Mouse Model Of Pancreatic Cancer Research Articles

Expanded ROS Generation and Hypoxia Reversal: Excipient-free Self-assembled Nanotheranostics for Enhanced Cancer Photodynamic Immunotherapy.

The efficacy of photodynamic therapy (PDT)-related cancer therapies is significantly restricted by two irreconcilable obstacles, i.e., low reactive oxygen species (ROS) generation capability and hypoxia which constrains the immune response. Herein, we developed a self-assembled clinical photosensitizer indocyanine green (ICG) and the HSP90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) nanoparticles (ISDN) without any excipient. We discovered that the hydrophobic interaction forces between ICG and 17-DMAG promote the photostability of ICG and its intersystem crossing process (ISC), thereby improving the ROS quantum yield from 0.112 to 0.46. Augmented ROS generation enhances PDT efficacy and further enhances immunogenic cell death (ICD) effects. 17-DMAG inhibits the HSP90/HIF-1α axis to dramatically reverse the immunosuppressive tumor microenvironment caused by PDT-aggravated hypoxia. In a mouse model of pancreatic cancer, ISDN markedly improve cytotoxic T lymphocyte infiltration and MHC I and MHC II activation, demonstrating the superior ICD effects in situ tumor and the powerful systematic antitumor immunity generation, eventually achieving vigorous antitumor and recurrence resistance. This study proposes an unsophisticated and versatile strategy to significantly improve PDT efficacy for enhancing systemic antitumor immunity and potentially extending it to multiple cancers. This article is protected by copyright. All rights reserved.

CYRI-B mediated macropinocytosis drives metastasis via lysophosphatidic acid receptor uptake.

Pancreatic ductal adenocarcinoma carries a dismal prognosis, with high rates of metastasis and few treatment options. Hyperactivation of KRAS in almost all tumours drives RAC1 activation, conferring enhanced migratory and proliferative capacity as well as macropinocytosis. Macropinocytosis is well understood as a nutrient scavenging mechanism, but little is known about its functions in trafficking of signaling receptors. We find that CYRI-B is highly expressed in pancreatic tumours in a mouse model of KRAS and p53-driven pancreatic cancer. Deletion of Cyrib (the gene encoding CYRI-B protein) accelerates tumourigenesis, leading to enhanced ERK and JNK-induced proliferation in precancerous lesions, indicating a potential role as a buffer of RAC1 hyperactivation in early stages. However, as disease progresses, loss of CYRI-B inhibits metastasis. CYRI-B depleted tumour cells show reduced chemotactic responses to lysophosphatidic acid, a major driver of tumour spread, due to impaired macropinocytic uptake of the lysophosphatidic acid receptor-1. Overall, we implicate CYRI-B as a mediator of growth and signaling in pancreatic cancer, providing new insights into pathways controlling metastasis.

PH-responsive targeted nanoparticles release ERK-inhibitor in the hypoxic zone and sensitize free gemcitabine in mutant K-Ras-addicted pancreatic cancer cells and mouse model.

Therapeutic options for managing Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest types of aggressive malignancies, are limited and disappointing. Therefore, despite suboptimal clinical effects, gemcitabine (GEM) remains the first-line chemotherapeutic drug in the clinic for PDAC treatment. The therapeutic limitations of GEM are primarily due to poor bioavailability and the development of chemoresistance resulting from the addiction of mutant-K-RAS/AKT/ERK signaling-mediated desmoplastic barriers with a hypoxic microenvironment. Several new therapeutic approaches, including nanoparticle-assisted drug delivery, are being investigated by us and others. This study used pH-responsive nanoparticles encapsulated ERK inhibitor (SCH772984) and surface functionalized with tumor-penetrating peptide, iRGD, to target PDAC tumors. We used a small molecule, SCH772984, to target ERK1 and ERK2 in PDAC and other cancer cells. This nanocarrier efficiently released ERKi in hypoxic and low-pH environments. We also found that the free-GEM, which is functionally weak when combined with nanoencapsulated ERKi, led to significant synergistic treatment outcomes in vitro and in vivo. In particular, the combination approaches significantly enhanced the GEM effect in PDAC growth inhibition and prolonged survival of the animals in a genetically engineered KPC (LSL-KrasG12D/+/LSL-Trp53R172H/+/Pdx-1-Cre) pancreatic cancer mouse model, which is not observed in a single therapy. Mechanistically, we anticipate that the GEM efficacy was increased as ERKi blocks desmoplasia by impairing the production of desmoplastic regulatory factors in PDAC cells and KPC mouse tumors. Therefore, 2nd generation ERKi (SCH 772984)-iRGD-pHNPs are vital for the cellular response to GEM and denote a promising therapeutic target in PDAC with mutant K-RAS.

Irreversible electroporation promotes a pro-inflammatory tumor microenvironment and anti-tumor immunity in a mouse pancreatic cancer model.

Pancreatic cancer is a significant cause of cancer-related mortality and often presents with limited treatment options. Pancreatic tumors are also notorious for their immunosuppressive microenvironment. Irreversible electroporation (IRE) is a non-thermal tumor ablation modality that employs high-voltage microsecond pulses to transiently permeabilize cell membranes, ultimately inducing cell death. However, the understanding of IRE's impact beyond the initiation of focal cell death in tumor tissue remains limited. In this study, we demonstrate that IRE triggers a unique mix of cell death pathways and orchestrates a shift in the local tumor microenvironment driven, in part, by reducing the myeloid-derived suppressor cell (MDSC) and regulatory T cell populations and increasing cytotoxic T lymphocytes and neutrophils. We further show that IRE drives induce cell cycle arrest at the G0/G1 phase in vitro and promote inflammatory cell death pathways consistent with pyroptosis and programmed necrosis in vivo. IRE-treated mice exhibited a substantial extension in progression-free survival. However, within a span of 14 days, the tumor immune cell populations reverted to their pre-treatment composition, which resulted in an attenuation of the systemic immune response targeting contralateral tumors and ultimately resulting in tumor regrowth. Mechanistically, we show that IRE augments IFN-γ signaling, resulting in the up-regulation of the PD-L1 checkpoint in pancreatic cancer cells. Together, these findings shed light on potential mechanisms of tumor regrowth following IRE treatment and offer insights into co-therapeutic targets to improve treatment strategies.

