Efficacy Of Cancer Immunotherapy Research Articles

From nature to clinic: Quercetin’s role in breast cancer immunomodulation

Immunotherapy has brought hope to many breast cancer patients, but not all patients benefit from it. Quercetin (Qu), a natural product found in various sources, has anti-inflammatory and anti-tumor properties. We conducted a review of the pharmacological research of Qu in regulating anti-tumor immunity in vivo and in vitro. Qu can directly regulate the local tumor microenvironment (TME) by enhancing the activity of immune cells which includes promoting the infiltration of T cells and natural killer (NK) cells, inhibiting the recruitment of myeloid-derived suppressor cells and tumor-associated macrophages. Additionally, Qu inhibits anaerobic glycolysis in tumor cells, thereby reducing the production and transport of lactic acid. It also suppresses tumor angiogenesis by targeting the vascular endothelial growth factor (VEGF) pathway and the vitamin D pathway. Furthermore, Qu can enhance the efficacy of immunotherapy for breast cancer by modulating the systemic microenvironment. This includes inhibiting obesity-related chronic inflammation to decrease the production of inflammatory factors, regulating the composition of intestinal microbiota, and intervening in the metabolism of intestinal flora. At the same time, we also address challenges in the clinical application of Qu, such as low absorption rates and unknown effective doses. In conclusion, we highlight Qu as a natural immunomodulator that enhances immune cell activity and has the potential to be developed as an adjunct for breast cancer.

Overview of acomparative analysis of microsatellite instability and standard mismatch repair protein-deficiency tests in alarge cancer cohort.

Mismatch repair deficiency (dMMR) with microsatellite instability (MSI) is frequent in cancer, particularly in gastrointestinal and endometrial malignancies. The increased tumor mutational burden renders dMMR/MSI tumors suitable targets for immune checkpoint inhibitors-provided the regulatory genetic defect can be detected. dMMR and MSI are considered equally effective predictors of the efficacy of ICIs; however, while dMMR testing is based on detection of missing MMR proteins in immunohistochemistry (IHC), MSI polymerase chain reaction (PCR) testing focuses on the consequences of dMMR at the genomic level. Aretrospective analysis was carried out in alarge cancer cohort (n = 1306). dMMR was tested by four IHC reactions (MLH1, PMS2, MSH2, MSH6), and MSI was assessed by pentaplex PCR (BAT-25, BAT-26, MONO-27, NR-21, NR-24) in 703cases. In 64cases (5%), technical failures (mostly poor preanalytical fixation) prevented dMMR/MSI testing. Tumors were colorectal (CRC; n: 978), cancer of unknown primary (n: 126), endometrial (n: 39), pancreatic (n: 36), and gastric (n: 33). dMMR was diagnosed as classical, nonclassical, or unusual, depending on IHC. The MSI-high incidence was 12.1% overall and similar in the CRC subcohort. Interestingly, the dMMR incidence was higher in the total cohort (20.3%) and similar in the CRC subcohort. The incidences of proficient MMR (pMMR) and microsatellite stability (MSS) were similar in the total cohort and in the CRC subcohort. A19.3% discrepancy was found between MMR IHC and MSI PCR for the entire cohort, independent of tumor types. In the case of pMMR, the discrepancy rate for MSS/MSI-low was low (2.0%; entire cohort and the CRC subcohort). However, the discrepancy between dMMR and MSI-high was high within the entire cohort (60.9%) and in the CRC (58.6%) and non-CRC subcohorts (68%). This high discrepancy was not due to tumors with alow T/N ratio. Regarding dMMR phenotypes, classical dMMR had a~ 60% correlation with MSI-high status, while non-classical dMMR had amuch lower and unusual dMMR avery low (< 10%) correlation with MSI-high in the entire cohort and in the CRC subcohort. Overall, the MSI PCR sensitivity for MMR IHC status was very low. dMMR and MSI-high likely result in an increased rate of structurally altered proteins, i.e., neoantigens, and the efficacy of cancer immunotherapies is thus expected to be higher. We compared MMR IHC to MSI PCR in alarge cohort of cancer patients to study how PCR test results correlate to MMR IHC. Our data imply that preanalytical factors strongly influence the results of MMR IHC and MSI PCR and may question the current dogma that dMMR phenotype and genetic MSI status are equivalent predictive markers for immunotherapies.

Targeting cuproptosis with nano material: new way to enhancing the efficacy of immunotherapy in colorectal cancer.

