Modulation Of Tumor Microenvironment Research Articles

Harnessing Metal Nanoparticles: Revolutionizing Cancer Therapy Through Targeted Drug Delivery and Tumor Microenvironment Modulation

Cancer remains a significant global health burden, claiming countless lives annually and incurring substantial direct and indirect economic costs. Despite advancements in therapeutic modalities, conventional cancer treatments, including chemotherapy, radiotherapy and surgery, are often hampered by limitations such as insufficient efficacy, dose-dependent side effects, high costs and patient tolerability. This has spurred extensive research into novel therapeutic approaches for this life-threatening disease. Metal nanoparticles (MNPs) have emerged as promising tools in cancer therapy due to their unique physicochemical properties spanning the past two decades. Owing to their size similarity to biological molecules, MNPs possess the inherent ability to penetrate cellular barriers, making them ideal carriers for targeted drug delivery. These multifunctional nanoplatforms offer distinct advantages over conventional therapeutics by enabling targeted delivery of anticancer agents to specific tumor sites, thereby enhancing therapeutic efficacy and minimizing systemic side effects. Photodynamic therapy and sonodynamic therapy represent particularly promising strategies that leverage MNPs for cancer treatment. This review delves into the potential applications of MNPs in modulating the tumor microenvironment, paving the way for the exploration of this vast and rapidly evolving field of nanomedicine.

Combinatorial cellular therapy in pediatric solid tumors with natural killer (NK) and genetically engineered myeloid cells (GEMys).

2561 Background: Early human studies with Natural Killer (NK) cells have shown promise, harnessing their ability to infiltrate into tumors and be tumoricidal. However, these effects can be limited by adenosine, reactive oxygen species, and TGF-β in the highly immune suppressive tumor microenvironment (TME). TGF-β and downstream SMAD3 signaling in Natural Killer (NK) cells have been shown to cause decreased cytokine production, downregulation of activating cell surface receptors, and attenuated cytotoxic function against solid tumors. Exposure to TGF-β during cell culture generates expanded NK cells with increased resistance to TGF-β signaling, dubbed TGF-β imprinted NK cells. In vitrostudies have shown that these cells have increased cytokine production and cytotoxic function in the presence of TGF-β. However, their in vivo trafficking, modulation of the TME, and therapeutic efficacy remain understudied. Our lab has previously shown that when given to tumor-bearing mice, myeloid cells modified to produce IL-12 (IL-12-Genetically Engineered Myeloid cells, aka IL-12 GEMys) are effective at homing to tumor and metastatic sites and, via IL-12 secretion and TME modulation, increase NK cell presence and activation in these sites. They hold great promise as combination therapy, enhancing the effectiveness of other cellular therapies such as NK cell therapy. A current clinical trial exploring TGF-β Imprinted, Ex Vivo Expanded, Universal Donor NK Cell Infusions in relapsed sarcomas is underway (NCT05634369). Methods: In vitro experiments were conducted with the xCELLigence real-time cell analysis system. The human osteosarcoma cell line 143B and human rhabdomyosarcoma cell line RH-30 were evaluated for cell death after co-culture with healthy donor NK cells or TGF-β imprinted NK cells (E:T ratio of 5:1) in isolation and in combination with IL-12 GEMys (E:T ratio of 2:1). Results: TGF-β imprinted NK cells are significantly more effective at tumor cell killing of both 143B and RH30 cell lines in-vitro compared to regular expanded NK cells (WT NK cells), with >90% decrease in cell index compared to 50-60%, respectively, after 48 hours of co-culture. IL-12 GEMys also significantly enhance the cytotoxic effects of WT NK cells, increasing cell killing to 70-80% compared to co-culture with untransduced GEMy controls. Conclusions: These initial in-vitro experiments provide insight into the promising effectiveness of NK-myeloid cell combination therapies in the treatment of pediatric sarcomas. Ongoing in vitroexperiments include cytokine quantification by ELISA and flow cytometric analysis of NK cell activation and proliferation markers. Our preliminary results provide rationale to continue studying the in vivo efficacy of TGF-β imprinted NK cell monotherapy and in combination with IL-12 GEMys in the treatment of tumor-bearing NSG mice.