Abstract CT059: Phase 1b trial Mipasetamab Uzoptirine (ADCT-601-102) dose escalation in patients with advanced bone and soft tissue sarcomas

Abstract Background: AXL is a cell surface receptor tyrosine kinase widely expressed in solid tumors (ST), including sarcomas. ADCT-601 (Mipasetamab uzoptirine; Mipa) is an antibody-drug conjugate comprising a humanized anti-AXL antibody conjugated via a cleavable linker to SG3199 (pyrrolobenzodiazepine dimer cytotoxin). Mipa demonstrated antitumor activity in pre-clinical mice models of sarcoma, adrenocortical carcinoma and pancreatic cancer, and clinical activity in ST patients (pts) in its first-in-human trial. Here, we report initial clinical data in pts with advanced bone and soft tissue sarcomas treated in dose escalation with Mipa. Objective: To characterize the safety and tolerability of Mipa in pts with sarcoma indications who exhausted standard of care therapy. Method: This is a phase 1b, open-label, dose-escalation, dose expansion study of Mipa (NCT05389462; EudraCT: 2021-00566-18). Pts received Mipa every 3 weeks (Q3W) at escalating dose levels, in a 3+3 dose escalation design. Results: As of 04 December 2023, 18 sarcoma patients (15 [83%], soft tissue sarcoma [STS] and 3 [17%] bone sarcoma), unselected for AXL expression, with a median number of 3 prior lines of therapy (1-10), were enrolled in 4 different dose cohorts: 7.5mg, 11mg, 13mg and 15mg. Reasons for treatment discontinuation were disease progression (10 pts [55.6%]), adverse events (3 pts [16.7%]) and consent withdrawal (2 pts [11.1%]). Treatment emergent adverse events (TEAE) were seen in 17 pts (94.4%). Most common TEAE (all grades and relationship [≥20%]) were palmar-plantar erythrodysesthesia syndrome (7 pts [38.9%]); anemia (6 pts [33.3%]); rash maculopapular (5 pts [27.8%]); cheilitis and constipation (4 pts each [22.2%]). TEAE≥grade 3 were seen in 9 pts (50%). Most common TEAE≥grade 3 (≥10%) were GGT increase (2 pts [11.1%]). Two dose limiting toxicities were seen: cheilitis grade 2 and grade 3 at 15mg and 13mg respectively. Cutaneous reactions, all grades, are more prominent in higher doses. Maximum tolerated dose (MTD) has not been established. In 17 sarcoma pts evaluable per RECISTv1.1, best overall response was partial response (PR) (2 pts [11.8%]), including a confirmed PR; stable disease (SD) (8 pts [47.1%]); progressive disease (7 pts [41.2%]). Tumor reductions was observed at 7.5mg, 11mg and 13mg. By week 12, 6/17 pts (35.3%) did not demonstrate PD . Initial IHC staining showed AXL expression in all sarcoma baseline biopsies tested so far. Initial pharmacokinetic (PK) data indicate exposures with moderate to marked interpatient variability; rapid clearance with no accumulation by Cycle 2. Updated biomarkers and PK data will be presented. Conclusion: The MTD was not established. Due to the incidence of TEAE judged related to Mipa and the preliminary activity observed, 15mg was selected as the highest dose to be tested in a fixed dose Q3W regimen. The study continues to enroll to further optimize Mipa dosing regimen and in dose escalation with gemcitabine. Citation Format: Brian Andrew Van Tine, Christopher T. Chen, Victor Moreno, Elizabeth J. Davis, Maria J. de Miguel, Antoine Italiano, Esma Saada-Bouzid, Mohammed Milhem, Claudia Valverde, Sant P. Chawla, Abdul Rafeh Naqash, Louise Carter, Robin Jones, Ilaria Conti, Joe Boni, Karin Havenith, Yvan LeBruchec, Serafino Pantano, Jean-Yves Blay. Phase 1b trial Mipasetamab Uzoptirine (ADCT-601-102) dose escalation in patients with advanced bone and soft tissue sarcomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT059.

Optimization of a mouse model of pancreatic cancer to simulate the human phenotypes of metastasis and cachexia

BackgroundPancreatic ductal adenocarcinoma (PDAC) presents with a high mortality rate. Two important features of PDAC contribute to this poor outcome. The first is metastasis which occurs in ~ 80% of PDAC patients. The second is cachexia, which compromises treatment tolerance for patients and reduces their quality of life. Although various mouse models of PDAC exist, recapitulating both metastatic and cachectic features have been challenging.MethodsHere, we optimize an orthotopic mouse model of PDAC by altering several conditions, including the subcloning of parental murine PDAC cells, implantation site, number of transplanted cells, and age of recipient mice. We perform spatial profiling to compare primary and metastatic immune microenvironments and RNA sequencing to gain insight into the mechanisms of muscle wasting in PDAC-induced cachexia, comparing non-metastatic to metastatic conditions.ResultsThese modifications extend the time course of the disease and concurrently increase the rate of metastasis to approximately 70%. Furthermore, reliable cachexia endpoints are achieved in both PDAC mice with and without metastases, which is reminiscent of patients. We also find that cachectic muscles from PDAC mice with metastasis exhibit a similar transcriptional profile to muscles derived from mice and patients without metastasis.ConclusionTogether, this model is likely to be advantageous in both advancing our understanding of the mechanism of PDAC cachexia, as well as in the evaluation of novel therapeutics.

Human anti-PSCA CAR macrophages possess potent antitumor activity against pancreatic cancer.