Colorectal cancer has emerged as one of the predominant malignant tumors globally. Immunotherapy, as a novel therapeutic methodology, has opened up new possibilities for colorectal cancer patients. However, its actual clinical efficacy requires further enhancement. Copper, as an exceptionally crucial trace element, can influence various signaling pathways, gene expression, and biological metabolic processes in cells, thus playing a critical role in the pathogenesis of colorectal cancer. Recent studies have revealed that cuproptosis, a novel mode of cell death, holds promise to become a potential target to overcome resistance to colorectal cancer immunotherapy. This shows substantial potential in the combination treatment of colorectal cancer. Conveying copper into tumor cells via a nano-drug delivery system to induce cuproptosis of colorectal cancer cells could offer a potential strategy for eliminating drug-resistant colorectal cancer cells and vastly improving the efficacy of immunotherapy while ultimately destroy colorectal tumors. Moreover, combining the cuproptosis induction strategy with other anti-tumor approaches such as photothermal therapy, photodynamic therapy, and chemodynamic therapy could further enhance its therapeutic effect. This review aims to illuminate the practical significance of cuproptosis and cuproptosis-inducing nano-drugs in colorectal cancer immunotherapy, and scrutinize the current challenges and limitations of this methodology, thereby providing innovative thoughts and references for the advancement of cuproptosis-based colorectal cancer immunotherapy strategies.

Type I Diabetes Mellitus impairs cytotoxic immunity through CEACAM5 upregulation in colorectal cancer : Exploring the intersection of autoimmune dysfunction and cancer progression: the role of NF-κB p65 in colorectal cancer.

Type 1 diabetes (T1D) is characterized by an autoimmune-mediated destruction of pancreatic beta cells and a chronic inflammatory state, which may influence the progression of colorectal cancer (CRC) through immune system dysregulation and enhanced tumor immune evasion. This study aims to elucidate the role of p65 in modulating the tumor microenvironment in CRC within the context of T1D and to determine how this modulation affects tumor growth, immune cell infiltration, and the expression of immune evasion molecules such as CEACAM5. NOD mice, which model T1D, were inoculated with MC38 colon carcinoma cells engineered to knock down p65. Tumor growth was monitored, and the tumor microenvironment was analyzed using flow cytometry to assess the infiltration of immune cells. The expression of Ki-67 and CEACAM5 in tumor cells was also evaluated. Additionally, in vitro assays were conducted to study the proliferation and activation of T cells co-cultured with tumor cells. Knockdown of p65 in tumor cells significantly inhibited tumor growth in NOD mice. This was accompanied by an increased infiltration of cytotoxic CD8+ T cells and no significant change in CD4+ or Foxp3 + T regulatory cells within the tumor microenvironment. There was a notable reduction in the expression of Ki-67 and CEACAM5, indicating decreased proliferation and potential immune evasion capabilities of the tumor cells. Our findings demonstrate that the NF-κB p65 subunit plays a crucial role in promoting tumor growth and modulating the immune microenvironment in CRC, particularly in the context of T1D. Knocking down p65 not only reduces tumor progression but also enhances the anti-tumor immune response by decreasing immune evasion mechanisms. These results suggest that targeting the NF-κB pathway may be a viable strategy to improve the efficacy of cancer immunotherapy, especially in patients with autoimmune diseases like T1D. Physical activity enhances the effect of immune checkpoint blockade by inhibiting the intratumoral HIF1-α/CEACAM5 axis.

In situ blockade of TNF-TNFR2 axis via oncolytic adenovirus improves antitumor efficacy in solid tumors.

Tumor necrosis factor (TNF) has been recognized as an immune activation factor in tumor immunotherapy. Our study demonstrated that TNF blockade markedly enhanced the antitumor efficacy of oncolytic adenovirus (AdV) therapy. To minimize systemic side effects, we engineered a recombinant oncolytic AdV encoding a TNF inhibitor (AdV-TNFi) to confine TNF blockade within the tumor microenvironment (TME). AdV-TNFi significantly improved therapeutic outcomes across various solid tumor models, including four murine and two golden hamster cancers. Immune cell profiling identified CD8+ T cells as the primary mediators of AdV-TNFi-induced antitumor effects, rather than CD4+ T or NK cells. Additionally, AdV-TNFi significantly decreased the infiltration of suppressive myeloid-derived immune cells within the TME and promoted long-term antitumor immune surveillance. Further investigation indicated that TNFR2, more than TNFR1, is pertinent to the immunosuppressive TME, with a recombinant AdV encoding anti-TNFR2 demonstrating comparable antitumor efficacy to AdV-TNFi. Moreover, AdV-TNFi enhanced the antitumor efficacy of gemcitabine and immune checkpoint blockades (ICBs), such as anti-PD-L1 and anti-TIGIT antibodies, in pancreatic carcinoma, and the anti-EGFR antibody in colon carcinoma. In conclusion, intratumoral blockade of the TNF/TNFR2 axis using AdV augments cancer immunotherapy efficacy while mitigating the risks associated with systemic TNF or TNFR2 suppression, warranting further clinical investigation.