Immune modulation of the liver metastatic colorectal cancer microenvironment via the oral CAPOX-mediated cGAS-STING pathway

We evaluated modulation of the immunosuppressive tumor microenvironment in both local and liver metastatic colorectal cancer (LMCC), focusing on tumor-associated macrophages, which are the predominant immunosuppressive cells in LMCC. We developed an orally administered metronomic chemotherapy regimen, oral CAPOX. This regimen combines capecitabine and a nano-micelle encapsulated, lysine-linked deoxycholate and oxaliplatin complex (OPt/LDC-NM). The treatment effectively modulated immune cells within the tumor microenvironment by activating the cGAS-STING pathway and inducing immunogenic cell death. This therapy modulated immune cells more effectively than did capecitabine monotherapy, the current standard maintenance chemotherapy for colorectal cancer. The macrophage-modifying effect of oral CAPOX was mediated via the cGAS-STING pathway. This is a newly identified mode of immune cell activation induced by metronomic chemotherapy. Moreover, oral CAPOX synergized with anti-PD-1 antibody (αPD-1) to enhance the T-cell–mediated antitumor immune response. In the CT26. CL25 subcutaneous model, combination therapy achieved a 91 % complete response rate with a confirmed memory effect against the tumor. This combination also altered the immunosuppressive tumor microenvironment in LMCC, which αPD-1 monotherapy could not achieve. Oral CAPOX and αPD-1 combination therapy outperformed the maximum tolerated dose for treating LMCC, suggesting metronomic therapy as a promising strategy.

Emerging Chemodynamic Nanotherapeutics for Cancer Treatment.

Chemodynamic therapy (CDT) has emerged as a transformative paradigm in the realm of reactive oxygen species -mediated cancer therapies, exhibiting its potential as a sophisticated strategy for precise and effective tumor treatment. CDT primarily relies on metal ions and hydrogen peroxide to initiate Fenton or Fenton-like reactions, generating cytotoxic hydroxyl radicals. Its notable advantages in cancer treatment are demonstrated, including tumor specificity, autonomy from external triggers, and a favorable side-effect profile. Recent advancements in nanomedicine are devoted to enhancing CDT, promising a comprehensive optimization of CDT efficacy. This review systematically elucidates cutting-edge achievements in chemodynamic nanotherapeutics, exploring strategies for enhanced Fenton or Fenton-like reactions, improved tumor microenvironment modulation, and precise regulation in energy metabolism. Moreover, a detailed analysis of diverse CDT-mediated combination therapies is provided. Finally, the review concludes with a comprehensive discussion of the prospects and intrinsic challenges to the application of chemodynamic nanotherapeutics in the domain of cancer treatment.

Patient-specific colorectal-cancer-associated fibroblasts modulate tumor microenvironment mechanics

Cancer-associated fibroblasts (CAFs) play a major role in reorganizing the physical tumor micro-environment and changing tissue stiffness. Herein, using an engineered three-dimensional (3D) model that mimics the tumor's native biomechanical environment, we characterized the changes in matrix stiffness caused by six patient-specific colorectal CAF populations. After 21days of culture, atomic force microscopy (AFM) was performed to precisely measure the local changes in tissue stiffness. Each CAF population exhibited heterogeneity in remodeling capabilities, with some patient-derived cells stiffening the matrix and others softening it. Tissue stiffening was mainly attributed to active contraction of the matrix by the cells, whereas the softening was due to enzymatic activity of matrix-cleaving proteins. This measured heterogeneity was lost when the CAFs were cocultured with colorectal cancer cells, as all samples significantly soften the tissue. The interplay between cancer cells and CAFs was critical as it altered any heterogeneity exhibited by CAFs alone.

Dual-targeted delivery of temozolomide by multi-responsive nanoplatform via tumor microenvironment modulation for overcoming drug resistance to treat glioblastoma.

