Establishment and characterization of a novel multidrug-resistant pancreatic ductal adenocarcinoma cell line, PDAC-X1.

Drug resistance remains a significant challenge in the treatment of pancreatic cancer. The development of drug-resistant cell lines is crucial to understanding the underlying mechanisms of resistance and developing novel drugs to improve clinical outcomes. Here, a novel pancreatic cancer cell line, PDAC-X1, derived from Chinese patients has been established. PDAC-X1 was characterized by the immune phenotype, biology, genetics, molecular characteristics, and tumorigenicity. In vitro analysis revealed that PDAC-X1 cells exhibited epithelial morphology and cell markers (CK7 and CK19), expressed cancer-associated markers (E-cadherin, Vimentin, Ki-67, CEA, CA19-9), and produced pancreatic cancer-like organs in suspension culture. In vivo analysis showed that PDAC-X1 cells maintained tumorigenicity with a 100% tumor formation rate. This cell line exhibited a complex karyotype, dominated by subtriploid karyotypes. In addition, PDAC-X1 cells exhibited intrinsic multidrug resistance to multiple drugs, including gemcitabine, paclitaxel, 5-fluorouracil, and oxaliplatin. In conclusion, the PDAC-X1 cell line has been established and characterized, representing a useful and valuable preclinical model to study the underlying mechanisms of drug resistance and develop novel drug therapeutics to improve patient outcomes.

Targeted delivery of CEBPA-saRNA for the treatment of pancreatic ductal adenocarcinoma by transferrin receptor aptamer decorated tetrahedral framework nucleic acid.

Pancreatic cancer, predominantly pancreatic ductal adenocarcinoma (PDAC), remains a highly lethal malignancy with limited therapeutic options and a dismal prognosis. By targeting the underlying molecular abnormalities responsible for PDAC development and progression, gene therapy offers a promising strategy to overcome the challenges posed by conventional radiotherapy and chemotherapy. This study sought to explore the therapeutic potential of small activating RNAs (saRNAs) specifically targeting the CCAAT/enhancer-binding protein alpha (CEBPA) gene in PDAC. To overcome the challenges associated with saRNA delivery, tetrahedral framework nucleic acids (tFNAs) were rationally engineered as nanocarriers. These tFNAs were further functionalized with a truncated transferrin receptor aptamer (tTR14) to enhance targeting specificity for PDAC cells. The constructed tFNA-based saRNA formulation demonstrated exceptional stability, efficient saRNA release ability, substantial cellular uptake, biocompatibility, and nontoxicity. In vitro experiments revealed successful intracellular delivery of CEBPA-saRNA utilizing tTR14-decorated tFNA nanocarriers, resulting in significant activation of tumor suppressor genes, namely, CEBPA and its downstream effector P21, leading to notable inhibition of PDAC cell proliferation. Moreover, in a mouse model of PDAC, the tTR14-decorated tFNA-mediated delivery of CEBPA-saRNA effectively upregulated the expression of the CEBPA and P21 genes, consequently suppressing tumor growth. These compelling findings highlight the potential utility of saRNA delivered via a designed tFNA nanocarrier to induce the activation of tumor suppressor genes as an innovative therapeutic approach for PDAC.

Combining CD40 agonist mitazalimab with mFOLFIRINOX in previously untreated metastatic pancreatic ductal adenocarcinoma (OPTIMIZE-1): a single-arm, multicentre phase 1b/2 study.

