Magnetic chromatography improves colloidal and MRI attributes of magnetoliposomes enabling evaluation of the impact of size on bio-distribution in an model of pancreatic cancer.

Magnetic chromatography was exploited to fractionate suspensions of magnetoliposomes (SML: lumen-free lipid-encapsulated clusters of multiple magnetic iron-oxide nanoparticles) improving their colloidal properties and relaxivity (magnetic resonance image contrast capability). Fractionation (i) removed sub-populations that do not contribute to the MRI response, and thus (ii) enabled evaluation of the size-dependence of relaxivity for the MRI-active part, which was surprisingly weak in the 55-90 nm range. MC was therefore implemented for processing multiple PEGylated SML types having average sizes ranging from 85 to 105 nm, which were then shown to have strongly size-dependent uptake in an pancreatic cancer model.

Immune regulatory adjuvant approach to mitigate subcutaneous immunogenicity of monoclonal antibodies.

Introduction: Immunogenicity continues to be a challenge for development and clinical utility of monoclonal antibodies, and there are gaps in our current ability to prevent anti-drug antibody development in a safe and antigen-specific manner.

Methods: To mitigate immunogenicity of monoclonal antibodies administered subcutaneously, O-phospho-L-serine (OPLS)-the head group of the tolerance-inducing phospholipid, phosphatidylserine-was investigated as an immunoregulatory adjuvant.

Results: Formulations of adalimumab, trastuzumab or rituximab with OPLS showed reduction in relative immunogenicity in mice compared to vehicle formulations, indicated by reduced anti-drug antibody development and significant reductions in CD138+ plasma cell differentiation in bone marrow.

Systems pharmacodynamic model of combined gemcitabine and trabectedin in pancreatic cancer cells. Part I.Çô Effects on signal transduction pathways related to tumor growth.

Pancreatic ductal adenocarcinoma (PDAC) is often chemotherapy-resistant, and novel drug combinations would fill an unmet clinical need. Previously we reported synergistic cytotoxic effects of gemcitabine and trabectedin on pancreatic cancer cells, but underlying protein-level interaction mechanisms remained unclear. We employed a reliable, sensitive, comprehensive, quantitative, high-throughput IonStar proteomic workflow to investigate the time course of gemcitabine and trabectedin effects, alone and combined, upon pancreatic cancer cells.

A synergistic two-drug therapy specifically targets a DNA repair dysregulation that occurs in p53-deficient colorectal and pancreatic cancers.

The tumor-suppressor p53 is commonly inactivated in colorectal cancer and pancreatic ductal adenocarcinoma, but existing treatment options for p53-mutant (p53) cancer are largely ineffective. Here, we report a therapeutic strategy for p53 tumors based on abnormalities in the DNA repair response. Investigation of DNA repair upon challenge with thymidine analogs reveals a dysregulation in DNA repair response in p53 cells that leads to accumulation of DNA breaks.

Fibroblast growth factor receptor 1 inhibition suppresses pancreatic cancer chemoresistance and chemotherapy-driven aggressiveness.

Aims: Pancreatic ductal adenocarcinoma (PDAC) is often intrinsically-resistant to standard-of-care chemotherapies such as gemcitabine. Acquired gemcitabine resistance (GemR) can arise from treatment of initially-sensitive tumors, and chemotherapy can increase tumor aggressiveness. We investigated the molecular mechanisms of chemoresistance and chemotherapy-driven tumor aggressiveness, which are understood incompletely.

Dual-Hit Strategy for Therapeutic Targeting of Pancreatic Cancer in Patient-Derived Xenograft Tumors.

Purpose: Paracrine activation of pro-fibrotic hedgehog (HH) signaling in pancreatic ductal adenocarcinoma (PDAC) results in stromal amplification that compromises tumor drug delivery, efficacy, and patient survival. Interdiction of HH-mediated tumor-stroma crosstalk with smoothened (SMO) inhibitors (SHHi) "primes" PDAC patient-derived xenograft (PDX) tumors for increased drug delivery by transiently increasing vascular patency/permeability, and thereby macromolecule delivery. However, patient tumor isolates vary in their responsiveness, and responders show co-induction of epithelial-mesenchymal transition (EMT).

