Pancreatic Tumors Research Articles

The evaluation of postoperative exocrine pancreatic insufficiency in patients with benign and low-malignant pancreatic tumor: A multicenter, prospective, observational study

Objectives: We assess the incidence of exocrine pancreatic insufficiency (EPI) at different time points after pancreatic surgery and explore pancreatic enzyme replacement therapy's (PERT) efficacy. Background: EPI is characterized by inadequate pancreatic enzymes, resulting in maldigestion and abdominal symptoms. EPI is a common postoperative complication of pancreatic surgery, yet often overlooked by surgeons. There is no clear answer to when EPI occurs after pancreatic surgery nor the duration of PERT after partial pancreatectomy. Methods: Benign or borderline pancreatic tumor patients undergoing surgeries were recruited between December 2020 and November 2021 from 10 medical centers in China. The EPI Questionnaire (EPI-Q) was performed at discharge, and 3-, 6-, 9-, and 12-month follow-ups to evaluate the occurrence of EPI. Statistical analyses were performed to identify the occurrence of EPI and explore PERT's efficacy. Results: Of the 146 patients, 105 (71.9%) were female, and the median age was 49 (range 16-78 yrs). Symptoms of EPI patients were most pronounced within 3 months post-surgery (15.7%), while most patients recovered after 1 year (96.9%). There was a negative correlation between symptom score and time since surgery. Lack of PERT in the 3-month post-surgery was associated with higher symptom scores in pancreatoduodenectomy (PD) patients, while not in distal pancreatectomy (DP) patients. Conclusions: Generally, the high-occurrence period for postoperative EPI is within 3 months after resection in patients with benign or borderline pancreatic tumors, and most will gradually recuperate with time. PERT can improve symptoms in PD patients, while reduced PERT duration may be considered for DP patients.

Phase 3 Trial of Cabozantinib to Treat Advanced Neuroendocrine Tumors.

Treatment options for patients with advanced neuroendocrine tumors are limited. The efficacy of cabozantinib in the treatment of previously treated, progressive extrapancreatic or pancreatic neuroendocrine tumors is unclear. We enrolled two independent cohorts of patients - those with extrapancreatic neuroendocrine tumors and those with pancreatic neuroendocrine tumors - who had received peptide receptor radionuclide therapy or targeted therapy or both. Patients were randomly assigned in a 2:1 ratio to receive cabozantinib at a dose of 60 mg daily or placebo. The primary end point was progression-free survival as assessed by blinded independent central review. Key secondary end points included objective response, overall survival, and safety. In the cohort of 203 patients with extrapancreatic neuroendocrine tumors, the median progression-free survival with cabozantinib was 8.4 months, as compared with 3.9 months with placebo (stratified hazard ratio for progression or death, 0.38; 95% confidence interval [CI], 0.25 to 0.59; P<0.001). In the cohort of 95 patients with pancreatic neuroendocrine tumors, the median progression-free survival with cabozantinib was 13.8 months, as compared with 4.4 months with placebo (stratified hazard ratio, 0.23; 95% CI, 0.12 to 0.42; P<0.001). The incidence of confirmed objective response with cabozantinib was 5% and 19% among patients with extrapancreatic and pancreatic neuroendocrine tumors, respectively, as compared with 0% with placebo. Grade 3 or higher adverse events were noted in 62 to 65% of the patients treated with cabozantinib, as compared with 23 to 27% of the patients who received placebo. Common treatment-related adverse events of grade 3 or higher included hypertension, fatigue, diarrhea, and thromboembolic events. Cabozantinib, as compared with placebo, significantly improved progression-free survival in patients with previously treated, progressive advanced extrapancreatic or pancreatic neuroendocrine tumors. Adverse events were consistent with the known safety profile of cabozantinib. (Funded by the National Cancer Institute and others; CABINET ClinicalTrials.gov number, NCT03375320.).

Nutrient Levels and Nutrient Sources in Pancreatic Tumors.

It has been known that poor tumor perfusion and dysregulated cancer cell metabolism give rise to tumor microenvironments with unphysiologic nutrient levels, but the precise alterations in metabolite abundance are not well defined. In a 2015 study in Cancer Research, Kamphorst and colleagues published a detailed comparison of the metabolome from human pancreatic tumors and benign tissues. Tumors were depleted in glucose and various nonessential amino acids but, surprisingly, enriched in essential amino acids. The authors attributed these nutrient imbalances to macropinocytosis of extracellular proteins, a RAS-driven amino acid acquisition pathway that was found to be increased in human tumors and supports pancreatic cancer cell growth during amino acid starvation. These findings substantially contributed to the understanding of altered nutrient levels in tumors and extracellular proteins as noncanonical nutrients. Intratumoral nutrient levels in different cancer contexts and signaling pathways that regulate nutrient acquisition by cancer cells remain a focus of current research. See related article by Kamphorst and colleagues, Cancer Res 2015;75:544-53.

Transformation of non-functioning pancreatic neuroendocrine tumours into insulinomas in multiple endocrine neoplasia type 1: a case report

Transformation of non-functioning pancreatic neuroendocrine tumours into insulinomas in multiple endocrine neoplasia type 1: a case report

Refractory hypercalcaemia in advanced metastatic pancreatic neuroendocrine tumour controlled on weekly denosumab

Refractory hypercalcaemia in advanced metastatic pancreatic neuroendocrine tumour controlled on weekly denosumab

Abstract B055: Harnessing cytomegalovirus immunity against pancreatic tumors for immunotherapy