Nuclear Molecular Imaging for Evaluating T Cell Exhaustion.

T cells are indispensable for the therapeutic efficacy of cancer immunotherapies, including immune checkpoint blockade. However, prolonged antigen exposure also drives T cells into exhaustion, which is characterized by upregulated inhibitory molecules, impaired effector functions, reduced cytotoxicity, altered metabolism, etc. Noninvasive monitoring of T cell exhaustion allows a timely identification of cancer patients that are most likely to benefit from immunotherapies. In this Review, we briefly explain the biological cascades underlying the modulation of inhibitory molecules, present a concise update on the nuclear molecular imaging tracers of T cell exhaustion, and then discuss the potential opportunities for future development.

Unraveling impact and potential mechanisms of baseline pain on efficacy of immunotherapy in lung cancer patients: a retrospective and bioinformatic analysis.

Pain is a prevalent discomfort symptom associated with cancer, yet the correlations and potential mechanisms between pain and the efficacy of cancer immunotherapy remain uncertain. Non-small cell lung cancer (NSCLC) patients who received immune checkpoint inhibitors (ICIs) in the inpatient department of Guangdong Provincial Hospital of Chinese Medicine from January 1, 2018, to December 31, 2021, were retrospectively enrolled. Through cox regression analysis, prognostic factors and independent prognostic factors affecting the efficacy of ICIs were identified, and a nomogram model was constructed. Hub cancer-related pain genes (CRPGs) were identified through bioinformatic analysis. Finally, the expression levels of hub CRPGs were detected using an enzyme-linked immunosorbent assay (ELISA). Before PSM, a total of 222 patients were enrolled in this study. Univariate and multivariate cox analysis indicated that bone metastasis and NRS scores were independent prognostic factors for the efficacy of ICIs. After PSM, a total of 94 people were enrolled in this study. Univariate cox analysis and multivariate cox analysis indicated that age, platelets, Dnlr, liver metastasis, bone metastasis, and NRS scores were independent prognostic factors for the efficacy of ICIs. A nomogram was constructed based on 6 independent prognostic factors with AUC values of 0.80 for 1-year, 0.73 for 2-year, and 0.80 for 3-year survival. ELISA assay results indicated that the level of CXCL12 significantly decreased compared to baseline after pain was relieved. Baseline pain is an independent prognostic factor affecting the efficacy of ICIs in lung cancer, potentially through CXCL12-mediated inflammation promotion and immunosuppression.

Obesity-Specific improvement of lung cancer outcomes and immunotherapy efficacy with metformin.

Pre-clinical cancer studies ascribe promising anticancer properties to metformin. Yet, clinical findings vary, casting uncertainty on its therapeutic value for non-small cell lung cancer (NSCLC) patients. We hypothesized that metformin could benefit obese and overweight patients with NSCLC. We retrospectively analyzed two clinical cohorts and employed complementary mouse models to test our hypothesis. One cohort included NSCLC patients with overweight BMI (≥25, n = 511) and non-overweight BMI (<25, n = 232) who underwent lobectomy, evaluating metformin's impact on clinical outcomes. Another cohort examined metformin's effect on progression-free survival (PFS) after immune checkpoint inhibitors (ICI) in overweight (n = 284) vs non-overweight (n = 184) NSCLC patients. Metformin's effects on tumor progression, antitumor immunity, and ICI response in obese and normal-weight mice were assessed with lung cancer models. Metformin is associated with increased recurrence-free survival in overweight patients (HR = 0.47 [95%CI = 0.24-0.94], p = .035) after lobectomy. It also corrected accelerated tumor growth in diet-induced obese mouse models in a lymphocyte-specific manner while reversing several mechanisms of immune suppression potentiated by obesity. PD-1 blockade coupled with metformin was more effective at limiting tumor burden in obese mice and correlated with PFS only in overweight patients on immunotherapy (HR = 0.60, [95%CI = 0.39-0.93], p = .024). Metformin may improve lung cancer-specific clinical outcomes in obese and overweight lung cancer patients and enhance immunotherapy efficacy in this growing population as well. This work identifies obesity as a potential predictive biomarker of metformin's anticancer and immunotherapy-enhancing properties in lung cancer while shedding light on the underlying immunological phenomena.

