Combined Treatment Research Articles

Abstract A047: Fibroblast-specific IL1 receptor inhibition reprograms the inflammatory stroma to overcome the immunosuppressive tumor microenvironment in pancreatic cancer

Abstract OBJECTIVE: KRAS-driven inflammatory signaling in pancreatic ductal adenocarcinoma (PDAC) promotes cancer-associated fibroblast (CAF) polarization and an immunosuppressive tumor microenvironment (iTME), driving therapeutic resistance. IL1α, a downstream product of KRAS signaling, activates the pro-inflammatory CAF (iCAF) phenotype and correlates with worse survival. Using patient and PDAC mouse model single-cell RNA sequencing (scRNAseq) data, we have shown that the IL1 Receptor (IL1R1) is highly enriched in the fibroblast compartment. However, the role of IL1R1 in modulating iCAFs and the iTME remains poorly understood. We hypothesize that CAF-specific disruption of IL1R1 signaling will reprogram cellular components of the PDAC TME to overcome the immunosuppressive milieu and therapeutic resistance. METHODS: The effects of IL1R1 inhibition on iCAF modulation in vivo were determined in Ptf1aCre/+, LSL-KrasG12D/+, Tgfbr2flox/flox (PKT) mice treated with IL1R1 antagonist. To determine if CAF-specific silencing of IL1R1 recapitulates the TME remodeling after IL1R1 inhibition, we generated a fibroblast-specific IL1R1KO mouse model Col1a2Cre/+;Il1r1flox/flox (CAF-Il1r1KO) and orthotopically injected KPC tumor cells for endpoint analysis. Flow cytometry was performed in primary tumors of CAF-Il1r1KO and littermate controls. Functional experiments evaluating myeloid-derived suppressor cell (MDSC) trafficking were performed using ex vivo bone marrow-derived cells (BMDCs) co-cultured with CAF/tumor-conditioned media (CM) with/without IL1R1 inhibition in a transwell system. MDSC contribution to iTME was assessed by co-culturing MDSCs from CAF-Il1r1KO tumors and splenic T cells from naïve C57BL/6 mice. To investigate the effects of IL1R1 deletion in overcoming therapeutic resistance, survival studies in CAF-Il1r1KO mice with chemotherapy were conducted. RESULTS: Treatment of PKT mice with IL1R1 antagonist diminished transcriptional levels of Il6 and Cxcl1, iCAF-associated cytokines, in the CAF compartment. Compared to littermate controls, orthotopic tumors in CAF-Il1r1KO showed significant reduction in tumor weights, increased CD8+ T cell infiltration, and overall reduction in polymorphonuclear (PMN) MDSC trafficking by flow cytometry. Moreover, migration of BMDCs was reduced when co-cultured with CAF/tumor CM and IL1R1 antagonist. In addition, co-culture of MDSCs from CAF-Il1r1KO mice with naïve T cells showed diminished inhibition of T cell functional activity. Chemotherapy treatment of orthotopic tumors in CAF-Il1r1KO mice showed significantly decreased tumor size and improved survival compared to tumors in littermate controls. CONCLUSION: Our findings illustrate a novel mechanism of CAF-specific disruption of IL1R1 signaling inhibiting trafficking of immunosuppressive MDSCs and increased infiltration of cytotoxic CD8+ T cells in the PDAC TME. These data pave the way for novel combinatorial treatment strategies targeting IL1R1 to overcome chemotherapeutic resistance through reprogramming of the stromal compartment in PDAC. Citation Format: Camille Acevedo, Samara Singh, Austin Dosch, Edmond W Box, Iago C Silva, Anna Bianchi, Siddharth Mehra, Haleh Amirian, Andrew Adams, Nagaraj Nagathihalli, Jashodeep Datta, Nipun B Merchant. Fibroblast-specific IL1 receptor inhibition reprograms the inflammatory stroma to overcome the immunosuppressive tumor microenvironment in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A047.

Abstract C074: Influence of Cell Death and Stress on the Tumor Microenvironment and EMT in Pancreatic Ductal Adenocarcinoma Through Single Cell and Spatial Transcriptomics

Abstract Pancreatic cancer remains one of the most deadly cancers, with over 450,000 fatalities in 2022 alone. The most lethal variation of this cancer is Pancreatic Ductal Adenocarcinoma (PDAC), with a 5-year survival rate of under 10%. Combination chemotherapy has provided major advances in this disease but it remains challenging for many reasons including the immunosuppressive nature of the tumor microenvironment (TME). PDAC has a highly desmoplastic microenvironment that suppresses antitumor immunity and promotes tumor cell invasion, metastasis, and resistance through epithelial to mesenchymal transition (EMT) of cancer cells. Cancer cells can undergo various forms of cell death, notably apoptosis, necrosis, autophagy, pyroptosis, and ferroptosis. These mechanisms are triggered by different cellular stressors and shape the microenvironment. Through the use of 15 Visium spatial transcriptomics samples from publicly available primary PDAC tumors and paired single-cell RNA (scRNA) data, we aim to understand how cell stress and cell death shape the tumor microenvironment (TME) and epithelial-mesenchymal transition (EMT). By leveraging information from known pathways in literature, we will identify cellular programs related to stress, death, and EMT. We will explore intracellular correlations within single-cell data and extracellular interactions within the TME using spatial data to uncover how different forms of cell death and stress signatures influence the TME and EMT spectrum. The initial phase involves identifying the types of stress that lead to various forms of cell death intracellularly and validating these gene signatures. Subsequently, we will apply these validated signatures to the spatial data to correlate each score and search for significant overlapping programs. This will extend beyond stress and death, incorporating TME signatures corresponding to different cell types and the EMT spectrum. By understanding the signals that promote the death of various cell populations, we aim to identify combination treatments that target both ends of the EMT spectrum. Additionally, this research will provide insights into the inflammatory impact of cell death on the TME. Our approach aims to inform the development of therapies that disrupt resistance mechanisms, ultimately improving treatment outcomes for patients with PDAC. This research can potentially reveal new therapeutic targets and strategies, enhancing our ability to combat this deadly disease. Citation Format: Rahul Bansal, Izabella Zamora, Samuel Wright, Nir Hacohen, Arnav Mehta. Influence of Cell Death and Stress on the Tumor Microenvironment and EMT in Pancreatic Ductal Adenocarcinoma Through Single Cell and Spatial Transcriptomics [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C074.