Abstract Immunotherapy has had very limited success in pancreatic cancer, due to its low mutational burden and immunosuppressive microenvironment. Our approach consists in redirecting pre- existing antiviral immunity against pancreatic tumors by delivering viral antigens using the tumor penetrating peptide iRGD .This peptide, targets the tumor vasculature through av integrins and neuropilin-1, delivering conjugated or co-administered cargo to tumors. Here we used mouse cytomegalovirus (CMV) as an infection model. CMV is a β-herpesvirus that induces a strong T-cell response in mice and humans, comprising &amp;gt;10% of all circulating CD4 and CD8 T cells mostly with effector-memory phenotype. Importantly, human CMV infects over 60% of the world’s population rendering it a suitable candidate for translation. Methods: Mice latently infected with CMV were orthotopically implanted with KPC pancreatic tumor cells and treated with systemic injections of vehicle or iRGD plus CMV class I and II binding peptides. Another cohort of age matched uninfected mice was used as a control. Tumor growth and mouse weight were monitored twice a week and CMV specific immune responses were measured in spleen, liver and tumor by flow cytometry, using tetramer staining and CMV specific peptide recall. Results: CMV infected mice receiving iRGD+CMV peptides responded to treatment as evidenced by delayed tumor growth associated with increased tumor necrosis and T cell infiltration. In addition, flow cytometry analysis of tumor, liver and spleen showed a significant increase in CMV specific T cells preferentially in the tumor. Surprisingly, these T cells preferentially infiltrated tumors regardless of the use of iRGD for tumor targeting of CMV peptides. Survival studies showed a marked increase in median survival, reaching 42 days in the infected and treated group, compared to 25 days in the vehicle treated one. The survival benefit was very similar in the presence or absence of iRGD. Combining this strategy with anti- PD1 and or anti-IL10R did not significantly improve the benefits of CMV therapy alone. On the other hand, combination with low dose gemcitabine (5mg/kg) significantly improved tumor growth delay and survival in the combination compared to either therapy alone. The median survival reached 49 days in the combination, compared to 39 for gemcitabine or CMV therapy alone and 32 for vehicle.Conclusions: We have recently performed single cell RNA sequencing in tumors from infected and CMV peptide or vehicle treated mice and will analyze the transcriptional profile and TCR sequence of the tumor infiltrating T cells. Preliminary analysis of this data shows a massive T cell infiltration and an increase in dendritic cells and macrophages in infected and treated mice. Taken together, this data shows we can deliver antigens to pancreatic tumors and elicit an anti-tumor immune response that results in delayed tumor growth and has a survival benefit. This is a mutation agnostic approach with high translational value, since more than 60% of the population has previous CMV immunity. Citation Format: Remi Marrocco, Jay Patel, Rithika Medari, Siming Sun, Kevin Gulay, Alexei Martsinkovskiy, Simon Brunel, Eduardo Lucero-Meza, Evangeline Mose, Andrew Lowy, Chris Benedict, Tatiana Hurtado de Mendoza. Harnessing cytomegalovirus immunity against pancreatic tumors for immunotherapy [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 B055.

Abstract B032: Evaluating T cell-inflammation in pancreatic neuroendocrine tumors

Abstract Background: Pancreatic neuroendocrine tumors (pNETs) are rare tumors arising from neuroendocrine cells in the pancreas. Their clinical behaviour and prognosis are variable and durable responses are often difficult to achieve with conventional therapies. Immunotherapy approaches may be efficacious in a subgroup of pNETs. In a recent study that did not include pNETs, we showed that a four-chemokine signature (c-Score: CCL4, CCL5, CXCL9, CXCL10) predicts T cell-inflammation and response to immune checkpoint inhibitors across cancers. We have hypothesized that the c-Score will also identify pNET subgroups with T cell-inflammation. Methods: The c-Score and hallmarks of the cancer-immunity cycle are being evaluated in pNETs as a cohort study (n=100 cases) of the Marathon of Hope Cancer Centres Network whole genome and transcriptome tumor sequencing (WGTS) project. The cohort study will compare pNET profiles with those of other pancreatic and peri-ampullary tumors. Results: As of June 1, 2024, primary tumor data from 23 cases were available for analysis, including 16 pNETs, 2 pancreatic ductal adenocarcinomas (PDAC), 2 pancreatic adenosquamous carcinoma (PASC), 2 distal cholangiocarcinomas (dCCA), and 1 ampullary carcinoma (AC). Dimension reduction by principle component analysis (PCA) revealed clustering based on histological subtype. Interestingly, PCA using immune genes also demonstrate subgrouping that overlapped with the histological subtypes, suggesting that immunity of pancreatic/peri-ampullary neoplasms may be directed by histological types rather than the pancreas gland itself. These cancers showed a broad distribution of c-Score expression, with pNETs having the lowest c-Score. Tumors with high expression of the c-Score, including 2 pNETs, had increased expression of cancer-immunity cycle gene sets. DUX4, FAM186A, and IGFN1 were amongst the most common genes mutated in all tumors. Conclusions: Early data suggest that pNETs generally harbor low c-Score values and hallmarks of cancer-immunity, with the existence of a subgroup of pNETs displaying T cell-inflammation. Citation Format: Joan Miguel Romero, James Vafiadis, Tess Aalto, Ruomeng Fang, Yifan Wang, George Zogopoulos. Evaluating T cell-inflammation in pancreatic neuroendocrine tumors [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 B032.

Abstract PR-18: RNF43 Loss Induces an IRE1-dependent Metabolic Reprogramming in Pancreatic Cystic Neoplasms