Expression of fibroblast growth factor receptor 1 correlates inversely with the efficacy of single-agent fibroblast growth factor receptor-specific inhibitors in pancreatic cancer.

Background And Purpose: Elevated fibroblast growth factor receptor (FGFR) activity correlates with pancreatic adenocarcinoma (PDAC) progression and poor prognosis. However, its potential as a therapeutic target remains largely unexplored.

Experimental Approach: The mechanisms of action and therapeutic effects of selective pan-FGFR inhibitors (pan-FGFRi) were explored using in vitro and in vivo PDAC models ranging from gemcitabine-sensitive to highly gemcitabine-resistant (GemR).

Systems Pharmacodynamic Model of Combined Gemcitabine and Trabectedin in Pancreatic Cancer Cells. Part II: Cell Cycle, DNA Damage Response, and Apoptosis Pathways.

Despite decades of research efforts, pancreatic adenocarcinoma (PDAC) continues to present a formidable clinical challenge, demanding innovative therapeutic approaches. In a prior study, we reported the synergistic cytotoxic effects of gemcitabine and trabectedin on pancreatic cancer cells. To investigate potential mechanisms underlying this synergistic pharmacodynamic interaction, liquid chromatography-mass spectrometry-based proteomic analysis was performed, and a systems pharmacodynamics model (SPD) was developed to capture pancreatic cancer cell responses to gemcitabine and trabectedin, alone and combined, at the proteome level.

Highly Reproducible Quantitative Proteomics Analysis of Pancreatic Cancer Cells Reveals Proteome-Level Effects of a Novel Combination Drug Therapy That Induces Cancer Cell Death via Metabolic Remodeling and Activation of the Extrinsic Apoptosis Pathway.

Pancreatic cancer patients have poor survival rates and are frequently treated using gemcitabine (Gem). However, initial tumor sensitivity often gives way to rapid development of resistance. Gem-based drug combinations are employed to increase efficacy and mitigate resistance, but our understanding of molecular-level drug interactions, which could assist in the development of more effective therapeutic regimens, is limited.

Integrated PK/PD Modeling Relates Smoothened Inhibitor Biomarkers to The Heterogeneous Intratumor Disposition of Cetuximab in Pancreatic Cancer Tumor Models.

Therapeutic antibodies have shown little efficacy in the treatment of pancreatic ductal adenocarcinomas (PDAC). Tumor desmoplasia, hypovascularity, and poor perfusion result in insufficient tumor cell exposure, contributing to treatment failure. Smoothened inhibitors of hedgehog signaling (sHHi) increase PDAC tumor permeability, perfusion, and drug delivery, and provide a tool to develop a quantitative, mechanistic understanding as to how the temporal dynamics of tumor priming can impact intratumor distribution of monoclonal antibodies (mAb).

Species-Deconvolved Proteomics for Investigation of Tumor-Stroma Interactions after Treatment of Pancreatic Cancer Patient-Derived Xenografts with Combined Gemcitabine and Paclitaxel.

Tumor-stroma interactions are critical in pancreatic ductal adenocarcinoma (PDAC) progression and therapeutics. Patient-derived xenograft (PDX) models recapitulate tumor-stroma interactions, but the conventional antibody-based immunoassay is inadequate to discriminate tumor and stromal proteins. Here, we describe a species-deconvolved proteomics approach embedded in IonStar that can unambiguously quantify the tumor (human-derived) and stromal (mouse-derived) proteins in PDX samples, enabling unbiased investigation of tumor and stromal proteomes with excellent quantitative reproducibility.

Alteration in Levels of Specific miRNAs and Their Potential Protein Targets between Human Pancreatic Cancer Samples, Adjacent Normal Tissue, and Xenografts Derived from These Tumors.