Abstract A004: A Phase 1B/2 trial of second line immunotherapy with pepinemab and avelumab for patients with metastatic pancreatic adenocarcinoma

Abstract Background: Pancreatic adenocarcinoma (PDAC) is a leading cause of cancer-related mortality with poor prognosis despite maximal therapy and is recalcitrant to approved immunotherapies. In PDAC, Semaphorin 4D (SEMA4D) expression is prognostic in patients who have undergone surgical resection and correlates with tumor infiltration of activated CD8+ T-cells. Furthermore, preclinical studies suggest that monoclonal blockade of SEMA4D supports CD8+T cells tumoral infiltration and activation, sensitizing PDAC to immune checkpoint blockade (ICB). Thus, we hypothesized that a humanized anti-SEMA4D antibody (pepinemab) may improve disease control and responsiveness to ICB in patients with PDAC. Methods: We designed a phase Ib/II single-arm clinical trial to evaluate the safety, tolerability, and efficacy of pepinemab with anti-PD-L1 (avelumab) in patients with chemotherapy-refractory PDAC (NCT05102721). The study follows a dose de-escalation schema starting at a dose combination of 20mg/kg pepinemab and 800mg avelumab every two weeks. Patient accrual for phase 1b utilizes the Bayesian Optimal Interval design targeting a dose-limiting toxicity rate of 30% or less. After 16 subjects receive a given combination dose, a Simon’s two stage assessment of futility will be undertaken with expansion to phase 2 if 2 or more subjects demonstrate response. Treatment response is assessed via RECIST 1.1 criteria with surveillance CT prior to enrollment and after completion of two cycles (8 weeks). Baseline and on-treatment tumor biopsies (after completion of one cycle, 4 weeks) are performed to analyze changes in immune, stromal, and genomic profiles to elucidate mechanisms of treatment response and failure. Patient reported outcomes are incorporated (FACT-Hep and FAACT subdomains) to assess disease-specific symptoms. Results: A total of 14 patients have been enrolled to date. Three subjects withdrew from the study prior to completing the evaluable period (four weeks of treatment) and nine subjects terminated treatment due to disease progression. Two subjects continue to receive combination treatment pending evaluation of tumor response. Baseline and on-treatment biopsies have been obtained and stored for correlative analysis from 8 evaluable subjects. One treatment-related adverse event occurred though the patient was able to complete treatment without further events. No treatment-related toxicities have been encountered. Conclusions: Combining pepinemab with avelumab appears to be safe and tolerable to date. Nine of eleven patients demonstrated disease progression, though 1 of these 9 demonstrated mixed response with some lesions showing radiologic partial and even complete response. Overall treatment response, survival data, and correlative science forthcoming. Citation Format: Luis I Ruffolo, Matthew Byrne, Bailey Hilty, Brian A Belt, Yatee Dave, Paul Burchard, Terrence Fisher, Elizabeth E. Evans, Crystal Mallow, Megan Boise, Darren Carpizo, Jen Jen Yeh, David C Linehan, Daniel Mulkerin. A Phase 1B/2 trial of second line immunotherapy with pepinemab and avelumab for patients with metastatic pancreatic adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A004.

Abstract A026: Studying the synergistic potential of a p53 reactivator with ROS-mediated therapies for the treatment of pancreatic cancer