Abstract Background: RNF43 is frequently mutated in intraductal papillary mucinous neoplasms (IPMNs), which are cystic precursor lesions of pancreatic ductal adenocarcinoma (PDAC). RNF43 encodes for an E3 ubiquitin ligase and was initially identified as a negative regulator of Wnt signaling in colorectal cancer. Clinical trials targeting ligand dependent Wnt signaling in RNF43-mutated cancers have failed to demonstrate any efficacy, suggesting other mechanisms may be involved. Methods: To elucidate the role of RNF43 in an organ specific context, we generated a genetically engineered mouse model with pancreas-specific loss of Rnf43 and co-expression of mutant Kras (referred to as Kras;Rnf43 mice). The Kras;Rnf43 mice develop pancreatic cystic lesions resembling human IPMNs, a subset of which progressive to invasive cancers. We generated derivative cell lines from the IPMN-associated cancers, referred to as Kras;Rnf43 lines. Single-cell RNA sequencing (scRNA-seq) was performed to compare murine PDAC arising in Kras;Rnf43 mice with that of the Kras;p53 (“KPC”) mice. To determine if observed perturbations were dependent on Rnf43, we also created isogenic Kras;Rnf43 cell lines with re-expression of full-length Rnf43 (Kras;Rnf43-RNF43OE). Results: Kras;Rnf43 tumors showed upregulation of several mitochondrial transcripts (Mt-Atp8, Atp5o.1, and Atp6v0c), as well as mitochondrial biogenesis markers (PPARGC1A and NFE2L2), compared to KPC mice. Concurrently, the oxidative phosphorylation (OXPHOS) pathway was enriched on proteomics analyses of Kras;Rnf43 cells, relative to isogenic cell lines with RNF43 restitution. Seahorse metabolic flux analyzer revealed enhanced mitochondrial OXPHOS activity in Kras;Rnf43 cell lines, along with increased mitophagy. Kras;Rnf43 cells harbored gene signatures indicative of endoplasmic reticulum (ER) stress compared to KPC lines. Endoplasmic reticulum-mitochondria contact sites (ERMCS) regulate ER stress and mitochondrial dynamics. Notably, Kras;Rnf43 cells had significantly increased ERMCS compared to KPC cells, and these were attenuated upon RNF43 re-expression. We further identified the ER stress sensor inositol-requiring protein 1 (IRE1) was markedly elevated in Kras;Rnf43 cells compared to KPC cells, and decreased upon RNF43 re-expression. Furthermore, IRE1 localized at the mitochondrial-associated membrane (MAM) and enhanced ERMCS formation via a non-canonical scaffolding function. Deletion of IRE1 by CRISPR/Cas9 editing in Kras;Rnf43 cells inhibited OXPHOS and significantly impaired cell viability. Conclusion: Our data suggests that bi-allelic loss of RNF43 caused increased mitochondrial function and OXPHOS dependency. This is largely attributed to upregulated level of IRE1, which localizes at MAM to promote ERMCS formation and OXPHOS in Kras;Rnf43 cells. IRE1-dependent reprogramming of mitochondrial bioenergetics serves as a cell survival mechanism. Therefore, targeting OXPHOS or the noncanonical function of IRE1 could be a potential strategy to inhibit the progression of RNF43-mutated IPMNs to PDAC. Citation Format: Akiko Sagara, Xiangdong Lv, Brandon Chen, Yuki Makino, Shui Ping So, Sonja M Woermann, Costas A Lyssiotis, Yatrik M Shah, Bidyut Ghosh, Xi Chen, Johannes F Fahrmann, Anirban Maitra. RNF43 Loss Induces an IRE1-dependent Metabolic Reprogramming in Pancreatic Cystic Neoplasms [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 PR-18.

Abstract B015: Duodenal aspiration biopsy in diagnosis of pancreatic neoplasms

Abstract Introduction Intraductal papillary mucinous neoplasms (IPMNs) are a subset of lesions with elevated malignant potential, warranting their inclusion in screening standards. Despite endoscopic ultrasound (EUS) with fine-needle aspiration biopsy (FNAB) serving as the standard for verification, the occurrence of erroneous conclusions remains significant. Consequently, analysis of pancreatic juice is considered as a potential adjunctive diagnostic method. However, the absence of methods for obtaining pancreatic juice in adequate volume and quality poses a barrier to the widespread adoption of this approach.Materials and MethodsA method of duodenal aspiration biopsy (DAB) was developed involving active aspiration from the lumen of duodenum, yielding large volume of the mix of pancreatic juice and bile uncontaminated by gastric juice. Patients diagnosed with pancreatic neoplasms utilizing EUS with FNAB, were enrolled and ALB was implemented as an adjunctive diagnostic procedure. Cytological analysis of the material obtained was performed along with measuring the level of carcinoembryonic antigen (CEA). The level &amp;gt;192 ng/mL was considered significant, according to the Fukuoka 2017 guidelines.ResultsIn patients with cystic neoplasms of the pancreas undergoing DAB, results of cytological examination were non-informative in certain cases. However, analysis of CEA levels in the pancreatic juice and bile mixture always demonstrated strong concordance with the degree of dysplasia. In some instances, elevated CEA values facilitated the adoption of a more aggressive treatment strategy, leading to the detection of carcinoma. Conversely, low CEA levels prompted the decision to opt for observation rather than radical surgery in other cases.ConclusionDiagnosing precancerous transformations of the pancreas remains a challenging task, characterized by a notable rate of false-positive or false-negative conclusions. The DAB method offers a promising solution, seamlessly integrating into routine clinical practice and offering supplementary data to enhance the verification of pancreatic cancer. Citation Format: Aleksei Kashintsev, Vitali Proutski. Duodenal aspiration biopsy in diagnosis of pancreatic neoplasms [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 B015.

Abstract B085: The HIF-2 transcription factor mediates resistance to ferroptosis in pancreatic adenocarcinoma

