Cancer Biology Commons^™

Investigation Into The A/Ss Of Cervical Cancer And Its Effects On Tumor Control Probability In Radiation Therapy, Cameron Thayer-Freeman

Theses and Dissertations--Radiation Medicine

The standard of care for locally advanced cervical cancer is chemoradiation, consisting of conventional external beam therapy (EBT) followed by a boost of high dose rate (HDR) brachytherapy. These two radiation treatments will illicit different degrees of biological response depending on the tissue in question, and quantifying the overall effect the combined treatments will have require some form of biological modeling. The linear quadratic (LQ) model of cell survival is the most widely used radiobiological model in clinics across the nation.

It is quantified by the parameters a and ß, which model how radiation generates lethal damage in a population …

Brain-Derived Extracellular Vesicles Potentially Mediate Crosstalk With Peripheral Organs In Neurodegenerative Diseases, Ramzi H. Hamdalla, Vibha B. Bhaskar, Changhai Tian

Toxicology and Cancer Biology Faculty Publications

Brain-Derived Extracellular vesicles (BDEVs) are emerging mediators of intra- and interorgan communication in neurodegenerative diseases (NDs) such as Alzheimer’s Disease (AD) and Parkinson’s Disease (PD). A growing body of evidence suggests that BDEVs play an important role in modulating intercellular communication within the central nervous system in the pathogenesis of many NDs. By transporting non-coding RNAs (e.g., miRNAs) and important pathological proteins, BDEVs also influence peripheral organs and contribute to the progression of disease in the central nervous system (CNS). This review extends the understanding of NDs beyond solely brain dysfunction and gives a novel framework for the progression of …

Investigation Of Genx Exposure To Pathways Associated With Colorectal Cancer Risk, Emily J. Ferguson

Theses and Dissertations--Toxicology and Cancer Biology

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants widely detected in drinking water and food sources, resulting in chronic human exposure. Among these compounds, hexafluoropropylene oxide dimer acid (HFPO-DA), commonly known as GenX, has been introduced as a short-chain replacement for legacy PFAS such as perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Although GenX is believed to be a safer alternative, emerging research suggests it can still affect human health.

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer-related death in the United States, highlighting the need to better understand environmental …

Uncovering The Mechanism Of Reep2-Mediated Emt-Driven Membrane Trafficking In Lung Adenocarcinoma, Kevin Fulp

Theses and Dissertations--Toxicology and Cancer Biology

Membrane trafficking is frequently disrupted during cancer progression, and the underlying mechanisms remain largely unknown. Currently, no effective drugs target dysregulated membrane trafficking for cancer treatment. Recent evidence has demonstrated that epithelial-to-mesenchymal transition (EMT) in lung adenocarcinoma (LUAD) employs a membrane trafficking program to coordinate cancer cell invasion and immunosuppression. To further dissect the pro-tumorigenic membrane trafficking program, we initiated an in vivo CRISPRi screen to assess more than 2,000 membrane trafficking-related genes in a syngeneic mouse LUAD model. We identified REEP2, an endoplasmic reticulum (ER) shaping protein, as a novel regulator of EMT-driven membrane trafficking. High REEP2 expression is …

Reep2-Driven Pro-Metastatic Secretion Promotes Lung Cancer Progression, Oluwafunminiyi E. Obaleye

Theses and Dissertations--Toxicology and Cancer Biology

Membrane trafficking plays a critical role in cellular function and is frequently dysregulated in cancer to promote metastasis. In lung adenocarcinoma (LUAD), the epithelial-to-mesenchymal transition (EMT) activating transcription factor, ZEB1, drives a pro-metastatic membrane trafficking program; however, the underlying molecular mechanisms remain poorly understood. Using a CRISPR interference (CRISPRi) in vivo screen of 2,099 membrane trafficking regulators in a syngeneic mouse model of EMT-driven LUAD, we identified REEP2 — an endoplasmic reticulum (ER) shaping protein — as a critical regulator of tumor progression. REEP2 mRNA expression correlates with poor prognosis, EMT signatures, and an immunosuppressive tumor microenvironment in LUAD patients. …

Artesunate Enhances The Efficacy Of Enzalutamide In Advanced Prostate Cancer, Xinyi Wang, Jinghui Liu, Fengyi Mao, Yifan Kong, Qiongsi Zhang, Chaohao Li, Daheng He, Chi Wang, Yanquan Zhang, Ruixin Wang, Sally R. Ellingson, Qiou Wei, Zhiguo Li, Xiaoqi Liu

