Biology subjects

DeMarco, K. D.

Publications and source records attributed to DeMarco, K. D..

4 recordsLinked to original sources

bioRxiv2025

Multiplexed cytokine and antigen mRNA administration generates durable anti-tumor immunity against pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a devastating malignancy characterized by limited therapeutic options for advanced disease. Immunotherapy, in particular, has had dismal success rates in the PDAC due to a tumor microenvironment (TME) that contributes to immune exclusion and poor drug delivery. Many cytokines necessary for Natural Killer (NK) and T cell chemotaxis, activation, and cytotoxicity are absent in the PDAC TME. Despite their early success, cytokine therapies have largely failed in the treatment of solid tumors as a result of the lack of efficacy of single cytokine administration and toxicities from systemic delivery. To overcome these limitations, we designed multiplexed mRNA cocktails encoding diverse interleukins, chemokines, and interferons for intratumoral delivery. Administration of a cytokine-encoding mRNA mixture into mice with orthotopically transplanted PDAC tumors achieved robust yet transient cytokine expression locally in the PDAC TME, leading to NK cell and CD8+ T cell immunity and reduced tumor growth and fibrosis in multiple mouse models. Combining cytokine mRNAs with those encoding tumor-associated antigens further activated CD8+ T cell-mediated tumor control and enhanced survival after just a single dose in PDAC-bearing mice. Remarkably, lipid-based nanoparticle (NP) encapsulation of an all-in-one cytokine and antigen mRNA cocktail allowed safe systemic administration and local delivery of these immunogenic signals to autochthonous PDAC tumors in genetically engineered mouse models, culminating in complete tumor responses in 50% of animals. These results suggest that multiplexed mRNA approaches to delivering cytokine signals and antigens generally absent in the TME could pave the way for an effective immunotherapy for PDAC.

cancer biology↗

bioRxiv2024

MYC and p53 alterations cooperate through VEGF signaling to repress cytotoxic T cell and immunotherapy responses in prostate cancer

Patients with castration-resistant prostate cancer (CRPC) are generally unresponsive to tumor targeted and immunotherapies. Whether genetic alterations acquired during the evolution of CRPC impact immune and immunotherapy responses is largely unknown. Using our innovative electroporation-based mouse models, we generated distinct genetic subtypes of CRPC found in patients and uncovered unique immune microenvironments. Specifically, mouse and human prostate tumors with MYC amplification and p53 disruption had weak cytotoxic lymphocyte infiltration and an overall dismal prognosis. MYC and p53 cooperated to induce tumor intrinsic secretion of VEGF, which by signaling through VEGFR2 expressed on CD8+ T cells, could directly inhibit T cell activity. Targeting VEGF-VEGFR2 signaling in vivo led to CD8+ T cell-mediated tumor and metastasis growth suppression and significantly increased overall survival in MYC and p53 altered CPRC. VEGFR2 blockade also led to induction of PD-L1, and in combination with PD-L1 immune checkpoint blockade produced anti-tumor efficacy in multiple preclinical CRPC mouse models. Thus, our results identify a genetic mechanism of immune suppression through VEGF signaling in prostate cancer that can be targeted to reactivate immune and immunotherapy responses in an aggressive subtype of CRPC. SignificanceThough immune checkpoint blockade (ICB) therapies can achieve curative responses in many treatment-refractory cancers, they have limited efficacy in CRPC. Here we identify a genetic mechanism by which VEGF contributes to T cell suppression, and demonstrate that VEGFR2 blockade can potentiate the effects of PD-L1 ICB to immunologically treat CRPC.

cancer biology↗

bioRxiv2023

Nanoparticle delivery of innate immune agonists combines with senescence-inducing agents to mediate T cell control of pancreatic cancer

Pancreatic ductal adenocarcinoma has quickly risen to become the 3rd leading cause of cancer-related death. This is in part due to its fibrotic tumor microenvironment (TME) that contributes to poor vascularization and immune infiltration and subsequent chemo- and immunotherapy failure. Here we investigated an innovative immunotherapy approach combining local delivery of STING and TLR4 innate immune agonists via lipid-based nanoparticles (NPs) co-encapsulation with senescence-inducing RAS-targeted therapies that can remodel the immune suppressive PDAC TME through the senescence-associated secretory phenotype. Treatment of transplanted and autochthonous PDAC mouse models with these regimens led to enhanced uptake of NPs by multiple cell types in the PDAC TME, induction of type I interferon and other pro-inflammatory signaling, increased antigen presentation by tumor cells and antigen presenting cells, and subsequent activation of both innate and adaptive immune responses. This two-pronged approach produced potent T cell-driven and Type I interferon-dependent tumor regressions and long-term survival in preclinical PDAC models. STING and TLR4-mediated Type I interferon signaling were also associated with enhanced NK and CD8+ T cell immunity in human PDAC. Thus, combining localized immune agonist delivery with systemic tumor-targeted therapy can synergize to orchestrate a coordinated innate and adaptive immune assault to overcome immune suppression and activate durable anti-tumor T cell responses against PDAC. SUMMARYCombining senescence-inducing MEK and CDK4/6 inhibitors with nanoparticle delivery of STING and TLR4 agonists leads to interferon-driven and cytotoxic T cell-mediated PDAC control.

cancer biology↗

bioRxiv2022

EZH2 inhibition remodels the inflammatory senescence-associated secretory phenotype to potentiate pancreatic cancer immune surveillance

T cell-activating immunotherapies that produce durable and even curative responses in some malignancies have failed in pancreatic ductal adenocarcinoma (PDAC) due to rampant immune suppression and poor tumor immunogenicity. We and others have demonstrated that induction of cellular senescence and its accompanying senescence-associated secretory phenotype (SASP) can be an effective approach to activate not only T cell but also cytotoxic Natural Killer (NK) cell-mediated anti-tumor immunity. Here we found that the pancreas tumor microenvironment (TME) suppresses NK and T cell surveillance following therapy-induced senescence through EZH2-mediated repression of pro-inflammatory SASP genes. Genetic or pharmacological inhibition of EZH2 or its methyltransferase activity stimulated the production of pro-inflammatory SASP chemokines CCL2 and CXCL9/10 that led to enhanced NK and T cell infiltration and tumor eradication in preclinical PDAC mouse models. EZH2 activity was also associated with suppression of SASP-associated inflammatory chemokines and cytotoxic lymphocyte immunity and reduced overall survival in a PDAC patient cohort. These results demonstrate that EZH2 mediates epigenetic repression of the pro-inflammatory SASP in the pancreas TME, and that EZH2 blockade in combination with senescence-inducing therapies could be a powerful means to potentiate NK and T cell surveillance in PDAC to achieve immune-mediated tumor control.

cancer biology↗