Abstract Ferroptosis is an iron-dependent form of cell death converging on lipid peroxidation, first identified by examining compounds with enhanced lethality to KRAS mutant cells. Two compounds widely used as ferroptosis inducers are erastin, which acts as an inhibitor of cystine import and thereby depletes cellular glutathione, and RSL-3, which inhibits glutathione peroxidase 4. Despite over 90% of pancreatic adenocarcinoma (PDAC) tumors harboring KRAS mutations, PDAC exhibits relative resistance to ferroptosis compared to other tumor types, and the mechanisms behind this resistance remain unclear. The pancreatic tumor environment is marked by severe hypoxia, due to poor vascularity and a dense fibrotic stroma, and so we hypothesized that hypoxia might mediate resistance to ferroptosis. Here we report that across a panel of human and murine PDAC cell lines, hypoxia induces resistance to both ferroptosis inducing agents, erastin and RSL-3. The effect of hypoxia was synergistic with exposure to pancreatic cancer tumor interstitial fluid, which induces a hypoxic-like gene expression profile even under normoxia and enhances hypoxic gene expression changes when combined with hypoxia. Our findings reveal that hypoxia-mediated resistance to ferroptosis is orchestrated by the hypoxia-inducible transcription factor HIF-2, as evidenced by its complete abolition in HIF-2 knockout cell lines, while the protective effect of hypoxia was maintained in HIF-1 knockout lines. RNA-seq analyses and chromatin immunoprecipitation studies (chIP) identified several HIF-2 target genes responsible for coordinating ferroptosis resistance mechanisms. Cysteine is a precursor for glutathione, and HIF-2 increased cystine import through upregulation of both components of the cystine-glutamate antiporter system Xc (SLC7A11 and SLC3A2) and increased cysteine biosynthesis via upregulation of transsulfuration pathway enzymes (CBS and CTH). In addition, HIF-2 upregulated Parkin, which we identify as a novel regulator of ferroptosis, thereby increasing mitophagy and decreasing reactive oxygen species. In vivo studies using human and murine PDAC xenograft models confirmed that HIF-2 knockout impaired tumor growth and increased susceptibility to the pro-ferroptotic agent sulfasalazine. Collectively, these data identify a mechanism by which PDAC evades ferroptosis and identifies a possible therapeutic strategy of combining HIF-2 inhibitors with pro-ferroptotic agents in pancreatic cancer. Citation Format: Maimon E Hubbi, Catherine Wang, Erin Hollander, Yasir Suhail, Kshitiz, Alexander Muir, Ben Z Stanger, Chi V Dang. The HIF-2 transcription factor mediates resistance to ferroptosis in 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 B085.

Abstract B042: Dissection of the T cell infiltrate in mouse pancreatic tumors reveals a diverse tumor-reactive T cell repertoire targeting neoantigens and tumor-associated antigens

Abstract Although pancreatic cancer is generally refractory to immune checkpoint blockade (ICB), recent studies of tumor-infiltrating T cells in human tumor samples demonstrated the presence of in vivo expanded, tumor-reactive T cell receptor (TCR) clonotypes. Here, we explored the T cell repertoire in ICB-refractory murine pancreatic cancer models by combining single-cell transcriptomics with functional TCR characterization. Our initial studies in an orthotopic, transplantable model revealed a remarkable diversity of tumor-reactive TCR clonotypes that could be distinguished from bystander T cells based on gene expression signatures. We identified TCRs exclusively reactive against the tumor of origin, TCRs that also react against an independently derived pancreatic tumor line, and TCRs broadly reactive to tumor cells of diverse tissue origin (e.g. MC38), the latter category being predominant. Subsequent studies were performed in an autochthonous mouse model, in which single focal tumors were induced in the pancreas by means of in vivo electroporation of gene constructs encoding mutant Kras and inducing CRISPR/Cas9-mediated inactivation of tumor suppressor genes. We analyzed the T cell repertoire in tumors with different levels of mutational burden by also inactivating DNA damage repair genes. Interestingly, even in mismatch repair-deficient tumors that featured a high mutational load, the anti-tumor T cell response was primarily directed against recurrent tumor-associated antigens (TAAs) rather than ‘private’ mutanome-encoded neoantigens. Several TAA-reactive TCRs also mediated reactivity against non-transformed cells. Immunopeptidome analysis thus far revealed the identity of 5 cognate antigens targeted by the tumor-reactive TCR repertoire: a mutanome-encoded neoantigen, an epitope encoded by an ectopically expressed endogenous retroviral provirus, and three epitopes derived from TAAs: Lon Peptidase 2 (LONP2), ATPase Na+/K+ Transporting Subunit Beta 3 (ATP1B3) and SEC24B, a component of secretory vesicles. Notably, the overexpression of LONP2 and ATP1B3 was found associated with progression of human cancers, whereas silencing was shown to suppress tumor cell growth. Overexpression of SEC24B in cancers has not been reported, but this protein plays an essential role in the secretory pathway of acinar cells. In summary, in-depth analysis of the natural T cell response in murine pancreatic cancer models revealed a diverse tumor-reactive T cell repertoire that is predominantly directed against TAAs, some of which are also expressed in normal somatic cells. These findings underline the importance of uncovering the antigen-specificity of the natural tumor-reactive TCR repertoire, both in mouse models and human tumor samples, to assess its therapeutic potential and safety with regard to personalized immunotherapy. Citation Format: Stefan Zens, Hannes Kehm, Daniel Baumann, Aline Konrad, Zibo Meng, Arnoud H. de Ru, Julian Mochayedi, Francesca Lucato, Angelika B. Riemer, Isabel Poschke, Michael Volkmar, Peter A. van Veelen, Rienk Offringa. Dissection of the T cell infiltrate in mouse pancreatic tumors reveals a diverse tumor-reactive T cell repertoire targeting neoantigens and tumor-associated antigens [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 B042.

Robotic single-port plus one-port splenic vessel-conserving spleen-preserving distal pancreatectomy: a case report.

Minimally invasive distal pancreatectomy is a safe and effective surgical approach for the treatment of distal pancreatic tumors. Recently, the da Vinci single-port (SP) system (Intuitive Surgical, Inc.) was introduced to overcome the previously known limitations of this approach. Here, we report our experience with robotic SP plus one-port splenic vessel-conserving spleen-preserving distal pancreatectomy (RSP + 1 SVc-SpDP). A 38-year-old male patient was incidentally found to have a pancreatic neuroendocrine tumor. On May 12, 2023, RSP + 1 SVc-SpDP was performed. The robotic SP was placed at the transumbilical site, and an additional 12-mm port was placed on the left side of the patient's abdomen. The surgical procedure was based on splenic vessel-conserving, spleen-preserving distal pancreatectomy. The operative time was 350 minutes, and the patient was discharged on postoperative day 8 without any complications. The initial experience of RSP + 1 SVc-SpDP using the da Vinci SP system showed the possibility of an alternative operation for distal pancreatectomy.