Due to the limitations of autologous chimeric antigen receptor (CAR)-T cells, alternative sources of cellular immunotherapy, including CAR macrophages, are emerging for solid tumors. Human induced pluripotent stem cells (iPSCs) offer an unlimited source for immune cell generation. Here, we develop human iPSC-derived CAR macrophages targeting prostate stem cell antigen (PSCA) (CAR-iMacs), which express membrane-bound interleukin (IL)-15 and truncated epidermal growth factor receptor(EGFR) for immune cell activation and a suicide switch, respectively. These allogeneic CAR-iMacs exhibit strong antitumor activity against human pancreatic solid tumors invitro and invivo, leading to reduced tumor burden and improved survival in a pancreatic cancer mouse model. CAR-iMacs appear safe and do not exhibit signs of cytokine release syndrome or other invivo toxicities. We optimized the cryopreservation of CAR-iMac progenitors that remain functional upon thawing, providing an off-the-shelf, allogeneic cell product that can be developed into CAR-iMacs. Overall, our preclinical data strongly support the potential clinical translation of this human iPSC-derived platform for solid tumors, including pancreatic cancer.

The MUC1–HIF-1α signaling axis regulates pancreatic cancer pathogenesis through polyamine metabolism remodeling

Dysregulation of polyamine metabolism has been implicated in cancer initiation and progression; however, the mechanism of polyamine dysregulation in cancer is not fully understood. In this study, we investigated the role of MUC1, a mucin protein overexpressed in pancreatic cancer, in regulating polyamine metabolism. Utilizing pancreatic cancer patient data, we noted a positive correlation between MUC1 expression and the expression of key polyamine metabolism pathway genes. Functional studies revealed that knockdown of spermidine/spermine N1-acetyltransferase 1 (SAT1), a key enzyme involved in polyamine catabolism, attenuated the oncogenic functions of MUC1, including cell survival and proliferation. We further identified a regulatory axis whereby MUC1 stabilized hypoxia-inducible factor (HIF-1α), leading to increased SAT1 expression, which in turn induced carbon flux into the tricarboxylic acid cycle. MUC1-mediated stabilization of HIF-1α enhanced the promoter occupancy of the latter on SAT1 promoter and corresponding transcriptional activation of SAT1, which could be abrogated by pharmacological inhibition of HIF-1α or CRISPR/Cas9-mediated knockout of HIF1A. MUC1 knockdown caused a significant reduction in the levels of SAT1-generated metabolites, N1-acetylspermidine and N8-acetylspermidine. Given the known role of MUC1 in therapy resistance, we also investigated whether inhibiting SAT1 would enhance the efficacy of FOLFIRINOX chemotherapy. By utilizing organoid and orthotopic pancreatic cancer mouse models, we observed that targeting SAT1 with pentamidine improved the efficacy of FOLFIRINOX, suggesting that the combination may represent a promising therapeutic strategy against pancreatic cancer. This study provides insights into the interplay between MUC1 and polyamine metabolism, offering potential avenues for the development of treatments against pancreatic cancer.

Abstract 3274: Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer

Abstract Background and Aims: Pancreatic cancer is one of the most lethal malignancies, partly due to resistance to conventional chemotherapy. The chemoresistance of malignant tumors is associated with epithelial-mesenchymal transition (EMT) and the stemness of cancer cells. The aim of this study is to investigate the availability and functional mechanisms of trefoil factor family 1 (TFF1), a tumor-suppressive protein in pancreatic carcinogenesis, to treat pancreatic cancer. Methods: To investigate the role of endogenous TFF1 in human and mice, specimens of human pancreatic cancer and genetically engineered mouse model of pancreatic cancer (KPC/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/TFF1−/−) were analyzed by immunohistochemistry (IHC). To explore the efficacy of extracellular administration of TFF1, recombinant and chemically synthesized TFF1 were administered to pancreatic cancer cell lines, a xenograft mouse model and a transgenic mouse model. Results: The deficiency of TFF1 was associated with increased EMT markers of cancer cells (Snail and Zeb1) in mouse models of pancreatic cancer, KPC. Analysis of the survival of patients who underwent chemotherapy for recurrent pancreatic cancer revealed that the expression of TFF1 in cancer cells was associated with better survival. Also, in the mouse model of pancreatic cancer, KPC mice showed improved survival when treated with gemcitabine, the KPC/TFF1KO mice did not. Pancreatic cancer cell lines were administered with gemcitabine and/or chemically synthesized TFF1, revealing that addition of TFF1 downregulated gemcitabine-induced EMT markers (Snail, Slug, ZEB1, and αSMA), Wnt pathway activation (β-catenin, TCF7, and EPHB3). In addition, TFF1 inhibited the expression of cancer stemness markers (CD133 and NANOG3) and the ability to form tumor sphere. Importantly, TFF1 accelerated the apoptosis of cancer cells induced by gemcitabine in vitro. In vivo, combined treatment of gemcitabine and subcutaneous administration of TFF1 arrested tumor growth in xenograft mouse model. Also, KPC mice with combined treatment showed the better survival rather than gemcitabine-alone treatment, with lower expression of CD133, high expression of ZEB1, and lower nuclear translocation of β-catenin. Conclusion: These results indicate that TFF1 can contribute to establishing a novel strategy to treat pancreatic cancer patients by enhancing chemosensitivity. Citation Format: Junpei Yamaguchi, Toshio Kokuryo, Yukihiro Yokoyama, Masaki Sunagawa, Taisuke Baba, Tomoki Ebata. Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3274.

