anti-tumor immunity. Observations of neutrophil-mediated immunomodulation and programmed cell death ligand 1 (PD-L1) modulation support integrating EUS-RFA with targeted immunotherapies for managing pancreatic adenocarcinoma. Integrating EUS-RFA in PDAC treatment promises direct cytoreduction and synergistic effects with molecular targeted therapies. Prospective clinical trials are crucial to assess the efficacy of this combined approach in improving outcomes and survival rates in advanced PDAC cases.

A Silver-Induced Absorption Red-Shifted Dual-Targeted Nanodiagnosis-Treatment Agent for NIR-II Photoacoustic Imaging-Guided Photothermal and ROS Simultaneously Enhanced Immune Checkpoint Blockade Antitumor Therapy.

Tumor metastasis remains a leading factor in the failure of cancer treatments and patient mortality. To address this, a silver-induced absorption red-shifted core-shell nano-particle is developed, and surface-modified with triphenylphosphonium bromide (TPP) and hyaluronic acid (HA) to obtain a novel nanodiagnosis-treatment agent (Ag@CuS-TPP@HA). This diagnosis-treatment agent can dual-targets cancer cells and mitochondria, and exhibits maximal light absorption at 1064nm, thereby enhancing nesr-infrared II (NIR-II) photoacoustic (PA) signal and photothermal effects under 1064nm laser irradiation. Additionally, the silver in Ag@CuS-TPP@HA can catalyze the Fenton-like reactions with H2 O2 in the tumor tissue, yielding reactive oxygen species (ROS). The ROS production, coupled with enhanced photothermal effects, instigates immunogenic cell death (ICD), leading to a substantial release of tumor-associated antigens (TAAs) and damage-associated molecular patterns, which have improved the tumor immune suppression microenvironment and boosting immune checkpoint blockade therapy, thus stimulating a systemic antitumor immune response. Hence, Ag@CuS-TPP@HA, as a cancer diagnostic-treatment agent, not only accomplishes targeted the NIR-II PA imaging of tumor tissue and addresses the challenge of accurate diagnosis of deep cancer tissue in vivo, but it also leverages ROS/photothermal therapy to enhance immune checkpoint blockade, thereby eliminating primary tumors and effectively inhibiting distant tumor growth.

Kinase Insert Domain Receptor Q472H Pathogenic Germline Variant Impacts Melanoma Tumor Growth and Patient Treatment Outcomes.

We previously reported a higher incidence of a pathogenic germline variant in the kinase insert domain receptor (KDR) in melanoma patients compared to the general population. Here, we dissect the impact of this genotype on melanoma tumor growth kinetics, tumor phenotype, and response to treatment with immune checkpoint inhibitors (ICIs) or targeted therapy. The KDR genotype was determined and the associations between the KDR Q472H variant (KDR-Var), angiogenesis, tumor immunophenotype, and response to MAPK inhibition or ICI treatment were examined. Melanoma B16 cell lines were transfected with KDR-Var or KDR wild type (KDR-WT), and the differences in tumor kinetics were evaluated. We also examined the impact of KDR-Var on the response of melanoma cells to a combination of VEGFR inhibition with MAPKi. We identified the KDR-Var genotype in 81/489 (37%) patients, and it was associated with a more angiogenic (p = 0.003) and immune-suppressive tumor phenotype. KDR-Var was also associated with decreased PFS to MAPKi (p = 0.022) and a trend with worse PFS to anti-PD1 therapy (p = 0.06). KDR-Var B16 murine models had increased average tumor volume (p = 0.0027) and decreased CD45 tumor-infiltrating lymphocytes (p = 0.0282). The anti-VEGFR treatment Lenvatinib reduced the tumor size of KDR-Var murine tumors (p = 0.0159), and KDR-Var cells showed synergistic cytotoxicity to the combination of dabrafenib and lenvatinib. Our data demonstrate a role of germline KDR-Var in modulating melanoma behavior, including response to treatment. Our data also suggest that anti-angiogenic therapy might be beneficial in patients harboring this genotype, which needs to be tested in clinical trials.

Nano-Regulator Inhibits Tumor Immune Escape via the "Two-Way Regulation" Epigenetic Therapy Strategy.