BACKGROUND: Current systemic therapies for metastatic pancreatic ductal adenocarcinoma are associated with poor outcomes with a 5-year overall survival rate under 5%. We aimed to assess the safety and antitumour activity of mitazalimab, a human CD40 agonistic IgG1 antibody, with modified FOLFIRINOX (mFOLFIRINOX; fluorouracil, leucovorin, oxaliplatin, and irinotecan), in chemotherapy-naive patients with metastatic pancreatic ductal adenocarcinoma. METHODS: OPTIMIZE-1 was a single-arm, multicentre, phase 1b/2 study which enrolled adults with histologically-confirmed metastatic pancreatic ductal adenocarcinoma and European Cooperative Oncology Group performance status 0 or 1 in 14 university hospitals in Belgium, France, and Spain. The primary endpoint of phase 1b was to determine the recommended phase 2 dose of intravenous mitazalimab (450 µg/kg or 900 µg/kg) when combined with intravenous mFOLFIRINOX (oxaliplatin 85 mg/m2, leucovorin 400 mg/m2, irinotecan 150 mg/m2, fluorouracil 2400 mg/m2). In the first 21-day treatment cycle, mitazalimab was administered on days 1 and 10, and mFOLFIRINOX on day 8. In subsequent 14-day cycles mitazalimab was administered 2 days after mFOLFIRINOX. The phase 2 primary endpoint was objective response rate. Activity and safety analyses were conducted on the full analysis set (all patients who received the combination of mitazalimab at the recommended phase 2 dose and mFOLFIRINOX for at least two treatment cycles) and safety set (all patients who received any study treatment), respectively. Enrolment is complete, and data represents a primary analysis of the ongoing trial. The trial is registered at Clinicaltrials.gov (NCT04888312). FINDINGS: Between Sept 29, 2021, and March 28, 2023, 88 patients were screened and 70 patients were enrolled (40 [57%] were female and 30 [43%] were male). In phase 1b, 900 µg/kg mitazalimab was determined as the recommended phase 2 dose. Overall, five patients received 450 µg/kg mitazalimab; 65 received 900 µg/kg mitazalimab. No dose-limiting toxicities were observed at 450 µg/kg, and one dose-limiting toxicity was observed at 900 µg/kg. 57 patients were evaluated for activity, and all 70 patients were included in the safety set. At data cutoff on Nov 14, 2023, median follow-up was 12·7 months (95% CI 11·1-15·7). Of the 57 patients, 29 (51%) remained on study and 18 (32%) remained on treatment. The primary endpoint (objective response rate >30%) was met (objective response rates in 23 [40%]; one-sided 90% CI ≥32 of 57 patients). The most common grade 3 or worse adverse events were neutropenia (18 [26%] of 70 patients), hypokalaemia (11 patients [16%]), and anaemia and thrombocytopenia (eight patients [11%]). Serious adverse events were reported in 29 (41%) of 70 patients, the most common being vomiting (five [7%] of 70 patients), decreased appetite (four [6%]), and diarrhoea and cholangitis (three [4%] of 70 patients for each), none considered related to mitazalimab. No treatment-related deaths were reported. INTERPRETATION: Mitazalimab with mFOLFIRINOX demonstrated manageable safety and encouraging activity, warranting continued development in a phase 3, randomised, controlled trial. The results from OPTIMIZE-1 pave the way for further exploration and confirmation of a novel immunotherapy treatment regimen for metastatic pancreatic ductal adenocarcinoma, which is a complex and aggressive cancer with very low survival rates and restricted treatment options. FUNDING: Alligator Bioscience.

Three-dimensional environment sensitizes pancreatic cancer cells to the anti-proliferative effect of budesonide by reprogramming energy metabolism.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is the most lethal cancer with an aggressive metastatic phenotype and very poor clinical prognosis. Interestingly, a lower occurrence of PDAC has been described in individuals with severe and long-standing asthma. Here we explored the potential link between PDAC and the glucocorticoid (GC) budesonide, a first-line therapy to treat asthma. METHODS: We tested the effect of budesonide and the classical GCs on the morphology, proliferation, migration and invasiveness of patient-derived PDAC cells and pancreatic cancer cell lines, using 2D and 3D cultures in vitro. Furthermore, a xenograft model was used to investigate the effect of budesonide on PDAC tumor growth in vivo. Finally, we combined genome-wide transcriptome analysis with genetic and pharmacological approaches to explore the mechanisms underlying budesonide activities in the different environmental conditions. RESULTS: We found that in 2D culture settings, high micromolar concentrations of budesonide reduced the mesenchymal invasive/migrating features of PDAC cells, without affecting proliferation or survival. This activity was specific and independent of the Glucocorticoid Receptor (GR). Conversely, in a more physiological 3D environment, low nanomolar concentrations of budesonide strongly reduced PDAC cell proliferation in a GR-dependent manner. Accordingly, we found that budesonide reduced PDAC tumor growth in vivo. Mechanistically, we demonstrated that the 3D environment drives the cells towards a general metabolic reprogramming involving protein, lipid, and energy metabolism (e.g., increased glycolysis dependency). This metabolic change sensitizes PDAC cells to the anti-proliferative effect of budesonide, which instead induces opposite changes (e.g., increased mitochondrial oxidative phosphorylation). Finally, we provide evidence that budesonide inhibits PDAC growth, at least in part, through the tumor suppressor CDKN1C/p57Kip2. CONCLUSIONS: Collectively, our study reveals that the microenvironment influences the susceptibility of PDAC cells to GCs and provides unprecedented evidence for the anti-proliferative activity of budesonide on PDAC cells in 3D conditions, in vitro and in vivo. Our findings may explain, at least in part, the reason for the lower occurrence of pancreatic cancer in asthmatic patients and suggest a potential suitability of budesonide for clinical trials as a therapeutic approach to fight pancreatic cancer.

