Curative therapeutic options for a number of immunological disorders remain to be established, and approaches for identifying drug candidates are relatively limited. Furthermore, phenotypic screening methods using induced pluripotent stem cell (iPSC)-derived immune cells or hematopoietic cells need improvement. In the present study, using immortalized monocytic cell lines derived from iPSCs, we developed a high-throughput screening (HTS) system to detect compounds that inhibit IL-1β secretion and NLRP3 inflammasome activation from activated macrophages.
View Article and Find Full Text PDFJAK2/STAT signaling promotes survival and expansion of myelodysplastic syndrome (MDS) clones, but little is known about the potential of JAK2/STAT as a therapeutic target in MDS. We investigated the effect of NS-018, a novel antagonist for JAK2, on the colony-forming ability of bone marrow mononuclear cells (BMMNCs) from high-risk MDS patients. NS-018 decreased colony-forming unit-granulocyte/macrophage (CFU-GM) colony numbers from MDS-derived BMMNCs in a dose-dependent manner, and this effect was significantly more potent than against normal BMMNCs.
View Article and Find Full Text PDFBackground: The myelodysplastic syndromes (MDS) are a group of stem cell disorders characterized by dysplasia of one or more hematopoietic cell lineages and a risk of progression to acute myeloid leukemia. The cytidine analog azacitidine (Vidaza), a hypomethylating agent, improves survival in patients with MDS, but its mechanism of action is not well understood.
Materials And Methods: The effects of azacitidine on the MDS-derived cell line SKM-1 were investigated by DNA methylation assay, cell proliferation assay, and a subcutaneous xenograft mouse model.
To investigate why 3-substituted benzamide derivatives show dual inhibition of Abl and Lyn protein tyrosine kinases, we determined their inhibitory activities against Abl and Lyn, carried out molecular modeling, and conducted a structure-activity relationship study with the aid of a newly determined X-ray structure of the Abl/Lyn dual inhibitor INNO-406 (formerly known as NS-187) bound to human Abl. We found that this series of compounds interacted with both kinases in very similar ways, so that they can inhibit both kinases effectively.
View Article and Find Full Text PDFMannan-binding protein (MBP) is a C-type serum lectin that is an important constituent of the innate immune defense because it activates the complement system via the lectin pathway. While the pig has been proposed to be an attractive source of xenotransplantable tissues and organs, little is known about porcine MBP. In our previous studies, phosphomannan, but not mannan, was found to be an effective inhibitor of the C1q-independent bactericidal activity of newborn piglet serum against some rough strains of Gram-negative bacteria.
View Article and Find Full Text PDFAdvanced-phase chronic myeloid leukemia patients treated with imatinib often relapse due to point mutations in the Abl kinase domain. We herein examine the in vitro and in vivo effects of a Bcr-Abl/Lyn dual tyrosine kinase inhibitor, NS-187, on seven mutated Bcr-Abl proteins. NS-187 inhibited both Tyr393-phosphorylated and Tyr393-unphosphorylated Abl, resulting in significant in vitro growth inhibition of cells expressing six of seven mutated Bcr-Abl kinases, though not T315I.
View Article and Find Full Text PDFA series of 3-substituted benzamide derivatives structurally related to STI-571 (imatinib mesylate), a Bcr-Abl tyrosine kinase inhibitor used to treat chronic myeloid leukemia (CML), was prepared and evaluated for antiproliferative activity against the Bcr-Abl-positive leukemia cell line K562. About ten 3-halogenated and 3-trifluoromethylated benzamide derivatives were identified as highly potent Bcr-Abl kinase inhibitors. One of these, NS-187 (9b), is a promising new candidate Bcr-Abl inhibitor for the therapy of STI-571-resistant chronic myeloid leukemia.
View Article and Find Full Text PDFAlthough the Abelson (Abl) tyrosine kinase inhibitor imatinib mesylate has improved the treatment of breakpoint cluster region-Abl (Bcr-Abl)-positive leukemia, resistance is often reported in patients with advanced-stage disease. Although several Src inhibitors are more effective than imatinib and simultaneously inhibit Lyn, whose overexpression is associated with imatinib resistance, these inhibitors are less specific than imatinib. We have identified a specific dual Abl-Lyn inhibitor, NS-187 (elsewhere described as CNS-9), which is 25 to 55 times more potent than imatinib in vitro.
View Article and Find Full Text PDFPurpose: The RNA interference effect is an alternative to antisense DNA as an experimental method of down-regulating a specific target protein. Although the RNA interference effect, which is mediated by small interfering RNA (siRNA) or micro-RNA, has potential application to human therapy, the hydrodynamic method usually used for rapid administration of oligonucleotides is unsuitable for use in humans. In this study, we have investigated the antitumor activity of a synthetic siRNA, B717, which is sequence specific for the human bcl-2 oncogene, complexed with a novel cationic liposome, LIC-101.
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