Abstract 467: Genetic ablation of microRNA-10b improves treatment outcomes in mouse models of pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a recalcitrant and lethal disease with an overall 5-year survival rate of less than 12%. PDAC is a heterogeneous disease characterized by highly aggressive cancer cells, extensive desmoplastic reaction, and hypovascularity. These unique features endow PDAC tumors with an array of innate resistance mechanisms against standard-of-care (SOC) chemotherapy: gemcitabine/nab-paclitaxel or FOLFIRINOX. Thus, there is clinical need to develop novel targets that enhance treatment efficacy of SOC chemotherapy. microRNA-10b (miR-10b) expression is frequently upregulated in PDAC and correlates with poor outcome. High levels of miR-10b expression within cancer cells correlates with poor treatment response to gemcitabine-containing neoadjuvant chemotherapy and poor overall clinical outcome. We and others reported that miR-10b exerts cancer cell-intrinsic pro-survival, anti-apoptotic, and pro-metastatic functions via downregulation of key target genes (i.e., BIM, PTEN, TIAM1). We hypothesize that upregulation of miR-10b expression is a chemoresistance mechanism to increase cell survival and inhibit apoptosis in PDAC. To test this hypothesis, we generated a KPC model (KrasG12D-driven, p53-deleted by Pdx1-Cre) with global Mir-10b gene knockout (Mir-10bKO). Animals were recruited when their tumor volume reached 200 mm3 by multi-mouse MR imaging and were randomly assigned to control or treatment groups (100 mg/kg of gemcitabine q4d). Tumor growth was monitored by weekly MR imaging sessions throughout the duration of the treatment. Untreated KPC;Mir-10bKO animals survived several weeks longer than untreated KPC animals (21.7 vs. 18 weeks, p = 0.056), suggesting a weak but detectable tumor promoting role of miR-10b. Remarkably, loss of miR-10b activity enhances treatment response to gemcitabine and significantly prolongs survival in this KPC model. Treated KPC animals lived only 5 weeks longer than untreated KPC (23 vs 18 weeks, p = 0.015), whereas KPC;Mir-10bKO lived 9 weeks longer (27 vs 18 weeks, p = 0.002). Notably, we observed a more durable response in treated female KPC;Mir-10bKO animals (n = 4) compared to any other experimental group (n > 5). We are currently performing tissue and molecular analyses to identify direct target genes involved in chemoresistance and sex-specific modulation of treatment response. Citation Format: Katarzyna Kempinska, Sudhakar Samuel, Saiprashanth Rajesh, Christiane Mallett, Lorenzo Sempere. Genetic ablation of microRNA-10b improves treatment outcomes in mouse models of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 467.

Abstract 5275: Celecoxib and chloroquine enhance the antitumor effect of immune checkpoint blockade therapy, in a syngeneic mouse model for pancreatic cancer

Abstract Immune checkpoint inhibitors (ICIs) have shown impressive clinical activities in some cancer types, but they have yet to demonstrate any meaningful clinical benefit in patients with pancreatic ductal adenocarcinoma (PDAC) except those with microsatellite instability high (MSI-H) tumors. Several recent studies showed that concomitant use of NSAIDs such as celecoxib by patients with certain cancers could improve the survival benefit of ICI treatment (e.g., Sebastian et al, Clin Lung Cancer, 2023;). Furthermore, autophagy inhibitors such as chloroquine were also reported to sensitize pancreatic tumors to the treatment of ICIs in mouse models for PDAC (Yamamoto, et al, Nature, 2020). We recently reported that the combination of chemotherapy (triple combination of nab-paclitaxel + gemcitabine + cisplatin) and a mouse surrogate of the IFc-enhanced anti-CTLA-4 antibody botensilimab, showed significantly improved antitumor activity in immune competent KPC syngeneic mouse model for PDAC [Tanne, et al, Cancer Res (13_Supplement), 2020]. In this study, we sought to determine whether or not the addition of celecoxib and/or chloroquine further improve the antitumor activity of triple chemotherapy and ICI in the syngeneic KPC model. We first found that celecoxib (30mg/kg P.O. QDx21) significantly enhanced the tumor growth inhibition when added to triple chemotherapy (Gemcitabine 70mg/kg I.P., Cisplatin 4mg/kg I.P., Nab-paclitaxel 25mg/kg I.V. days 1,4 and 7) plus the murine equivalents of botensilimab (100ug I.P. BIW for three weeks) and balstilimab (200ug I.P. BIW for three weeks) (p=0.004, N=10). We then performed a pilot study to assess if adding chloroquine could further improve the activity. While adding chloroquine (60mg/kg I.P. QDx21) alone did not significantly affect tumor growth the addition of both chloroquine and celecoxib greatly improve the tumor growth inhibition compared to just the triple chemotherapy and ICIs (p=0.009, N=5). Overall, our data showed that celecoxib or the combination of celecoxib and chloroquine could substantially sensitize the mouse pancreatic tumors to the treatment of chemotherapy and ICIs. (This work was supported in part by the Seena Magowitz Foundation and the Purple Pansies) Citation Format: Jaeger Moore, Dhan Chand, Daniel Levey, Daniel Von Hoff, Haiyong Han. Celecoxib and chloroquine enhance the antitumor effect of immune checkpoint blockade therapy, in a syngeneic mouse model for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5275.

Abstract 6649: Tumor treating fields (TTFields) induce an anti-tumor immune response in a pancreatic cancer mouse model

