Design Of Novel Tyrosine Kinase Inhibitors And Studies Of Anti Glioma Mechanism

Brain tumor is a kind of primary or metastatic tumors.Glioma accounts for 45%of intracranial tumors,which is one of the most dangerous types of brain tumors.Glioblastoma(GBM)is the most malignant glioma with high proliferation,infiltration and metastasis.The current chemotherapy for brain tumors generally uses an alkylating agent,temozolomide,but it can only slow down the incidence of glioblastoma and the average survival time of patients is only about one year.On the other hand,the acquisition of drug resistance is a persistent clinical problem for temozolomide during the treatment of GBM.However,its molecular mechanisms to develop therapeutic resistance remain poorly understood.Therefore,the development of new anti-glioblastoma drugs is of upmost important.Protein tyrosine kinases are a class of kinases with the signal transduction function.They play a vital role in the development of brain tumors.FAK,SRC and FGFR1 are all belong to protein tyrosine kinases.They have a similar structure in the catalytic domain of protein kinases,and are located upstream of multiple signal pathways related to malignant glioblastoma.They are the important targets for the development of targeted inhibitors of malignant glioblastoma.Currently,a variety of FAK,SRC and FGFR1 inhibitors have been developed and used in clinic to treat various primary or metastatic tumors.In addition,a variety of FAK inhibitors have entered clinical trials for the treatment of solid tumors,including brain tumors.In this thesis,the pathogenesis of brain tumors and tyrosine kinases were introduced,and especially the structural characteristics,the relationship with tumor and the research progress of FAK,SRC and FGFR1 kinase inhibitors were focused.In the first part of this thesis,a series of covalent irreversible inhibitors and covalent reversible inhibitors of FAK were designed according to the conserved and different sequences of amino acid in the protein tyrosine kinases,the structural similarity of kinases,and the principle of bioisostere.The covalent structures of these compounds were confirmed by crystal structure of FAK complexed with 7a1.Otherwise,covalent reversible inhibitors of FAK were also characterized by LC-MS/MS method.The kinase assay showed IC50 value of these compounds for FAK in the range of 0.6-16.3 nM.Among them,the compound 7f showed a good selectivity for FAK against other protein kinases.It was shown that 7a1,7g,9b and 9c could inhibit the migration and proliferation of several glioblastoma cell lines with IC50 values in the range from 0.13 to 7.2 ?M.The underlying mechanism against glioblastomas for this series of inhibitors has shown that they could induce G2/M phase cell cycle arrest,inhibited the phosphorylation of FAK and down-regulated AKT/NF-?B and ERK/NF-?B signaling pathways,thereby resulting in the inhibition of tumor growth.In the second part of this thesis,a series of pyrimidine based FAK/FGFR1 dual inhibitors were designed according to the structural characteristics of FAK and FGFR1 kinase and their inhibitors.Among them,compound 2j,2k and 2m showed an excellent inhibitory activity for FAK and FGFR1.It was shown that these compounds could significantly inhibit glioblastoma cell proliferation,migration and invasion.The results of the mechanism of action of this series of compounds against U87-MG cells showed that the inhibition of the phosphorylation of FAK and FGFR1 resulted in the decrease of the activation of downstream Erk1/2 and NF-?B signaling pathways.The preliminary results of the experiments in vivo indicated that compounds 2k have potential prospects as anti-glioblastoma agents.In the third part of this thesis,a series of 1,3,4-oxadiazoles or 1,3,4-thiadiazoles or pyrimidine derivatives were also designed to prepare dual inhibitors of Src and FAK kinases according to the structural characteristics of Src and FAK kinase and their inhibitors.The kinase assay showed that the series of pyrimidine compounds have inhibitory activities with outstanding potency for Src and FAK kinases.On the contrary,the other two series of compounds only showed the inhibitory activity against Src kinase.Otherwise,these compounds could inhibit the proliferation of U87-MG cell line.Finally,the results of structural superposition,3D-QSAR,molecular docking and molecular dynamics simulation could explain that the difference in the inhibitory activity between compounds 3h and Dasatinib was due to the shift of binding sites,which were caused by the change of stereoscopic and electrostatic fields induced by the introduction of 1,3,4-oxadiazole skeleton.In this thesis,a series of FAK covalent irreversible or reversible inhibitors,dual FAK/FGFR1 inihibitors and dual Src/FAK inhibitors with an inhibitory effect on glioma cells were sucessfully developed,and the theory for modification of dual Src/FAK inhibitors was provided.