scholarly journals Intralesional injection of Rose Bengal augments the efficacy of gemcitabine chemotherapy against pancreatic tumors

2021 ◽  
Author(s):  
Patrick Innamarato ◽  
Jennifer Morse ◽  
Amy Mackay ◽  
Sarah Asby ◽  
Matthew Beatty ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Patients ◽  
Tumor Cells ◽  
Rose Bengal ◽  
Pancreatic Tumor ◽  
Advanced Pancreatic Cancer ◽  
Standard Of Care ◽  
Pancreatic Tumors ◽  
Intralesional Injection

Abstract Background Chemotherapy regimens that include the utilization of gemcitabine are the standard of care in pancreatic cancer patients. However, most patients with advanced pancreatic cancer die within the first 2 years after diagnosis, even if treated with standard of care chemotherapy. This study aims to explore combination therapies that boost the efficacy of standard of care regimens in pancreatic cancer patients. Methods In this study, we used PV-10, a 10% solution of rose bengal, to induce the death of human pancreatic tumor cells in vitro. Murine in vivo studies were carried out to examine the effectiveness of the direct injection of PV-10 into syngeneic pancreatic tumor cells in causing lesion-specific ablation. Intralesional PV-10 treatment was combined with systemic gemcitabine treatment in tumor-bearing mice to investigate the control of growth among treated tumors and distal untreated tumors. The involvement of the immune-mediated clearance of tumors was examined in immunogenic tumor models that express ovalbumin (OVA). Results In this study, we demonstrate that the injection of PV-10 into mouse pancreatic tumors caused lesion-specific ablation. We show that the combination of intralesional PV-10 with the systemic administration of gemcitabine caused lesion-specific ablation and delayed the growth of untreated distal tumors. We observed that this treatment strategy was markedly more successful in immunogenic tumors that express the neoantigen, OVA, suggesting that the combination therapy enhanced the immune clearance of tumors. Moreover, the regression of tumors in mice that received PV-10 in combination with gemcitabine was associated with the depletion of splenic CD11b+Gr-1+ cells and increases in damage associated molecular patterns HMGB1, S100A8, and IL-1α. Conclusions These results demonstrate that intralesional therapy with PV-10 can enhance the efficacy gemcitabine against pancreatic tumors.

scholarly journals Intralesional injection of rose bengal augments the efficacy of gemcitabine chemotherapy against pancreatic tumors

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Patrick Innamarato ◽  
Jennifer Morse ◽  
Amy Mackay ◽  
Sarah Asby ◽  
Matthew Beatty ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Patients ◽  
Rose Bengal ◽  
Advanced Pancreatic Cancer ◽  
Standard Of Care ◽  
In Vivo Studies ◽  
Pancreatic Tumors ◽  
Intralesional Injection

Abstract Background Chemotherapy regimens that include the utilization of gemcitabine are the standard of care in pancreatic cancer patients. However, most patients with advanced pancreatic cancer die within the first 2 years after diagnosis, even when treated with standard of care chemotherapy. This study aims to explore combination therapies that could boost the efficacy of standard of care regimens in pancreatic cancer patients. Methods In this study, we used PV-10, a 10% solution of rose bengal, to induce the death of human pancreatic tumor cells in vitro. Murine in vivo studies were carried out to examine the effectiveness of the direct injection of PV-10 into syngeneic pancreatic tumors in causing lesion-specific ablation. Intralesional PV-10 treatment was combined with systemic gemcitabine treatment in tumor-bearing mice to investigate the control of growth among treated tumors and distal uninjected tumors. The involvement of the immune-mediated clearance of tumors was examined in immunogenic tumor models that express ovalbumin (OVA). Results In this study, we demonstrate that the injection of PV-10 into mouse pancreatic tumors caused lesion-specific ablation. We show that the combination of intralesional PV-10 with the systemic administration of gemcitabine caused lesion-specific ablation and delayed the growth of distal uninjected tumors. We observed that this treatment strategy was markedly more successful in immunogenic tumors that express the neoantigen OVA, suggesting that the combination therapy enhanced the immune clearance of tumors. Moreover, the regression of tumors in mice that received PV-10 in combination with gemcitabine was associated with the depletion of splenic CD11b+Gr-1+ cells and increases in damage associated molecular patterns HMGB1, S100A8, and IL-1α. Conclusions These results demonstrate that intralesional therapy with PV-10 in combination with gemcitabine can enhance anti-tumor activity against pancreatic tumors and raises the potential for this strategy to be used for the treatment of patients with pancreatic cancer.