Tumor immune escape caused by low levels of tumor immunogenicity and immune checkpoint-dependent suppression limits the immunotherapeutic effect. Herein, a "two-way regulation" epigenetic therapeutic strategy is proposed using a novel nano-regulator that inhibits tumor immune escape by upregulating expression of tumor-associated antigens (TAAs) to improve immunogenicity and downregulating programmed cell death 1 ligand 1 (PD-L1) expression to block programmed death-1 (PD-1)/PD-L1. To engineer the nano-regulator, the DNA methyltransferase (DNMT) inhibitor zebularine (Zeb) and the bromodomain-containing protein 4 (BRD4) inhibitor JQ1 are co-loaded into the cationic liposomes with condensing the toll-like receptor 9 (TLR9) agonist cytosine-phosphate-guanine (CpG) via electrostatic interactions to obtain G-J/ZL. Then, asparagine-glycine-arginine (NGR) modified material carboxymethyl-chitosan (CMCS) is coated on the surface of G-J/ZL to construct CG-J/ZL. CG-J/ZL is shown to target tumor tissue and disassemble under the acidic tumor microenvironment (TME). Zeb upregulated TAAs expression to improve the immunogenicity; JQ1 inhibited PD-L1 expression to block immune checkpoint; CpG promote dendritic cell (DC) maturation and reactivated the ability of tumour-associated macrophages (TAM) to kill tumor cells. Taken together, these results demonstrate that the nano-regulator CG-J/ZL can upregulate TAAs expression to enhance T-cell infiltration and downregulate PD-L1 expression to improve the recognition of tumor cells by T-cells, representing a promising strategy to improve antitumor immune response.

The Complexity of the Tumor Microenvironment in Hepatocellular Carcinoma and Emerging Therapeutic Developments

This review explores various aspects of the HCC TME, including both cellular and non-cellular components, to elucidate their roles in tumor development and progression. Specifically, it highlights the significance of cancer-associated fibroblasts (CAFs) and their contributions to tumor progression, angiogenesis, immune suppression, and therapeutic resistance. Moreover, this review emphasizes the role of immune cells, such as tumor-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), and regulatory T-cells (Tregs), in shaping the immunosuppressive microenvironment that promotes tumor growth and immune evasion. Furthermore, we also focused only on the non-cellular components of the HCC TME, including the extracellular matrix (ECM) and the role of hypoxia-induced angiogenesis. Alterations in the composition of ECM and stiffness have been implicated in tumor invasion and metastasis, while hypoxia-driven angiogenesis promotes tumor growth and metastatic spread. The molecular mechanisms underlying these processes, including the activation of hypoxia-inducible factors (HIFs) and vascular endothelial growth factor (VEGF) signaling, are also discussed. In addition to elucidating the complex TME of HCC, this review focuses on emerging therapeutic strategies that target the TME. It highlights the potential of second-line treatments, such as regorafenib, cabozantinib, and ramucirumab, in improving overall survival for advanced HCC patients who have progressed on or were intolerant to first-line therapy. Furthermore, this review explores the implications of the Barcelona Clinic Liver Cancer (BCLC) staging and classification system in guiding HCC management decisions. The BCLC system, which incorporates tumor stage, liver function, and performance status, provides a framework for treatment stratification and prognosis prediction in HCC patients. The insights gained from this review contribute to the development of novel therapeutic interventions and personalized treatment approaches for HCC patients, ultimately improving clinical outcomes in this challenging disease.

Abstract C071: HBI-2375, a selective inhibitor of MLL1-WDR5 interaction, possesses desirable preclinical characteristics in solid tumors in combination with checkpoint inhibitors and also in leukemias in the future clinical investigations

Abstract MLL1 (mixed lineage leukemia1) interaction with WDR5 (WD repeat domain 5) is critical for its histone methyl transferase (HMT) activity leading to transcriptional regulation of gene expression. MLL1 dysregulation such as its translocation at chromosome 11q23 results in generation of MLL1 fusion genes and leukemia development. Additionally, recent studies indicated a role for MLL1-WDR5 interaction in solid tumors progression via directly affecting cancer cells or by suppression of tumor immunity. Therefore, MLL1-WDR5 interaction is an important target in the discovery of anti-cancer drugs for both leukemia and solid tumors. HUYABIO recently identified HBI-2375 as a selective inhibitor of MLL1-WDR5 interaction. HBI-2375 showed potent inhibition of WDR5 (IC50=4.48 nM) and inhibited MV4-11 cellular proliferation (average IC50=3.15 µM) in CTG assays. In addition, HBI-2375 was stable in liver S9 and whole blood, with moderate to high plasma protein binding rates in multiple species, and acceptable hERG IC50 (17 µM). Furthermore, HBI-2375 displayed reasonable oral PK properties (Cmax, T1/2, AUC, and F%) in mouse and dog. In vivo, HBI-2375 has shown significant dose dependent anti-tumor activity in MV4-11 xenograft AML model along with reduction in methylation of H3K4 in the tumors harvested from the treated animals demonstrating the targeted disruption of HMT activity in cancer cells by HBI-2375. Furthermore HBI-2375 in combination with PD-1 mAb significantly inhibited tumor growth in MC38, colorectal tumor model, and in 3LL lung carcinoma syngeneic tumor models. Flow cytometry and IHC showed significant increase in the infiltration of CD8+ CTLs in the combination group further providing immune-driven mechanisms for greater efficacy of combination therapy. Gene expression analysis also identified genes that are involved in promoting immune system activity in the combination group. Therefore, HBI-2375 may represent a first-in-class MLL1-WDR5 inhibitor in the clinic. Citation Format: Farbod Shojaei, Che Fang, Jill M Ricono, Mireille Gillings. HBI-2375, a selective inhibitor of MLL1-WDR5 interaction, possesses desirable preclinical characteristics in solid tumors in combination with checkpoint inhibitors and also in leukemias in the future clinical investigations [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 C071.