Triple Blockade of Oncogenic RAS Signaling Using KRAS and MEK Inhibitors in Combination with Irradiation in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest of human malignancies and carries an exceptionally poor prognosis. It is mostly driven by multiple oncogenic alterations, with the highest mutation frequency being observed in the KRAS gene, which is a key oncogenic driver of tumorogenesis and malignant progression in PDAC. However, KRAS remained undruggable for decades until the emergence of G12C mutation specific KRAS inhibitors. Despite this development, this therapeutic approach to target KRAS directly is not routinely used for PDAC patients, with the reasons being the rare presence of G12C mutation in PDAC with only 1-2% of occurring cases, modest therapeutic efficacy, activation of compensatory pathways leading to cell resistance, and absence of effective KRASG12D or pan-KRAS inhibitors. Additionally, indirect approaches to targeting KRAS through upstream and downstream regulators or effectors were also found to be either ineffective or known to cause major toxicities. For this reason, new and more effective treatment strategies that combine different therapeutic modalities aiming at achieving synergism and minimizing intrinsic or adaptive resistance mechanisms are required. In the current work presented here, pancreatic cancer cell lines with oncogenic KRAS G12C, G12D, or wild-type KRAS were treated with specific KRAS or SOS1/2 inhibitors, and therapeutic synergisms with concomitant MEK inhibition and irradiation were systematically evaluated by means of cell viability, 2D-clonogenic, 3D-anchorage independent soft agar, and bioluminescent ATP assays. Underlying pathophysiological mechanisms were examined by using Western blot analyses, apoptosis assay, and RAS activation assay.

Power-Doppler-based NH002 microbubble sonoporation with chemotherapy relieves hypoxia and enhances the efficacy of chemotherapy and immunotherapy for pancreatic tumors.

Pancreatic ductal adenocarcinoma (PDAC) poses challenges due to late-stage diagnosis and limited treatment response, often attributed to the hypoxic tumor microenvironment (TME). Sonoporation, combining ultrasound and microbubbles, holds promise for enhancing therapy. However, additional preclinical research utilizing commercially available ultrasound equipment for PDAC treatment while delving into the TME's intricacies is necessary. This study investigated the potential of using a clinically available ultrasound system and phase 2-proven microbubbles to relieve tumor hypoxia and enhance the efficacy of chemotherapy and immunotherapy in a murine PDAC model. This approach enables early PDAC detection and blood-flow-sensitive Power-Doppler sonoporation in combination with chemotherapy. It significantly extended treated mice's median survival compared to chemotherapy alone. Mechanistically, this combination therapy enhanced tumor perfusion and substantially reduced tumor hypoxia (77% and 67%, 1- and 3-days post-treatment). Additionally, cluster of differentiation 8 (CD8) T-cell infiltration increased four-fold afterward. The combined treatment demonstrated a strengthening of the anti-programmed death-ligand 1(αPDL1) therapy against PDAC. Our study illustrates the feasibility of using a clinically available ultrasound system with NH-002 microbubbles for early tumor detection, alleviating hypoxic TME, and improving chemotherapy and immunotherapy. It suggests the development of an adjuvant theragnostic protocol incorporating Power-Doppler sonoporation for pancreatic tumor treatment.