Glioblastoma (GBM) is the most aggressive primary brain tumor with low survival rate. Currently, temozolomide (TMZ) is the first-line drug for GBM treatment of which efficacy is unfortunately hindered by short circulation time and drug resistance associated to hypoxia and redox tumor microenvironment. Herein, a dual-targeted and multi-responsive nanoplatform is developed by loading TMZ in hollow manganese dioxide nanoparticles functionalized by polydopamine and targeting ligands RAP12 for photothermal and receptor-mediated dual-targeted delivery, respectively. After accumulated in GBM tumor site, the nanoplatform could respond to tumor microenvironment and simultaneously release manganese ion (Mn2+), oxygen (O2) and TMZ. The hypoxia alleviation via O2 production, the redox balance disruption via glutathione consumption and the reactive oxygen species generation, together would down-regulate the expression of O6-methylguanine-DNA methyltransferase under TMZ medication, which is considered as the key to drug resistance. These strategies could synergistically alleviate hypoxia microenvironment and overcome TMZ resistance, further enhancing the anti-tumor effect of chemotherapy/chemodynamic therapy against GBM. Additionally, the released Mn2+ could also be utilized as a magnetic resonance imaging contrast agent for monitoring treatment efficiency. Our study demonstrated that this nanoplatform provides an alternative approach to the challenges including low delivery efficiency and drug resistance of chemotherapeutics, which eventually appears to be a potential avenue in GBM treatment.

Protein tyrosine phosphatases: emerging role in cancer therapy resistance.

Tyrosine phosphorylation of intracellular proteins is a post-translational modification that plays a regulatory role in signal transduction during cellular events. Dephosphorylation of signal transduction proteins caused by protein tyrosine phosphatases (PTPs) contributed their role as a convergent node to mediate cross-talk between signaling pathways. In the context of cancer, PTP-mediated pathways have been identified as signaling hubs that enabled cancer cells to mitigate stress induced by clinical therapy. This is achieved by the promotion of constitutive activation of growth-stimulatory signaling pathways or modulation of the immune-suppressive tumor microenvironment. Preclinical evidences suggested that anticancer drugs will release their greatest therapeutic potency when combined with PTP inhibitors, reversing drug resistance that was responsible for clinical failures during cancer therapy. This review aimed to elaborate recent insights that supported the involvement of PTP-mediated pathways in the development of resistance to targeted therapy and immune-checkpoint therapy. This review proposed the notion of PTP inhibition in anticancer combination therapy as a potential strategy in clinic to achieve long-term tumor regression. Ongoing clinical trials are currently underway to assess the safety and efficacy of combination therapy in advanced-stage tumors.

Abstract PO2-04-08: Translational insights from a phase 1, first-in-human (FIH) clinical trial of the anti-HER2 CAR macrophage CT-0508 in participants with HER2 positive metastatic breast cancer and other HER2 overexpressing solid tumors