Abstract A051: Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis

Abstract Introduction: Persistent inflammation due to alcoholic chronic pancreatitis (ACP) is associated with pancreatic ductal adenocarcinoma (PDAC). Myeloid cell infiltration within the pancreas, particularly with oncogenic mutant KrasG12D/+ (*Kras), is crucial for driving PDAC carcinogenesis. Our previous work demonstrated that hyperactivation of cyclic AMP response element binding protein (CREB) accelerates ADM/PanIN progression with heightened fibroinflammation. However, the association between CREB in precursor neoplastic lesions and innate myeloid cells remains unclear. Methods: We established an ACP mouse model using an alcohol diet along with prolonged caerulein administration in Ptf1aCreERTM/+; LSL-KrasG12D/+ (KC), and CREB deleted [Crebfl/fl in KC (KCC-/-)] mice. Single-cell RNA sequencing (scRNA-seq) of the mouse pancreas, multiparametric immunophenotyping of tumor-infiltrating myeloid cells and chromatin immunoprecipitation (ChIP-seq) with CREB pulldown were performed. Cytokine arrays and qPCR studies followed co-culture assays using mouse neutrophils (J774M) and macrophages (RAW 264.7) with epithelial cell lines harboring *Kras with in vitro ACP induction were conducted. Results: ACP induction in KC mice led to increased infiltration of neutrophils and alternatively activated macrophages with the pancreas. Conversely, Creb-deleted mice exhibited significantly reduced myeloid cell infiltration despite ACP induction. ChIP-Seq and qPCR identified CREB-regulated chemokines and immunomodulators as mediators of myeloid cell trafficking. Co-culture of mouse neutrophils and macrophages with KC-ACP conditioned media significantly increased IL-1 receptor antagonist (Il-1ra) expression and secretion. Single-cell transcriptomic analysis revealed heightened Il1rn mRNA levels in neutrophils and macrophages in KC-ACP when compared with KC pancreatic tumors. Creb-deleted PDAC models showed strong downregulation of Il1rn in macrophages, confirming CREB’s role in modulating myeloid cell interactions via epithelial cell signaling. Conclusions: Our findings highlight that CREB activation in epithelial cells under ACP conditions facilitates crosstalk with myeloid cells, promoting IL-1ra upregulation in neutrophils and macrophages. This CREB-driven regulation of IL-1ra in myeloid cells contributes to inflammation-associated tumorigenesis. Targeting this axis may offer a novel therapeutic approach to curb pancreatic cancer progression. Citation Format: Siddharth Mehra, Sudhakar Jinka, Varun Krishnamoorthy, Supriya Srinivasan, Anna Bianchi, Andrew Adams, Haleh Amirian, Manan Patel, Jashodeep Datta, Nipun Merchant, Nagaraj Nagathihalli. Innate immune cell dynamics and pancreatic tumor progression in alcoholic pancreatitis [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 A051.

Abstract PR-01: Systemic targeting of therapeutic RNA to pancreatic ductal adenocarcinoma via a novel, cell-penetrating, and nucleic acid-binding monoclonal antibody

Abstract There is intense interest in developing nucleic acid ligands for immune stimulation of the tumor microenvironment via pattern recognition receptors (PRRs), particularly for treating “cold” tumors like pancreatic ductal adenocarcinoma (PDAC). However, selective delivery of intact and functional RNAs after intravenous administration in a tumor-specific manner to avoid systemic toxicity has been challenging. Many current efforts rely on the direct intra-tumoral injection of RNAs or other stimulatory immune ligands, which is therapeutically sub-optimal, especially for pancreatic tumors and metastases. Here, we present a groundbreaking and unique cancer treatment approach using a lupus-derived, cell-penetrating antibody to deliver nucleic acids to PDAC tumors in vivo. This antibody, a modified version of the initially reported 3E10-D31N, designated TMAB3, forms non-covalent complexes with RNAs. We tested our delivery platform in genetically engineered mouse models (Pdx-1 Cre KrasG12D) and flank and orthoptic allographs of pancreatic cancer (Pdx-1 Cre KrasG12D, p53R172H/- KPC cells) in immunocompetent models. Using 3p-hpRNA, an agonist of the pattern recognition receptor retinoic acid-inducible gene-I (RIG-I), we observed robust anti-tumor efficacy of systemically administered TMAB3/3p-hpRNA complexes in an orthotopic pancreatic cancer model. Treatment tripled animal survival and decreased tumor growth, specifically targeting the malignant cells, with a 1500-fold difference in RNA delivery into tumor cells versus non-malignant cells within the tumor mass. While an immunosuppressive microenvironment typically characterizes PDAC, we found that RIG-I stimulation via TMAB3/3p-hpRNA treatment elicited a potent anti-tumoral immune response characterized by induction of apoptosis in tumor cells and infiltration of CD8+ T cells using single-cell RNASeq and confirming using FACS and immunocompromised mice. In vitro and in vivo studies demonstrated that cancer-cell delivery was mediated by nucleoside transporter ENT2, which is highly expressed in PDAC compared to healthy and benign tissues. These results were recapitulated in orthogonal models of immunologically cold tumors, including melanoma and medulloblastoma. Together, these studies demonstrate that the TMAB3 antibody can 1) precisely localize and enter pancreatic tumor cells, 2) promote CD8+ T cell infiltrates, and 3) rapidly deliver RNA payloads specifically to tumors. Given the known stromal barrier in pancreatic ductal adenocarcinoma, TMAB3 provides a novel targeted delivery platform for a broad range of therapeutics for these difficult-to-treat tumors. Citation Format: Diana Martinez-Saucedo, Elias Quijano, Zaira Ianniello, Madison Rackear, Yanfeng Liu, Denise Hegan, Haoting Chen, Xinning Shan, Robert Tseng, Deanne Yugawa, Natasha Pinto-Medici, Sumedha Chowdhury, Ranjit S Bindra, Marie E Robert, W. Mark Saltzman, Luisa F Escobar-Hoyos, Peter M Glazer. Systemic targeting of therapeutic RNA to pancreatic ductal adenocarcinoma via a novel, cell-penetrating, and nucleic acid-binding monoclonal antibody [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 PR-01.