Herein, we describe the global comparison of miRNAs in human pancreatic cancer tumors, adjacent normal tissue, and matched patient-derived xenograft models using microarray screening. RNA was extracted from seven tumor, five adjacent normal, and eight FI PDX tumor samples and analyzed by Affymetrix GeneChip miRNA 4.0 array.

Long-circulating magnetoliposomes as surrogates for assessing pancreatic tumour permeability and nanoparticle deposition.

Nanocarriers are candidates for cancer chemotherapy delivery, with growing numbers of clinically-approved nano-liposomal formulations such as Doxil® and Onivyde® (liposomal doxorubicin and irinotecan) providing proof-of-concept. However, their complex biodistribution and the varying susceptibility of individual patient tumours to nanoparticle deposition remains a clinical challenge. Here we describe the preparation, characterisation, and biological evaluation of phospholipidic structures containing solid magnetic cores (SMLs) as an MRI-trackable surrogate that could aid in the clinical development and deployment of nano-liposomal formulations.

FOLFIRINOX Pharmacodynamic Interactions in 2D and 3D Pancreatic Cancer Cell Cultures.

The multi-drug combination regime, FOLFIRINOX, is a standard of care chemotherapeutic therapy for pancreatic cancer patients. However, systematic evaluation of potential pharmacodynamic interactions among multi-drug therapy has not been reported previously. Here, pharmacodynamic interactions of the FOLFIRINOX agents (5-fluorouracil (5-FU), oxaliplatin (Oxa) and SN-38, the active metabolite of irinotecan) were assessed across a panel of primary and established pancreatic cancer cells.

Comparative Proteomic Analysis Identifies Key Metabolic Regulators of Gemcitabine Resistance in Pancreatic Cancer.

Pancreatic adenocarcinoma (PDAC) is highly refractory to treatment. Standard-of-care gemcitabine (Gem) provides only modest survival benefits, and development of Gem resistance (GemR) compromises its efficacy. Highly GemR clones of Gem-sensitive MIAPaCa-2 cells were developed to investigate the molecular mechanisms of GemR and implemented global quantitative differential proteomics analysis with a comprehensive, reproducible ion-current-based MS1 workflow to quantify ∼6000 proteins in all samples.

Formation of hydrated PEG layers on magnetic iron oxide nanoflowers shows internal magnetisation dynamics and generates high in-vivo efficacy for MRI and magnetic hyperthermia.

Multicore magnetic iron oxide nanoparticles, nanoflowers (NFs), have potential biomedical applications as efficient mediators for AC-magnetic field hyperthermia and as contrast agents for magnetic resonance imaging due to their strong magnetic responses arising from complex internal magnetic ordering. To realise these applications amenable surface chemistry must be engineered that maintain particle dispersion. Here a catechol-derived grafting approach is described to strongly bind polyethylene glycol (PEG) to NFs and provide stable hydrogen-bonded hydrated layers that ensure good long-term colloidal stability in buffers and media even at clinical MRI field strength and high concentration.

Single-treatment tumor ablation with photodynamic liposomal irinotecan sucrosulfate.

Irinotecan (IRI) loaded actively into PEGylated liposomes via a sucrosulfate gradient has been approved recently to treat advanced pancreatic cancer. In this study, a similar liposomal composition was developed that includes a low mole fraction (1 mol.%) of porphyrin-phospholipid (PoP), a photosensitizer that stably incorporates into liposomes, to confer light-triggered IRI release.

Synergistic Pharmacodynamic Effects of Gemcitabine and Fibroblast Growth Factor Receptor Inhibitors on Pancreatic Cancer Cell Cycle Kinetics and Proliferation.

Median survival of pancreatic ductal adenocarcinoma cancer (PDAC) is 6 months, with 9% 5-year survival. Standard-of-care gemcitabine (Gem) provides only modest survival benefits, and combination therapies integrating novel targeted agents could improve outcomes. Fibroblast growth factor (FGF) receptors (FGFRs) play important roles in PDAC growth and invasion.