Abstract Background: In pre-clinical studies, CAR macrophages (CAR-M) phagocytose tumor cells, activate the tumor microenvironment (TME), recruit T cells, and induce anti-tumor T cell immunity. CT-0508 is a first-in-class CAR-M product comprised of autologous monocyte-derived macrophages expressing an anti-HER2 CAR. In pre-clinical models, anti-HER2 CAR-M was able to control the growth of syngeneic metastatic HER2+ breast cancer. Here we present preliminary clinical results and translational data from Group 1 of the CT-0508 Phase 1 FIH study. Methods: This multi-center, open-label study is evaluating CT-0508’s safety, tolerability, and manufacturing feasibility in 18 participants with advanced solid tumors overexpressing HER2 with progression on prior therapies. Monocytes are isolated from mobilized apheresis products, differentiated into macrophages, and engineered with an anti-HER2 CAR. Group 1 participants (n = 9) receive a fractionated dose on days 1, 3, 5 and Group 2 participants (n = 9) receive the full dose on day 1. CT-0508 is administered without preparative chemotherapy. Serial blood samples and biopsies (baseline and 2 post-treatment) are collected to investigate safety, pharmacokinetics, and mechanism of action. AU565 and 4T1-HER2 cell lines were utilized to model human and murine breast cancer, respectively, in vitro and in vivo. Results: Nine participants (6F/3M) have been treated in Group 1, comprising breast (4), esophageal (2), cholangiocarcinoma, ovarian, and parotid gland cancers, with a median age of 58. Participants had received a median of 3 (range, 2-11) prior lines of therapy; 8 had received prior anti-HER2 therapy. CT-0508 was successfully manufactured and well tolerated with no dose-limiting toxicities. Three related SAEs occurred in 2 participants: grade 1 CRS with hospitalization for monitoring and grade 2 infusion reaction that resolved within 1 hour were reported in one participant. Grade 2 CRS with fever and hypoxia occurred in another participant and resolved within ~ 72 hours. Five additional participants experienced Grade 1-2 CRS and/or infusion reactions with rapid resolution. There were no cases of Grade 3 or 4 CRS. There were no major organ toxicities. Post-infusion cytokines were transiently elevated in most participants enrolled in group 1 and were self-limiting. Four of the 7 participants evaluated had stable disease. CT-0508 was transiently detectable in the blood and was detected in the TME of 8/9 participants. CT-0508 modulated the TME, leading to myeloid cell activation, effector T cell infiltration, activation, and proliferation. TCR sequencing demonstrated newly expanding T cell clones in the blood post-treatment that accumulated within the TME, suggesting expansion of tumor-reactive T cells upon CT-0508 infusion. Data from participants enrolled in Group 1 will be presented. Most of these patients were breast cancer patients with HER2 overexpressing metastatic disease. Conclusions: CT-0508 was feasible to manufacture and had acceptable safety and tolerability. Early correlative data demonstrate trafficking, TME modulation, and induction of anti-tumor T cell immunity in participants with HER2 overexpressing solid tumors including metastatic breast cancer. The study is actively enrolling (NCT04660929). Citation Format: Yara Abdou, Joanne Mortimer, Paula Pohlmann, Melissa Johnson, Richard Maziarz, Jennifer M. Specht, Claire Dees, Naoto Ueno, Yuan Yuan, Mathew Angelos, Saar Gill, Olga Shestova, Jonathon Serody, Saul Priceman, Rehman Qureshi, Poonam Sonawane, Stefano Pierini, Maria Cecilia Oliveira-Nunes, Daniel Cushing, Michael Klichinsky, Thomas Condamine, Ramona Swaby, Kim Reiss. Translational insights from a phase 1, first-in-human (FIH) clinical trial of the anti-HER2 CAR macrophage CT-0508 in participants with HER2 positive metastatic breast cancer and other HER2 overexpressing solid tumors [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-04-08.

Combination treatment with PD1/PDL-1 inhibitors for sarcomas: state of the art, next questions.

Only a small fraction of sarcomas exhibit recognized parameters of immune sensitivity, such as tumor mutational burden, PDL-1 expression, or microsatellite instability. Combined strategies aimed to modulate tumor microenvironment to increase the efficacy of PD1/PDL-1 inhibitors in sarcoma. Most explored prospective studies were based on combinations of PD1/PDL-1 inhibitors with antiangiogenics, other immune checkpoints, or chemotherapy. Results on 6-month PFS rate, median PFS, and ORR in trials using PD1/PDL-1 inhibitors plus antiangiogenics ranged respectively as 46.9-55%, 4.7-7.8 months and 21-36.7%. In combination with other immune checkpoint inhibitors, the results of median PFS and ORR ranged from 2.8-4.1 months and 10-16%, respectively. In combination with chemotherapy, the best results were obtained with doxorubicin-based regimens compared to other agents. Duplet-based chemotherapy plus anti-PD1/PDL-1 obtained the highest ORR (56.2%) compared with doxorubicin (19-36.7%). Currently, the most robust predictive biomarker for anti-PD1/PDL-1 efficacy is the presence of tertiary lymphoid structures (TLS) with mature dendritic cells. Even when direct comparisons between PD1/PDL-1 inhibitor-based combinations and single agents have not been performed yet in sarcoma, some combinations appear promising. Studies controlling heterogeneity by biomarker or histotype selection contribute to an increase in efficacy or knowledge crucial for future comparative trials.

PI3K/mTOR inhibition induces tumour microenvironment remodelling and sensitises pS6high uterine leiomyosarcoma to PD-1 blockade.

