birinapant and Pancreatic-Neoplasms

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.. 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.. PTX alone (15 nM) elicited dose-dependent G2/M-phase arrest and cellular polyploidy. Combined BRP/PTX (150/15 nM) reduced G2/M by 35% and polyploid cells by 45%, and increased apoptosis by 20%. Whereas BRP or PTX alone produced no change in the pro-apoptotic protein pJNK, and a slight increase in the anti-apoptotic protein Bcl2, the drug combination increased pJNK and decreased Bcl2 significantly compared to the vehicle control. A multi-scale, mechanism-based mathematical model was developed to investigate integrated birinapant/paclitaxel effects on temporal profiles of key proteins involved in kinetics of cell growth, death, and cell cycle distribution.. The model, consistent with the observed reduction in the Bcl2/BAX ratio, suggests that BRP-induced apoptosis of mitotically-arrested cells is a major contributor to the synergy between BRP and PTX. Coupling proteomic and cellular response profiles with multi-scale pharmacodynamic modeling provides a quantitative mechanistic framework for evaluating pharmacodynamically-based drug-drug interactions in combination chemotherapy, and could potentially guide the development of promising drug regimens.

Topics: Adenocarcinoma; bcl-2-Associated X Protein; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dipeptides; Dose-Response Relationship, Drug; Drug Synergism; Gene Expression Regulation, Neoplastic; Humans; Indoles; MAP Kinase Kinase 4; Paclitaxel; Pancreatic Neoplasms; Protein Interaction Maps; Proteomics; Proto-Oncogene Proteins c-bcl-2

Topics: Adenocarcinoma; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Dipeptides; Humans; Indoles; Paclitaxel; Pancreatic Neoplasms; Proteomics

Topics: Deoxycytidine; Dipeptides; Gemcitabine; Humans; Indoles; Pancreatic Neoplasms; Proteomics

The anticancer effects of combined gemcitabine and birinapant were demonstrated as synergistic in PANC-1 cells in vitro. In this study, pharmacokinetic information derived from experiments and the literature was utilized to develop full physiologically-based pharmacokinetic (PBPK) models that characterize individual drugs. The predicted intra-tumor drug concentrations were used as the driving force within a linked PBPK/PD model for treatment-mediated changes in tumor volume in a xenograft mouse model. The efficacy of the drug combination in vivo was evaluated mathematically as exhibiting additivity. The network model developed for drug effects in the in vitro cell cultures was applied successfully to link the in vivo tumor drug concentrations with tumor growth inhibition, incorporating more mechanistic features and accounting for disparate drug interaction outcomes in vitro and in vivo.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Deoxycytidine; Dipeptides; Female; Gemcitabine; Heterografts; Humans; Indoles; Male; Mice; Mice, Nude; Middle Aged; Models, Biological; Pancreatic Neoplasms; Tumor Burden; Xenograft Model Antitumor Assays

Gemcitabine combined with birinapant, an inhibitor of apoptosis protein antagonist, acts synergistically to reduce pancreatic cancer cell proliferation. A large-scale proteomics dataset provided rich time-series data on proteome-level changes that reflect the underlying biological system and mechanisms of action of these drugs. A multiscale network model was developed to link the signaling pathways of cell cycle regulation, DNA damage response, DNA repair, apoptosis, nuclear factor-kappa β (NF-κβ), and mitogen-activated protein kinase (MAPK)-p38 to cell cycle progression, proliferation, and death. After validating the network model under different conditions, the Sobol Sensitivity Analysis was applied to identify promising targets to enhance gemcitabine efficacy. The effects of p53 silencing and combining curcumin with gemcitabine were also tested with the developed model. Merging proteomics analysis with systems modeling facilitates the characterization of quantitative relations among relevant signaling pathways in drug action and resistance, and such multiscale network models could be applied for prediction of combination efficacy and target selection.

Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Cell Proliferation; Deoxycytidine; Dipeptides; Gemcitabine; Humans; Indoles; Models, Biological; Pancreatic Neoplasms; Proteomics; Signal Transduction

Combination chemotherapy is standard treatment for pancreatic cancer. However, current drugs lack efficacy for most patients, and selection and evaluation of new combination regimens is empirical and time-consuming. The efficacy of gemcitabine, a standard-of-care agent, combined with birinapant, a pro-apoptotic antagonist of Inhibitor of Apoptosis Proteins (IAPs), was investigated in pancreatic cancer cells. PANC-1 cells were treated with vehicle, gemcitabine (6, 10, 20 nM), birinapant (50, 200, 500 nM), and combinations of the two drugs. Temporal changes in cell numbers, cell cycle distribution, and apoptosis were measured. A basic pharmacodynamic (PD) model based on cell numbers, and a mechanism-based PD model integrating all measurements, were developed. The basic PD model indicated that synergistic effects occurred in both cell proliferation and death processes. The mechanism-based model captured key features of drug action: temporary cell cycle arrest in S phase induced by gemcitabine alone, apoptosis induced by birinapant alone, and prolonged cell cycle arrest and enhanced apoptosis induced by the combination. A drug interaction term Ψ was employed in the models to signify interactions of the combination when data were limited. When more experimental information was utilized, Ψ values approaching 1 indicated that specific mechanisms of interactions were captured better. PD modeling identified the potential benefit of combining gemcitabine and birinapant, and characterized the key interaction pathways. An optimal treatment schedule of pretreatment with gemcitabine for 24-48 h was suggested based on model predictions and was verified experimentally. This approach provides a generalizable modeling platform for exploring combinations of cytostatic and cytotoxic agents in cancer cell culture studies.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Cycle; Cell Line, Tumor; Deoxycytidine; Dipeptides; Gemcitabine; Humans; Indoles; Models, Theoretical; Pancreatic Neoplasms