Fig. 2
Effects of KF1601 on FLT3 signaling pathway and thrombo-inflammatory responses. A Immunoblotting analysis of FLT3 signaling pathway in K562-FLT3 cells treated with KF1601, ponatinib (Pona) for 4h. B Immunoblotting analysis of FLT3 signaling pathway in K562-FLT3-IR cells treated with KF1601, ponatinib for 17h. C Cell images of K562-FLT3 cells at day 4 post-treatment with compounds, and images of K562-FLT3-IR cells at day 6 post-treatment with compounds. D and E Cell viability measurement of K562-FLT3 cells at day 4 post-treatment with compounds (D), and that of K562-FLT3-IR cells at day 6 post-treatment with compounds (E). F and G Immunoblotting analysis of FLT3 protein in BMMCs from BP CML patients (1588(BP) and 2084(BP)). BMMCs from CP CML patients (1588(CP) and 903(CP)) were used as negative controls for FLT3 expression. H and I Immunofluorescence images of FLT3 expression (green) on the cell surface in 1588(BP) and 2084(BP) cells. 1332(CP) and 2084(CP) were used as negative controls for FLT3 expression. DAPI (blue) was used as a nuclear marker. J and K Cell viability measurement of PBMCs from normal donors and BMMCs from BP CML patients. PBMCs and BMMCs were subjected to treatment with either imatinib (J) or KF1601 (K) for 4 days. 2084 (BP) harbors BCR::ABL1 T315I mutation with a distinct FLT3 expression pattern (F); 1588 (BP) harbors BCR::ABL1 E255V mutation with a distinct FLT3 expression pattern (G). n = 3 per group. L The left panel illustrates the pivotal role of FLT3 in BP-CML progression and TKI resistance. The right panel illustrates potential of KF1601 may overcome TKI resistance by targeting mutant forms of BCR::ABL1 while also addressing the FLT3-mediated signaling pathways. L Thrombo-inflammatory responses in carotid arteries. Ponatinib induced occlusion of carotid arteries with extensive vessel wall damage. Conversely, in mice treated with KF1601, carotid arteries remained unoccluded, with the vessel walls preserved intact. M Evaluation of thrombus size in testicular arteries. The size of thrombus induced by KF1601 was approximately one-tenth that induced by ponatinib. N KDR inhibition. Ponatinib exhibited a KDR inhibition potency tenfold greater than that of KF1601