Uterine leiomyosarcomas (uLMS) are aggressive tumours with poor prognosis and limited treatment options. Although immune checkpoint blockade (ICB) has proven effective in some 'challenging-to-treat' cancers, clinical trials showed that uLMS do not respond to ICB. Emerging evidence suggests that aberrant PI3K/mTOR signalling can drive resistance to ICB. We therefore explored the relevance of the PI3K/mTOR pathway for ICB treatment in uLMS and explored pharmacological inhibition of this pathway to sensitise these tumours to ICB. We performed an integrated multiomics analysis based on TCGA data to explore the correlation between PI3K/mTOR dysregulation and immune infiltration in 101 LMS. We assessed response to PI3K/mTOR inhibitors in immunodeficient and humanized uLMS patient-derived xenografts (PDXs) by evaluating tumour microenvironment modulation using multiplex immunofluorescence. We explored response to single-agent and a combination of PI3K/mTOR inhibitors with PD-1 blockade in humanized uLMS PDXs. We mapped intratumoural dynamics using single-cell RNA/TCR sequencing of serially collected biopsies. PI3K/mTOR over-activation (pS6high) associated with lymphocyte depletion and wound healing immune landscapes in (u)LMS, suggesting it contributes to immune evasion. In contrast, PI3K/mTOR inhibition induced profound tumour microenvironment remodelling in an ICB-resistant humanized uLMS PDX model, fostering adaptive anti-tumour immune responses. Indeed, PI3K/mTOR inhibition induced macrophage repolarisation towards an anti-tumourigenic phenotype and increased antigen presentation on dendritic and tumour cells, but also promoted infiltration of PD-1+ T cells displaying an exhausted phenotype. When combined with anti-PD-1, PI3K/mTOR inhibition led to partial or complete tumour responses, whereas no response to single-agent anti-PD-1 was observed. Combination therapy reinvigorated exhausted T cells and induced clonal hyper-expansion of a cytotoxic CD8+ T-cell population supported by a CD4+ Th1 niche. Our findings indicate that aberrant PI3K/mTOR pathway activation contributes to immune escape in uLMS and provides a rationale for combining PI3K/mTOR inhibition with ICB for the treatment of this patient population.

Gene Expression Profiling to Predict Prognostic Biomarkers for Relapse in Multiple Myeloma

Background: Multiple myeloma (MM), an incurable malignancy of plasma cells (PCs), is the second most common hematological cancer caused primarily by structural variations (chromosomal aberrations and somatic mutations). The majority of the patients acquired resistance against standard therapeutic approaches for MM and experienced relapse despite the continuous advances in MM therapies.Methods: We performed Differential Gene Expression (DGE), literature mining and SNV analysis of Next Generation Sequencing (NGS) data of Newly Diagnosed MM (NDMM) and Relapsed/Refractory MM (RRMM). The selected Differentially Expressed Genes (DEGs) were subjected to functional enrichment and pathway analysis. Immune cells infiltration analysis was also performed to estimate immune cells variations in the Tumor Microenvironment (TME) of RRMM. Result: CSF1R, VCAN, NRP1, COL22A1, BPI, BIRC5, MNX1, FAT1, ERG, TCL1A, AFF3 were selected after DGE, literature mining and SNV analysis. The functional enrichment of these DEGs showed significant enrichment for positive regulation of cell population proliferation, serene/threonine kinase activity, endothelial cell proliferation, cytokine binding, G protein activity and GDP binding, whereas KEGG pathway analysis revealed vital role of PI3K-Akt signaling pathway along with various cancer pathways. The immune cells infiltration analysis revealed the higher count of neutrophils and lesser level of T cells (CD8+) in TME of RRMM. Conclusion: Our study suggests that neutrophils play an important role in modulation of TME in RRMM. The selected DEGs have previously been identified in progression, drug resistance and relapse of various cancers. The role of these biomarkers in RRMM has not been explored yet. Therefore, neutrophils, selected DEGs and PI3K-Akt signaling pathway are potential targets to investigate in RRMM.Keywords: Multiple Myeloma; Relapse; Differential Expression; Immune Cell Infiltration; Literature Mining

Engineering CRISPR/Cas9 therapeutics for cancer precision medicine.