Single-cell and spatial transcriptomics reveal POSTN+ cancer-associated fibroblasts correlated with immune suppression and tumour progression in non-small cell lung cancer.

Cancer-associated fibroblasts (CAFs) are potential targets for cancer therapy. Due to the heterogeneity of CAFs, the influence of CAF subpopulations on the progression of lung cancer is still unclear, which impedes the translational advances in targeting CAFs. We performed single-cell RNA sequencing (scRNA-seq) on tumour, paired tumour-adjacent, and normal samples from 16 non-small cell lung cancer (NSCLC) patients. CAF subpopulations were analyzed after integration with published NSCLC scRNA-seq data. SpaTial enhanced resolution omics-sequencing (Stereo-seq) was applied in tumour and tumour-adjacent samples from seven NSCLC patients to map the architecture of major cell populations in tumour microenvironment (TME). Immunohistochemistry (IHC) and multiplexed IHC (mIHC) were used to validate marker gene expression and the association of CAFs with immune infiltration in TME. A subcluster of myofibroblastic CAFs, POSTN+ CAFs, were significantly enriched in advanced tumours and presented gene expression signatures related to extracellular matrix remodeling, tumour invasion pathways and immune suppression. Stereo-seq and mIHC demonstrated that POSTN+ CAFs were in close localization with SPP1+ macrophages and were associated with the exhausted phenotype and lower infiltration of T cells. POSTN expression or the abundance of POSTN+ CAFs were associated with poor prognosis of NSCLC. Our study identified a myofibroblastic CAF subpopulation, POSTN+ CAFs, which might associate with SPP1+ macrophages to promote the formation of desmoplastic architecture and participate in immune suppression. Furthermore, we showed that POSTN+ CAFs associated with cancer progression and poor clinical outcomes and may provide new insights on the treatment of NSCLC.

Abstract A098: HBI-2376, HUYABIO clinical stage SHP2 inhibitor, displays efficacy signal in patients with KRAS mutations in early clinical studies

Abstract SHP2 is an attractive target in oncology drug development due to its dual roles in tumor progression: i) direct growth and proliferation of cancer cells; ii) acting as an immune checkpoint molecule to suppress tumor immunity. HBI-2376 is an orally bioavailable selective SHP2 inhibitor developed for the treatment of solid tumors harboring KRAS or EGFR mutations, such as non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and pancreatic cancer (PAC). Additionally, HBI-2376 has the potential to suppress tumor growth via induction of the activity of immune infiltrating cells in the TME (tumor microenvironment). Preclinical studies showed greater potency of HBI-2376 to inhibit cell proliferation in a variety of cancer cell lines compared to other SHP2 inhibitors such as TNO-155 (Novartis AG) and RMC-4550 (Revolution Medicines). Additionally, HBI-2376 was found to be more efficacious in tumor growth inhibition than TNO-155 and RMC-4550 in NCI-H1975L858R_T790M_C797S osimertinib-resistant cell line and other tumor models. Furthermore, Western blotting showed inhibition of p-ERK and DUSP6 in HBI-2376 treated cells indicative of a biomarker of response to the therapy. In addition to xenograft models, we tested efficacy of HBI-2376 as single agent or in combination with anti-PD-1 mAb in MC38 CRC syngeneic model. HBI-2376 showed greater efficacy in tumor growth inhibition vs. TNO-155 and RMC-4550 both as single agent and in combination therapy. IHC data showed reduction in infiltration of M2 macrophages (F4/80+Arg1+) in the HBI-2376 treated tumors suggesting a mechanism of action for its greater efficacy in MC38 model. HBI-2376 is currently being tested in Phase 1 clinical trials. Consistent with preclinical studies, we have observed efficacy signals in early cohorts in two patients with partial responses (PR). Both patients were harboring KRAS mutations beyond KRAS G12C. Additionally, HBI-2376 was well tolerated with no SAEs or DLTs in the first four cohorts indicative of a good tolerability in cancer patients. Analysis of pERK in PBMCs isolated from the treated patients showed dose dependent inhibition in pERK further supporting a mechanism driven response to HBI-2376. Therefore, the preclinical and clinical data may represent HBI-2376 as the best-in-class SHP2 inhibitor. Citation Format: Farbod Shojaei, Jill M Ricono, Che Fang, Yan Xing, John Ning, Gloria Lee, Mireille Gillings. HBI-2376, HUYABIO clinical stage SHP2 inhibitor, displays efficacy signal in patients with KRAS mutations in early clinical studies [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 A098.

Fibrinogen-like protein 2 promotes tumor immune suppression by regulating cholesterol metabolism in myeloid-derived suppressor cells

BackgroundMyeloid-derived suppressor cells (MDSCs) are crucial mediators of tumor-associated immune suppression. Targeting the accumulation and activation of MDSCs has been recognized as a promising approach to enhance the effectiveness of...