Efficient Biomarker for Immunotherapy: Measuring Broad Clones Effector Tumor Antigen-Specific T Cells in the Blood of Esophageal Cancer Patients.

Cancer is the result of the interactions between tumor cells and tumor-specific immune responses. The current biomarkers detect tumor cells' properties, but accurate measurement of tumor-specific immunity is lacking. Most immunotherapies work by activating new effector tumor antigen-specific T cells (ETASTs) or reactivating pre-existing ETASTs' repertoire. The responses to immunotherapy depend on the increase of ETASTs. The amount of ETASTs, especially in blood, is critical for therapeutic efficacy. Distinguishing ETASTs from other T cells by their structural characteristics is difficult. Therefore, nanoparticles loading whole tumor antigens are utilized to activate broad clones ETASTs pre-existing in peripheral blood, followed by detecting them. Thus, the differences between ETASTs and other T cells are transformed to the differences between activated states and unactivated states. By measuring the markers of activated states and cytotoxic functions, we can distinguish ETASTs from other T cells. Nanoparticles loading mixed multiple allogeneic tumor tissue lysates or mixed multiple tumor cell lines can be utilized as universal nanoparticles to replace nanoparticles loading personalized tumor tissue. ETASTs (TATAN-activated CD8+IFN-γ+) in esophageal cancer patients are more than those in healthy people. Measurement of the ETASTs in the blood of esophageal cancer patients before and after ongoing therapy showed that ETATSs increased in the blood of patients who were responsive to immunotherapy but did not increase in the blood of nonresponders. These illustrated that therapeutic efficacy was positively correlated with the level of ETASTs in PBMC. Altogether, this study provides us a highly accurate and specific biomarker for predicting the therapeutic efficacy of cancer immunotherapy and potentially other therapies, such as radiotherapy.

Abstract C021: Tumor-associated microbiota suppresses anti-tumor immunity by driving cDC1 dysfunction in lung cancer

Abstract Type 1 conventional dendritic cells (cDC1s) are critical for initiating and sustaining tumor-reactive CD8 T cells; lack of functional cDC1s is a key driver for failed tumor immunosurveillance and immunotherapy. However, what factors cause the cDC1 insufficiency in the tumor microenvironment (TME) remain poorly understood. Commensal microbiota has emerged as a key regulator of TME and the efficacy of cancer immunotherapies. Nonetheless, most studies have focused on the intestinal microbiome; it remains underexplored whether and how the local microbiota within tumors influences the anti-cancer immunity. Using the autochthonous Kras LSL-G12D/+ ; p53 flox/flox (KP) mouse model of lung cancer, we found an increased local bacterial burden and altered bacterial composition associated with lung tumors. Importantly, this local microbiota suppresses the anti-tumor CD8 T cell response both at baseline and in response to ICB therapies. Specifically, single-cell RNA-seq analysis revealed that the microbiota shapes the functional subsets of tumor-reactive CD8 T cells. Bacterial depletion promotes the accumulation of stem-like Tpex cells (precursor of exhausted T cells) in the TME, which serve as a reservoir of effector CD8 T cells and mediate an effective response upon ICB treatment. To distinguish the function of the local microbiota within TME from the distal gut microbiota, we developed a new method of aerosolized antibiotic treatment, which selectively ablates the intra-tumoral lung microbiota while preserving the intact gut microbiota. Using this approach, we demonstrated that removal of the intra-tumoral lung microbiota markedly improves the tumor-reactive T cell response and sensitizing “cold” lung tumors to ICB therapies. Mechanistically, we identified cDC1s as a central player in microbiota-mediated suppression of anti-tumor immunity. Local microbiota diminishes cDC1 quality and quantity in the lung TME, resulting in impaired T cell priming and Tpex maintenance. At the molecular level, our data revealed that bacterial products derived from the local microbiota induce type I interferon expression in tumor-associated myeloid cells and enhance GM-CSF production from cancer cells: chronic type I interferon and GM-CSF signaling acts cooperatively to reduce the functional cDC1 population. Combining in vitro cDC1 assays, competitive bone marrow chimera experiments and cDC1-specific knockout models, we establish the causal relationships between the local microbiota, IFN-I and GM-CSF signaling in cDC1s, and the tumor response to ICB. Altogether, our study uncovered a dominant role of tumor-associated microbiota in inhibiting cDC1s and suppressing anti-tumor immunity through type I IFN and GM-CSF dependent pathways in lung cancer. Our findings not only identify the intra-tumoral microbiota as a critical therapeutic target for lung cancer treatment, but also provide new insights into the tissue-specific, context-dependent regulatory mechanisms of cDC1s in the TME. Citation Format: Qiang Dong, Chengcheng Jin. Tumor-associated microbiota suppresses anti-tumor immunity by driving cDC1 dysfunction in lung cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C021.