Markey Cancer Center Faculty Publications

Prostate cancer (PCa) is one of the leading causes of death among men worldwide. Treatments targeting the androgen receptor pathway remain the standard therapy for PCa patients. Enzalutamide (ENZ), a second-generation androgen receptor inhibitor, was developed to treat castration-resistant prostate cancer. However, while patients initially respond to ENZ, drug resistance typically develops within a few months. Artesunate (ART), a semisynthetic derivative of the Artemisinin plant, is approved for antimalaria treatment. In this study, we conducted an FDA-approved drug screening and identified ART as a potential candidate for overcoming ENZ resistance in PCa. Mechanistically, ART induces the degradation of c-Myc, enhancing …

Artesunate Enhances The Efficacy Of Enzalutamide In Advanced Prostate Cancer, Xinyi Wang, Jinghui Liu, Fengyi Mao, Yifan Kong, Qiongsi Zhang, Chaohao Li, Daheng He, Chi Wang, Yanquan Zhang, Ruixin Wang, Sally R. Ellingson, Qiou Wei, Zhiguo Li, Xiaoqi Liu

Toxicology and Cancer Biology Faculty Publications

Prostate cancer (PCa) is one of the leading causes of death among men worldwide. Treatments targeting the androgen receptor pathway remain the standard therapy for PCa patients. Enzalutamide (ENZ), a second-generation androgen receptor inhibitor, was developed to treat castration-resistant prostate cancer. However, while patients initially respond to ENZ, drug resistance typically develops within a few months. Artesunate (ART), a semisynthetic derivative of the Artemisinin plant, is approved for antimalaria treatment. In this study, we conducted an FDA-approved drug screening and identified ART as a potential candidate for overcoming ENZ resistance in PCa. Mechanistically, ART induces the degradation of c-Myc, enhancing …

Characterizing And Targeting The Non-Catalytic Functions Of Phosphatase Of Regenerating Liver 3 (Prl-3) In Oncogenesis And Cancer Progression, Jeffery T. Jolly

Theses and Dissertations--Molecular and Cellular Biochemistry

Phosphatase of Regenerating Liver 3 (PRL-3) is frequently upregulated in various cancers and is associated with poor patient prognosis. Although traditionally studied for its phosphatase activity, PRL-3 also interacts with the CNNM family of magnesium transporters through its catalytic site, and these two functions are mutually exclusive at any given time. Most previous studies relied on a commonly used PRL-3 mutation that disrupts both phosphatase activity and CNNM binding, making it challenging to determine which function drives its oncogenic effects. To address this gap in the field, I utilized a panel of PRL-3 mutants that selectively disrupt either phosphatase activity …

Spermidine And Polyamine Blockade As Key Mediators Of Intestinal Epithelial Cell Functions, Madison Lynn Flory

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Frequently, alterations in the composition of the gut microbiota and its metabolites are linked with intestinal diseases, including inflammatory bowel disease and colorectal cancer. However, the direct connections between alterations in the microbiome and disease states often remain elusive. Prior research has identified increases in both polyamines, which are a class of microbial metabolite, and in the abundance of bacteria that can produce polyamines, in a murine colorectal cancer model. Understanding the significance of the interaction between these microbial metabolites and intestinal epithelial cells (IECs) will provide new and expanded evidence of the importance of the gut microbiome in colorectal …

Cardiac Injury Regulates Neuroinflammation Through Extracellular Vesicle–Mediated Heart-Brain Crosstalk, Qingxuan Li, Ramzi H. Hamdalla, Neha Dhyani, Lijun Sun, Lie Gao, Tara L. Rudebush, Irving H. Zucker, Changhai Tian

Toxicology and Cancer Biology Faculty Publications

Cognitive impairment is common in heart failure patients, contributing to morbidity and mortality. This impairment may be linked to neuroinflammation in heart failure. However, the primacy of the heart-brain axis remains to be completely understood. Here, we elucidate the potential effects of myocardial injury on pathways and inflammatory mediators responsible for cognitive impairment using a rodent myocardial injury model. The results demonstrate direct extracellular vesicle (EV)-mediated heart-brain crosstalk and the glial uptake of cardiac EVs. In addition, brain inflammation was also elicited following myocardial injury. Moreover, cardiac EVs promote brain microglial cell activation in vitro, potentially mediated by EV-enriched micro-RNAs …

