The synthetic route of R changed derivatives

The synthetic route of R-changed derivatives is shown in . Compounds – were prepared from commercially available 4-nitro-1-indazole (). After same two steps with , the N-substituted indazole of was produced using the Suzuki reaction in a good yield (85%). Reduction of was performed using Pd/C, and the amide coupling of and using commercially available HATU. Each step was isolated via column chromatography. Having successfully achieved good enzyme and/or cellular activities, the drug metabolism and pharmacokinetic profiles for the more potent compounds ( and ) were evaluated. To understand the potential drug-drug interaction liabilities of these compounds, a CYP (Cytochromes P450) reversible inhibition assay using human liver microsomes was conducted. In this test, compound showed weak inhibition of five major CYP enzymes, whereas compound inhibited four CYP enzymes either strongly or moderately (IC range from <0.25 to 2.02 μM) except CYP2D6 (). These results indicate that compound has a lower risk of drug-drug interactions than compound . Moreover, compound showed both good oral bioavailability (F = 36%) in mice () and also an IC value >50 μM for the binding capacity to the hERG (Human ether-a-go-go-related gene) membrane. Based on these results, compound was chosen for further study. To determine the biochemical selectivity for compound , twenty eight kinases were tested. As summarized in , compound was highly selective against FMS and inhibited FMS with an IC of 2 nM. It also inhibited the receptor tyrosine kinases c-RAF and DDR2 (IC < 100 nM for both) and FGFR1, KDR, MEKL, and Tie2 (IC 100–600 nM). However, the other twenty one kinases were inhibited only at much higher concentrations of . The inhibition potential of compound on the migration of tumor Niflumic acid kinase by TAMs was evaluated via an invasion assay using MDA-MB-231 cells (human breast adenocarcinoma cells) and RAW264.7 cells (mouse macrophage cells). Compound inhibited the migration of MDA-MB-231 cells in a dose-dependent manner; the inhibitory effect after treatment with 1 μM was 67% (). The anti-tumor effects of compound against breast cancer in combination with cytotoxic agents was evaluated using an tumor cell growth inhibition assay. As shown in , paclitaxel dose- dependently induced FMS expression in MDA-MB-231 cells, and compound effectively reduced paclitaxel-induced FMS expression. In a combination study with paclitaxel and compound in MDA-MB-231 cells, treatment with compound (5 μM) alone showed a reduction in cell growth by 20%, whereas treatment with paclitaxel in combination with compound showed a synergistic growth inhibition effect (CI < 0.1) compared with treatment with paclitaxel alone. () In summary, we identified and optimized a novel and potent class of FMS kinase inhibitors based on a thieno[3,2-]pyrimidine core. One of these, compound , was employed in an efficacy study to demonstrate its potential benefit in the treatment of cancer. The inhibition of FMS signaling by compound was efficacious in reducing the migration of cancer cells and showed a synergistic anti-tumor activity against breast cancer in combination with a cytotoxic agent. Declarations of interest
Funding
Introduction Cells of the monocyte-macrophage lineage play fundamental roles in integrating innate and adaptive arms of immune defense and aberrations of development or function of this cell lineage are incompatible with an effective immune system [1], [2]. Macrophages are key contributors to highly prevalent immunological diseases [3], [4], [5] such as rheumatoid arthritis, inflammatory bowel disease, and demyelinating neurological diseases [6], [7], [8]. Macrophages also play key homeostatic roles in non-immune tissues and contribute to diseases such as atherosclerosis and cancer [9], [10], [11]. Colony-stimulating factor-1 receptor (CSF-1R) is a receptor tyrosine kinase (RTK) essential for macrophage development and physiological functions, such as cell proliferation, differentiation, spreading, migration, phagocytosis and cytokine secretion [12]. Similar to other RTKs, ligand binding of Colony-stimulating factor-1 (CSF-1) activates CSF-1R by inducing conformational changes, dimerization, and trans-phosphorylation, leading to association of key cytoplasmic signalling intermediates. This activates signal transduction cascades, including the PI3-kinase/AKT, Ras/Erk, and Rho/Rac pathways [13], [14].