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy with few therapeutic options. Tumor Treating Fields (TTFields) are low-intensity electric fields that disrupt cellular processes critical for cancer cell division and tumor progression and are approved for the treatment of glioblastoma and pleural mesothelioma. A phase 3 clinical trial is in progress to test the efficacy and safety of TTFields concomitant with standard-of-care gemcitabine and nab-paclitaxel (GnP) as front-line treatment of locally advanced PDAC. TTFields have been shown to induce immunogenic cell death (ICD) in cancer cells and elicit a systemic anti-cancer immune response. Accordingly, the benefit of applying TTFields together with immune checkpoint inhibitors (ICI) was demonstrated in a phase 3 study in patients with non-small cell lung carcinoma. This preclinical study investigated TTFields-induced immune responses in PDAC. Methods: An orthotopic PDAC tumor model was established by inoculating 4 × 105 Panc02 pancreatic cancer cells with stable luciferase expression into the pancreas tail of immune-competent C57BL/6 mice. The mice were randomized into four groups following bioluminescence detection of tumor volume: control, TTFields (150 kHz, 10 days), GnP (50 mg/kg for each drug, i.p. injected once a week for a total of two administrations), and GnP + TTFields. At the end of treatment, tumor volume was measured using caliper, and blood was collected for spectral flow cytometry-based immunophenotyping and ELISA testing for the ICD marker HMGB-1. In vitro, Panc02 cells were treated for 72h with TTFields (150 kHz, 1.62 V/cm RMS) and examined by flow cytometry for apoptosis and ATP secretion (using quinacrine staining) and surface exposure of calreticulin. Results: TTFields markedly reduced the tumor size in Panc02 tumor-bearing mice compared to control mice. Analysis of peripheral blood effector (CD62L-CD44+) and central (CD62L+CD44+) memory T cells demonstrated the induction of circulating effector-memory cytotoxic CD8+ T cells. Additionally, serum HMGB-1 concentrations were significantly elevated in mice treated with TTFields compared to control mice, implying the involvement of ICD in the response to TTFields. In vitro, TTFields application induced apoptosis of Panc02 cells and increased ICD, as indicated by increased surface exposure of calreticulin and ATP depletion. When TTFields were used in Panc02 tumor bearing mice concomitantly with GnP, a substantial reduction in tumor size was detected, and a complete tumor regression was observed in a number of mice. Conclusions: Our results suggest that TTFields may enhance the effects of standard-of-care chemotherapy for the treatment of PDAC. Furthermore, TTFields were shown to induce ICD and activate an antitumor immune response in PDAC, supporting future studies evaluating the efficacy of TTFields together with ICI in PDAC. Citation Format: Tal Kan, Tharwat Haj Khalil, Yiftah Barsheshet, Tali Voloshin, Avital Vorontsov, Boris Brant, Lilach Koren, Roni Blatt, Shay Cahal, Efrat Zemer-Tov, Rom Paz, Anat Klein-Goldberg, Catherine Tempel Brami, Sara Jacobovitch, Alexandra Volodin, Bella Koltun, Cfir David, Adi Haber, Moshe Giladi, Uri Weinberg, Yoram Palti. Tumor treating fields (TTFields) induce an anti-tumor immune response in a pancreatic cancer mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6649.

Abstract 2176: Differences in gut microbial composition alter pancreatic tumorigenesis

Abstract Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related deaths by 2030, and currently has a 5-year survival rate of roughly 10%. With long-term survival rates in patients being exceedingly low, understanding what factors delineate survival is imperative. When comparing spontaneous transgenic mouse models of pancreatic cancer housed in geographically distinct vivaria, regardless of a common lineage, we observed drastically different phenotype states in the respective locations. We hypothesize that the gut microbiome results in different gene expression profiles, leading to alterations in pancreatic tumorigenesis. Using various sequencing techniques, including 16s rRNA and RNA sequencing of the gut, we identified unique signatures at these respective institutions. Subsequent fecal microbiota transplantation and single bacterial species colonization experiments were performed to evaluate the ability of microbiomes/specific microbiota to alter the rate of tumorigenesis. In addition to probing the gut microbiome, circulating metabolites from individual mice were quantified, and correlated to phenotype state. Following identification of potentially tumorigenic bacterially derived metabolites, single bacteria colonization experiments were utilized to determine the downstream effects of identified metabolites as well as the ability of directly altering the metabolic landscape to drive tumorigenesis. Additionally, murine derived pancreatic cancer cells were exposed to both identified bacteria alone or bacterially produced metabolite and analyzed by metrics such as proliferation and relative expression of transcription factors associated with cancer development in vitro. Taken together, these data demonstrate the ability of distinct gut microbiomes to directly alter the metabolic landscape in mice, thus differentially altering the progression of pancreatic lesions. By better understanding the factors that stratify survivorship, we can begin to employ clinically actionable methodologies in the treatment or prevention of pancreatic cancer. Citation Format: Rian M. Howell, Jose Enriquez Ortiz, Olivia Le Roux, Vidhi Chandra, Le Li, Pratip K. Bhattacharya, Florencia McAllister. Differences in gut microbial composition alter pancreatic tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2176.

Abstract 3323: Novel Pan-RAS inhibitor ADT-007: A unique mechanism of antitumor selectivity in pancreatic and colorectal carcinoma models

Abstract Multiple types of RAS mutations activate RAS isoforms, HRAS, NRAS, or KRAS, that drive oncogenic signaling leading to uncontrolled cell proliferation and tumor development. RAS mutations occur de novo in approximately one-third of all human cancers, and are especially prevalent in pancreatic, colorectal, and lung tumors. Where RAS mutations are less frequent in other cancers, such as breast cancer, RAS can be pathologically activated by growth factor receptors that engage numerous downstream effectors. The currently FDA-approved KRAS-targeted drugs are designed to covalently inactivate only G12C KRAS mutants, however, this mutation is only prevalent in lung cancer. The most common mutations in pancreatic ductal adenocarcinoma (PDAC) are KRAS-G12D, KRAS-G12V, and KRAS-G12R. Our novel class of pan-RAS inhibitors, exemplified by ADT-007, addresses the urgent need for pan-RAS inhibitors with antitumor activity in cancers harboring these common mutations. These pan-RAS inhibitors have unique pharmacological properties that allow for selective killing of cancer cells harboring RAS mutations. ADT-007 inhibited growth of an array of carcinoma tumor cell lines in vitro with single digit nM IC50 values regardless of RAS mutant allele, and inhibited RAS activation and MAPK/AKT signaling. Because it is a pan-RAS inhibitor, ADT-007 may not be susceptible to commonly reported mechanisms of resistance to covalent KRAS inhibitors, such as activation of wild type (WT) alleles or secondary RAS mutations. Differentiated normal epithelial or hepatic cells, and tumor cells with WT RAS were insensitive to ADT-007 due to enzymatic detoxification of ADT-007 via glucuronidation, representing a novel mechanism of tumor selectivity. An orally bioavailable prodrug of ADT-007 (ADT-1004) is well tolerated in vivo, and produced sustained concentrations of ADT-007 well above IC50 values in plasma and even higher levels in tumors. Daily oral administration of ADT-1004 significantly inhibited RAS signaling and tumor growth in orthotopic and PDX mouse models of pancreatic cancer. Citation Format: Junwei Wang, Adam B. Keeton, Sindhu Ramesh, Peyton Johnson, Yulia Y. Maxuitenko, Jeremy B. Foote, Chung-Hui Huang, Kristy L. Berry, Khalda Fadlalla, Bandi D. Reddy, Ganji P. Nagaraju, Elmar Nurmemmedov, Ivan Babic, Vadim Gaponenko, Xi Chen, Bassel F. El-Rayes, Donald J. Buchsbaum, Gary A. Piazza. Novel Pan-RAS inhibitor ADT-007: A unique mechanism of antitumor selectivity in pancreatic and colorectal carcinoma models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3323.