Abstract Introduction: Pancreatic cancer, with a dismal five-year survival rate of just 12%, demands innovative approaches due to its resistance to current therapies. TP53 mutations, present in 75% of patients, make mutant p53 an appealing target. Thus, p53 reactivation, restoring its tumour suppressor functions, represents a promising strategy to address this challenge. While the proposed reactivator has shown efficacy in other malignancies, its potential in pancreatic cancer therapy requires further exploration. Methods: In this project, we have assessed the potential of repurposing a reactivator of mutant p53 protein, to inactivate pancreatic cancer cells. We have performed RNA-sequencing analysis in patient-derived models available in the lab, to study the signalling pathways regulated by the p53 reactivator anticancer activity. We have also studied the possibility to synergistically combine this repurposing strategy with reactive oxygen species (ROS)-mediated therapeutic approaches, as we previously observed p53 reactivation inhibits the glutathione antioxidant pathway. Results: The combination treatment induced synergistic cell death (3-fold increase) compared to monotherapy as evaluated by different molecular assays (e.g. MTT and Live/Death Assay). It also increased ROS levels (Flow cytometry) and induced paraptosis and apoptosis (Western Blot, Tomography Electron Microscopy). The RNA-seq data revealed differential expression of more than 200 genes, confirming the activation of oxidative stress and a cellular response to unfolded proteins. Moreover, Sanger sequencing results demonstrated that the sensibility of each pancreatic model to treatment was dependent on the mutational status of TP53. Conclusion/discussion: The combination therapy of a TP53 reactivator and a ROS mediated therapeutic strategy works synergistically in patient derived models, inducing cell death and changes in the expression of certain RNAs directly involved in unfolded protein response. This pilot study shows that this combination is a feasible strategy to treat pancreatic cancer, setting the path for its testing on in vivo models. Citation Format: Daniel Parra Sánchez, Andrés García-Sampedro, Isabela Laughland, Sylvain Peuget, Galina Selivanova, Stephen P Pereira, Pilar Acedo. Studying the synergistic potential of a p53 reactivator with ROS-mediated therapies for the treatment of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A026.

Integrative analysis of pan-cancer single-cell data reveals a tumor ecosystem subtype predicting immunotherapy response

Tumor ecosystem shapes cancer biology and potentially influence the response to immunotherapy, but there is a lack of direct clinical evidence. In this study, we utilized EcoTyper and publicly available scRNA-Seq cohorts from ICI-treated patients. We found a ecosystem subtype (ecotype) was linked to improved responses to immunotherapy. Then, a novel immunotherapy-responsive ecotype signature (IRE.Sig) was established and validated through the analysis of pan-cancer data. Utilizing IRE.Sig, machine learning models successfully predicted ICI responses in both validation and testing cohorts, achieving area under the curve (AUC) values of 0.72 and 0.71, respectively. Furthermore, using 5 CRISPR screening cohorts, we identified several potential drugs that may augment the efficacy of ICI. We also elucidated the candidate cellular biomarkers of response to the combined treatment of pembrolizumab plus eribulin in breast cancer. This signature has the potential to serve as a valuable tool for patients in selecting appropriate immunotherapy treatments.

Management of Rhizoctonia blight of groundnut using antagonistic effects of bioagents and organic amendments

Rhizoctonia blight disease caused by Rhizoctonia solani in groundnut crop is one of the most devastating diseases occurring worldwide. The disease affects the morphological and physiological parameters of the crop leading to reduction in pod yield as well as oil yield. The pathogen was isolated locally and identified as Rhizoctonia solani based on molecular characterization. The efficacy of different bioagents in reducing the radial growth of pathogen was tested in vitro and highest mycelia growth inhibition was recorded by Trichoderma asperellum (89.07 %). Among the fungicides tested, 100 % mycelial growth inhibition was observed by use of Carbendazim 50 WP, Tebuconazole 25.9 % EC, Hexaconazole 5 % suspension concentrate (SC) and Tebuconazole 50 % + Trifloxystrobin 25 % water-dispersible granule (WG). Among different organic substances tested in vitro, neem seed cake achieved maximum mycelial growth inhibition of 50.74 % and 54.08 % at 10 % and 20 % concentrations respectively. In the field experiment, treatment with application of neem seed cake to the soil at 500 kg/ha + application of mustard seed cake to the soil at 500 kg/ha + treatment of seeds with Tebuconazole at 1.5 g/kg of seed + treatment of seeds with T. asperellum at 10 g/kg of seed was found to be the best in enhancing plant health, growth promotion and oil yield. The combined treatment of bioagent, fungicide and organic amendment recorded maximum number of branches (14.00), number of leaves (668.33), plant dry weight (64.17 g), 100 pod weight (65.00 g) and oil yield (47.33 %) compared to the control and other treatments along with reduction of the disease (59.61 %). In the physiological parameters study, the same treatment also recorded maximum pigment contents viz. Chlorophyll a (1.843 mg/g), Chlorophyll b (0.555 mg/g), total chlorophyll (2.397 mg/g) and carotenoid content (0.084 mg/g) but with minimum phenol content (1.693 mg/g). Thus, it can be concluded that integration of selective inputs in the combined treatment of Neem seed cake, Mustard seed cake, Tebuconazole and T. asperellum could enhance the plant health, morphological growth and physiological parameters and increased the oil yield in groundnut along with reduction of the disease.

Abstract C046: Targeting wild-type IDH1 sensitizes homologous recombination proficient pancreatic cancer to PARP inhibition

