pazopanib and dabrafenib

Necroptosis represents a form of programmed cell death that can be engaged by various upstream signals, for example by ligation of death receptors, by viral sensors or by pattern recognition receptors. It depends on several key signaling proteins, including the kinases Receptor-Interacting Protein (RIP)1 and RIP3 and the pseudokinase mixed-lineage kinase domain-like protein (MLKL). Necroptosis has been implicated in a number of physiological and pathophysiological conditions and is disturbed in many human diseases. Thus, targeted interference with necroptosis signaling may offer new opportunities for the treatment of human diseases. Besides structure-based drug design, in recent years drug repositioning has emerged as a promising alternative to develop drug-like compounds. There is accumulating evidence showing that multi-targeting kinase inhibitors, for example Dabrafenib, Vemurafenib, Sorafenib, Pazopanib and Ponatinib, used for the treatment of cancer also display anti-necroptotic activity. This review summarizes recent evidence indicating that some anticancer kinase inhibitors also negatively affect necroptosis signaling. This implies that some cancer therapeutics may be repurposed for other pathologies, e.g. ischemic or inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Antioxidants; Apoptosis; Drug Repositioning; Humans; Imidazoles; Indazoles; Necrosis; Oximes; Pyridazines; Pyrimidines; Reperfusion Injury; Sorafenib; Sulfonamides; Systemic Inflammatory Response Syndrome; Vemurafenib

Topics: Administration, Oral; Antineoplastic Combined Chemotherapy Protocols; Bone Neoplasms; Carcinoma, Non-Small-Cell Lung; Combined Modality Therapy; Diagnosis, Differential; Femoral Neoplasms; Fracture Fixation, Intramedullary; Fractures, Spontaneous; Humans; Imidazoles; Indazoles; Lung Neoplasms; Male; Middle Aged; Oximes; Pyrimidines; Radiodermatitis; Radiotherapy, Adjuvant; Sulfonamides

A sensitive and selective method of high performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS) has been developed for the simultaneous quantification of six anticancer protein kinase inhibitors (PKIs), dabrafenib, trametinib, vemurafenib, cobimetinib, pazopanib, regorafenib, and two active metabolites (regorafenib-M2 and regorafenib-M5) in human plasma. Plasma protein precipitation with methanol enables the sample extraction of 100 μL aliquot of plasma. Analytes are detected by electrospray triple-stage quadrupole mass spectrometry and quantified using the calibration curves with stable isotope-labeled internal standards. The method was validated based on FDA recommendations, including assessment of extraction yield (74-104%), matrix effects, analytical recovery (94-104%) with low variability (<15%). The method is sensitive (lower limits of quantification within 1 to 200 ng/mL), accurate (intra- and inter-assay bias: -0.3% to +12.7%, and -3.2% to +6.3%, respectively) and precise (intra- and inter-assay CVs within 0.7-7.3% and 2.5-8.0%, respectively) over the clinically relevant concentration range (upper limits of quantification 500 to 100,000 ng/mL). This method is applied in our laboratory for both clinical research programs and routine therapeutic drug monitoring service of PKIs.

Topics: Administration, Oral; Antineoplastic Agents; Azetidines; Child; Chromatography, High Pressure Liquid; Humans; Imidazoles; Indazoles; Indoles; Limit of Detection; Linear Models; Oximes; Phenylurea Compounds; Piperidines; Pyridines; Pyridones; Pyrimidines; Pyrimidinones; Reproducibility of Results; Sulfonamides; Tandem Mass Spectrometry; Vemurafenib

Studies focused on the killing of activated B-RAF melanoma cells by the histone deacetylase (HDAC) inhibitor AR42. Compared to other tumor cell lines, PDX melanoma isolates were significantly more sensitive to AR42-induced killing. AR42 and the multi-kinase inhibitor pazopanib interacted to activate: an eIF2α-Beclin1 pathway causing autophagosome formation; an eIF2α-DR4/DR5/CD95 pathway; and an eIF2α-dependent reduction in the expression of c-FLIP-s, MCL-1 and BCL-XL. AR42 did not alter basal chaperone activity but increased the ability of pazopanib to inhibit HSP90, HSP70 and GRP78. AR42 and pazopanib caused HSP90/HSP70 dissociation from RAF-1 and B-RAF that resulted in reduced 'RAF' expression. The drug combination activated a DNA-damage-ATM-AMPK pathway that was associated with: NFκB activation; reduced mTOR S2448 and ULK-1 S757 phosphorylation; and increased ULK-1 S317 and ATG13 S318 phosphorylation. Knock down of PERK, eIF2α, Beclin1, ATG5 or AMPKα, or expression of IκB S32A S36A, ca-mTOR or TRX, reduced cell killing. AR42, via lysosomal degradation, reduced the protein expression of HDACs 2/5/6/10/11. In vivo, a 3-day exposure of dabrafenib/trametinib resistant melanoma cells to the AR42 pazopanib combination reduced tumor growth and enhanced survival from ~25 to ~40 days. Tumor cells that had adapted through therapy exhibited elevated HGF expression and the c-MET inhibitor crizotinib enhanced AR42 pazopanib lethality in this evolved drug-resistant population.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Combined Chemotherapy Protocols; Autophagosomes; Blotting, Western; Cell Line, Tumor; Cell Survival; Drug Resistance, Neoplasm; Drug Synergism; Endoplasmic Reticulum Chaperone BiP; Eukaryotic Initiation Factor-2; Histone Deacetylase 6; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Imidazoles; Indazoles; Kaplan-Meier Estimate; Male; Melanoma; Mice, Nude; Microscopy, Fluorescence; Oximes; Phenylbutyrates; Pyridones; Pyrimidines; Pyrimidinones; RNA Interference; Signal Transduction; Sulfonamides; Xenograft Model Antitumor Assays