Aiming to explore novel BRAFV600E and VEGFR-2 dual inhibitors, a series of 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed, synthesized and biologically evaluated in this study. Most of the synthesized 1H-pyrazolo[3,4-d]pyrimidine compounds displayed moderate to high potent activity in both enzymatic and cellular proliferation assays. Among these compounds, 9e, 9g, 9m and 9u showed remarkably high inhibitory activities against both BRAFV600E and VEGFR-2 kinase comparable to positive control Sorafenib. Particularly, compound 9u also showed potent anti-proliferative activity against BRAFV600E-expressing A375 (IC50 = 1.74 μM) and H-29 (IC50 = 6.92 μM) as well as VEGFR-2-expressing HUVEC (IC50 = 5.89 μM), which was also comparable to Sorafenib. Furthermore, kinase selectivity profile showed that 9u had almost poor or no significant inhibitory activity against wild-type BRAF and 15 other tested protein kinases. Flow cytometric analysis showed that compound 9u mainly arrested the A375 and HUVEC cell lines in the G0/G1 stage with a concentration-dependent effect. In addition, the molecular docking and molecular dynamics simulations suggested that 9u adopted a similar binding pattern with Sorafenib at the ATP-binding sites of BRAFV600E and VEGFR-2. Taken together, these results indicated that compound 9u may serve as novel lead compound in research on more effective BRAFV600E and VEGFR-2 dual inhibitors.
Keywords: 1H-pyrazolo[3,4-d]pyrimidine; BRAF(V600E); Dual inhibitor; Tyrosine kinase; VEGFR-2.
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