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of cancer-related mortality in the United States. While Poly (ADP-ribose) polymerase (PARP) inhibitors show promise for PDAC with Homologous Recombination Deficiency (HRD), this mutation is present in less than 10% of cases. Our research focuses on exploiting a vulnerability in the remaining 90% of HR proficient (HRP) tumors. We identified that wild-type isocitrate dehydrogenase 1 (IDH1) plays a critical role in HR repair. By inhibiting IDH1, we discovered suppression of the homologous recombination (HR) pathway, leading to compromised genomic integrity. This renders cancer cells more susceptible to PARP inhibitor therapy, offering a novel therapeutic approach for HRP PDAC. Methods:We assessed the impact of IDH1 inhibition on HR pathway activity using Western blotting to measure HR repair protein levels and HR reporter assays. The effect of IDH1 inhibition (Ivosidenib) combined with PARP inhibition (Olaparib) on in vitro growth inhibition was assessed through drug combination assays. Additionally, we investigated the molecular mechanisms underlying the synergistic effects of the drug combination. To further evaluate the therapeutic potential of IDH1 inhibition in combination with PARP inhibitors, we examined tumor growth in xenograft models of PDAC in athymic nude mice and survival studies were performed in C57BL/6J mice transplanted with orthotopic murine pancreatic cancer. Results:Wild-type IDH1 blockade induces a BRCA-like phenotype by decreasing α-ketoglutarate (αKG) levels and causing histone hypermethylation. This leads to decreased HR repair efficiency in HRP pancreatic cancer cells (MiaPaCa-2 and Panc-1), resulting in a strong synergistic effect when combined with the DNA-damaging agent Olaparib. The combination treatment significantly reduced cell survival in both short and long-term assays. Furthermore, we discovered that these compounds complemented each other in the DNA damage response, leading to increased γ-H2AX (DNA damage marker) and apoptosis. In vivo studies using murine PDAC models demonstrated that the combination of ivosidenib and olaparib synergistically enhanced anti-tumor activity compared to either single agent alone. Conclusion:These data provide novel insight into the mechanisms underlying in the context of HRP cancer susceptibility to a dual treatment approach involving an IDH1 inhibitor and a PARP inhibitor. This approach holds promise for precision medicine in pancreatic cancer treatment, although further pre- clinical studies are needed for validation and refinement. Citation Format: Mehrdad Zarei, Omid Hajihassani, Hallie J. Graor, Soubhi Tahhan, Alexander W. Loftus, Faith Nakazzi, Semmer A. Ali, Parnian Naji, Luke D. Rothermel, Jonothan R. Brody, Jordan M. Winter. Targeting wild-type IDH1 sensitizes homologous recombination proficient pancreatic cancer to PARP inhibition [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C046.

Melatonin and Bacterial Cellulose Regulate the Expression of Inflammatory Cytokines, VEGF, PCNA, and Collagen in Cutaneous Wound Healing in Diabetic Rats.

The poor healing of diabetic wounds is characterized by prolonged inflammation and decreased collagen deposition. Diabetic patients exhibit changes in the plasma concentrations of pro-inflammatory cytokines, and the role of specific dressings may have an impact on healing. This study aims to evaluate the effects of a combined treatment comprising a bacterial cellulose dressing and melatonin application on the regulation and expression of inflammatory cytokines, VEGF, PCNA, and collagen in the healing of cutaneous wounds of diabetic rats. Pro-inflammatory cytokines, including IL-6, TNF-α, and VEGF, along with PCNA and type I and III collagen, were evaluated after 14 days. Immunohistochemistry showed decreased levels of IL-6, TNF-α, and VEGF, along with an increased expression of PCNA and type I collagen, in the groups treated exclusively with melatonin and bacterial cellulose associated with melatonin compared to the control and the commercial healing agent. It was concluded that treating the skin lesions of diabetic animals supplemented with melatonin using a bacterial cellulose-based dressing has positive effects in regulating the expression of inflammatory cytokines, vascular endothelial growth factor, and collagen, showing that this association could be a viable therapy approach in wound healing.

Abstract C024: Quantitative mass spectrometry-based multi-omic profiling to overcome drug resistance in pancreatic cancer post KRAS G12D inhibition

Abstract Recently developed inhibitors targeting the KRASG12D oncoprotein are undergoing clinical trial evaluation including in patients with pancreatic adenocarcinoma (PDAC). However, resistance to such targeted therapies is a frequent occurrence, potentially undermining the long-term success of KRAS inhibitors (KRASi). To uncover the adaptive pathways and cell surface biomarkers to KRASi and to identify effective drug combinations that can overcome resistance, we employ a mass spectrometry-based quantitative temporal proteomics workflow. This approach allows us to map the proteomic changes in response to KRASi in both in vitro and in vivo PDAC models. We identify and quantify 10,898 proteins, creating the most extensive proteomic dataset related to KRASi to date. We identify shared mechanisms of both acute and long-term adaptation to KRASi across PDAC models. Utilizing this proteomic information, we are pinpointing drug combinations that pair KRASi with inhibitors of CDK4/6, AURKA, and mTOR to increase cytotoxicity and thereby reduce development of long-term resistance. Surfaceome analyses identifies cell surface proteins upregulated upon acute and long-term KRASi, including TACSTD2 (Trop-2). Antibody-drug conjugates targeting upregulated surface proteins may be a useful orthogonal approach towards preventing or circumventing KRASi resistance with testing of Trop-2 and other candidates ongoing. In summary, through mass spectrometry-based quantitative temporal proteomics, we identify proteomic adaptations to KRASi in PDAC and propose combination treatments with promising therapeutic potential. Citation Format: Qijia Yu, Nicole Sindoni, Huan Zhang, Ziyue Li, Joao A. Paulo, Andrew J. Aguirre, Joseph D. Mancias. Quantitative mass spectrometry-based multi-omic profiling to overcome drug resistance in pancreatic cancer post KRAS G12D inhibition [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C024.