Abstract C049: Implementing human bone marrow organoids to interrogate microenvironmental influences on the efficacy of blood cancer immunotherapies

Abstract Cancers perpetuate immunosuppressive niches that fuel progression and hinder the clinical utility of immunotherapies. Pre-clinical validation of immunotherapies often relies on 2D models that lack spatial complexity, or mouse models that do not fully recapitulate the human tumor microenvironment (TME). We recently developed a human induced pluripotent stem cell (iPSC)-derived bone marrow organoid platform, creating a robust system to interrogate cancer-stroma cross talk. Here, we further develop the model to create the first in vitro system for evaluation of blood cancer immunotherapies in a human tissue environment. We focused on targeting myeloproliferative neoplasms (MPNs) – chronic blood cancers affecting ∼400,000 individuals in the US that are currently largely incurable. 1/3 of MPNs are driven by a mutation in calreticulin (mutCALR), and the mutCALR oncoprotein is displayed on the cell surface of disease-initiating stem cells and fibrosis-driving megakaryocytes. MPNs are characterized by pronounced inflammation and fibrosis (“myelofibrosis”). Therapeutic antibodies have entered first-in-human trials, and we recently presented pre-clinical data for the first mutCALR-directed CAR-T cell therapy. However, it is unclear how the TME may limit the efficiency of these agents. To address this, we first tested the utility of the organoid platform to evaluate target killing of leukemic cell lines and cells from patients using the anti-CD33 antibody-drug conjugate (ADC) gemtuzumab. The ADC showed good penetration and potent target cell killing in organoids, with only minimal reduction in efficacy in TGFβ-rich/fibrotic microenvironments. We then developed more sophisticated ‘chimeroids’ comprising the iPSC organoid scaffold engrafted with malignant stem cells plus CAR-Ts. Addition of mutCALR-directed CAR-Ts induced highly selective killing of mutCALR+ stem/progenitor cells with minimal toxicity to non-malignant cells including niche cells (n=5 donors), replicating the highly specific and robust killing seen in 2D cultures. To evaluate the impact of TME perturbations on CAR-T phenotype and function, we generated a scRNAseq dataset of 161,970 cells from ‘healthy’ and ‘myelofibrotic’ organoids engrafted with patient-derived mutCALR+ cells plus CAR-Ts, pre-stimulating organoids with two immunoregulatory cytokines highly abundant in myelofibrosis -TGFβ and Galectin-1. CAR- Ts exposed to mutCALR+ cells showed a 2x expansion of CD8+ effector memory cells, with significant enrichment of IFNγ, TNFα and IL-2 signaling gene-sets. The proportion of immunosuppressive Tregs increased in a high TGFβ TME, but not with Galectin-1. Ongoing analyses are further interrogating crosstalk between CAR-T, target cells, and niche components, and exploring the pro-inflammatory impact of CAR-T killing on the marrow niche – a potential mediator of delayed hematopoietic recovery. These studies demonstrate the utility of human organoids to evaluate blood cancer-targeting immunotherapies within a relevant human TME, with broad relevance for mechanistic and translational studies. Citation Format: Zoë C. Wong, Yuqi Shen, Alex Rampotas, Isaac Gannon, Charlotte Brierley, Camelia Benlabiod, Nawshad Hayder, Eleanor Murphy, Aude-Anaïs Olijnik, Claire Roddie, Martin Pulé, Adam J. Mead, Abdullah O. Khan, Bethan Psaila. Implementing human bone marrow organoids to interrogate microenvironmental influences on the efficacy of blood cancer immunotherapies [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C049.

Harnessing Bacterial Agents to Modulate the Tumor Microenvironment and Enhance Cancer Immunotherapy.