BICC1 drives pancreatic cancer stemness and chemoresistance by facilitating tryptophan metabolism.

Pancreatic adenocarcinoma is the fourth leading cause of malignancy-related deaths, with rapid development of drug resistance driven by pancreatic cancer stem cells. However, the mechanisms sustaining stemness and chemotherapy resistance in pancreatic ductal adenocarcinoma (PDAC) remain unclear. Here, we demonstrate that Bicaudal C homolog 1 (BICC1), an RNA binding protein regulating numerous cytoplasmic mRNAs, facilitates chemoresistance and stemness in PDAC. Mechanistically, BICC1 activated tryptophan catabolism in PDAC by up-regulating indoleamine 2,3-dioxygenase-1 (IDO1) expression, a tryptophan-catabolizing enzyme. Increased levels of tryptophan metabolites contribute to NAD+ synthesis and oxidative phosphorylation, leading to a stem cell-like phenotype. Blocking BICC1/IDO1/tryptophan metabolism signaling greatly improves the gemcitabine (GEM) efficacy in several PDAC models with high BICC1 level. These findings indicate that BICC1 is a critical tryptophan metabolism regulator that drives the stemness and chemoresistance of PDAC and thus a potential target for combinatorial therapeutic strategy against chemoresistance.

Exploring Splicing Modulation as an Innovative Approach to Combat Pancreatic Cancer: SF3B1 Emerges as a Prognostic Indicator and Therapeutic Target.

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges in terms of prognosis and treatment. Recent research has identified splicing deregulation as a new cancer hallmark. Herein, we investigated the largely uncharacterized alternative splicing profile and the key splicing factor SF3B1 in PDAC pancreatic cells and tissues as a potential discovery source of plausible drug targets and new predictive biomarkers of clinical outcome. The research involved a transcriptome-wide analysis, comparing profiles of splicing profiles in PDAC primary cells with normal ductal cells. This revealed more than 400 significant differential splicing events in genes involved in regulation of gene expression, primarily related to mRNA splicing, and metabolism of nucleic acids. PDAC cultures were highly sensitive to the SF3B1 modulators, E7107 and Pladienolide-B, showing IC50s in the low nanomolar range. These compounds induced apoptosis, associated to induction of the MCL-1/S splice variant. and reduced cell migration, associated to RON mis-splicing. In an orthotopic mouse model, E7107 showed promising results. Furthermore, we evaluated SF3B1 expression in specimens from 87 patients and found a significant association of SF3B1 expression with progression-free and overall survival. In conclusion, SF3B1 emerges as both a potential prognostic factor and therapeutic target in PDAC, impacting cell proliferation, migration, and apoptosis. These findings warrant future studies on this new therapeutic strategy against PDAC.

Injectable hybrid hydrogels enable enhanced combination chemotherapy and roused anti-tumor immunity in the synergistic treatment of pancreatic ductal adenocarcinoma.

Chemotherapy and immunotherapy have shown no significant outcome for unresectable pancreatic ductal adenocarcinoma (PDAC). Multi-drug combination therapy has become a consensus in clinical trials to explore how to arouse anti-tumor immunity and meanwhile overcome the poorly tumoricidal effect and the stroma barrier that greatly hinders drug penetration. To address this challenge, a comprehensive strategy is proposed to fully utilize both the ferroptotic vulnerability of PDAC to potently irritate anti-tumor immunity and the desmoplasia-associated focal adhesion kinase (FAK) to wholly improve the immunosuppressive microenvironment via sustained release of drugs in an injectable hydrogel for increasing drug penetration in tumor location and averting systematic toxicity. The injectable hydrogel ED-M@CS/MC is hybridized with micelles loaded with erastin that exclusively induces ferroptosis and a FAK inhibitor defactinib for inhibiting stroma formation, and achieves sustained release of the drugs for up to 12 days. With only a single intratumoral injection, the combination treatment with erastin and defactinib produces further anti-tumor performance both in xenograft and KrasG12D-engineered primary PDAC mice and synergistically promotes the infiltration of CD8+ cytotoxic T cells and the reduction of type II macrophages. The findings may provide a novel promising strategy for the clinical treatment of PDAC.