Abstract 2087: Targeting lipid metabolism in pancreatic cancer

Abstract Background PIKfyve is a lipid kinase that serves as the sole source of cellular PI(3,5)P2 and PI5P, critical phosphatidylinositols for autophagy and lysosome function. Pancreatic ductal adenocarcinoma (PDAC) is known to upregulate and depend on lysosomal functions such as autophagy to exist in its harsh, nutrient-disrupted microenvironment. Thus, we aimed to establish PIKfyve as a therapeutic target in PDAC. Using a PIKfyve-knockout genetically engineered mouse model of pancreatic cancer (KC and KPC), we determined that PIKfyve was necessary for PDAC development. Given these results, we hypothesized that PIKfyve was critical for maintaining metabolic homeostasis in PDAC and that inhibiting PIKfyve would be an efficacious therapeutic strategy for PDAC. Methods and results We first validated the known role of PIKfyve in regulating autophagy using CRISPRi mediated knockdown, PIKfyve inhibitors Apilimod and ESK981, and a PIKfyve degrader, which all demonstrated that PIKfyve perturbation disrupted autophagic flux and suppressed PDAC cell growth. Little is known about the metabolic impacts of PIKfyve inhibition in PDAC beyond disruption of autophagy. Thus, we paired RNA-seq and a metabolic CRISPR screen to discover that PIKfyve inhibition obligated PDAC cells to upregulate de novo lipid synthesis. Specifically, PDAC cells upregulated fatty acid synthesis genes ACACA and FASN upon PIKfyve inhibition. Additionally, these genes were synthetically critical in the context of PIKfyve inhibition. We further performed metabolomics and lipidomics which revealed accumulation of sphingolipids upon PIKfyve inhibition. Given this, we concluded that PIKfyve regulates lipid homeostasis in PDAC. To further establish PIKfyve as a target in PDAC, we investigated the role of PIKfyve upon inhibition of KRAS, which drives PDAC through MAPK pathway signaling. First, KRAS/MAPK inhibition diminished expression of FASN and ACACA, genes synthetically essential upon PIKfyve inhibition. Additionally, KRAS/MAPK inhibition upregulated autophagy which was attenuated upon concurrent PIKfyve inhibition. Given this metabolic conflict between KRAS/MAPK and PIKfyve, we assessed the effects of dual inhibiting KRAS/MAPK and PIKfyve in a syngeneic orthotopic model. Encouragingly, combination therapy of trametinib (MEK inhibitor) and ESK981 eliminated tumor burden in most of mice, while single treatments only had modest effects. Further, we established a patient-derived xenograft model and showed that while the treatment with individual compounds trametinib, MRTX-1133 (KRASG12D inhibitor), and ESK981 all suppressed tumor growth, the combination of ESK981 and trametinib or ESK981 and MRTX-1133 caused substantial tumor regression in nearly all mice. Taken together, targeting lipid metabolism through inhibition of PIKfyve is a promising therapeutic strategy for PDAC, particularly in combination with the numerous KRAS/MAPK inhibitors in clinical development. Citation Format: Caleb Cheng, Jasmine P. Wisniewski, Ahmet Korkaya, Bailey Jackson, Rahul Mannan, Somnath Mahapatra, Nicholas Rossiter, Rupam Bhattacharyya, Pietro Morlacchi, Sydney Peters, Yuanyuan Qiao, Costas A. Lyssiotis, Arul M. Chinnaiyan. Targeting lipid metabolism in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2087.

Abstract 2367: STING agonist ADU-S100 improves the antitumor response of CLDN18.2/CD3 BiTEs by enhancing stem-like tumor-reactive CD8+ T cells in pancreatic adenocarcinoma

