Design,Synthesis And Bioactivity Evaluation Of CDK4 Inhibitors And FLT3 Inhibitors

As a kind of disease that seriously endangers human life and health,cancer has become one of the major public health problems that people cannot avoid in their daily lives.Small molecule targeted drugs,especially selective protein kinase inhibitors,have become an important means of cancer treatment because of their advantages of safety and efficiency.With the continuous development of molecular biology and molecular pathology,more and more tumor markers have come into people’s field of vision,making researchers more research goals.Cyclin-dependent kinase 4(CDK4),involved in regulating G1/S phase,is a key factor in the cell cycle regulation network,and plays an important role in cell cycle ordering.Disorders of CDK4 and its mediated signaling pathway are prevalent in the process of tumorigenesis and development.The regulation of cell cycle recovery through CDK4 inhibitors has become an attractive trend in the development of tumor-targeted therapies.FMS-like tyrosine kinase 3(FLT3),an expression product of proto-oncogene,plays an important role in the key steps of blood cell proliferation,differentiation and survival,and is an important marker of different hematological malignancy.The development of novel selective FLT3 inhibitors with high efficiency and low toxicity as anti-cancer drugs has become one of the important directions of small molecule targeted therapy for acute myeloid leukemia.Therefore,in this paper,CDK4 and FLT3 were used as targets for the design,synthesis and bioactivity evaluation of inhibitors.In this paper,based on the interaction modes between the listed CDK4 inhibitors and the target protein,we designed and synthesized four series of 7H-pyrrolo[2,3-d]pyrimidine derivatives,totally 22 compounds,by introducing hydrophilic substituted double-bond fragments into the structure of Ribociclib.Through a series of bioactivity evaluations,we found that compound C-Ⅳ-1 had better inhibitory effect on proliferation of human breast cancer cells and acute myeloid leukemia cells than Ribociclib,and could effectively induce G0/G1 phase arrest and apoptosis.At the kinase level,compound C-Ⅳ-1 could selectively inhibit CDK4 among the tested kinases.Compound C-Ⅳ-1 could inhibit tumor growth in xMDA-MB-231 subcutaneous xenograft mice at the dosage of 30-100 mg/kg/d.The inhibitory effect was comparable to Ribociclib and the weight of mice had no significant change.Based on the hit compound 2.123 obtained by our group in the early screening,two kinds of indolin-2-one derivatives with FLT3 as target,totally 37 compounds,were designed and synthesized with the help of molecular docking technology in the fourth part of this paper.The main design idea is to enhance the interaction between the compound and the related hydrophobic pockets by extending the hydrophobic fragments and restricting the configuration,so as to improve the inhibitory activity.We performed the preliminary biological evaluations of the synthesized indolin-2-one derivatives by in vitro tumor cell proliferation inhibition assay,in vitro kinase inhibition assay,cell cycle and apoptosis assay.We found that A-Ⅰ-13 and A-Ⅲ-2 had strong inhibitory activity against MV4-11 cells(ICso<0.8 μM),and A-I-13 could induce G0/G1 phase arrest and apoptosis in MV4-11 cells.At the kinase level,both of them could selectively inhibit FLT3 among the tested kinases,and the 50%inhibitory concentration of A-III-2 reached 28 nM.Follow-up studies on the mechanism and the in vivo pharmacodynamic evaluation are progressing.As an important source of drug research and development,the accumulation and enrichment of nitrogen-containing heterocyclic compounds library is of great significance.In the fifth part of this paper,a total of 44 nitrogen-containing heterocyclic compounds of 2-aminonicotinonitrile and 1H-pyrazole were synthesized through the development of two new synthetic methodologies.We preliminarily screened some compounds against human breast cancer cell lines in vitro,and found three hit compounds with anti-tumor activity,which provide a compound resource for the future research of targeted inhibitors.