Abstract B062: Low dose dual epigenetic therapy utilizing hypomethylating agents and HDAC inhibitors prolong survival in an orthotopic PDAC model and alter the tumor microenvironment

Abstract Background: We have previously studied the effect of hypomethylating agent Decitabine (5- aza-dC; DAC) on pancreatic cancer using the KPC model (KrasG12D/+;Trp53R172H/+;Pdx1- Cre) and observed increased CD4+/CD8+ TILs, greater PD1 expression and slowed tumor growth with increased tumor necrosis. Subsequently we showed a significant survival benefit with DAC+αPD1 compared to either single agent. However, we identified a specific myeloid cell population initially identified by Chi3l3 expression that may be responsible for treatment resistance or escape. Based on prior observations of synergy specifically affecting tumor infiltrating myeloid and lymphoid cells, we focused on identifying a dual epigenetic strategy (a combination of DAC plus histone deacetylase inhibitors (HDACi)) to enhance immunological synergy and test their treatment efficacy with αPD1. Methods: We used a combination primary KPC-derived cell lines, bone marrow (BMDM) and peritoneum derived (PM) myeloid cells and T cells in co-culture systems to assess cytotoxic synergy (Bliss/Lowe consensus) and immune effects (cytokine release, myeloid cell polarization and T cell activation) to evaluate combinations of DAC+HDACi. The KPC orthotopic model relying on US monitoring of tumor size for standardized initiation of therapy was used for survival analysis and profiling in treatment combinations of DAC+HDACi+αPD1. Results: We showed that hypomethylation therapy exerts a primarily paracrine effect on myeloid cells and this polarization results in a decrease in DAC–induced T cell activation. We therefore selected HDAC inhibitors that in combination with DAC alter this paracrine effect. We selected specific HDAC inhibitors based on induction of class of HDAC expression following hypomethylation therapy, highest Bliss synergy scores at low doses and reversal of cytokine release, M2 polarization and T cell inactivation. Three HDAC inhibitors were chosen for in vivo testing, Domatinostat, Pracinostat and Entinostat. Using the treatment paradigm of ultra-low dose DAC+ HDACi (mainly to minimize toxicity) combined with αPD1 in the KPC orthotopic model we show that the triple combination (DAC + Entinostat + αPD1) is well-tolerated and results in a significant survival benefit compared to single and dual agent combinations. In addition, we also demonstrate a reduction in the Chi3l3 expressing myeloid cell population. Conclusions: Our results show that the combination of hypomethylating agent plus HDAC inhibitor has several beneficial effects on the tumor immune response in PDAC. HDAC inhibitors specifically reduce the suppressive myeloid cell population we previously identified after DAC therapy. The combination of dual low dose epigenetic therapy using a hypomethylating agent plus HDAC inhibitor followed by αPD1 results in significant survival benefit in the orthotopic KPC model. Citation Format: Stephen Muzyka, Arturo Orlacchio, Amanda Ackermann, Yasmine Chinda, Yoona Shim, Igor Dolgalev, Tamas Gonda. Low dose dual epigenetic therapy utilizing hypomethylating agents and HDAC inhibitors prolong survival in an orthotopic PDAC model and alter the tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B062.

Abstract C052: Repurposing Statins to Target Gemcitabine Resistance in Pancreatic Cancer

Abstract Pancreatic ductal adenocarcinoma (PDA) is a lethal malignancy with a devastating prognosis. Gemcitabine, a pyrimidine anti-metabolite, is a cornerstone in PDA therapy, but resistance remains a major hurdle in clinical care. Metabolic reprogramming is an important driver of chemoresistance. Accordingly, targeting these altered metabolic pathways can improve response to treatment. To investigate metabolic vulnerabilities, we generated models of acquired PDA gemcitabine resistance. Screening common metabolic inhibitors we observed that gemcitabine-resistant cells were exquisitely susceptible to statins, inhibitors of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. This is due to a downregulation of the mevalonate biosynthesis pathway in gemcitabine-resistant cells. Importantly, the statin sensitivity correlates with the extent of the gemcitabine resistance, suggesting this metabolic vulnerability is gradually gained during acquisition of resistance. Rescue experiments showed that statins induce apoptosis by reduced protein geranylation of small GTPases. Finally, we find that pitavastatin inhibits growth of gemcitabine resistant tumors in immune competent models. Collectively, these data suggest that targeting the HMG-CoA reductase is a metabolic vulnerability that is gained in PDA cells upon the acquisition of gemcitabine resistance. The treatment combination of gemcitabine and pitavastatin, two widely used compounds in patients, has potential to translate into an immediate clinical benefit and improve survival in this deadly disease. Citation Format: Sabrina Calderon, Alica K. Beutel, Ethan Nghiem, Rima Singh, Natalie Yousefian, Cecily Anaraki, Kevin Gulay, Dennis Juarez, Alexander Kleger, Thomas Seufferlein, Alexander Muir, Cholsoon Jang, Herve Tiriac, David Fruman, Christopher Halbrook. Repurposing Statins to Target Gemcitabine Resistance in Pancreatic Cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C052.