Developing Novel Therapeutic Strategies For Mcrc With A Brafv600e Mutation, Mariah Geisen

Theses and Dissertations--Toxicology and Cancer Biology

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. The overall incidence rates of CRC have decreased in those over 50, but there is an increasing incidence rate in those under 50. Risk factors for CRC include diet, family history, and a sedentary lifestyle. Early detection of CRC is key to patient survival and treatment response. Localized CRC has a survival rate of 90% and allows for surgical resection and chemotherapy. The 5-year survival for metastatic CRC (mCRC) is significantly reduced to around 14%. Despite early detection, 50% of patients will develop metastasis after surgical resection and …

A Probabilistic Approach To Estimate The Temporal Order Of Pathway Mutations Accounting For Intra-Tumor Heterogeneity, Menghan Wang, Yanqi Xie, Jinpeng Liu, Austin Li, Li Chen, Arnold Stromberg, Susanne Arnold, Chunming Liu, Chi Wang

Markey Cancer Center Faculty Publications

The development of cancer involves the accumulation of somatic mutations in several essential biological pathways. Delineating the temporal order of pathway mutations during tumori- genesis is crucial for comprehending the biological mechanisms underlying cancer development and identifying potential targets for therapeutic intervention. Several computational and statistical methods have been introduced for estimating the order of somatic mutations based on mutation profile data from a cohort of patients. However, one major issue of current methods is that they do not take into account intra-tumor heterogeneity (ITH), which limits their ability to accurately discern the order of pathway mutations. To address this …

Elucidation Of Mismatch Repair Regulation By Abl1: Advantages/Disadvantages Of Tyrosine Kinase Inhibitor Treatment, Hannah Daniels

Theses and Dissertations--Toxicology and Cancer Biology

DNA mismatch repair (MMR) is a critical repair process necessary for not only repairing mispairs incorporated into the DNA during replication, but also for inducing apoptosis in response to certain types of DNA damage. MMR is required for maintaining genomic integrity and due to the importance of this pathway, any impairment of its function can lead to increased mutation frequency, which is well known to be a driving force of cancer development, progression, and resistance. Despite extensive studies involving the proteins involved in the MMR pathway, the regulation of those proteins remains relatively unknown. Regulation of MLH1, a protein necessary …

Acquired Treatment Resistance In Prostate Cancer Via The Production Of Radiation Derived Extracellular Vesicles Containing Mitochondrial Proteins, Caitlin Miller

Theses and Dissertations--Toxicology and Cancer Biology

Radiation treatment (RT) is one of the most commonly administered treatments for prostate cancer (PCa) patients, yet the recurrence of tumors after RT remains one of the significant challenges in the eradication of PCa. In addition to induction of DNA damage, ROS production, and cell death, we found that RT promotes Extracellular vesicle (EV) production in PCa cells, at least in part, through H₂O₂ production (Miller CE et al., Antioxidants 2022, PMID 36358489). Since we observed EV production upon RT, EVs and their contents could play a role(s) in cancer survival after RT. By using flow cytometry …

Porcupine’S Role In The Enhancement Of Enzalutamide Efficacy In Drug Resistant Prostate Cancer, Katelyn Jones

Theses and Dissertations--Toxicology and Cancer Biology

Androgen receptor (AR) signaling continues to participate as a vital component of castration-resistant prostate cancer (CRPC). Subsequently, this has led to the development of Androgen Signaling Inhibitors (ASI), specifically Enzalutamide (ENZ), which is a direct inhibitor of AR, to clinically manage CRPC. Inevitably, ENZ treatment only provides improvement for approximately two months before advancing to an incurable form, ENZ-resistant CRPC. With PCa ranking as the second leading cause of cancer-related deaths in USA males, there is an urgency and necessity for the discovery and development of novel therapeutic approaches for CRPC. Wnt signaling has been extensively documented in its involvement …

Therapeutic Approaches And Novel Mechansims In Cancer Progression, Kendall Simpson

