Although rat sarcoma viral oncogene homolog (RAS) mutations occur in about 30% of solid tumors, targeting RAS mutations other than KRAS-G12C is still challenging. As an alternative approach, developing inhibitors targeting RAF, the downstream effector of RAS signaling, is currently one of the main strategies for cancer therapy. Selective v-raf murine sarcoma viral oncogene homolog B1 (BRAF)-V600E inhibitors Vemurafenib, Encorafenib, and Dabrafenib have been approved by FDA and received remarkable clinical responses, but these drugs are ineffective against RAS mutant tumors due to limited inhibition on dimerized RAF.
View Article and Find Full Text PDFSignal Transduct Target Ther
January 2023
Enhancer of zeste homolog 2 (EZH2), an enzymatic subunit of PRC2 complex, plays an important role in tumor development and progression through its catalytic and noncatalytic activities. Overexpression or gain-of-function mutations of EZH2 have been significantly associated with tumor cell proliferation of triple-negative breast cancer (TNBC) and diffuse large B-cell lymphoma (DLBCL). As a result, it has gained interest as a potential therapeutic target.
View Article and Find Full Text PDFDrug resistance remains a major challenge in the clinical treatment of gastrointestinal stromal tumours (GISTs). While acquired on-target mutations of mast/stem cell growth factor receptor (KIT) kinase is the major resistance mechanism, activation of alternative signalling pathways may also play a role. Although several second- and third-generation KIT kinase inhibitors have been developed that could overcome some of the KIT mutations conferring resistance, the low clinical responses and narrow safety window have limited their broad application.
View Article and Find Full Text PDFActivating mutations in EZH2, the catalytic component of PRC2, promote cell proliferation, tumorigenesis, and metastasis through enzymatic or non-enzymatic activity. The EZH2-Y641 gain-of-function mutation is one of the most significant in diffuse large B-cell lymphoma (DLBCL). Although EZH2 kinase inhibitors, such as EPZ-6438, provide clinical benefit, certain cancer cells are resistant to the enzymatic inhibition of EZH2 because of the inability to functionally target mutant EZH2, or because of cells' dependence on the non-histone methyltransferase activity of EZH2.
View Article and Find Full Text PDFThe enhancer of zeste homologue 2 (EZH2) is the catalytic subunit of polycomb repressive complex 2 that catalyzes methylation of histone H3 lysine 27 (H3K27). Overexpression or mutation of EZH2 has been identified in hematologic malignancies and solid tumors. Based on the structure of EPZ6438 () and the binding model with PRC2, we designed a series of analogues aiming to improve the activities of EZH2 mutants.
View Article and Find Full Text PDFAccumulated pieces of evidence have shown that PI3Kδ plays a critical role in chronic obstructive pulmonary disease (COPD). Using a fragment-hybrid approach, we discovered a potent and selective PI3Kδ inhibitor . In the biochemical assay, inhibits PI3Kδ (IC = 14 nM) with high selectivity over other class I PI3Ks (56∼83 fold).
View Article and Find Full Text PDFDue to the critical tumorigenic role of fused NTRK genes in multiple cancers, TRK kinases have attracted extensive attention as a drug discovery target. Starting from an indazole based scaffold, through the type II kinase inhibitor fragments hybrid design approach with a ring closure strategy, we discovered a novel potent type II TRK kinase inhibitor compound 34 (IHMT-TRK-284), which exhibited IC values of 10.5 nM, 0.
View Article and Find Full Text PDFActa Pharmacol Sin
April 2021
Inhibition of glycolysis process has been an attractive approach for cancer treatment due to the evidence that tumor cells are more dependent on glycolysis rather than oxidative phosphorylation pathway. Preliminary evidence shows that inhibition of phosphoglycerate kinase 1 (PGK1) kinase activity would reverse the Warburg effect and make tumor cells lose the metabolic advantage for fueling the proliferation through restoration of the pyruvate dehydrogenase (PDH) activity and subsequently promotion of pyruvic acid to enter the Krebs cycle in glioma. However, due to the lack of small molecule inhibitors of PGK1 kinase activity to treat glioma, whether PGK1 could be a therapeutic target of glioma has not been pharmacologically verified yet.
View Article and Find Full Text PDFGlioblastoma (GBM) patients have extremely poor prognoses, and currently no effective treatment available including surgery, radiation, and chemotherapy. MAPK-interacting kinases (MNK1/2) as the downstream of the MAPK-signaling pathway regulate protein synthesis in normal and tumor cells. Research has shown that targeting MNKs may be an effective strategy to treat GBM.
View Article and Find Full Text PDFAngiogenesis is an essential process in tumor growth, invasion and metastasis. VEGF receptor 2 (VEGFR2) inhibitors targeting tumor angiogenic pathway have been widely used in the clinical cancer treatment. However, most of currently used VEGFR2 kinase inhibitors are multi-target inhibitors which might result in target-associated side effects and therefore limited clinical toleration.
View Article and Find Full Text PDFStarting from a bipyridine-sulfonamide scaffold, medicinal chemistry optimization leads to the discovery of a novel Plasmodium falciparum PI4K kinase (PfPI4K) inhibitor compound 15g (CHMFL-PI4K-127, IC: 0.9 nM), which exhibits potent activity against 3D7 Plasmodium falciparum (P. falciparum) (EC: 25.