Abstract B023: Unravelling fibroinflammatory and immune signatures for pancreatic cancer early detection

Abstract Pancreatic cancer is associated with late-stage diagnosis and poor patient prognosis. The disease is characterised by chronic dysregulated immunity and inflammation. Moreover, chronic pancreatitis is linked with an increased risk of pancreatic cancer. Tissue remodelling during disease progression involves a complex network of cells and a crosstalk between cancer cells, stromal components and immune cells, but it remains poorly explored. Thus, to improve the outcome of patients, there is a need for better understanding of biological changes associated with the initiation and progression of pancreatic cancer at the molecular and spatial levels. Using samples obtained from our Accelerated Diagnosis of neuroEndocrine and Pancreatic TumourS (ADEPTS) biobank, we have evaluated blood samples for the discovery of non- invasive biomarkers to discriminate patients with pancreatic cancer from symptomatic patients without cancer. In this pilot study, the transcriptome of peripheral blood mononuclear cells (PBMCs), isolated using a ficoll gradient was explored to identify PDAC-associated mRNA signatures. Moreover, the Olink® Explore Inflammation and Oncology panels were performed in a cohort of 40 patients with early stage (I-II) PDAC, 40 chronic pancreatitis samples and 40 control patients with benign symptomatic upper GI diseases. To validate and enrich these results, a panel of inflammatory and immune markers including immunoglobulins, cytokines and chemokines was also run using multiplex techniques. Symptoms observed in our cohort were also analysed together with clinical (e.g diabetic status, biochemistry profile) and demographic data (age, sex, ethnicity, post code etc). We have identified mRNA transcriptome signatures and differentially expressed proteins associated with inflammatory and immunological processes in PDAC compared to benign symptomatic samples. Our results offer potential diagnostic utility for early-stage disease. Additionally, our unique cohort of patient samples comprising of those with confirmed PDAC and those presenting to clinic with benign disease and similar non-specific symptoms, allows for the development of non-invasive diagnostic tests with better translational applicability. Future work will involve the validation of these findings in a larger patient cohort and the use of NanoString GeoMx® Digital Spatial Profiler to perform whole transcriptome and proteome profiling in human chronic pancreatic and pancreatic cancer tissue samples. Citation Format: Kyra Fraser, Maria Rosado, Stephen P Pereira, Pilar Acedo. Unravelling fibroinflammatory and immune signatures for pancreatic cancer early detection [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 B023.

Abstract B093: The evaluation of the gene expression profile of pancreatic ductal adenocarcinomas (PDACs) in 3D cell culture vs in vivo and development of new 3D PDACs' models for an evaluation of anti-cancer drug testing

Abstract In the ever-evolving landscape of biomedical research, 3D Cell Culture (3DCC) systems have emerged as pivotal tools for mimicking in vivo environments and fostering more physiologically relevant cellular responses. Despite promises, 3DCC based drug discovery efforts didn’t fulfil the hopes. The classic way 3DCC is done, always starts with 2D cell culture (2DCC) followed by brief 3 day 3DCC and finally drug testing. Following those observations we decided to mimic much more than just brief 3DCC state but enhance the culture by constant 3DCC to 3DCC passages. We characterized the gene expression profiles and proteomic characteristics of pancreatic tumors concluding that prolonged 3DCC is the closest to an in vivo model. The protracted cultivation periods mimic the intricacies of the in vivo environment, enabling a more accurate representation of the molecular dynamics within pancreatic tumors. In our study, we identified a panel of genes characterized by similar expression levels between prolonged 3D cell culture and in vivo conditions, while displaying significant divergence between 2D cultures and short-term 3D cultures when compared to in vivo. These genes play a pivotal role in the progression and treatment of cancer, underscoring the potential of prolonged 3DCC of LifeGel® significance in understanding tumor biology and devising therapeutic strategies. Furthermore, we also investigated the implications of prolonged 3D in vitro cultures on evaluating anti-cancer drug activities. The findings highlight the significance of 3DCC in enhancing our understanding of pancreatic tumor biology and in refining drug screening methodologies for more effective therapeutic interventions. By providing a biomimetic microenvironment, our hydrogels facilitate the formation of complex cellular structures, enabling more accurate representation of tissue architecture and cellular interactions. We delivered LifeGel® platform which presents a myriad of opportunities for researchers seeking to enhance the fidelity and translatability of their in vitro studies into pre-clinial models. Citation Format: Marcin Krzykawski, David Earnshaw, Krzysztof Kus, Artur Pirog, Sachin Kote, Mark Treherne, Justyna Kocik-Krol. The evaluation of the gene expression profile of pancreatic ductal adenocarcinomas (PDACs) in 3D cell culture vs in vivo and development of new 3D PDACs' models for an evaluation of anti-cancer drug testing [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 B093.