Circulating immune-related proteins associated with immune checkpoint inhibitor efficacy in patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Most patients with pancreatic ductal adenocarcinoma (PDAC) do not benefit from immune checkpoint inhibitor treatment. However, the phase II study CheckPAC (NCT02866383) showed a clinical benefit (CB) rate of 37% and a response rate of 14% in patients with metastatic PDAC receiving stereotactic radiation therapy and nivolumab with or without ipilimumab. Translational studies were initiated to characterize the patients who would benefit from this treatment. Here, we evaluated the association between treatment outcome and 92 circulating immuno-oncology-related proteins in patients from the CheckPAC trial. MATERIALS AND METHODS: The study included 78 patients with chemoresistant metastatic PDAC treated with nivolumab ± ipilimumab combined with radiotherapy. Proteins were measured in serum samples collected at baseline and on treatment with the use of the Olink Target 96 Immuno-Oncology panel. A cohort of 234 patients with metastatic PDAC treated with first-line chemotherapy were also included. RESULTS: High levels of Fas ligand (FASLG) and galectin 1 (Gal-1) and low levels of C-C motif chemokine 4 were associated with CB. High FASLG and Gal-1 were associated with longer progression-free survival in univariable analysis. In the multivariable Cox regression analysis, the association was significant for Gal-1 (P < 0.001) but not significant for FASLG (P = 0.06). A focused unsupervised hierarchal clustering analysis, including T-cell activation and immune checkpoint-related proteins, identified clusters of patients with higher CB rate and higher tumor expression of leukocyte or T-cell markers (CD3, CD45, granzyme B). Thirty-six proteins increased significantly during immunotherapy. Several proteins (including FASLG, checkpoint proteins, and immune activation markers) increased independently of response during immunotherapy but did not increase in the cohort of patients treated with chemotherapy. CONCLUSIONS: Circulating levels of immune-related proteins like FASLG and Gal-1 might be used to predict the efficacy of checkpoint inhibitors in patients with metastatic PDAC.

6:2 Cl-PFESA, a proposed safe alternative for PFOS, diminishes the gemcitabine effectiveness in the treatment of pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC)/pancreatic cancer, is a highly aggressive malignancy with poor prognosis. Gemcitabine-based chemotherapy remains the cornerstone of PDAC treatment. Nonetheless, the development of resistance to gemcitabine among patients is a major factor contributing to unfavorable prognostic outcomes. The resistance exhibited by tumors is modulated by a constellation of factors such as genetic mutations, tumor microenvironment transforms, environmental contaminants exposure. Currently, comprehension of the relationship between environmental pollutants and tumor drug resistance remains inadequate. Our study found that PFOS/6:2 Cl-PFESA exposure increases resistance to gemcitabine in PDAC. Subsequent in vivo trials confirmed that exposure to PFOS/6:2 Cl-PFESA reduces gemcitabine's efficacy in suppressing PDAC, with the inhibition rate decreasing from 79.5 % to 56.7 %/38.7 %, respectively. Integrative multi-omics sequencing and molecular biology analyses have identified the upregulation of ribonucleotide reductase catalytic subunit M1 (RRM1) as a critical factor in gemcitabine resistance. Subsequent research has demonstrated that exposure to PFOS and 6:2 Cl-PFESA results in the upregulation of the RRM1 pathway, consequently enhancing chemotherapy resistance. Remarkably, the influence exerted by 6:2 Cl-PFESA exceeds that of PFOS. Despite 6:2 Cl-PFESA being regarded as a safer substitute for PFOS, its pronounced effect on chemotherapeutic resistance in PDAC necessitates a thorough evaluation of its potential risks related to gastrointestinal toxicity.

Pancreatic Cancer and Venous Thromboembolism.

