Discoidin domain receptor 1 (DDR1) is an emerging potential molecular target for new anticancer drug discovery. We have discovered a series of 3-(2-(pyrazolo[1,5-a]pyrimidin-6-yl) ethynyl)benzamides that are selective and orally bioavailable DDR1 inhibitors. The two most promising compounds (7rh and 7rj) inhibited the enzymatic activity of DDR1, with IC50 values of 6.8 and 7.0 nM, respectively, but were significantly less potent in suppressing the kinase activities of DDR2, Bcr-Abl, and c-Kit. Further study revealed that 7rh bound with DDR1 with a Kd value of 0.6 nM, while it was significantly less potent to the other 455 kinases tested. The S(35) and S(10) selectivity scores of 7rh were 0.035 and 0.008, respectively. The compounds also potently inhibited the proliferation of cancer cells expressing high levels of DDR1 and strongly suppressed cancer cell invasion, adhesion, and tumorigenicity. Preliminary pharmacokinetic studies suggested that they possessed good PK profiles, with oral bioavailabilities of 67.4% and 56.2%, respectively.
Bcr-Abl(T315I) mutation-induced imatinib resistance remains a major challenge for clinical management of chronic myelogenous leukemia (CML). Herein, we report GZD824 (10a) as a novel orally bioavailable inhibitor against a broad spectrum of Bcr-Abl mutants including T315I. It tightly bound to Bcr-Abl(WT) and Bcr-Abl(T315I) with K(d) values of 0.32 and 0.71 nM, respectively, and strongly inhibited the kinase functions with nanomolar IC(50) values. The compound potently suppressed proliferation of Bcr-Abl-positive K562 and Ku812 human CML cells with IC(50) values of 0.2 and 0.13 nM, respectively. It also displayed good oral bioavailability (48.7%), a reasonable half-life (10.6 h), and promising in vivo antitumor efficacy. It induced tumor regression in mouse xenograft tumor models driven by Bcr-Abl(WT) or the mutants and significantly improved the survival of mice bearing an allograft leukemia model with Ba/F3 cells harboring Bcr-Abl(T315I). GZD824 represents a promising lead candidate for development of Bcr-Abl inhibitors to overcome acquired imatinib resistance.
The EGFR(T790M) mutant contributes approximately 50% to clinically acquired resistance against gefitinib or erlotinib. However, almost all the single agent clinical trials of the second generation irreversible EGFR inhibitors appear inadequate to overcome the EGFR(T790M)-related resistance. We have designed and synthesized a series of 2-oxo-3,4-dihydropyrimido[4,5-d]pyrimidinyl derivatives as novel EGFR inhibitors. The most potent compounds, 2q and 2s, inhibited the enzymatic activities of wild-type and mutated EGFRs, with IC(50) values in subnanomolar ranges, including the T790M mutants. The kinase inhibitory efficiencies of the compounds were further validated by Western blot analysis of the activation of EGFR and downstream signaling in cancer cells harboring different mutants of EGFR. The compounds also strongly inhibited the proliferation of H1975 non small cell lung cancer cells bearing EGFR(L858R/T790M), while being significantly less toxic to normal cells. Moreover, 2s displayed promising anticancer efficacy in a human NSCLC (H1975) xenograft nude mouse model.
The structure-based design of 1,
2, 3, 4-tetrahydroisoquinoline
derivatives as selective DDR1 inhibitors is reported. One of the representative
compounds, 6j, binds to DDR1 with a Kd value of 4.7 nM and suppresses its kinase activity with
an IC50 value of 9.4 nM, but it is significantly less potent
for a panel of 400 nonmutated kinases. 6j also demonstrated
reasonable pharmacokinetic properties and a promising oral therapeutic
effect in a bleomycin-induced mouse pulmonary fibrosis model.
We assess the power of forward guidance-promises about future interest rates-as a monetary tool in a liquidity trap using a quantitative incomplete-markets model. Our results suggest the effects of forward guidance are negligible. A commitment to keep future nominal interest rates low for a few quarters-although macro indicators suggest otherwise-has only trivial effects on current output and employment. We explain theoretically why in complete markets models forward guidance is powerful-generating a "forward guidance puzzle"-and why this puzzle disappears in our model. We also clarify theoretically ambiguous conclusions from previous research about the effectiveness of forward guidance in incomplete and complete markets models.
A series of N-(3-((1H-pyrazolo[3,4-b]pyridin-5-yl)ethynyl)benzenesulfonamides were designed as the first class of highly selective ZAK inhibitors. The representative compound 3h strongly inhibits the kinase activity of ZAK with an IC of 3.3 nM and dose-dependently suppresses the activation of ZAK downstream signals in vitro and in vivo, while it is significantly less potent for the majority of 403 nonmutated kinases evaluated. Compound 3h also exhibits orally therapeutic effects on cardiac hypertrophy in a spontaneous hypertensive rat model.
Spiroapplanatumines A-Q (1-12, 14-16, 18, and 20), new spiro meroterpenoids respectively bearing a 6/5/7 or 6/5/5 ring system, along with three known compounds, spirolingzhines A, B, and D, were isolated from the fruiting bodies of the fungus Ganoderma applanatum. Their structures including absolute configurations were assigned by using spectroscopic methods, ECD and C NMR calculations, and single-crystal X-ray diffraction analysis. Biological evaluation of all the compounds disclosed that compounds 7 and 8 inhibited JAK3 kinase with IC values of 7.0 ± 3.2 and 34.8 ± 21.1 μM, respectively.
A series of N-(3-ethynyl-2,4-difluorophenyl)-sulfonamides were identified as new selective Raf inhibitors. The compounds potently inhibit B-Raf V600E with low nanomolar IC 50 values and exhibit excellent target specificity in a selectivity profiling investigation against 468 kinases. They strongly suppress proliferation of a panel of human cancer cell lines and patient-derived melanoma cells with B-Raf V600E mutation while being significantly less potent to the cells with B-Raf WT . The compounds also display favorable pharmacokinetic properties with a preferred example (3s) demonstrating significant in vivo antitumor efficacy in a xenograft mouse model of B-Raf V600E mutated Colo205 human colorectal cancer cells, supporting it as a promising lead compound for further anticancer drug discovery.
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