The discovery of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) technology has revolutionized field of cancer treatment. This review explores usage of CRISPR/Cas9 for editing and investigating genes involved in human carcinogenesis. It provides insights into the development of CRISPR as a genetic tool. Also, it explores recent developments and tools available in designing CRISPR/Cas9 systems for targeting oncogenic genes for cancer treatment. Further, we delve into an overview of cancer biology, highlighting key genetic alterations and signaling pathways whose deletion prevents malignancies. This fundamental knowledge enables a deeper understanding of how CRISPR/Cas9 can be tailored to address specific genetic aberrations and offer personalized therapeutic approaches. In this review, we showcase studies and preclinical trials that show the utility of CRISPR/Cas9 in disrupting oncogenic targets, modulating tumor microenvironment and increasing the efficiency of available anti treatments. It also provides insight into the use of CRISPR high throughput screens for cancer biomarker identifications and CRISPR based screening for drug discovery. In conclusion, this review offers an overview of exciting developments in engineering CRISPR/Cas9 therapeutics for cancer treatment and highlights the transformative potential of CRISPR for innovation and effective cancer treatments.

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette–Guérin Immunotherapy of Bladder Cancer

Breaking Barriers: Modulation of Tumor Microenvironment to Enhance Bacillus Calmette–Guérin Immunotherapy of Bladder Cancer

Preclinical evaluation of two phylogenetically distant arenavirus vectors for the development of novel immunotherapeutic combination strategies for cancer treatment

BackgroundEngineered arenavirus vectors have recently been developed to leverage the body’s immune system in the fight against chronic viral infections and cancer. Vectors based on Pichinde virus (artPICV) and lymphocytic...

Tumor Microenvironment Modulation by Cancer-Derived Extracellular Vesicles

The tumor microenvironment (TME) plays an important role in the process of tumorigenesis, regulating the growth, metabolism, proliferation, and invasion of cancer cells, as well as contributing to tumor resistance to the conventional chemoradiotherapies. Several types of cells with relatively stable phenotypes have been identified within the TME, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), neutrophils, and natural killer (NK) cells, which have been shown to modulate cancer cell proliferation, metastasis, and interaction with the immune system, thus promoting tumor heterogeneity. Growing evidence suggests that tumor-cell-derived extracellular vesicles (EVs), via the transfer of various molecules (e.g., RNA, proteins, peptides, and lipids), play a pivotal role in the transformation of normal cells in the TME into their tumor-associated protumorigenic counterparts. This review article focuses on the functions of EVs in the modulation of the TME with a view to how exosomes contribute to the transformation of normal cells, as well as their importance for cancer diagnosis and therapy.

New avenues for the treatment of immunotherapy-resistant pancreatic cancer.

Pancreatic cancer (PC) is characterized by its extremely aggressive nature and ranks 14th in the number of new cancer cases worldwide. However, due to its complexity, it ranks 7th in the list of the most lethal cancers worldwide. The pathogenesis of PC involves several complex processes, including familial genetic factors associated with risk factors such as obesity, diabetes mellitus, chronic pancreatitis, and smoking. Mutations in genes such as KRAS, TP53, and SMAD4 are linked to the appearance of malignant cells that generate pancreatic lesions and, consequently, cancer. In this context, some therapies are used for PC, one of which is immunotherapy, which is extremely promising in various other types of cancer but has shown little response in the treatment of PC due to various resistance mechanisms that contribute to a drop in immunotherapy efficiency. It is therefore clear that the tumor microenvironment (TME) has a huge impact on the resistance process, since cellular and non-cellular elements create an immunosuppressive environment, characterized by a dense desmoplastic stroma with cancer-associated fibroblasts, pancreatic stellate cells, extracellular matrix, and immunosuppressive cells. Linked to this are genetic mutations in TP53 and immunosuppressive factors that act on T cells, resulting in a shortage of CD8+ T cells and limited expression of activation markers such as interferon-gamma. In this way, finding new strategies that make it possible to manipulate resistance mechanisms is necessary. Thus, techniques such as the use of TME modulators that block receptors and stromal molecules that generate resistance, the use of genetic manipulation in specific regions, such as microRNAs, the modulation of extrinsic and intrinsic factors associated with T cells, and, above all, therapeutic models that combine these modulation techniques constitute the promising future of PC therapy. Thus, this study aims to elucidate the main mechanisms of resistance to immunotherapy in PC and new ways of manipulating this process, resulting in a more efficient therapy for cancer patients and, consequently, a reduction in the lethality of this aggressive cancer.

CAR products from novel sources: a new avenue for the breakthrough in cancer immunotherapy.