Abstract Background: Immunotherapy with CLDN18.2/CD3 BiTEs (bispecific T-cell engagers) has shown clinical activity in pancreatic adenocarcinoma. However, only few patients benefit from the treatment, and most responders develop acquired resistance. STING agonists may promote the development of stem-like central memory CD8+ T cells and enhance antitumor responses. This study aimed to investigate the synergistic effect and related mechanism of STING agonist plus CLDN18.2/CD3 BiTEs regimen. Methods: Single-cell RNA sequencing and flow cytometry were used to examine the tumor immune landscape in humanized PDX mouse models. By qPCR, western blot and flow cytometry, an orthotopic transplantation mouse model of pancreatic cancer and an in vitro tumor-PBMC coculture system were established to reveal the potential molecular mechanism of STING agonist ADU-S100 in optimizing the effects of CLDN18.2/CD3 BiTEs (IBI389). Results: In PDAC organoids, IBI389 induced potent, specific cytotoxicity, the CLDN18.2 BiTEs significantly engaged human CD3+ T cells with tumor cells in an organoid-PBMC coculture system in vitro, resulting in the formation of the immunological synapse (IS). IBI389 monotherapy significantly suppressed tumor growth and improved survival in vivo in hCD3e C57BL/6 and humanized hCD34+ PDX mouse models. Further, single-cell RNA sequencing and flow cytometry analysis revealed that the intertumoral TCF1+PD-1+ stem-like T cells and STING signaling activity of T cells were enriched in the early stage of tumor development and sharply decreased in the late stage during CLDN18.2 BiTEs administration. Furthermore, we discovered that the STING agonist ADU-S100 could significantly induce the enrichment of TCF1+PD-1+ stem-like CD8+ T cells in vitro and in vivo, increasing IBI389’s therapeutic effects. Furthermore, humanized PDX mice that were given the combination of IBI389 and ADU-S100 and survived after complete tumor rejection were rechallenged with PDX tumors. Humanized PDX tumors and hCD3e KPC orthotopic tumors from mice treated with the combination contained increased numbers of TCF1+PD-1+ stem-like CD8+ T cells, CD4+CD127+ memory T cells, CD8+CD127+ memory T cells, and fewer numbers of CD4+PD-1+Tim-3+ exhausted T cells, CD8+PD-1+Tim-3+ exhausted T cells and CD4+CD25+ Treg cells. Conclusions: Pancreatic tumors appear to evade immune response by inducing immune-suppressive tumor microenvironment development. In mice, the combination of STING agonist ADU-S100 and CLDN18.2 BiTEs increased the proportion of memory and stem-like CD4+ and CD8+ T cells while decreasing the proportion of regulatory and exhausted T cells in pancreatic tumors, eradicating all detectable tumors. This data may be utilized to formulate immune-based combination therapies for PDAC. Citation Format: Tianxing Zhou, Jingrui Yan, Bin Wang, Yongjie Xie, Chao Yang, Jun Yu, Jihui Hao. STING agonist ADU-S100 improves the antitumor response of CLDN18.2/CD3 BiTEs by enhancing stem-like tumor-reactive CD8+ T cells in pancreatic adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2367.

Abstract 442: Exploring targetable pathways: Unveiling changes in tumor physiology through dietary modification by a ketogenic diet

Abstract Background: A ketogenic diet, with high fat (90% kCal) and low carbohydrate (5% kCal) intake, induces ketosis [2], altering cancer cell carbon utilization toward the tricarboxylic acid cycle (TCA) [3]. While the overall impact on cancer growth is unclear, most literature suggests an anti-cancer effect. Our hypothesis aims to uncover pancreatic cancer cell adaptations to the ketogenic diet, revealing metabolic vulnerabilities for informed therapeutic strategies. Methods: Mice on a ketogenic or normal diet (control) underwent pancreatic cancer xenograft observation. Tumor metabolites were analyzed with LC/GC-MS, oxidative stress with NAD(P)+/NAD(P)H, and Lipid Peroxidation assays. Western blot assessed enzyme expression. In vitro studies used Seahorse FX Analyzer for mitochondrial function and PicoGreen for cell growth quantification. Ivosidenib and CB839 were used for combination therapies. Result: A ketogenic diet induces a metabolic shift in pancreatic cancer, altering nutrient and metabolite levels in diverse in vivo models. Besides the expected increase in TCA metabolites, heightened amino acid anaplerosis, particularly with glutamine and glutamate, was observed. Examination of the diet's impact on oxidative phosphorylation enzymes revealed increased BDH1 expression, aiding ketone body utilization, and upregulation of cytosolic IDH1 for antioxidant defense. Enzymes involved in glutamine uptake and conversion, like ASCT2 and GLS, showed altered expression. Simultaneously, we explored tumor microenvironment vulnerabilities, detecting a significant increase in reactive oxygen species (ROS) levels, specifically lipid peroxidation, in mice on the ketogenic diet. Given these pancreatic cancer adaptations, we hypothesized that combining therapeutics to elevate ROS levels and target the glutamine pathway would substantially impede tumor growth. To test this, we combined a ketogenic diet with an IDH1 inhibitor for antioxidant defense hindrance and a glutaminase inhibitor to impair mitochondrial function, resulting in a marked reduction in tumor proliferation compared to individual treatments. Conclusion: A ketogenic diet demonstrates a robust anti-tumor effect in various pancreatic cancer mouse models, likely arising from the diminished glucose and increased fatty acid load inherent in the diet. Metabolic adaptation towards an oxidative phosphorylation (OXPHOS) phenotype makes pancreatic cancer especially susceptible to antioxidant and mitochondrial inhibitors, as well as inhibitors of glutamine-metabolizing enzymes. Citation Format: Omid Hajihassani, Mehrdad Zarei, Soubhi Tahhan, Peter Gallagher, William Beegan, James Choi, Shihong Lei, Aya Murray, Alexander Loftus, Kevin Lebo, Helen Cheng, Anusha Mudigonda, Sydney Alibeckoff, Karen Ji, Jonathan Hue, Hallie Graor, Jordan Winter. Exploring targetable pathways: Unveiling changes in tumor physiology through dietary modification by a ketogenic diet [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 442.

Abstract 2128: Surufatinib treatment in pancreatic cancer: unveiling the role of GPR34 in TAMs and enhancing immunotherapy efficacy