585 Intralesional injection of rose bengal improves the efficacy of gemcitabine chemotherapy against pancreatic cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A620-A620
Author(s):  
Patrick Innamarato ◽  
Shari Pilon-Thomas ◽  
Jennifer Morse ◽  
Sarah Asby ◽  
Amy Mackay ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Cells ◽  
Rose Bengal ◽  
Tumor Model ◽  
Standard Of Care ◽  
Pancreatic Tumors ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Panc02 Tumor ◽  
Single Tumor

BackgroundChemotherapy regimens that include gemcitabine are considered standard of care in patients with advanced pancreatic ductal adenocarcinoma (PDAC). However, most patients with PDAC die within 2 years of diagnosis, even with these standard of care regimens. In this study, we explored the ability of intratumoral injections of PV-10, a 10% solution of rose bengal, to induce lesion-specific ablation and control of metastatic pancreatic tumors in a murine model.MethodsPV-10 was cultured with human pancreatic cancer cell lines overnight and cell death was measured via Annexin-V and DAPI staining. Murine pancreatic tumor cells (Panc02) were injected subcutaneously in one flank to establish a single tumor model; to establish a bilateral tumor model, Panc02 tumor cells were implanted in the opposite flanks. On day 7, a single tumor was treated with intralesional PV-10. Gemcitabine (60 mg/kg) was injected intraperitoneally twice per week for 2 weeks. These experiments were repeated using Panc02 cells modified to overexpress the neoantigen ovalbumin (OVA). Control mouse tumor were directly injected with PBS. Tumor growth of PV-10 injected tumors and non-injected bystander tumors on the opposite flank were measured. Damage associated molecular patterns (DAMPs) in serum and immune cell frequencies within the spleens of tumor-bearing mice were measured to identify an associated systemic response with tumor lytic treatment regimen.ResultsWe established that less than 50% of human and murine pancreatic cells were alive after a 24 hour incubation with 200µM PV-10 in vitro. The combination of intralesional PV-10 with the systemic administration of gemcitabine delayed the growth treated tumors and non-injected distal tumors. In contrast, gemcitabine monotherapy failed to delay tumor growth in bilateral Panc02 tumor models. We observed that this treatment strategy was markedly more successful in immunogenic Panc02OVA tumors resulting in lesion-specific ablation in 5/8 mice compared to 0/8 mice that were treated with gemcitabine monotherapy. This suggests that the combination therapy enhanced the immune-mediated clearance of tumors. Moreover, regression of tumors in mice that received PV-10 in combination with gemcitabine was associated with the depletion of splenic CD11b+Gr-1+ cells and increases in damage associated molecular patterns HMGB1, S100A8, and IL-1α.ConclusionsTogether, these results demonstrate that intralesional therapy with PV-10 can enhance the efficacy gemcitabine against pancreatic tumors.Ethics ApprovalStudies were performed under approved Institutional Review Board (IRB) laboratory protocols at the H. Lee Moffitt Cancer Center (Tampa, FL).

Biologically optimized schedule of gemcitabine and nab-paclitaxel regimen in metastatic pancreatic adenocarcinoma.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. TPS4168-TPS4168
Author(s):  
Laith I. Abushahin ◽  
Anne M. Noonan ◽  
John L. Hays ◽  
Pannaga G. Malalur ◽  
Ashish Manne ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Cells ◽  
Pancreatic Adenocarcinoma ◽  
Cell Lines ◽  
Dose Intensity ◽  
Standard Of Care ◽  
Significance Level ◽  
Pancreatic Cancer Cells ◽  
Metastatic Pancreatic Adenocarcinoma