Abstract A014: Protein-informed gene methylation signatures to predict treatment response and outcomes in pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDA) is a deadly cancer with dismal outcomes. We need new biomarkers to optimize the limited treatment combinations used in current clinical practice. Many machine-learning models have been presented based on mutational or transcriptome data claiming to predict outcomes. Still, they do not provide actionable targets (genes) that could improve treatment response. Moreover, DNA-methylation changes that influence gene/protein expression have been explored for this purpose. From the literature, we curated a 122-gene panel (January 1970 to April 2024) constructed on the proteins with preclinical (on cell lines or mouse models) or clinical (tissue-based studies) evidence suggesting their individual roles in influencing response to drugs often used in managing PDA such as gemcitabine (Gem), nab-paclitaxel, oxaliplatin, 5-fluorouracil, irinotecan, and cisplatin. We hypothesized that methylation changes in these genes are surrogates for gene/protein expression and tested their clinical significance in The Cancer Genome Atlas (TCGA) PDA population (n=184). The goal was to develop methylation signatures composed of specific cytosines followed by guanine residue (CpG) sites that aid in identifying patients at high risk of treatment failure and poor outcomes. We used elastic net multivariate analysis to calculate survival and plot Kaplan Meier plots based on our gene panel. The alpha (α) used for this script was calculated based on the lowest mean error and the minimum lambda (λ) value accordingly for each iteration (100 iterations to calculate the best values for α and λ). Our analysis yielded 28 methylation signatures that could identify high-risk PDA patients with poor overall survival (OS). The number of CpG sites in these signatures ranged from 1 to 1933. The differences in OS for these signatures were better than those available in the literature. The best signature had 18 CpG sites (17 months (m) vs. not evaluable) followed by a 53-CpG site signature (16 m vs. 67m) and a 6-CpG site signature (17m vs. 67m). A signature with the highest CpG sites (1933) was not better than those with smaller ones (16m vs. 21m). Multiple signatures had >1 CpG sites from one gene. Early growth response 1 (EGR1) coding the KCNH2 gene has featured in most signatures. One CpG site in this gene had a clinically significant prognostic value (15m vs. 30m). Other frequently featured genes were CCDC85A, EGFR, SST, and HMGA1. The main drawbacks for this study were that Gem-related genes (> 60) dominated the panel, and those with Gem treatment dominated the patient population. This panel should be further refined to make it more relevant to current clinical practice. We provide preliminary evidence suggesting the clinical significance of our panel and lay the foundation for future studies that would enable us to personalize prognostication and treatment selection in PDA patients. Our work can provide novel therapeutic targets that, alone or in combination with chemotherapy, can improve the outcomes for PDA. Citation Format: Ashish Manne, Harshitha Puram, Deepak Sherpally, Sravan Jeepalyam, Upender Manne. Protein-informed gene methylation signatures to predict treatment response and outcomes in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A014.

Abstract C045: Targeting metabolic heterogeneity in pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the US. This poor prognosis is related to the complex tumor microenvironment and tumor heterogeneity that drives resistance to chemotherapy. Here the heterogeneity of the stromal, immune, and malignant epithelial cell populations enables signaling and metabolic crosstalk mechanisms that drive immune suppression and resistance to therapy. Recently, our group unveiled that multiple distinct metabolic subclasses of cancer cells coexist within individual PDAC tumors. Among these, two PDAC clonal populations can engage in metabolic symbiosis that supports mitochondrial metabolism. One subtype has a constitutively high integrated stress response (ISR), enabling resistance to mitochondrial inhibitors. Further, these cells release asparagine that supports the mitochondrial metabolism of the other subtype that are more sensitive to mitochondrial inhibition. Given these observations, we are developing approaches to disrupt this metabolic symbiosis. Clonal PDAC cells with constitutively active ISR exhibit increased sensitivity to inhibition of the redox activity of Redox factor 1/Apurinic-apyrimidinic endonuclease 1 (Ref-1). Importantly, this can be leveraged to disrupt the support of the mitochondrial metabolism of clonal symbiotic pairs. Moreover, polyclonal PDAC cell lines representative of the heterogeneity seen in PDAC patients show a highly synergistic response to the combination of Ref-1 redox inhibitors with mitochondrial inhibitors. These data suggest this treatment combination will be synergistic in polyclonal tumors that exist in most PDAC patients. Overall, these data have the potential to lead to new avenues to directly target heterogenous populations of cancer cells to treat pancreatic cancer- an urgent clinical need. Citation Format: Taryn Morningstar, Cecily Anaraki, Lorenzo Scipioni, Giulia Tedeschi, Michelle Digman, Aimee Edinger, Claus Jorgensen, Melissa Fishel, Christopher J Halbrook. Targeting metabolic heterogeneity in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C045.

Delivery of extracellular vesicles loaded with immune checkpoint inhibitors for immunotherapeutic management of glioma

Glioma is a common primary malignant brain tumor with low survival rate. Immunotherapy with immune checkpoints inhibitors (ICI) can be a choice for glioma management, and extracellular vesicles (EVs) are recognized as a potential drug delivery system for various disease management due to their enhanced barrier permeation ability and immunomodulatory effect. The aim of this study is to develop ICI-loaded EVs (ICI/EV) that have sufficient efficacy in managing glioma. Calcium phosphate particles (CaP) were used to stimulate the secretion of EVs from murine macrophage cells. CaP conditioning of cells showed an enhanced amount of EVs secretion and macrophage polarization toward a proinflammatory phenotype. The CaP-induced EVs were shown to polarize macrophages into proinflammatory phenotype in vitro, as correlated with the conditioning method. ICI/EVs were successfully prepared with high loading efficiency using the sonication method. The EVs can be distributed throughout the entire brain upon intranasal administration and facilitate ICIs distribution into glioma lesion. Combinatory treatment with ICI/EVs showed benefit in glioma-bearing mice by reducing their tumor volume and prolonging their survival. Cytotoxic T cell infiltration, polarization of tumor-associated macrophage, and lower tumor proliferation were observed in ICI/EVs-treated mice. The developed ICI/EVs showed promise in immunotherapeutic management of glioma.