Abstract Background: Pancreatic cancer, often resistant due to its immunologically "cold" nature and tumor-associated macrophages (TAMs), presents challenges in chemotherapy and immunotherapy. This study uses single-cell transcriptomics to assess TAM subsets in response to surufatinib, an inhibitor targeting CSF-1R, FGFR1, and VEGFR1-3. Methods: Surufatinib-treated patient samples were analyzed using single-cell RNA sequencing to identify altered macrophage subsets. Additional techniques, such as flow cytometry, tissue microarrays, co-culture assays, and macrophage-specific knockout mice, were used for further study. Western blot and immunofluorescence clarified the molecular functions of TAMs, and the impact of targeting these TAMs on PD-1 therapy was evaluated in a pancreatic cancer mouse model. Results: Single-cell RNA sequencing revealed macrophage subsets with increased GPR34 expression following surufatinib treatment. The Gpr34fl/flLYZ2Cre mouse orthotopic-transplanted tumor model, treated with gemcitabine and albumin-bound paclitaxel, showed significantly reduced tumor growth compared to the control group, with notably lower percentages of exhausted T (Tex) cells and regulatory T (Treg) cells, and a significant increase in cytotoxic T cells in tumor tissue. LysoPS, produced by chronically injured pancreatic cancer cells, promotes the differentiation of bone marrow-derived monocytes (BMDM) into an immunosuppressive phenotype, an effect abolished after siGpr34 transfection. The LysoPS-GPR34 axis can significantly activate the NF-κB signaling pathway in BMDMs, potentially inducing the senescence-related secretory phenotype (SASP) and contributing to the macrophages' immunosuppressive phenotype. Combining a GPR34 antagonist with αPD-1 and PD-L1 inhibitors significantly curbed tumor growth and enhanced the immune environment in KPC mice. Conclusions: Elevated GPR34 in TAMs enhances immunosuppression via the NF-κB pathway, affecting T cell distribution. GPR34's role could be key in optimizing surufatinib treatment for pancreatic cancer, indicating new therapeutic avenues. Citation Format: Xiaofan Guo, Yuxiao Liu, Yuning Song, Jing Huang, Wenbo Zhu, Peijun Xu, Jun Yu, Song Gao, Jihui Hao. Surufatinib treatment in pancreatic cancer: unveiling the role of GPR34 in TAMs and enhancing immunotherapy efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2128.

Abstract 6831: Single-cell-based epigenetic and transcriptomic analysis in the KPC pancreatic cancer mouse model revealed dynamiccharacteristic subtypes of cancer-associated fibroblasts

Abstract Pancreatic cancer features robust fibrosis, with 40-80% fibrotic tissue and a dense stroma, highlighting the crucial need to grasp cellular interactions in the cancer microenvironment. In this study, we used single-cell RNA sequencing (scRNA-seq) to analyze pancreatic tissues from 60-day-old normal mouse (n=1) (GSE125588) and KPC (LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre) cancer model with tumor diameter of 1-2 cm (n=2) (GSE129455). By examining fibroblast clusters, we identified distinct subtypes of cancer-associated fibroblasts (CAFs), and revealed four clusters: normal fibroblasts cluster, inflammatory CAFs (iCAFs) cluster marked by increased expression of IL6 and other cytokines, myofibroblast CAFs (myCAFs) cluster solely in the KPC model, and antigen-presenting CAFs (apCAFs) cluster expressing Mesothelin. We found that expression pattern of iCAFs in the KPC appeared similar to normal cells than myCAFs, suggesting a potential role in inhibiting cancer. it is reported that mesothelial cells might transition to apCAFs under the influence of IL6 and TGFβ due to tissue damage and inflammatory effects. This transition was visualized in our apCAF cluster, suggesting a potential pathway for the transformation of mesothelial cells into apCAFs. Next, in order to analyze epigenetic profiles of fibroblasts, we conducted single-cell Assay for Transposase-Accessible Chromatin with high-throughput sequencing (scATAC-seq) using 90-day-old KPC mice (n=2) and a wild-type mouse (n=1).scATAC-seq showed that there are mainly two clusters of fibroblasts, one cluster corresponded to myCAF, enriched with PDPN, while the other represented iCAF cluster, enriched with COL1A2. These data suggest that in terms of the epigenetic state, myCAF contain several different CAFs and have the potential to differentiate into either myCAFs or other type of based on certain stimulation. Ultimately, CAF differentiated into three distinct subtypes as revealed by scRNA-seq. This highlights that despite similar epigenetic states, various transcription factors characterize the functionality of these fibroblast subtypes. Further exploration of the underlying mechanism that lead to different CAF subtypes might help in controlling the microenvironment of pancreatic cancer. Citation Format: Keita Sasaki, Keiko Shinjo, Xingxing Wang, Kohei Kumegawa, Reo Raruyama, Shinji Mii, Yoshiteru Murofushi, Miho Suzuki, Atsushi Enomoto, Yutaka Kondo. Single-cell-based epigenetic and transcriptomic analysis in the KPC pancreatic cancer mouse model revealed dynamiccharacteristic subtypes of cancer-associated fibroblasts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6831.

Efficient Assessment of Tumor Vascular Shutdown by Photodynamic Therapy on Orthotopic Pancreatic Cancer Using High-Speed Wide-Field Waterproof Galvanometer Scanner Photoacoustic Microscopy.

To identify the vascular alteration by photodynamic therapy (PDT), the utilization of high-resolution, high-speed, and wide-field photoacoustic microscopy (PAM) has gained enormous interest. The rapid changes in vasculature during PDT treatment and monitoring of tumor tissue activation in the orthotopic pancreatic cancer model have received limited attention in previous studies. Here, a fully two-axes waterproof galvanometer scanner-based photoacoustic microscopy (WGS-PAM) system was developed for in vivo monitoring of dynamic variations in micro blood vessels due to PDT in an orthotopic pancreatic cancer mouse model. The photosensitizer (PS), Chlorin e6 (Ce6), was utilized to activate antitumor reactions in response to the irradiation of a 660 nm light source. Microvasculatures of angiogenesis tissue were visualized on a 40 mm2 area using the WGS-PAM system at 30 min intervals for 3 h after the PDT treatment. The decline in vascular intensity was observed at 24.5% along with a 32.4% reduction of the vascular density at 3 h post-PDT by the analysis of PAM images. The anti-vascularization effect was also identified with fluorescent imaging. Moreover, Ce6-PDT increased apoptotic and necrotic markers while decreasing vascular endothelial growth factor (VEGF) expression in MIA PaCa-2 and BxPC-3 pancreatic cancer cell lines. The approach of the WGS-PAM system shows the potential to investigate PDT effects on the mechanism of angiographic dynamics with high-resolution wide-field imaging modalities.