TPS4168 Background: Metastatic pancreatic adenocarcinoma has a poor prognosis, and improvements in therapy have been challenging. Alongside efforts in developing novel agents, there is a need to optimize and maximize the benefit of currently approved drugs. Gemcitabine + nab-paclitaxel is a frequently used regimen for pancreatic adenocarcinoma. Nab-paclitaxel is albumin–bound chemotherapy; hence the role of albumin uptake is critical for its effect. Caveolae are small membrane invaginations essential for transendothelial albumin uptake. Cav-1 is the principal structural component of caveolae. Williams and colleagues have published a series of preclinical studies demonstrating that tumor cell-specific Cav-1 expression directly correlates with albumin and albumin-bound chemotherapy uptake and subsequent apoptotic response in tumor cells. In vitro studies showed that exposure of pancreatic cancer cells to Gemcitabine resulted in up-regulation of Cav-1 peaking 48 hours after gemcitabine exposure. This Cav-1 up-regulation correlated with increased temporal albumin cellular uptake. In addition, Williams and colleagues noted that exposure of pancreatic cancer cell lines to Gemcitabine resulted in a time–specific re-entry of cells into the G2/M phase (nab-paclitaxel cytotoxicity phase) between 48-60 hours after gemcitabine treatment. Collectively this data suggest that infusing nab-paclitaxel after 48 hours of gemcitabine infusion would be optimal for both increased uptake as well as increased susceptible tumor cells. We had previously shown this effect on multiple cell lines as well as mouse models. Methods: This is a phase II trial; patients will receive a standard of care chemotherapy regimen consisting of FDA-approved Gemcitabine + nab-paclitaxel with modification of the schedule to deliver nab-paclitaxel 48 hours (2 days) after gemcitabine infusions. The primary endpoint is ORR, with a null hypothesis of 20% vs. a target of 35%. Employing a 2-stage design (minimax) and assuming 80% power and a 0.05 significance level, a total of 53 patients will be required. In the first stage, if at least 7/31 patients respond to therapy, an additional 22 patients will be added for a total of 53 patients. The study will be terminated early if ≤ six patients respond in the first stage. Observation of response in at least 16/53 patients would be required to warrant further investigation of this infusion schedule of combination therapy. The secondary endpoints include the safety of the regimen schedule, Relative dose intensity, disease control rate, PFS, and OS. The trial opened to enrollment in June 2020 and is accepting patients. Clinical trial information: NCT04115163.

scholarly journals Pancreatic tumor cell metastasis is restricted by MT1-MMP binding protein MTCBP-1

2018 ◽  
Vol 218 (1) ◽  
pp. 317-332 ◽  
Author(s):  
Li Qiang ◽  
Hong Cao ◽  
Jing Chen ◽  
Shaun G. Weller ◽  
Eugene W. Krueger ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Pancreatic Tumor ◽  
Binding Protein ◽  
Critical Role ◽  
Inverse Correlation ◽  
Pancreatic Tumors ◽  
Matrix Remodeling ◽  
Peripheral Tissues

The process by which tumor cells mechanically invade through surrounding stroma into peripheral tissues is an essential component of metastatic dissemination. The directed recruitment of the metalloproteinase MT1-MMP to invadopodia plays a critical role in this invasive process. Here, we provide mechanistic insight into MT1-MMP cytoplasmic tail binding protein 1 (MTCBP-1) with respect to invadopodia formation, matrix remodeling, and invasion by pancreatic tumor cells. MTCBP-1 localizes to invadopodia and interacts with MT1-MMP. We find that this interaction displaces MT1-MMP from invadopodia, thereby attenuating their number and function and reducing the capacity of tumor cells to degrade matrix. Further, we observe an inverse correlation between MTCBP-1 and MT1-MMP expression both in cultured cell lines and human pancreatic tumors. Consistently, MTCBP-1–expressing cells show decreased ability to invade in vitro and metastasize in vivo. These findings implicate MTCBP-1 as an inhibitor of the metastatic process.

scholarly journals Pancreatic cancer organoids recapitulate disease and allow personalized drug screening

2019 ◽  
Vol 116 (52) ◽  
pp. 26580-26590 ◽  
Author(s):  
Else Driehuis ◽  
Arne van Hoeck ◽  
Kat Moore ◽  
Sigrid Kolders ◽  
Hayley E. Francies ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Bile Duct ◽  
Tumor Cells ◽  
Drug Screening ◽  
Pancreatic Tumor ◽  
Genetic Alterations ◽  
Therapeutic Agents ◽  
In Vitro Testing ◽  
Distal Bile Duct

We report the derivation of 30 patient-derived organoid lines (PDOs) from tumors arising in the pancreas and distal bile duct. PDOs recapitulate tumor histology and contain genetic alterations typical of pancreatic cancer. In vitro testing of a panel of 76 therapeutic agents revealed sensitivities currently not exploited in the clinic, and underscores the importance of personalized approaches for effective cancer treatment. The PRMT5 inhibitor EZP015556, shown to targetMTAP(a gene commonly lost in pancreatic cancer)-negative tumors, was validated as such, but also appeared to constitute an effective therapy for a subset of MTAP-positive tumors. Taken together, the work presented here provides a platform to identify novel therapeutics to target pancreatic tumor cells using PDOs.