Effect of Sodium-Glucose Co-Transporter 2 Inhibitors Combined with Metformin on Pancreatic Cancer Cell Lines.

Pancreatic cancer (PC) is the ninth-leading cause of cancer-related deaths worldwide. Diabetic patients have an increased risk and mortality rates for PC. Sodium-glucose co-transporter 2 (SGLT2) inhibitors and metformin (Met) are widely used anti-diabetic medications. Both Met and SGLT2 inhibitors have anticancer properties in PC, but nothing is known concerning their combined effect. So, we investigated the in vitro effect of SGLT2 inhibitors combined with Met. Canagliflozin and dapagliflozin possessed cytotoxic, antiproliferative, and pro-apoptotic properties in the tested PC cell lines. In PANC-1 cells, the antimigratory and pro-apoptotic effects were enhanced when dapagliflozin was combined with Met, and G1 cell cycle arrest was enhanced when dapagliflozin or canagliflozin was combined with Met. In AsPC-1 cells, the cytotoxic effect and the G1 cell cycle arrest were enhanced when canagliflozin and dapagliflozin, respectively, were combined with Met. Only the cytotoxic effects of SGLT2 inhibitors, but not the combination treatments, involved PI3K and JNK-dependent pathways in AsPC-1 cells. In conclusion, combination treatments increased the anticancer effects in a cell type-dependent way in the two investigated cell lines. Additionally, the cytotoxic effect of SGLT2 inhibitors was dependent on the PI3K and JNK pathways in AsPC-1 cells, but Met appears to act via a distinct mechanism.

Effect of Blending Cashew Apple (Anacardium occidentale L.) and Aonla (Emblica officinalis Gaertn.) Juice on Fermentation of Wine

A Completely Randomized Design (CRD) was employed to assess nine different treatment combinations, varying in juice ratios and fermentation conditions. The study aimed to evaluate the effects of blending cashew apple and aonla juices on the quality and fermentation characteristics of the resulting wine. While studying the chemical composition of cashew apple and aonla juice, cashew apple juice had a maximum value for T.S.S., reducing sugars, total sugars and pH. Aonla aonla juice had a maximum value for titratable acidity, ascorbic acid and tannin content. The T.S.S. of must was adjusted to 24 ºBrix and pH kept natural. The T.S.S. and pH was found to be decreased during fermentation of must. The treatment T5 i.e. 60 % cashew apple: 40 % aonla juice (6.13 ºBrix) recorded lowest T.S.S. and T9 i.e. 20 % cashew apple: 80 % aonla juice (10.53 ºBrix) recorded highest T.S.S. at 12th day of fermentation. The lowest pH recorded in treatment T9 i.e. 20 % cashew apple: 80 % aonla juice (2.10) and highest recorded in T1 i.e. 100 % cashew apple juice (3.38) at 12th day of fermentation. On the other hand, titratable acidity of must was found to be increased during fermentation of must. The minimum titratable acidity was found in treatment T1 i.e. 100 % cashew apple juice (0.62 %) and maximum was recorded in T9 i.e. 20 % cashew apple: 80 % aonla juice (1.74 %) at 12th day of fermentation. The yeast count increases rapidly until the 3rd day (1524 x 103) and after that yeast count subsequently declined until the fermentation reaches the 12th day (36.07 x 103), irrespective of treatments. At the end of fermentation (12th day) highest yeast count was recorded by treatment T5 i.e. 60 % cashew apple: 40 % aonla juice (60 x 103) and lowest yeast count was recorded by treatment T9 i.e. 20 % cashew apple: 80 % aonla juice (21 x103). Wine recovery from must ranged between 73.86 and 83.20 per cent. As a result, treatment T5 (60 % cashew apple juice: 40 % aonla juice) showed better fermentation among all other treatments.

Effects of Vermicast and Arbuscular Mycorrhizal Fungi (AMF) on the Establishment of Cacao (Theobroma cacao Linn.) Seedlings Grown in Degraded Soil

Declining soil fertility poses a significant challenge for cacao production, particularly for establishing seedlings. This study investigated the potential effects of vermicast and arbuscular mycorrhizal fungi (AMF) to enhance cacao seedling establishment in degraded soil conditions. The study was conducted in a low-cost protective structure established at the Abaca Project Experimental Area of the University of Southeastern Philippines, Mampising, Mabini, Davao de Oro, from December 2018 to April 2019. Furthermore, a Completely Randomized Design (CRD) was employed with eight (8) treatments and three (3) replications with eight (8) sample plants per replicate. The following are the treatment combinations: No Application (T1), Recommended Rate (T2), Vermicast (T3), AMF (T4), Vermicast + AMF (T5), Recommended Rate + AMF (T6), Recommended Rate + Vermicast (T7), and Recommended Rate + AMF + Vermicast (T8). The results of the study reveal that the application of vermicast and AMF combined with inorganic fertilizer based on the recommended rate increased the growth and development of cacao seedlings in degraded soil in terms of plant height (16.40%), length of leaves (14.59%), the width of leaves (12.11%), number of leaves (1.26%), leaf color (41%), stem diameter, shoot weight (60%), dry matter yield (116%) and root:shoot ratio (63.16%) compared to control or no application. Thus, the judicious use of inorganic fertilizer, vermicast, and AMF improves the establishment of cacao seedlings in soils with degraded conditions.