Abstract B075: Functional characterization of TGF-β-dependent cancer-associated fibroblasts in pancreatic cancer using novel in vitro and in vivo models

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant cancer- associated fibroblasts (CAFs) which contribute to a tumor-promoting, chemotherapy-resistant and immunosuppressive tumor microenvironment (TME). However, CAF-ablating therapeutic strategies have thus far failed in clinical trials. One potential reason is that PDAC CAFs are heterogeneous and plastic. It was recently discovered that myofibroblastic CAFs (myCAFs) and inflammatory CAFs (iCAFs) can originate from pancreatic stellate cells (PSCs) via TGF-β and IL-1 signaling, respectively. However, their functional heterogeneity remains to be elucidated. We hypothesize that distinct CAF subtypes exhibit different tumor-promoting roles mediated by targetable signaling mechanisms. To this end, we aimed at characterizing the functions of TGF- β-dependent myCAFs in shaping the TME and influencing PDAC progression. Methods: We generated novel myCAF-depleted PDAC mouse models by orthotopically injecting PDAC organoids derived from KPC (Kras LSL-G12D/+ ; Trp53 LSL-R172H/+ ; Pdx1-Cre) mice into Fap-Tgfbr2 knockout (Fap-tTA; Rosa26 LSLtdTom/+ ; tet-O-Cre; Tgfbr2 fl/fl ) mice. The pancreatic tumors were analyzed by flow cytometry, histology and single-cell RNA-sequencing (scRNAseq). In a complementary approach, we generated myCAF-enriched PDAC mouse models by orthotopically co-injecting KPC PDAC organoids and novel TGF-β-driven ‘myCAF-locked’ murine PSCs. In addition, to further dissect myCAF-malignant cell signaling crosstalk, KPC PDAC organoids and myCAF-locked PSCs were co-cultured and then flow-sorted for bulk RNA- sequencing. Results: MyCAF-depleted PDAC tumors from Fap-Tgfbr2 knockout mice had a significant decrease in myCAFs, and a significant expansion of iCAFs, compared to control mice. Additionally, Masson’s trichrome staining indicated significant reduction in collagen content in the TME upon myCAF depletion. Moreover, scRNAseq analysis revealed that myCAF depletion shaped the composition of innate immune cells, including macrophages and neutrophils. Notably, although primary tumor growth was not altered, liver and lung metastases decreased, while diaphragm metastases and ascites increased, in myCAF-depleted PDAC mice. Conversely, liver and lung metastases increased, while diaphragm metastases and ascites decreased in myCAF-enriched PDAC mouse models, suggesting that TGF-β-dependent myCAFs play a role in promoting distant metastases. In line with this, transcriptomic analysis of PDAC organoids co-cultured with myCAF-locked PSCs showed enrichment of pathways in epithelial-mesenchymal transition, hypoxia, VEGF, WNT and cell-matrix interactions. Conclusion: Our study demonstrates that TGF-β-dependent CAFs are not only largely responsible for collagen deposition in PDAC, but also possess immune-modulating properties. Moreover, our study supports a role of TGF-β-dependent CAFs in promoting PDAC metastasis to the liver and the lungs, potentially through upregulating pro-metastatic pathways in the malignant cells. Citation Format: Priscilla S.W. Cheng, Muntadher Jihad, Judhell S. Manansala, Weike Luo, Gianluca Mucciolo, Sara Pinto Teles, Giulia Biffi. Functional characterization of TGF-β-dependent cancer-associated fibroblasts in pancreatic cancer using novel in vitro and in vivo models [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 B075.

Abstract C078: Chromatin accessibility profiling of human pancreatic tumors reveals epigenetic features of malignant and stromal cell subtypes

Abstract Pancreatic ductal adenocarcinoma (PDAC) disease progression involves complex cell state transitions in both malignant and non-malignant populations within the tumor microenvironment. To uncover PDAC cell states and epigenetic features associated with clinical outcome, we profiled 40 tumor samples (33 primary tumors and 7 metastases) from 39 patients with single cell ATAC-seq, along with 10 sample-matched single cell RNA-seq profiles. Through topic modeling of high dimensional chromatin data, we uncovered distinct cis-regulatory networks underlying the classical and basal-like molecular subtypes of PDAC, which showed differential activity in basal-classical hybrid cells. Furthermore, delineation of epigenetic alterations by basal, classical, and hybrid subtypes revealed a core set of chromatin regions opened in all PDAC subtypes relative to ductal and acinar cells. These universally open regions showed striking overlap with gastrointestinal enhancers, highlighting a common endoderm lineage infidelity process across pancreatic tumors. Within the stromal compartment, we identified novel regulators of myofibroblastic cancer-associated fibroblasts (myCAFs) and inflammatory CAFs (iCAFs) from enhancer networks active in each CAF subtype. Importantly, our data uncover a highly prognostic gene program active in only one of two distinct myCAF chromatin states found in our data, highlighting a putative tumor-promoting myCAF subpopulation. Our work provides a high-resolution description of epigenetic cell state heterogeneity in PDAC, revealing novel regulators and gene programs associated with PDAC subtypes and clinical outcome. Citation Format: Kevin MacPherson-Hawthorne, Jason M. Link, Patrick Worth, Brett Sheppard, Andrew Fields, Colin Daniel, Andrew Nishida, Carl Pelz, Trent Waugh, Ethan Agritelle, John Muschler, Andrew Adey, Rosalie Sears. Chromatin accessibility profiling of human pancreatic tumors reveals epigenetic features of malignant and stromal cell subtypes [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 C078.

Abstract B031: Alternate pain management strategies: targeting pancreatic cancer-related pain with Flavonoid