scholarly journals Fe2P nanorods based photothermal therapy combined with immune checkpoint inhibitors for pancreatic cancer

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shanshan Liu ◽  
Jiawen He ◽  
Ruixiang Song ◽  
Mengmeng Zhang ◽  
Lianghao Huang ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cell Death ◽  
Photothermal Therapy ◽  
Pancreatic Tumor ◽  
Local Treatment ◽  
Advanced Pancreatic Cancer ◽  
Tumor Model ◽  
Pancreatic Tumors ◽  
Tumor Cell Death ◽  
Primary Tumors

Abstract Treatment of pancreatic cancer is faced with great difficulties and challenges due to high lethality and metastasis. Synergism of targeted therapy and immunotherapy has been considered as ideal strategy to both eliminate primary tumors and control metastases. For the treatment of advanced pancreatic cancer, we demonstrated a local photothermal therapy (PTT) following administration of monoclonal antibody of programmed death ligand 1 (αPD-L1). Fe2P nanorods were employed as a Fenton agent and photothermal agent, which modified with DSPE-PEG2000-Mal for improved biocompatibility and Mal mediated-antigen presentation. Under a low dose laser irradiation at 980 nm, Fe2P-PEG-Mal nanorods (NRs) mediated PTT could induce immunogenic tumor cell death that can cause dendritic cells (DCs) infiltration and maturation. In a bilateral pancreatic tumor model, the local treatment of NRs-PTT on primary tumor could cause the increased infiltration of cytotoxic T lymphocytes (CTLs) and decreased residential of M2 macrophages in untreated distal tumors. Furthermore, subsequently intervened αPD-L1 could enhance cell death triggered by CTLs in distal tumors through reversing immunosuppression. An orthotopic pancreatic tumor model was used to further confirm the therapeutic outcome. Finally, the combination of NRs based PTT and αPD-L1 based immunotherapy was able to significantly eliminate orthotopic pancreatic tumors and reduce mesentery metastases. Thus, the strategy may provide a more effective treatment for pancreatic cancer.

scholarly journals Pancreatic Cancer Cell Lines Can Induce Prostaglandin E2 Production from Human Blood Mononuclear Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Svitlana P. Grekova ◽  
Assia Angelova ◽  
Laurent Daeffler ◽  
Zahari Raykov
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Cells ◽  
Pancreatic Tumor ◽  
Mononuclear Cells ◽  
Pancreatic Tumors ◽  
Tumor Spread ◽  
Pancreatic Cancer Cells ◽  
Wide Range ◽  
Blood Mononuclear Cells ◽  
Cox 2

Accumulating evidence suggests an important role for cyclooxygenase-2 (COX-2) in the pathogenesis of a wide range of malignancies. The protumorigenic properties of COX-2 are generally thought to be mediated by its product, PGE2, which is shown to promote tumor spread and growth by multiple mechanisms but most importantly through modulation of the local immune response in the tumor. Pancreatic tumor cells produce various amounts of PGE2, some of them being even deficient in COX enzymes or other PGE2synthases. Here we describe that, beside pancreatic tumor cells or stromal fibroblasts, human peripheral blood mononuclear cells can also produce PGE2upon coculture with pancreatic cancer cells. Stimulating of cellular cPLA2 within PBMCs by secreted factors, presumably sPLA2, from tumor cells appeared crucial, while the direct contact between PBMCs and PDACs seemed to be dispensable for this effect. Our data is emphasizing the complex interactions participating in the formation of the tolerogenic immune milieu within pancreatic tumors.

scholarly journals 3373 Modulation of Hedgehog Signaling Alters Immune Infiltration in Pancreatic Cancer

2019 ◽  
Vol 3 (s1) ◽  
pp. 16-16
Author(s):  
Nina Steele ◽  
Valerie Irizarry-Negron ◽  
Veerin Sirihorachai ◽  
Samantha Kemp ◽  
Eileen Carpenter ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Bone Marrow ◽  
Tumor Microenvironment ◽  
Mouse Model ◽  
Tumor Cells ◽  
Pancreatic Tumors ◽  
Hh Signaling ◽  
Immune Profiling