Cancer immunotherapy has revolutionized cancer treatment by leveraging the immune system to attack tumors. However, its effectiveness is often hindered by the immunosuppressive tumor microenvironment (TME), where a complex interplay of tumor, stromal, and immune cells undermines antitumor responses and allows tumors to evade immune detection. This review explores innovative strategies to modify the TME and enhance immunotherapy outcomes, focusing on the therapeutic potential of engineered bacteria. These bacteria exploit the unique characteristics of the TME, such as abnormal vasculature and immune suppression, to selectively accumulate in tumors. Genetically modified bacteria can deliver therapeutic agents, including immune checkpoint inhibitors and cytokines, directly to tumor sites. This review highlights how bacterial therapeutics can target critical immune cells within the TME, such as myeloid-derived suppressor cells and tumor-associated macrophages, thereby promoting antitumor immunity. The combination of bacterial therapies with immune checkpoint inhibitors or adoptive cell transfer presents a promising strategy to counteract immune suppression. Continued research in this area could position bacterial agents as a powerful new modality to reshape the TME and enhance the efficacy of cancer immunotherapy, particularly for tumors resistant to conventional treatments.

Loss of CDKN2A Enhances the Efficacy of Immunotherapy in EGFR Mutant Non-Small Cell Lung Cancer.

Mutant epidermal growth factor receptor (EGFR) is a common driver of non-small cell lung cancer (NSCLC). While mutant EGFR has been reported to limit the efficacy of immunotherapy, a subset of EGFR mutant NSCLC patients benefit from treatment with immune checkpoint inhibitors. A better understanding of how co-occurring genomic alterations in oncogenic driver genes impact immunotherapy efficacy may provide a more complete understanding of cancer heterogeneity and identify biomarkers of response. Here, we investigated the effects of frequent EGFR co-mutations in EGFR mutant lung cancer models and identified loss-of-function mutation of CDKN2A as a potential sensitizer to anti-PD-1 treatment in vitro and in vivo. Mechanistically, CDKN2A loss impacted the composition of the tumor immune microenvironment (TIME) by promoting the expression of PD-L2 through reduced ubiquitination of c-Myc, and mutant EGFR cooperated to upregulate c-Myc and PD-L2 by activating the MAPK pathway. Blocking PD-L2 induced anti-tumor immune responses mediated by CD8+ T cells in EGFR/CDKN2A co-mutated lung cancer. Importantly, a small-molecule PD-L2 inhibitor, zinc undecylenate, remodeled the TIME of EGFR/CDKN2A co-mutant tumors and enhanced the anti-tumor efficacy of EGFR-tyrosine kinase inhibitors. Collectively, these results identify EGFR/CDKN2A co-mutation as a distinct subtype of NSCLC that shows superior sensitivity to immune checkpoint blockade and reveals a potential combined therapeutic strategy for treating this NSCLC subtype.

Peritumoral Venous Vessels: Autobahn and Portal for T cells to Melanoma Brain Metastasis.

Melanoma brain metastasis is associated with high morbidity and mortality and remains a major clinical challenge. Despite recent successes with combination immune checkpoint inhibitors (ICI) in the treatment of affected patients, the mechanistic underpinnings of T cell entry and response to these drugs in brain metastasis are poorly understood. Using real-time intravital microscopy, Messmer and colleagues identified peritumoral venous vessels (PVVs) as critical sites for T cell entry into brain metastases, a process accelerated by ICI treatment. The expression of intercellular adhesion molecule 1 (ICAM-1) on PVVs was found to be important for T cell recruitment in pre-clinical models and associated with increased T cell infiltration in human brain metastatic lesions. This study highlights PVVs as key vascular entry points for T cells into brain metastases, laying the foundation for enhancing the efficacy of cancer immunotherapies.

Combination of ataxia telangiectasia and Rad3-related inhibition with ablative radiotherapy remodels the tumor microenvironment and enhances immunotherapy response in lung cancer

We investigated the combined effects of ataxia telangiectasia and Rad3-related (ATR) inhibition, ablative radiotherapy, and immune checkpoint inhibitor (ICI) therapy against lung cancer. ATR inhibitor was administered combined with ablative radiotherapy to assess its radiosensitizing effect on lung cancer cells. Treatment response and survival were evaluated in vivo using A549 xenograft flank tumor and synchronous LLC lung and flank tumor mouse models. Mice received ablative radiotherapy (12 Gy/d for 2 d), ATR inhibitor, and ICI. The tumor microenvironment was assessed in irradiated flank and non-irradiated lung tumors. Programmed death-ligand 1 expression was upregulated after irradiation. ATR inhibition attenuated this upregulation. ATR inhibitor pretreatment decreased cell survival after irradiation by inhibiting DNA double-strand break repair, inducing mitotic cell death, and altering cell cycle progression. ATR inhibition enhanced radiation-induced damage-associated molecular patterns determined by high mobility group box 1 quantification and activated the cyclic GMP-AMP synthase-stimulator of interferon genes pathway. Combined ATR inhibition and ablative radiotherapy inhibited tumor growth and improved survival in mice. Adding ICI therapy further enhanced local antitumor effects, reducing the metastatic lung tumor burden and remodeling the tumor microenvironment through immunogenic cell death induction and enhanced immune cell infiltration. Triple therapy increased immune cell infiltration in distant non-irradiated lung tumors and stimulated the generation of protective T-cell immunity in splenocytes. Safety analysis showed minimal toxicity. ATR inhibition enhanced the efficacy of ablative radiotherapy and immunotherapy in lung cancer. These findings underscore the importance of combination therapies for enhancing systemic antitumor immune responses and outcomes.