Addition of Bempedoic Acid to Statin-Ezetimibe versus Statin Titration in Patients with High Cardiovascular Risk: A Single-Centre Prospective Study.

Reducing levels of low-density lipoprotein cholesterol (LDL-C) below recommended thresholds is a core component of cardiovascular prevention strategies. We hypothesized that the addition of bempedoic acid to patients already on statin-ezetimibe therapy was more effective than titrating the statin dose in reducing LDL-C. The study enrolled 120 patients at high cardiovascular risk and with LDL-C above 70 mg/dL. They were randomly divided into two groups: the bempedoic acid (BA) group, taking bempedoic acid in addition to statin plus ezitimibe, and the statin titration (ST) group, including patients who doubled the dose of statin. At 12 weeks, the BA group presented a more significant decrease in LDL-C compared to the ST group (-22.9% vs. 7.5% p 0.002). The total cholesterol decreased significantly in the BA group compared to ST (-14.8% vs.-4.7%; p 0.013) No significant between-group changes in HDL and triglycerides occurred. At 12 weeks, the number of patients who reached LDL-C lower than 70 mg/dL was 38 (63%) in the BA group versus 22 (37%) in the ST group (between groups, p 0.034). In the BA group, the LDL-lowering effect of bempedoic acid was similar between patients taking atorvastatin and rosuvastatin. No side effects occurred during the follow up period. In conclusion, the addition of bempedoic acid to statin-ezetimibe combined treatment was more effective than doubling the dose of statin in reducing LDL-C levels and increased the number of patients reaching the LDL-C goal.

Integrated biological control of Diaspis echinocacti (Bouché) on Opuntia ficus-indica (L.) Mill (Cactaceae) using predatory ladybirds and fungal pathogens

Diaspis echinocacti (Bouché) (Hemiptera: Diaspididae) causes severe damage to Opuntia spp. (Cactaceae) worldwide, necessitating effective control measures. In this study, we tested the single and combined use of predatory ladybirds and a fungal pathogen on D. echinocacti infesting Opuntia ficus-indica (L.) Mill. Plants under screenhouse conditions (mean 26.32 °C, 55.1% RH.). The treatments were: untreated control, 0.003% Tween 80 (TW), Chilocorus bipustulatus (Coleoptera: Coccinellidae) (CB) alone, Exochomus nigripennis (Coleoptera: Coccinellidae) (EN) alone, entomopathogenic fungi Alternaria murispora (AM) alone, AM + CB, AM + EN, and mineral oil (MO) (positive control). Treatment efficacy was evaluated weekly for five weeks. AM + EN and AM + CB treatments significantly reduced egg counts to 4.89 and 2.44 by week 5, respectively. For motile stages, the AM + CB and AM + EN treatments were most effective, reducing counts to 6.89 and 9.56 by week 5. AM alone resulted in the highest number of mummies (D. echinocacti killed by A. murispora) (29.67) by week 5. For predator densities, C. bipustulatus peaked at 36.11 individuals per cladode by week 3 in the CB-only treatment, while E. nigripennis peaked at 32.33 individuals per cladode by week 3 in the EN-only treatment. Both CB and EN densities were higher in single treatments compared to the combined treatments throughout the study. Combining A. murispora with C. bipustulatus or E. nigripennis significantly reduced D. echinocacti infestations on O. ficus-indica without affecting plant quality (visual score >9 by week 5). Prolonged exposure enhanced efficacy, showing promise for effective non-chemical pest management.

Dual-strategy approach for Rhynchophorus ferrugineus control: Endophytic Beauveria bassiana and Bacillus thuringiensis topical application

In an innovative approach to biological pest management, the entomopathogenic efficacy of endophytically colonized Beauveria bassiana and topically applied Bacillus thuringiensis was evaluated against various larval instars (2nd, 4th, and 6th) of the red palm weevil (RPW), Rhynchophorus ferrugineus. Initially, date palm leaf petioles were inoculated with five distinct isolates of the fungus to ascertain their endophytic potential over two years. Subsequently, the most proficiently colonized fungal isolate was selected for subsequent experimentation. During individual entomopathogen applications, larval instars of RPW were presented with plant petioles and colonized with fungus at 30 days post-inoculation or immersed in bacterial inoculum. Ιn combined treatments, larvae were exposed to both entomopathogen-treated plant petioles concurrently. The tested bacterium was administered at three concentrations (30, 40, and 50 μg/ml). Larval mortalities were markedly lower in treatments involving individual entomopathogens, whereas integrated applications yielded higher mortalities. Treatments associated with heightened larval mortalities corresponded to diminished pupation, adult emergence, and egg eclosion rates. Furthermore, the simultaneous application of both entomopathogens bolstered larval mortalities of RPW both additively and synergistically, with concentration also playing an important role. Similarly, the developmental periods of various insect stages were substantially influenced by combined entomopathogen applications. The inherent prevalence of these pathogens and their ability to colonize crop plants internally for extended periods render them promising agents against cryptic-feeding insects like RPW. However, further evaluation of suitable entomopathogen strains and optimal doses under field conditions is imperative before formulating concrete recommendations for date palm growers.