Data driven polypharmacological drug design for lung cancer: analyses for targeting ALK, MET, and EGFR.

Drug design of protein kinase inhibitors is now greatly enabled by thousands of publicly available X-ray structures, extensive ligand binding data, and optimized scaffolds coming off patent. The extensive data begin to enable design against a spectrum of targets (polypharmacology); however, the data also reveal heterogeneities of structure, subtleties of chemical interactions, and apparent inconsistencies between diverse data types. As a result, incorporation of all relevant data requires expert choices to combine computational and informatics methods, along with human insight. Here we consider polypharmacological targeting of protein kinases ALK, MET, and EGFR (and its drug resistant mutant T790M) in non small cell lung cancer as an example. Both EGFR and ALK represent sources of primary oncogenic lesions, while drug resistance arises from MET amplification and EGFR mutation. A drug which inhibits these targets will expand relevant patient populations and forestall drug resistance. Crizotinib co-targets ALK and MET. Analysis of the crystal structures reveals few shared interaction types, highlighting proton-arene and key CH-O hydrogen bonding interactions. These are not typically encoded into molecular mechanics force fields. Cheminformatics analyses of binding data show EGFR to be dissimilar to ALK and MET, but its structure shows how it may be co-targeted with the addition of a covalent trap. This suggests a strategy for the design of a focussed chemical library based on a pan-kinome scaffold. Tests of model compounds show these to be compatible with the goal of ALK, MET, and EGFR polypharmacology.

Chronic myelogenous leukemia with the e6a2 BCR-ABL and lacking imatinib response: presentation of two cases.

The BCR-ABL fusion gene represents the hallmark of chronic myelogenous leukemia (CML) and is derived from a translocation between chromosome 9 and 22. The majority of CML patients have a breakpoint in the major BCR region of the BCR gene giving rise to e13a2 or e14a2 BCR-ABL transcripts. Occasionally, other BCR breakpoints occur. The current report describes two e6a2 CML patients with imatinib treatment failure and unusual disease progression. One patient was Philadelphia chromosome positive and one was Philadelphia chromosome negative with an atypical BCR-ABL rearrangement, ins (22;9).

Intracellular and surface distribution of monocyte tissue factor: application to intersubject variability.

OBJECTIVE: The high and low responder phenomenon describes individual differences in lipopolysaccharide (LPS)-induced monocyte tissue factor (TF) activity. We characterized patterns of intracellular accumulation, externalization, and shedding of TF in response to LPS in mononuclear cells (MNCs) from high responders (HRs) and low responders (LRs). METHODS AND RESULTS: After 2 hours of LPS stimulation of whole blood, flow cytometry analyses revealed a larger population of TF-positive monocytes in HRs (32.0+/-3.5%) versus LRs (11.2+/-1.2%; P< or =0.05), along with a stronger mean fluorescence intensity of TF signal in HRs (7.1+/-0.5 arbitrary units [AU]) compared with LRs (5.4+/-0.4 AU; P< or =0.05). The LPS-treated blood of the HR group contained 2-fold more TF-positive microparticles than LRs. In-cell Western assay demonstrated higher intracellular accumulation of TF in mononuclear cells (MNCs) from LRs because LPS induced a 3.7-fold increase of total TF levels in LRs versus a 1.5-fold increase in HRs. In contrast, in response to LPS stimulation, MNCs from HRs exhibited a 4-fold induction of surface TF, whereas MNCs from LRs only had a minor increase in surface TF levels. CONCLUSIONS: The higher availability of surface TF antigen on MNCs from HRs and TF-containing microparticles might make these individuals more susceptible to hypercoagulation.