Pancreatic ductal adenocarcinoma (PDAC) accounts for more than 90% of all pancreatic cancers and is the most fatal of all cancers. The treatment response from combination chemotherapies is far from satisfactory and surgery remains the mainstay of curative strategies. These challenges warrant identifying effective treatments for combating this deadly cancer. PDAC tumor progression is associated with the robust activation of the coagulation system. Notably, cancer-associated thrombosis (CAT) is a significant risk factor in PDAC. CAT is a concept whereby cancer cells promote thromboembolism, primarily venous thromboembolism (VTE). Of all cancer types, PDAC is associated with the highest risk of developing VTE. Hypoxia in a PDAC tumor microenvironment also elevates thrombotic risk. Direct oral anticoagulants (DOACs) or low-molecular-weight heparin (LMWH) are used only as thromboprophylaxis in PDAC. However, a precision medicine approach is recommended to determine the precise dose and duration of thromboprophylaxis in clinical setting.

Triphenylphosphonium-Conjugated Palmitic Acid for Mitochondrial Targeting of Pancreatic Cancer Cells: Proteomic and Molecular Evidence.

Pancreatic ductal adenocarcinoma (PDAC)'s resistance to therapies is mainly attributed to pancreatic cancer stem cells (PCSCs). Mitochondria-impairing agents can be used to hamper PCSC propagation and reduce PDAC progression. Therefore, to develop an efficient vector for delivering drugs to the mitochondria, we synthesized tris(3,5-dimethylphenyl)phosphonium-conjugated palmitic acid. Triphenylphosphonium (TPP) is a lipophilic cationic moiety that promotes the accumulation of conjugated agents in the mitochondrion. Palmitic acid (PA), the most common saturated fatty acid, has pro-apoptotic activity in different types of cancer cells. TPP-PA was prepared by the reaction of 16-bromopalmitic acid with TPP, and its structure was characterized by 1H and 13C NMR and HRMS. We compared the proteomes of TPP-PA-treated and untreated PDAC cells and PCSCs, identifying dysregulated proteins and pathways. Furthermore, assessments of mitochondrial membrane potential, intracellular ROS, cardiolipin content and lipid peroxidation, ER stress, and autophagy markers provided information on the mechanism of action of TPP-PA. The findings showed that TPP-PA reduces PDAC cell proliferation through mitochondrial disruption that leads to increased ROS, activation of ER stress, and autophagy. Hence, TPP-PA might offer a new approach for eliminating both the primary population of cancer cells and PCSCs, which highlights the promise of TPP-derived compounds as anticancer agents for PDAC.

Sphingosine is involved in PAPTP-induced death of pancreas cancer cells by interfering with mitochondrial functions.

Pancreas ductal adenocarcinoma belongs to the most common cancers, but also to the tumors with the poorest prognosis. Here, we pharmacologically targeted a mitochondrial potassium channel, namely mitochondrial Kv1.3, and investigated the role of sphingolipids and mutated Kirsten Rat Sarcoma Virus (KRAS) in Kv1.3-mediated cell death. We demonstrate that inhibition of Kv1.3 using the Kv1.3-inhibitor PAPTP results in an increase of sphingosine and superoxide in membranes and/or membranes associated with mitochondria, which is enhanced by KRAS mutation. The effect of PAPTP on sphingosine and mitochondrial superoxide formation as well as cell death is prevented by sh-RNA-mediated downregulation of Kv1.3. Induction of sphingosine in human pancreas cancer cells by PAPTP is mediated by activation of sphingosine-1-phosphate phosphatase and prevented by an inhibitor of sphingosine-1-phosphate phosphatase. A rapid depolarization of isolated mitochondria is triggered by binding of sphingosine to cardiolipin, which is neutralized by addition of exogenous cardiolipin. The significance of these findings is indicated by treatment of mutated KRAS-harboring metastasized pancreas cancer with PAPTP in combination with ABC294640, a blocker of sphingosine kinases. This treatment results in increased formation of sphingosine and death of pancreas cancer cells in vitro and, most importantly, prolongs in vivo survival of mice challenged with metastatic pancreas cancer. KEY MESSAGES: Pancreatic ductal adenocarcinoma (PDAC) is a common tumor with poor prognosis. The mitochondrial Kv1.3 ion channel blocker induced mitochondrial sphingosine. Sphingosine binds to cardiolipin thereby mediating mitochondrial depolarization. Sphingosine is formed by a PAPTP-mediated activation of S1P-Phosphatase. Inhibition of sphingosine-consumption amplifies PAPTP effects on PDAC in vivo.