Theses and Dissertations--Toxicology and Cancer Biology

Prostate cancer (PCa) remains the most diagnosed cancer among men in the United States. There are various therapeutic routes that are implored to combat this fatal disease, and our work aims to increase the options made available to PCa patients. A combination treatment of Enzalutamide (Enz), an FDA approved drug for castration-resistant PCa patients, and Metformin, an FDA approved drug for type 2 diabetes, was utilized to enhance the efficacy of Enz in Enz-resistant PCa, both in vitro and in vivo. Thymic Lymphoma is one of the most common malignancies that can occur in various tissues and organs. Genomic stability …

Delineating Contributions Of Genotype And Lineage To Lung Cancer Therapy Response, Kassandra Jo Naughton

Theses and Dissertations--Toxicology and Cancer Biology

Non-small cell lung cancer (NSCLC) heterogeneity is a major challenge for determining effective treatment strategies. Adenocarcinomas (ADCs) and squamous cell carcinomas (SCCs) are histologically and epigenetically distinct subtypes of NSCLC. Patients with ADC tumors harboring mutations in both KRAS and LKB1 (aka STK11) have lower survival rates than those with KRAS-only tumors. KRAS/LKB1 tumors are not only aggressive, but also respond poorly to immunotherapy. However, these data are limited to ADCs, and it is unclear if SCCs with this genotype are also resistant to immunotherapy. We developed a mouse model of Kras^mut/Lkb1^mut capable of producing …

Zebrafish Drug Screening Identifies Erlotinib As An Inhibitor Of Wnt/ Β-Catenin Signaling And Self-Renewal In T-Cell Acute Lymphoblastic Leukemia, Majd A. Al-Hamaly, Anna H. Cox, Meghan G. Haney, Wen Zhang, Emma C. Arvin, Shilpa Sampathi, Mary Wimsett, Chunming Liu, Jessica S. Blackburn

Markey Cancer Center Faculty Publications

The Wnt/β-catenin pathway’s significance in cancer initiation, progression, and stem cell biology underscores its therapeutic potential. However, the clinical application of Wnt inhibitors remains limited due to challenges posed by off-target effects and complex cross-talk of Wnt signaling with other pathways. In this study, we leveraged a zebrafish model to perform a robust and rapid drug screening of 773 FDA-approved compounds to identify Wnt/β-catenin inhibitors with minimal toxicity. Utilizing zebrafish expressing a Wnt reporter, we identified several drugs that suppressed Wnt signaling without compromising zebrafish development. The effi- cacy of the top hit, Erlotinib, extended to human cells, where it …

Abl1/2 And Ddr1 Cooperate To Stabilize Braf/Craf To Drive Erk1/2 Reactivation And Promote Mek Inhibitor Resistance In Nras-Mutant Melanomas, Anastasia Lyon

Theses and Dissertations--Pharmacology and Nutritional Sciences

This study addresses the escalating incidence of NRAS-mutant melanomas, a type of skin cancer lacking FDA-approved targeted therapies. Despite ongoing research targeting the RAF/MEK/ERK pathway, existing drugs fail to enhance progression-free survival due to acquired resistance. This project identifies a novel role for ABL1/2 and DDR1 kinases in driving drug resistance and proliferation of NRAS-mutant melanoma cells. ABL1/2 and DDR1 cooperate to promote RAF homodimerization and protein stability in order to reactivate MEK/ERK signaling to drive MEK1/2 inhibitor (MEKi) resistance and promote survival of resistant cells. By targeting ABL1/2 and DDR1 with nilotinib, a FDA-approved anti-leukemic inhibitor, we …

Development And Biological Evaluation Of Selective Small-Molecule Inhibitors Of The Human Cytochrome P450 1b1, Austin Hachey

Theses and Dissertations--Chemistry

The human cytochrome P450 1B1 (CYP1B1) is an emerging target for small- molecule therapeutics. Several solid tumors overexpress CYP1B1 to the degree that it has been referred to as a universal tumor antigen. Conversely, its expression is low in healthy tissues. CYP1B1 may drive tumorigenesis through promoting the formation of reactive toxins from environmental pollutants or from endogenous hormone substrates. Additionally, the expression of CYP1B1 in tumors is associated with resistance to several common chemotherapies and with poor prognoses in cancer patients. However, inhibiting CYP1B1 with small molecules has been demonstrated in cellular and murine model systems to reverse this …

Understanding The Role Of Peroxiredoxin Iv In Colorectal Cancer Development, Pratik Thapa