Abstract Purpose For up to 90% of cancer patients, pain is a substantial symptom, contributing to morbidity and, possibly, mortality. In this study we sought to test the hypothesis that a flavonoid, derived from Cannabis, and previously shown to suppress cancer cell growth in vitro and tumor progression in mice in vivo, could also reduce the pain caused by pancreatic tumors in vivo. Methods A subcutaneous tumor in the dorsum of C57BL/6 mouse was generated by sub- dermal injection of KPC mouse pancreatic cancer cell line (ATCC). All the mice were video recorded to observe and analyze their spontaneous pain-related behaviors, including facial washing, dorsal hunching, dorsal skin twitch, licking of dorsal skin and overall locomotion around the cage. Two five minute recording sessions were analyzed by a blinded observer during times before the cancer cell injection (Baseline), after tumor growth, to about 8mm diameter (30d and 37d post-injection) and just before and then 24h after intra-tumor injection of the flavonoid ( Group A: FBL-03G, 1 nmole in 100µL) or Vehicle(100µL; Group B). Pain-related behavioral changes were averaged from the two recording sessions and analyzed from Baseline, just before FBL-03G and 24h after and compared between test compound-and vehicle injected groups (n=7 in each), using non-parametric statistics. Results Facial washing (events/5min) was: reduced to 87% of Baseline in tumor-bearing mice, then increased by 150% at 24h post-injection in Group A (FBL-03G); reduced to 65% of Baseline in tumor-bearing mice of Group B, then reduced a further 9% by Vehicle. Dorsal hunching, which events occur only after tumor growth (Baseline =0), was reduced at 24h by 62% in Group A but increased by 75% in Group B. Dorsal twitch, also absent before tumor growth, was reduced by 64% in Group A, but increased by 19% in Group B. Dorsal skin licking was reduced from Baseline by 33% in tumor-bearing mice of Group A, then increased by 76% after FBL-03g injection whereas licking, reduced by 22% by tumors in Group B and then by an additional 4% by vehicle (Group B). Tumors reduced locomotion by 58% in Group A, which was reversed by 32% after FBL-03g (Group A); vehicle injection resulted in a 38% reduction in locomotion (Group B). Thus, in 4 of the 5 pain-related behaviors from tumors quantitated symptoms were reversed by FBL-03G and oppositely affected, or not at all, by Vehicle. Conclusions These results indicate a substantial relief of spontaneous pain-related pain in this mouse model of pancreatic cancer. Such an acute effect occurs much more rapidly than the previously published in vitro suppression of KPC cell growth (assayed after 9-12d of treatment) or the reduction of tumor size (1-7 weeks) in vivo and suggest that the anti-hyperalgesic affect is due to mechanisms that do not involve reduction in tumor mass. The findings, using a single dose and a small number of mice, appear promising for further studies that examine a range of doses or FBL-03G and its actions in intra-pancreatic tumors. Citation Format: Sayeda Yasmin-Karim, Suheera Haq, Mike Makrigiorgos, Gary Strichartz, Geraud Richards, Natasha Rayman. Alternate pain management strategies: targeting pancreatic cancer-related pain with Flavonoid [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 B031.

Abstract C068: Phenotypic plasticity and functional divergence of neutrophilic MDSCs in pancreatic cancer

Abstract BACKGROUND: Circulating polymorphonuclear neutrophils (PMN) traffic to pancreatic cancer (PDAC)-derived cues, where they acquire specialization as myeloid-derived suppressor cells (MDSC) to exert immune tolerance and stromal inflammation. We sought to dissect the developmental heterogeneity of PMN/MDSCs during PDAC tumorigenesis, molecular networks underlying these fate transitions, and their correlation with oncologic outcomes in PDAC patients. METHODS:Pancreatic tumors &amp; spleens from Ptf1a Cre/+;LSL-Kras G12D/+;Tgfbr2 fl/fl (PKT) mice at 4 and 6 wks of age, along with pancreata/spleens from age-matched littermates, were subjected to single-cell RNA sequencing (scRNAseq). Clustering and splicing kinetics identified distinct populations of circulating and tissue-resident PMN/MDSCs. Ingenuity Pathway Analysis (IPA) nominated unique surface markers for each subset, which was validated by flow cytometry. Paired RNA-ATAC sequencing and functional studied were performed in marker- sorted PMNs. RESULTS: scRNAseq of PKT tumors/spleens revealed striking temporal and phenotypic heterogeneity in PMN subclusters with PDAC tumorigenesis. RNA velocity analysis identified distinct terminal-state (TS) populations in tumors and circulation. The intratumoral-TS fate of PMNs resembled MDSC-like specialization, with enrichment of gene programs indicating suppressive function (Tnf,Il1b,Cd14). Conversely, spleen-TS PMNs showed imprinting of trafficking programs (Cxcr2,Il1rap,Gab2). Intriguingly, a discrete PMN cluster in both spleen and tumors displayed upregulated MHC-II and co-stimulatory molecule genes (H2-Ab,Cd79a,Cd80). IPA of differentially expressed genes with transmembrane localization nominated Cd170, Cd162, and MHC-II as surface markers for tumor-TS, spleen-TS, and MHC-II PMN subsets, which were validated by flow cytometry. RNAseq of Cd170/SiglecF+ intratumoral MDSCs revealed upregulation in inflammatory and pro-survival signaling pathways (Akt/mTor-PID, Il1-KEGG, Myc targets-HALLMARK), with TNF as top predicted upstream regulator by IPA. Enrichment in fibrosis-related genes were supported by Smad4 motif enrichment in Cd170+ RNA/ATAC-seq, suggesting novel profibrotic function. Transcription factor (TF) inference in MHC-II+ PMNs revealed high activity scores for TFs (Rora,Irf1) regulating antigen presentation pathways. Ex vivo co-culture of T-cells with marker-sorted PMNs showed reduced T-cell proliferation/activation preferentially with Cd170+ MDSCs, which were partially and completely reversed upon Cd162+ and MHC-II+ PMN co-culture, respectively. In human PDAC scRNAseq data, increased ratio of CD170:MHC-II PMN correlated with chemoresistance and poor survival. CONCLUSIONS: Phenotypic plasticity of PMNs during PDAC progression drive functional divergence and terminal fate determinism in distinct tissue niches. Relative dosage of MDSCs to MHC-II+ PMN may have prognostic and predictive value. Mechanisms governing fate transitions in PMN subsets could pave the way for future therapeutic targets to overcome immunotherapy resistance in PDAC. Citation Format: Anna Bianchi, Manan Patel, Da Yin, Haleh Amirian, Karthik Rajkumar, Andrew Mark Adams, Erin Dickey, Harper Margaret Marsh, Nagaraj Nagathihalli, Nipun Merchant, Dmitry Gabrilovich, Jashodeep Datta. Phenotypic plasticity and functional divergence of neutrophilic MDSCs 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 C068.