PAK1 inhibition increases TRIM21-induced PD-L1 degradation and enhances responses to anti-PD-1 therapy in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) is a common malignancy with a 5-year survival <10 %. Immunosuppressive tumor microenvironment (TME) plays a critical role in the progression of PDA. In recent years, programmed death-ligand 1 (PD-L1)/programmed cell death protein-1 (PD-1) blockade has emerged as a potent anti-tumor immunotherapy, while is yet to achieve significant clinical benefits for PDA patients. P21-Activated kinase 1 (PAK1) is highly upregulated in PDA and has been reported to be involved in the regulation of anti-tumor immunity. This study aims to investigate the combined effect of PAK1 inhibition and anti-PD-1 therapy on PDA and the underlying mechanisms. We have shown that PAK1 expression positively correlated with PD-L1 in PDA patients, and that inhibition of PAK1 downregulated PD-L1 expression of PDA cells. More importantly, we have demonstrated that PAK1 competed with PD-L1 in binding to tripartite motif-containing protein 21 (TRIM21), a ubiquitin E3 ligase, resulting in less ubiquitination and degradation of PD-L1. Moreover, PAK1 inhibition promoted CD8+ T cells activation and infiltration. In a murine PDA model, the combination of PAK1 inhibition and anti-PD-1 therapy showed significant anti-tumor effects compared with the control or monotherapy. Our results indicated that the combination of PAK1 inhibition and anti-PD-1 therapy would be a more effective treatment for PDA patients.

CHES1 modulated tumorigenesis and senescence of pancreas cancer cells through repressing AKR1B10.

Pancreatic ductal adenocarcinoma (PDAC), is characteristic by a heterogeneous tumor microenvironment and gene mutations, conveys a dismal prognosis and low response to chemotherapy and immunotherapy. Here, we found that checkpoint suppressor 1 (CHES1) served as a tumor repressor in PDAC and was associated with patient prognosis. Functional experiments indicated that CHES1 suppressed the proliferation and invasion of PDAC by modulating cellular senescence. To further identify the downstream factor of CHES1 in PDAC, label-free quantitative proteomics analysis was conducted, which showed that the oncogenic Aldo-keto reductase 1B10 (AKR1B10) was transcriptionally repressed by CHES1 in PDAC. And AKR1B10 facilitated the malignant activity and repressed senescent phenotype of PDAC cells. Moreover, pharmaceutical inhibition of AKR1B10 with Oleanolic acid (OA) significantly induced tumor regression and sensitized PDAC cells to gemcitabine, and this combined therapy did not cause obvious side effects. Rescued experiments revealed that CHES1 regulated the tumorigenesis and gemcitabine sensitivity through AKR1B10-mediated senescence in PDAC. In summary, this study revealed that the CHES1/AKR1B10 axis modulated the progression and cellular senescence in PDAC, which might provide revenues for drug-targeting and senescence-inducing therapies for PDAC.

Exploring in vivo combinatorial chemo-immunotherapy: Addressing p97 suppression and immune reinvigoration in pancreatic cancer with tumor microenvironment-responsive nanoformulation.