Theses and Dissertations--Toxicology and Cancer Biology

Reactive oxygen species (ROS) are oxygen-containing free radicals and/or molecules that are more reactive than O₂. ROS such as hydroxyl radical (•OH) and hydrogen peroxide (H₂O₂) are produced naturally in the body as a result of reactions such as aerobic respiration and oxidative protein folding. ROS undergo reduction-oxidation (redox) reactions and mediate cell signaling. Accumulation of excessive ROS can damage DNA, RNA, protein and lipids. Antioxidants are enzymes and small molecules that react with ROS to modulate redox signaling and to prevent and repair oxidative damage. Examples of antioxidants include glutathione, thioredoxin, superoxide dismutase, …

Targeting Ezh2 To Improve Outcomes Of Lung Squamous Cell Carcinoma, Tanner Ducote

Theses and Dissertations--Toxicology and Cancer Biology

Only 20% of patients diagnosed with lung squamous cell carcinoma (LSCC) respond to immunotherapy. Anti-PD1 immunotherapy is most commonly prescribed to these patients; however, most will become refractory. It is important to understand the mechanisms underlying this problem to increase durability and survival. Building upon the work of other groups, our lab has demonstrated that the inhibition of the histone methyltransferase, EZH2, is crucial to maintaining an immunologically responsive microenvironment. Based on our data, we hypothesize that combining EZH2 inhibitors with anti-PD1 therapy will increase response and durability. To study non-small cell lung cancers (NSLC) our lab uses a variety …

Bioinformatic Analysis Of Proteomic And Genomic Data From Nsclc Tumors On Prognostic And Predictive Factors Of Immunotherapy Treatment, Mark Wuenschel

Theses and Dissertations--Pharmacy

Recent lung cancer research has led to advancements in molecular immunology, resulting in development of small molecule inhibitors, or immune checkpoint inhibitors, that propagate an anti-tumor T cell response. Despite increased overall and progression-free survival with reduced adverse effects compared to traditional chemotherapy, treating advanced stage lung adenocarcinoma patients remains non-curative, and evidence of non-responders or tumor recurrence to immune checkpoint inhibitor therapy is growing. Also, compared to traditional chemotherapy, there is a lower percentage of patients who respond to small molecule inhibitors. In this analysis of proteomic and genomic data from The Cancer Proteome Atlas and Global Data Commons …

Advancements In Glycogen Detection And Spatial Profiling Reveals A New Therapeutic Path For Ewing Sarcoma: A Non-Traditional Glycogen Storage Disease, Lyndsay E. A. Young

Theses and Dissertations--Molecular and Cellular Biochemistry

Glycogen is the primary glucose storage carbohydrate in mammals, and it is synthesized in most tissues. As glycogen architecture modulates its role in metabolism, it is essential to accurately evaluate and quantify glycogen, glycogen phosphate, and chain length of glucose monomers. Simultaneous quantitation of glycogen architecture is challenging. This work describes a highly-sensitive method for the detection of both glycogen-derived glucose and glucose-phosphate esters utilizing gas-chromatography coupled mass spectrometry (GCMS). We then integrated this glycogen quantitation workflow into a routinely utilized metabolomics-based assay. The work presented describes a workflow for the normalization of polar metabolites utilizing amino acids derived from …

The Role Of Dynamin Related Protein 1-Mediated Mitochondrial Dynamics In Colorectal Cancer, Sumati Raj Hasani

Theses and Dissertations--Molecular and Cellular Biochemistry

Cancer cells are known for their ability to adapt variable metabolic programs depending on the availability of specific nutrients. Consequently, metabolic reprogramming has been increasingly recognized as a major mechanism that fuels tumorigenesis and disease progression. Here, we have investigated the role of a pro-fission factor, Dynamin-Related Protein 1 (Drp1), in promoting metabolic adaptation in colon cancer.