Ly6E on tumor cells impairs anti-tumor T-cell responses: a novel mechanism of tumor-induced immune exclusion

BackgroundLymphocyte antigen 6 complex, locus E (Ly6E) has been initially demonstrated to involve in T cell activity and impair viral infectivity. Recently, high expression levels of Ly6E have been reported in tumor microenvironment (TME) of various types of cancers. However, the immunoregulatory mechanism of Ly6E manipulating TME remains unknown.MethodsTCGA database and Kaplan–Meier plotter database were used to evaluate the correlation between Ly6E expression levels and cancer patient survival. After analyzing Ly6E expression levels in human breast cancer tissues and tumor cell lines, we generated Ly6E knockout (KO) and overexpression (OE) mouse cell lines. Cell proliferation ability in vitro and the ability of growth and metastasis in mouse tumor models were compared between KO/OE and wild-type tumor cells. On day 7 after tumor implantation, tumor tissues were separated for flow cytometric assay, bulk RNA sequencing and single-cell RNA sequencing (ScRNA-seq). The role of Ly6E-expressing tumor cell on macrophage was analyzed in vitro.ResultsOur result surprisingly found that high Ly6E expression levels were associated with CD8+ T cell exclusion in tumor tissues and resistance to immunotherapy. Our data showed that knockout of Ly6E in tumor cells prompts tumor regression and inhibits tumor metastases, and Ly6E-OE tumor cells vice versa. The enhanced anti-tumor effect of Ly6E knockout in tumor cells was dependent on T cell response and formed long-lasting memory. The increase in the CD8+ T-cell infiltration into the tumor islet of Ly6E-KO tumors confirmed the role of Ly6E on T cell exclusion. ScRNA-seq analysis showed that M2 macrophages are particularly abundant in the Ly6E-expressing tumor tissues, especially M2-4 macrophage cluster identified by high levels of Arg-1, indicates that Ly6E-expressing tumor cells might restrict T cell infiltration via M2 macrophages. Moreover, in vitro assay showed that cell culture media derived from Ly6E-positive tumor cells promoted macrophage migration and M2 polarization.ConclusionOur study illuminated that Ly6E-expressing tumor cells facilitated the accumulation of M2 macrophages in TME, which contributes to CD8+ T cell exclusion and provides new insights for improving efficacy of cancer immunotherapy.

Chitosan-based hydrogels in cancer therapy: Drug and gene delivery, stimuli-responsive carriers, phototherapy and immunotherapy

Nanotechnology has transformed the oncology sector by particularly targeting cancer cells and enhancing the efficacy of conventional therapies, not only improving efficacy of conventional therapeutics, but also reducing systemic toxicity. Environmentally friendly materials are the top choice for treating cancer. Chitosan, sourced from chitin, is widely used with its derivatives for the extensive synthesis or modification of nanostructures. Chitosan has been deployed to develop hydrogels, as 3D polymeric networks capable of water absorption with wide biomedical application. The chitosan hydrogels are biocompatible and biodegradable structures that can deliver drugs, genes or a combination of them in cancer therapy. Increased tumor ablation, reducing off-targeting feature and protection of genes against degradation are benefits of using chitosan hydrogels in cancer therapy. The efficacy of cancer immunotherapy can be improved by chitosan hydrogels to prevent emergence of immune evasion. In addition, chitosan hydrogels facilitate photothermal and photodynamic therapy for tumor suppression. Chitosan hydrogels can synergistically integrate chemotherapy, immunotherapy, and phototherapy in cancer treatment. Additionally, chitosan hydrogels that respond to stimuli, specifically thermo-sensitive hydrogels, have been developed for inhibiting tumors.

EDNRA regulates the tumour immune environment and predicts the efficacy and prognosis of cancer immunotherapy.