Pancreatic ductal adenocarcinoma (PDAC) has an extremely devastating nature with poor prognosis and increasing incidence, making it a formidable challenge in the global fight against cancer-related mortality. In this innovative preclinical investigation, the VCP/p97 inhibitor CB-5083 (CB), miR-142, a PD-L1 inhibitor, and immunoadjuvant resiquimod (R848; R) were synergistically encapsulated in solid lipid nanoparticles (SLNs). These SLNs demonstrated features of peptides targeting PD-L1, EGFR, and the endoplasmic reticulum, enclosed in a pH-responsive polyglutamic (PGA)-polyethylene glycol (PEG) shell. The homogeneous size and zeta potential of the nanoparticles were stable for 28 days at 4°C. The study substantiated the concurrent modulation of key pathways by the CB, miR, and R-loaded nanoformulation, prominently affecting VCP/Bip/ATF6, PD-L1/TGF-ß/IL-4, -8, -10, and TNF-α/IFN-γ/IL-1, -12/GM-CSF/CCL4 pathways. This adaptable nanoformulation induced durable antitumor immune responses and inhibited Panc-02 tumor growth by enhancing T cell infiltration, dendritic cell maturation, and suppressing Tregs and TAMs in mice bearing Panc-02 tumors. Furthermore, tissue distribution studies, biochemical assays, and histological examinations highlighted enhanced safety with PGA and peptide-modified nanoformulations for CB, miR, and/or R in Panc-02-bearing mice. This versatile nanoformulation allows tailored adjustment of the tumor microenvironment, thereby optimizing the localized delivery of combined therapy. These compelling findings advocate the potential development of a pH-sensitive, three-in-one PGA-PEG nanoformulation that combines a VCP inhibitor, a PD-L1 inhibitor, and an immunoadjuvant for cancer treatment via combinatorial chemo-immunotherapy.

Correlation between Angiotensin Inhibitor Administration and Longer Survival in Patients Who Underwent Curative Resection for Pancreatic Cancer.

PURPOSE: The microenvironment of pancreatic ductal adenocarcinoma (PDAC) with extensive desmoplastic stroma contributes to aggressive cancer behavior. Angiotensin system inhibitors (ASIs) reduce stromal fibrosis and are a promising therapeutic strategy. The purpose of this study was to examine how ASIs affected the oncological results of patients who had their PDAC removed. MATERIALS AND METHODS: A retrospective assessment was conducted on the clinicopathological and survival data of patients who received curative resection for PDAC at Severance Hospital between January 2012 and December 2019. RESULTS: A total of 410 participants (228 male and 182 female), with a median follow-up period of 12.8 months, were included in this study. Patients were divided into three groups, based on ASI use and history of hypertension: group 1, normotensive and never used ASI (n=210, 51.2%); group 2, ASI non-users with hypertension (n=50, 12.2%); and group 3, ASI users with hypertension (n=150, 36.6%). The three groups did not differ significantly in terms of age, sex, kind of operation, T and N stages, or adjuvant and neoadjuvant therapy. Moreover, there was no discernible difference in disease-free survival between those who used ASI and those who did not (p=0.636). The 5-year overall survival (OS) rates in groups 1, 2, and 3 were 52.6%, 32.3%, and 38.0%, respectively. However, the OS rate of ASI users was remarkably higher than that of non-users (p=0.016). CONCLUSION: In patients with resected PDAC, ASI is linked to longer survival rates. Furthermore, for individuals with hypertension, ASI in conjunction with conventional chemotherapy may be an easy and successful treatment option.

The trend toward more target therapy in pancreatic ductal adenocarcinoma.

INTRODUCTION: Despite the considerable progress made in cancer treatment through the development of target therapies, pancreatic ductal adenocarcinoma (PDAC) continues to exhibit resistance to this category of drugs. As a result, chemotherapy combination regimens remain the primary treatment approach for this aggressive cancer. AREAS COVERED: In this review, we provide an in-depth analysis of past and ongoing trials on both well-known and novel targets that are being explored in PDAC, including PARP, EGFR, HER2, KRAS, and its downstream and upstream pathways (such as RAF/MEK/ERK and PI3K/AKT/mTOR), JAK/STAT pathway, angiogenesis, metabolisms, epigenetic targets, claudin, and novel targets (such as P53 and plectin). We also provide a comprehensive overview of the significant trials for each target, allowing a thorough glimpse into the past and future of target therapy. EXPERT OPINION: The path toward implementing a target therapy capable of improving the overall survival of PDAC is still long, and it is unlikely that a monotherapy target drug will fulfill a meaningful role in addressing the complexity of this cancer. Thus, we discuss the future direction of target therapies in PDAC, trying to identify the more promising target and combination treatments, with a special focus on the more eagerly awaited ongoing trials.