OBJECTIVES/SPECIFIC AIMS: Pancreatic ductal adenocarcinoma (PDA) has a dismal 5-year survival rate of 9%, making this disease one of the deadliest human malignancies (https://seer.cancer.gov/). Primary barriers to the treatment of pancreatic cancer include extensive stromal interactions and sustained immune suppression. Aberrant Hedgehog (HH) pathway activity is a hallmark of pancreatic tumorigenesis. Tumor-derived HH ligands signal in a paracrine fashion to the surrounding stroma to influence tumor growth. Expression of HH ligands increases during PDA progression, and previous work has shown that genetic deletion of Sonic HH (Shh) from the epithelium of mice with pancreatic tumors results in increased Indian HH (Ihh) expression. This research aims to investigate the translational impact of changes in immune infiltration following deletion of IHH in a preclinical mouse model of pancreatic cancer. METHODS/STUDY POPULATION: Ihh was deleted in tumor cells lines (IhhKO) derived from a genetically engineered mouse model of pancreatic cancer (LSL-KrasG12D/+;LSL-TrpR270H;P48-Cre), using CRISPR/Cas-9 gene editing to assess the role of Ihh in the tumor microenvironment. The level of HH signaling was determined using tumor cell co-cultures with Gli1lacZ fibroblasts (derived from mice with a lacZ reporter allele knocked into the Gli1 locus), in which Beta Galactosidase activity serves as a readout for HH signaling. WT and IhhKO tumor cells were orthotopically transplanted into the pancreas of syngeneic C57BL/6 mice. Human pancreas samples were obtained from surgical resection of pancreatic adenocarcinoma, or fine needle biopsy procedure (FNB). Immune profiling of mouse and human pancreatic tumors was performed using Cytometry Time-of-Flight analysis (CyTOF), and tumor composition was analyzed by single-cell RNA sequencing (scRNA seq). In vitro cultures with pancreatic fibroblasts treated with either WT or IhhKO tumor cell conditioned media (CM) were cultured with bone-marrow derived macrophages to assess tumor crosstalk. RESULTS/ANTICIPATED RESULTS: Tumor cells lacking Ihh were generated through CRISPR/Cas-9 deletion, and this was confirmed by qRT-PCR. Co-culture of IhhKO tumor cells with Gli1lacZ fibroblasts results in decreased Gli1 expression both in vitro and in vivo. Immune profiling revealed that tumors lacking Ihh have significantly fewer tumor associated macrophages (CD11b+/F4/80+/CD206+), resulting in decreased presence of immunosuppressive factors such as arginase 1 and PDL1. Immune phenotyping of human pancreatic tissues revealed similar populations of immunosuppressive myeloid cells present in tumors. In vitro co-cultures demonstrated that, in the presence of bone-marrow derived macrophages, immunosuppressive IL-6 production was reduced in pancreatic fibroblasts cultured with IhhKO-CM, as compared to fibroblasts cultured with WT-CM, providing mechanistic insight into the in vivo phenotype observed. Further, scRNA seq analysis suggests that modulation of HH signaling in the tumor microenvironment alters chemokine and immunomodulatory signaling pathways driven by fibroblasts in the pancreatic tumor microenvironment. DISCUSSION/SIGNIFICANCE OF IMPACT: HH signaling in pancreatic fibroblasts contributes to the establishment of an immune suppressive environment in pancreatic cancer. Combining methods to target HH signaling and immune checkpoint therapy has translational potential in treating pancreatic cancer patients.

scholarly journals Pimavanserin: A Novel Autophagy Modulator for Pancreatic Cancer Treatment

Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5661
Author(s):  
Sharavan Ramachandran ◽  
Itishree S. Kaushik ◽  
Sanjay K. Srivastava
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Patients ◽  
Pancreatic Tumor ◽  
Tumor Model ◽  
Annexin V ◽  
Pancreatic Tumors ◽  
Transmission Electron Microscopy Analysis ◽  
Genomic Databases ◽  
Apoptotic Effects