Our studies have shown that fatty acid (FAs) uptake alters cellular metabolic pathways in colon cancer cells to favor fatty acid oxidation through the activation of Drp1. Uptake of FAs induces mitochondrial fragmentation by promoting ERK-dependent phosphorylation of Drp1 at the S616 site, …

Conserved Novel Interactions Between Post-Replicative Repair And Mismatch Repair Proteins Have Differential Effects On Dna Repair Pathways, Anna K. Miller

Theses and Dissertations--Toxicology and Cancer Biology

DNA mismatch repair (MMR) is the DNA repair mechanism that repairs base-base mispairs and small insertions and deletions remaining after replication. MMR is also required for apoptosis after certain types of exogenous DNA damage that result in damage-associated mispairs. The basic MMR mechanism is well understood; however, proteins associated with MMR continue to be identified. The roles of these interacting proteins in MMR are largely unknown. We have identified the yeast protein Rad5 as a novel interactor of the critical MMR proteins Msh2 and Mlh1. Rad5 is a DNA helicase and E3 ubiquitin ligase involved in post-replicative repair. However, to …

Elucidating The Functional Importance Of Peroxiredoxin Iv In Prostate Cancer And Its Secretion Mechanism, Na Ding

Theses and Dissertations--Toxicology and Cancer Biology

Prostate cancer is the most common and second leading cause of cancer death in men. Prevailing theories state that inflammation may drive prostate carcinogenesis via oxidative stress and the generation of reactive oxygen species (ROS) that induce somatic mutagenesis. Since high proliferating cells or cancer cells exhibit aberrant metabolism to satisfy the needs of energy for rapid cell proliferation, they also generate high levels of ROS which stimulates the expression of cellular antioxidants to overcome the dysregulation of redox homeostasis through the regulation of redox-sensitive transcription factors. Among different antioxidants, peroxiredoxin (Prx) family proteins are the highly conserved and mostly …

Beyond Mitosis, Plk1-Mediated Phosphorylation Re-Wires Cancer Metabolism And Promotes Cancer Progression, Qiongsi Zhang

Theses and Dissertations--Toxicology and Cancer Biology

Polo-like kinase 1 (PLK1) is a well- characterized regulator of cell division and is known to be highly expressed in certain types of tumors. It has been demonstrated the multifaceted roles of PLK1 in regulation of transcription, translation, epigenetics, DNA damage and cellular metabolism et al. Despite these findings, the precise mechanisms by which PLK1 regulates these processes beyond mitosis remain unclear. PLK1-mediated phosphorylation and misregulation of its substrates has been linked to tumorigenesis, cancer progression, drug resistance and worse prognosis. In this study, we investigated the non-canonical functions of PLK1 in cancer metabolism and drug resistance. We found that …

Upregulation Of Cd36, A Fatty Acid Translocase, Promotes Colorectal Cancer Metastasis By Increasing Mmp28 And Decreasing E-Cadherin Expression, James Drury, Piotr G. Rychahou, Courtney O. Kelson, Mariah E. Geisen, Yuanyuan Wu, Daheng He, Chi Wang, Eun Y. Lee, B. Mark Evers, Yekaterina Y. Zaytseva

Surgery Faculty Publications

Altered fatty acid metabolism continues to be an attractive target for therapeutic intervention in cancer. We previously found that colorectal cancer (CRC) cells with a higher metastatic potential express a higher level of fatty acid translocase (CD36). However, the role of CD36 in CRC metastasis has not been studied. Here, we demonstrate that high expression of CD36 promotes invasion of CRC cells. Consistently, CD36 promoted lung metastasis in the tail vein model and GI metastasis in the cecum injection model. RNA-Seq analysis of CRC cells with altered expression of CD36 revealed an association between high expression of CD36 and upregulation …

Novel Mechanism Of Endogenous Pancreatic Cancer Cell Expression Of Immune Checkpoint Programmed Cell-Death 1 Protein (Pd-1) Inducing Epithelial-To-Mesenchymal Transition (Emt) Through The Met Pathway And Promoting Cancer Progression In An Immune-Independent Process, Megan M. Harper

Theses and Dissertations--Clinical and Translational Science

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers with few treatment options, necessitating an urgent need for novel therapeutics. Immuno-oncologic (IO) therapies have revolutionized anti-cancer regimens in the past decade but typically involve reactivation of adaptive immune responses. In particular, immune checkpoint PD-1 is traditionally expressed only on immune cells while PD-L1 (PD-1 ligand) is overexpressed on cancer cells. When tumor-endogenous PD-L1 binds the PD-1 receptor on T-cells, the immune cells undergo anergy resulting in self-tolerance and cancer cell immune evasion. However, contrary to standard dogma, we previously demonstrated tumor-endogenous PD-1 expression in PDAC. Our data indicated that …