Chimeric antigen receptor (CAR) T cell therapy has transformed cancer immunotherapy. However, significant challenges limit its application beyond B cell-driven malignancies, including limited clinical efficacy, high toxicity, and complex autologous cell product manufacturing. Despite efforts to improve CAR T cell therapy outcomes, there is a growing interest in utilizing alternative immune cells to develop CAR cells. These immune cells offer several advantages, such as major histocompatibility complex (MHC)-independent function, tumor microenvironment (TME) modulation, and increased tissue infiltration capabilities. Currently, CAR products from various T cell subtypes, innate immune cells, hematopoietic progenitor cells, and even exosomes are being explored. These CAR products often show enhanced antitumor efficacy, diminished toxicity, and superior tumor penetration. With these benefits in mind, numerous clinical trials are underway to access the potential of these innovative CAR cells. This review aims to thoroughly examine the advantages, challenges, and existing insights on these new CAR products in cancer treatment.

Abstract LB444: Identification of a novel and selective Transglutaminase 2 (TGM2) inhibitors modulate tumor microenvironment in Glioblastoma

Abstract Background: TGM (Transglutaminase) family enzymes are Ca2+ dependent and engaged in specific posttranslational modifications by cross-linking extracellular matrix (ECM) proteins. ECM protein complex is more stable and resistant to enzymatic degradation. These enzymes modify proteins by cross-linking epsilon-(gamma-glutamyl), lysine, or (gamma-glutamyl) polyamine bonds. TGM2 (Transglutaminase 2) is a ubiquitous enzyme, and its expression is identified in the cytoplasm, plasma membrane, and the nucleus of various cells. The membrane-bound form of TGM2 binds GTP and functions as a G protein. TGM2 regulates cell survival, proliferation, migration, and modulation through ECM organization. We explored the role of TGM2 in Glioblastoma cells and its role in modulating the tumor microenvironment, cell proliferation, and survival. In addition to TGM2's role in GBM tumors, its expression has been linked to resistance to certain therapies in glioblastoma was investigated. Targeted modulation of macrophages with TGM2 inhibitors impacts the immune response against GBM, potentially enhancing the efficacy. Understanding the intricate interplay between TGM2, and GBM-associated macrophages is a key component of the tumor microenvironment (TME) and crucial for the development of targeted TGM2 inhibitors. Materials and Methods: Human Transglutaminase 2 (hTGM2) activity of inhibitors was assayed using the fluorescent transamination assay incorporating dansylcadaverine into glutamine-donor substrate N, N-dimethyl casein, and DCC. Cellular efficacies of selected TGM2 inhibitors evaluated in U138 and U87 glioblastoma cells in CellTiter-Glo Luminescent cell viability assay. Results: We have identified a series of novel small molecule TGM2 inhibitors based on our initial lead fragment hits with an IC50s 6-29 uM from our in-house MolecuLern fragment library. Fragments2Lead (F2L) optimizations strategies, synthesis, and SAR studies provided a lead SLX-9029 and SLX-9031 inhibitors with IC50s of 1.2, 1.5 uM in inhibiting TGM2 activity in our established cell-free fluorescent transamination assay. The initial TMG2 inhibitor leads further screening for TGM2-expressed U138 and U87 glioblastoma cells demonstrating promising cellular efficacies as singles agents. Additional GBM cell profiling, combination studies along with safety secondary pharmacology, cellular toxicities, and PK results will be discussed. Conclusion: In summary, we identified promising lead TGM2 inhibitors that show activity in both cell-free and cell-based TGM2-expressed GMB cells. The TGM family members, selectivity, additional GBM cellular profiling, ADME, cellular toxicity, and in vivo PK studies are underway, and these results will be presented. Citation Format: Hariprasad Vankayalapati, Chenyu Lin, Zhaoang li, Kyle Medley, David J. Bearss. Identification of a novel and selective Transglutaminase 2 (TGM2) inhibitors modulate tumor microenvironment in Glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB444.