The potential role of endothelin receptor A (EDNRA) in cancer immunotherapy has been demonstrated; however, the mechanism of its therapeutic value remains to be investigated. This study aimed to reveal the potential link between cancer immunotherapy and EDNRA in human tumours. Clinical characteristics and gene expression information were acquired from the Cancer Genome Atlas database. The correlation between EDNRA expression and immune infiltration was analysed by tumour immune estimation resource (TIMER) and tumour-immune system interaction database (TISIDB). EDNRA expression in different cancer types were performed via qPCR. Immunohistochemistry was used to detect the relationships between EDNRA protein and immune checkpoints. The results have founded that EDNRA was differentially expressed in various tumours, and highly associated with patient's age and tumour stage. It is also of high potential prognostic value in predicting patient survival. It has been verified that the EDNRA, JAK-STAT, and TGF-β signalling pathways are involved in cancers. In general, EDNRA positively correlated with immunomodulatory agents, immune cell infiltration, and immunotherapy markers. Immunohistochemical analysis of breast cancer tissues showed that EDNRA was positively correlated with NRP1 expression. Furthermore, patients with low EDNRA levels showed a superior response to immunotherapy. The functional study found that EDNRA expression is upregulated in MDA-MB-231 and HepG2 cells, and knockdown of EDNRA inhibits proliferation and migration of cells. In conclusion, the immunotherapeutic function of EDNRA was elucidated in this study. EDNRA may be an important target in tumour immunotherapy and provide new insights for tumour immunotherapy.

Metabolic pathways fueling the suppressive activity of myeloid-derived suppressor cells.

Myeloid-derived suppressor cells (MDSC) are considered an aberrant population of immature myeloid cells that have attracted considerable attention in recent years due to their potent immunosuppressive activity. These cells are typically absent or present in very low numbers in healthy individuals but become abundant under pathological conditions such as chronic infection, chronic inflammation and cancer. The immunosuppressive activity of MDSC helps to control excessive immune responses that might otherwise lead to tissue damage. This same immunosuppressive activity can be detrimental, particularly in cancer and chronic infection. In the cancer setting, tumors can secrete factors that promote the expansion and recruitment of MDSC, thereby creating a local environment that favors tumor progression by inhibiting the effective immune responses against cancer cells. This has made MDSC a target of interest in cancer therapy, with researchers exploring strategies to inhibit their function or reduce their numbers to improve the efficacy of cancer immunotherapies. In the context of chronic infections, MDSC can lead to persistent infections by suppressing protective immune responses thereby preventing the clearance of pathogens. Therefore, targeting MDSC may provide a novel approach to improve pathogen clearance during chronic infections. Ongoing research on MDSC aims to elucidate the exact processes behind their expansion, recruitment, activation and suppressive mechanisms. In this context, it is becoming increasingly clear that the metabolism of MDSC is closely linked to their immunosuppressive function. For example, MDSC exhibit high rates of glycolysis, which not only provides energy but also generates metabolites that facilitate their immunosuppressive activity. In addition, fatty acid metabolic pathways, such as fatty acid oxidation (FAO), have been implicated in the regulation of MDSC suppressive activity. Furthermore, amino acid metabolism, particularly arginine metabolism mediated by enzymes such as arginase-1, plays a critical role in MDSC-mediated immunosuppression. In this review, we discuss the metabolic signature of MDSC and highlight the therapeutic implications of targeting MDSC metabolism as a novel approach to modulate their immunosuppressive functions.

In Situ Self-Assembly of Antibody-Rhamnose Complex as a Pre-Targeting Strategy for Enhanced Cancer Immunotherapy.

Enhancing the Fc effector functions of monoclonal antibodies (mAbs) is a proven strategy for improving cancer immunotherapy. In this study, we present a novel pre-targeting approach that integrates host-guest chemistry with an antibody-recruiting concept to create mAbs with superior effector functions. Using rituximab (RTX), a clinically approved anti-CD20 mAb, as our model, we modified RTX by conjugating it with adamantane (Ada) derivatives and various polyethylene glycol (PEG) linkers to produce RTX-Ada conjugates. These conjugates effectively formed RTX-rhamnose (Rha) complexes in situ through self-assembly, driven by host-guest interactions with Rha-modified β-cyclodextrin. This mechanism successfully redirected endogenous anti-Rha antibodies to target cells, enhancing the availability of Fc domains for improved effector functions, including complement-dependent cytotoxicity (CDC). A structure-activity relationship study indicated that the potency of these in situ complexes was significantly influenced by the length of the PEG linker used; shorter PEG linkers correlated with higher CDC activity. Given the variability in endogenous antibody levels among individuals, this strategy presents a flexible and promising platform for enhancing the efficacy of mAb-based cancer immunotherapy.