Pharmacodynamic modeling of synergistic birinapant/paclitaxel interactions in pancreatic cancer cells.

Background: For most patients, pancreatic adenocarcinoma responds poorly to treatment, and novel therapeutic approaches are needed. Standard-of-care paclitaxel (PTX), combined with birinapant (BRP), a bivalent mimetic of the apoptosis antagonist SMAC (second mitochondria-derived activator of caspases), exerts synergistic killing of PANC-1 human pancreatic adenocarcinoma cells.

Methods: To investigate potential mechanisms underlying this synergistic pharmacodynamic interaction, data capturing PANC-1 cell growth, apoptosis kinetics, and cell cycle distribution were integrated with high-quality IonStar-generated proteomic data capturing changes in the relative abundance of more than 3300 proteins as the cells responded to the two drugs, alone and combined.

Controlled coupling of an ultrapotent auristatin warhead to cetuximab yields a next-generation antibody-drug conjugate for EGFR-targeted therapy of KRAS mutant pancreatic cancer.

Background: Antibody-drug conjugate (ADC) construction poses numerous challenges that limit clinical progress. In particular, common bioconjugation methods afford minimal control over the site of drug coupling to antibodies. Here, such difficulties are overcome through re-bridging of the inter-chain disulfides of cetuximab (CTX) with auristatin-bearing pyridazinediones, to yield a highly refined anti-epidermal growth factor receptor (EGFR) ADC.

DR5-targeted, chemotherapeutic drug-loaded nanoparticles induce apoptosis and tumor regression in pancreatic cancer in vivo models.

Pancreatic cancer is usually advanced and drug resistant at diagnosis. A potential therapeutic approach outlined here uses nanoparticle (NP)-based drug carriers, which have unique properties that enhance intra-tumor drug exposure and reduce systemic toxicity of encapsulated drugs. Here we report that patients whose pancreatic cancers express elevated levels of Death Receptor 5 (DR5) and its downstream regulators/effectors FLIP, Caspase-8, and FADD had particularly poor prognoses.

Establishment and Characterisation by Expression Microarray of Patient-Derived Xenograft Panel of Human Pancreatic Adenocarcinoma Patients.

Pancreatic cancer remains among the most lethal cancers worldwide, with poor early detection rates and poor survival rates. Patient-derived xenograft (PDX) models have increasingly been used in preclinical and clinical research of solid cancers to fulfil unmet need. Fresh tumour samples from human pancreatic adenocarcinoma patients were implanted in severe combined immunodeficiency (SCID) mice.

Repurposing of Cetuximab in antibody-directed chemotherapy-loaded nanoparticles in EGFR therapy-resistant pancreatic tumours.

The anti-Epidermal Growth Factor Receptor (EGFR) antibody Cetuximab (CTX) has demonstrated limited anti-cancer efficacy in cells overexpressing EGFR due to activating mutations in RAS in solid tumours, such as pancreatic cancer. The utilisation of antibodies as targeting components of antibody-drug conjugates, such as trastuzumab emtansine (Kadcyla), demonstrates that antibodies may be repurposed to direct therapeutic agents to antibody-resistant cancers. Here we investigated the use of CTX as a targeting agent for camptothecin (CPT)-loaded polymeric nanoparticles (NPs) directed against KRAS mutant CTX-resistant cancer cells.

Tumor Priming by SMO Inhibition Enhances Antibody Delivery and Efficacy in a Pancreatic Ductal Adenocarcinoma Model.

Despite frequent overexpression of numerous growth factor receptors by pancreatic ductal adenocarcinomas (PDAC), such as EGFR, therapeutic antibodies have not proven effective. Desmoplasia, hypovascularity, and hypoperfusion create a functional drug delivery barrier that contributes to treatment resistance. Drug combinations that target tumor/stroma interactions could enhance tumor deposition of therapeutic antibodies, although clinical trials have yet to support this strategy.