Pancreatic tumors exhibit high basal autophagy compared to that of other cancers. Several studies including those from our laboratory reported that enhanced autophagy leads to apoptosis in cancer cells. In this study, we evaluated the autophagy and apoptosis inducing effects of Pimavanserin tartrate (PVT). Autophagic effects of PVT were determined by Acridine Orange assay and Transmission Electron Microscopy analysis. Clinical significance of ULK1 in normal and pancreatic cancer patients was evaluated by R2 and GEPIA cancer genomic databases. Modulation of proteins in autophagy signaling was assessed by Western blotting and Immunofluorescence. Apoptotic effects of PVT was evaluated by Annexin-V/APC assay. Subcutaneous xenograft pancreatic tumor model was used to evaluate the autophagy-mediated apoptotic effects of PVT in vivo. Autophagy was induced upon PVT treatment in pancreatic ducal adenocarcinoma (PDAC) cells. Pancreatic cancer patients exhibit reduced levels of autophagy initiator gene, ULK1, which correlated with reduced patient survival. Interestingly, PVT induced the expression of autophagy markers ULK1, FIP200, Atg101, Beclin-1, Atg5, LC3A/B, and cleavage of caspase-3, an indicator of apoptosis in several PDAC cells. ULK1 agonist LYN-1604 enhanced the autophagic and apoptotic effects of PVT. On the other hand, autophagy inhibitors chloroquine and bafilomycin blocked the autophagic and apoptotic effects of PVT in PDAC cells. Notably, chloroquine abrogated the growth suppressive effects of PVT by 25% in BxPC3 tumor xenografts in nude mice. Collectively, our results indicate that PVT mediated pancreatic tumor growth suppression was associated with induction of autophagy mediated apoptosis.

scholarly journals WDR5-H3K4me3 epigenetic axis regulates OPN expression to compensate PD-L1 function to promote pancreatic cancer immune escape

2021 ◽  
Vol 9 (7) ◽  
pp. e002624
Author(s):  
Chunwan Lu ◽  
Zhuoqi Liu ◽  
John D Klement ◽  
Dafeng Yang ◽  
Alyssa D Merting ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Protein Level ◽  
Pancreatic Tumor ◽  
Immune Escape ◽  
Epigenetic Mechanism ◽  
Human Pancreatic Cancer ◽  
Pancreatic Tumors ◽  
Genome Wide

BackgroundDespite PD-L1 (Programmed death receptor ligand-1) expression on tumor cells and cytotoxic T lymphocytes tumor infiltration in the tumor microenvironment, human pancreatic cancer stands out as one of the human cancers that does not respond to immune checkpoint inhibitor (ICI) immunotherapy. Epigenome dysregulation has emerged as a major mechanism in T cell exhaustion and non-response to ICI immunotherapy, we, therefore, aimed at testing the hypothesis that an epigenetic mechanism compensates PD-L1 function to render pancreatic cancer non-response to ICI immunotherapy.MethodsTwo orthotopic pancreatic tumor mouse models were used for chromatin immunoprecipitation-Seq and RNA-Seq to identify genome-wide dysregulation of H3K4me3 and gene expression. Human pancreatic tumor and serum were analyzed for osteopontin (OPN) protein level and for correlation with patient prognosis. OPN and PD-L1 cellular location were determined in the tumors using flow cytometry. The function of WDR5-H3K4me3 axis in OPN expression were determined by Western blotting. The function of H3K4me3-OPN axis in pancreatic cancer immune escape and response to ICI immunotherapy was determined in an orthotopic pancreatic tumor mouse model.ResultsMouse pancreatic tumors have a genome-wide increase in H3K4me3 deposition as compared with normal pancreas. OPN and its receptor CD44 were identified being upregulated in pancreatic tumors by their promoter H3K4me3 deposition. OPN protein is increased in both tumor cells and tumor-infiltrating immune cells in human pancreatic carcinoma and is inversely correlated with pancreatic cancer patient survival. OPN is primarily expressed in tumor cells and monocytic myeloid-derived suppressor cells (M-MDSCs), whereas PD-L1 is expressed in tumor cells, M-MDSCs, polymorphonuclear MDSCs and tumor-associated macrophages. WDR5 is essential for H3K4me3-specific histone methyltransferase activity that regulates OPN expression in tumor cells and MDSCs. Inhibition of WDR5 significantly decreased OPN protein level. Inhibition of WDR5 or knocking out of OPN suppressed orthotopic mouse pancreatic tumor growth. Inhibition of WDR5 also significantly increased efficacy of anti-PD-1 immunotherapy in suppression of mouse pancreatic tumor growth in vivo.ConclusionsOPN compensates PD-L1 function to promote pancreatic cancer immune escape. Pharmacological inhibition of the WDR5-H3K4me3 epigenetic axis is effective in suppressing pancreatic tumor immune escape and in improving efficacy of anti-PD-1 immunotherapy in pancreatic cancer.

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