Abstract LB346: Dynamic changes in the tumor microenvironment from initial diagnosis through sequential therapies in patients with large B cell lymphoma undergoing axicabtagene ciloleucel (axi-cel) treatment

Abstract Axicabtagene ciloleucel (axi-cel), marketed as YESCARTA®, is an approved autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory large B cell lymphoma patients following one prior therapeutic intervention. The pivotal ZUMA-1 trial (NCT02348216), a Phase 1/2 multicenter study, reported an impressive 83% objective response rate and a robust 58% complete response rate at 5 years (Locke et al., Lancet Oncol. 2019). Subsequently, ZUMA-7 (NCT03391466), a Phase 3 multicenter trial focusing on patients with one prior systemic therapy, demonstrated comparable outcomes with an 83% objective response rate and a remarkable 65% complete response rate at 2 years (Locke et al., Lancet Oncol. 2022). Previous studies have highlighted the crucial connection between the tumor microenvironment (TME) and CAR T-cell therapy outcomes. Notably, the pre-treatment tumor immune contexture has been proposed as a major determinant of clinical outcomes in ZUMA-1 and ZUMA-7 patients (Scholler et al., Nature Medicine 2022; Locke et al., Nature Medicine, in press; ASH2023 oral presentation #226). This study aims to provide novel insights into the dynamic changes in the TME from initial diagnosis through sequential therapeutic interventions in large B-cell lymphoma patients treated with axi-cel. Utilizing multiplex immunohistochemistry (Brightplex®), we analyzed 165 commercial tumor biopsies (at diagnosis), 100 ZUMA-7 samples (40 at diagnosis, 60 after 1 prior therapeutic line), and 35 ZUMA-1 samples (20 pre- and 15 post-CAR T infusion). Three Brightplex® assays were developed to assess T-cell (CD3 CD8 FOXP3 TIM3 PD1 LAG3 GZMB) and macrophages infiltration (CD68 CD64 CD163 CD204 CD206 PDL1), along with single staining for the NK cell marker, NKP46. Our findings revealed significant changes and evolution from diagnosis through post-axi-cel infusion: a significant decrease in lymphocyte levels (cytotoxic, helper, and regulatory, with p-values of 0.042, 1.3e-05, 0.024, respectively), a notable decrease in M1 macrophages proportion (p-value=5.8e-06), and a substantial increase in M2 macrophages proportion (p-value=4.5e-10) across different lines of standard care therapy. Importantly, high baseline proportions of protumor M2 macrophages may serve as predictors of disease relapse post-axi-cel treatment, while low baseline M2 proportions could be associated with a complete response. This comprehensive characterization of the immune contexture provides crucial insights to better highlight TME modification depending on the line of therapy, and further correlative analysis of cell subsets will be presented, contributing to a deeper understanding of treatment impact on the TME in large B cell lymphoma. Citation Format: Michael Mattie, Regis Perbost, Aurelie Auguste, Sarah Turcan, Jenny J. Kim, Christina To, Jenny Nater, Simone Filosto, Rhine R. Shen, Jérôme Galon. Dynamic changes in the tumor microenvironment from initial diagnosis through sequential therapies in patients with large B cell lymphoma undergoing axicabtagene ciloleucel (axi-cel) treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB346.

SDCBP modulates tumor microenvironment, tumor progression and anti-PD1 efficacy in colorectal cancer.

Anti-programmed cell death 1 (aPD1) therapy has yielded limited success in patients with colorectal cancer (CRC). Syndecan binding protein (SDCBP), encodes a PDZ domain-containing protein that is essential for cellular processes, including cell adhesion, migration, and signal transduction. Here, we investigated the effect of SDCBP on tumor progression, immunotherapy, and the tumor microenvironment (TME) in CRC. High expression of SDCBP is associated with non-response to immunotherapy and correlated with poorer disease-free survival (DFS) in CRC patients. Inhibiting SDCBP by transfecting shRNA or using its inhibitor zinc pyrithione (ZnPT) hindered proliferation and metastasis while enhancing the efficacy of aPD1 treatment in a mouse xenograft model and liver metastasis model. The TME of CRC was significantly altered following ZnPT treatment characterized by a reduced amount of M2 macrophages and a heightened percentage of M1 macrophages. The co-culture system of CRC cells and macrophages provided evidence that SDCBP silencing promoted the repolarisation of M2 macrophages into M1. SDCBP promotes the proliferation, metastasis, and immunotherapy resistance of CRC. Thus, ZnPT represents an effective SDCBP inhibitor and exhibits considerable potential for combination with aPD1 to enhance immunotherapy efficacy.