View Article and Find Full Text PDFAll-trans retinoic acid (ATRA) is known to be a potent inhibitor of FLT3-ITD acute myeloid leukemia (AML) cells, although the exact mechanism remains unclear. In this work, we report that ATRA causes fatal mitotic catastrophe in FLT3-ITD AML cells by degrading Chk1 kinase, and therefore preventing DNA damage repair. In order to explore a further enhancement in the inhibitory effect of ATRA on FLT3-ITD AML cells, we investigated the suitability of a combination of ATRA and DNA damage drug SN38.
View Article and Find Full Text PDFAcute myeloid leukemia (AML) is reported to be vulnerable to transcription disruption due to transcriptional addiction. Cyclin-dependent kinase 9 (CDK9), which regulates transcriptional elongation, has attracted extensive attention as a drug target. Although several inhibitors, such as alvocidib and dinaciclib, have shown potent therapeutic effects in clinical trials on AML, the lack of high selectivity for CDK9 and other CDKs has limited their optimal clinical efficacy.
View Article and Find Full Text PDFGain-of-function mutations of c-KIT kinase play crucial pathological roles for the gastrointestinal stromal tumors (GISTs). Despite the success of imatinib as the first-line treatment of GISTs, dozens of drug-acquired resistant mutations emerge, and c-KIT T670I is one of the most common mutants among them. Although several kinase inhibitors are capable of overcoming the T670I mutant, none of them can achieve the selectivity over the c-KIT wild-type (wt), which also plays important roles in a variety of physiological functions such as hematopoiesis.
View Article and Find Full Text PDFDespite of the great success of imatinib as the first-line treatment for GISTs, the majority of patients will develop drug-acquired resistance due to secondary mutations in the cKIT kinase. Sunitinib and regorafenib have been approved as the second and third line therapies to overcome some of these drug-resistance mutations; however, their limited clinical response, toxicity and resistance of the activation loop mutants still makes new therapies bearing different cKIT mutants activity spectrum profile highly demanded. Through a drug repositioning approach, we found that cabozantinib exhibited higher potency than imatinib against primary gain-of-function mutations of cKIT.
View Article and Find Full Text PDFThere is still a great demand in the clinic for the drugs which can overcome a variety of imatinib resistant ABL mutants. Starting from a type I inhibitor axitinib, which has been reported to overcome ABL-T315I mutant induced resistance, through a structure guided drug design approach and binding mode switch strategy, we have discovered a novel type II ABL inhibitor 24 (CHMFL-ABL-121), which significantly improved the inhibitory activity against ABL wt and a broad spectrum of mutants including the most prevalent imatinib-resistant gatekeeper mutant T315I. 24 exhibited IC values of 2 nM and 0.
View Article and Find Full Text PDFThrough a structure-guided rational drug design approach, we have discovered a highly selective inhibitor compound 40 (JSH-150), which exhibited an IC of 1 nM against CDK9 kinase in the biochemical assay and achieved around 300-10000-fold selectivity over other CDK kinase family members. In addition, it also displayed high selectivity over other 468 kinases/mutants (KINOMEscan S score(1) = 0.01).
View Article and Find Full Text PDFPI3Kδ, which is mainly expressed in leukocytes, plays a critical role in B-cell receptor mediated signaling pathway and has been extensively studied as a drug discovery target for B cell malignances such as AML, CLL etc. In this manuscript, we report the discovery, SAR optimization and pharmacological evaluation of a novel series of aminothiazole-pyridine containing PI3Kδ inhibitors. Among them compound 15i (CHMFL-PI3KD-317) displays an IC of 6 nM against PI3Kδ in the ADP-Glo biochemical assays.
View Article and Find Full Text PDFThrough exploration of the non-highly conserved allosteric hydrophobic pocket generated by DFG-out shifting in the inactive conformation, we discovered a highly selective type II PDGFRα kinase inhibitor 15i (CHMFL-PDGFRα-159), which exhibited strong potency against purified PDGFRα (IC: 132 nM) but not structurally similar PDGFRβ, ABL, c-KIT and VEGFR2 kinases. In addition, it displayed a high selectivity profile (S score (10) = 0.02) at the concentration of 1 μM among 468 kinases/mutants in the KINOMEscan profiling.
View Article and Find Full Text PDFKIT kinase V559D mutation is the most prevalent primary gain-of-function mutation in Gastrointestinal Stromal Tumors (GISTs). Here we reported a highly selective KIT V559D inhibitor CHMFL-KIT-031, which displayed about 10-20 fold selectivity over KIT wt in the biochemical assay (IC: 28 nM over 168 nM; Kd: 266 nM versus 6640 nM) and in cell (EC: 176 nM versus 2000 nM for pY703) examination. It also displayed 15∼400-fold selectivity over other primary mutants such as L576P and secondary mutants including T670I, V654A (ATP binding pocket) as well as N822K and D816V (activation loop).
View Article and Find Full Text PDFBMX is a member of TEC family nonreceptor tyrosine kinase and is involved in a variety of critical physiological and pathological processes. Through combination of irreversible inhibitor design and type II inhibitor design approaches, we have discovered a highly selective and potent type II irreversible BMX kinase inhibitor compound 41 (CHMFL-BMX-078), which exhibited an IC of 11 nM by formation of a covalent bond with cysteine 496 residue in the DFG-out inactive conformation of BMX. It displayed a high selectivity profile (S score(1) = 0.
View Article and Find Full Text PDFBackground: The neurotropic parasite T. gondii is widespread among mammalian hosts including humans. During the course of T.
View Article and Find Full Text PDFZhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi
February 2015
Objective: To construct a transgenic strain of Toxoplasma gondii high-expressing ROP18.
Methods: The gene sequence of encoding ROP18 was amplified by RT-PCR with RNA of T. gondii RH strain.