and regulates blood vessel growth by activating intracellular signalling pathways that enhance the proliferation of vascular ECs. Current clinical trials have suggested that therapeutic strategies targeting tumour angiogenesis via the VEGF/VEGFR kinase axis are promising approaches for the treatment of cancer. The RAF/MEK/MAPK pathway is one of the most important VEGF/VEGFR-activated signalling pathways. In this pathway, the serine/threonine protein kinase RAF is a downstream effector of small GTPase RAS, which stimulates the proliferation, invasion and secretion of angiogenic factors. Stimulation of VEGFRs thus initiates a mitogenic kinase cascade that culminates in the phosphorylation of transcription factors that, in turn, exert profound effects on the expression of genes related to cellular proliferation and tumourigenesis. The functions of the RAF/MEK/MAPK pathway in many tumours depend on extracellular signals from receptor TK at the cell surface to the nucleus via a cascade of specific phosphorylation events. This pathway 
thus plays a central role in regulating mammalian cell proliferation and shows great promise as a therapeutic target. Recently, small-molecule multikinase inhibitors targeting VEGFRs and RAF have been shown to have therapeutic potential in preclinical and/or clinical testing against various solid tumours, including melanoma, renal cell tumours and non-small cell lung cancer. For example, sorafenib, which can inhibit both VEGFRs and RAF, has been used successfully in the clinic to prolong the survival rate of hepatocarcinoma patients. However, quite a few multi-target therapies show toxicity and have only moderate response rates. The aim of the present research was to design smallmolecule multikinase inhibitors for cancer therapy, in particular, VEGFR2 and PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19809470 RAF kinases inhibitors, which selectively block pathological neovascularization and cancer prolifera- tion. We previously reported the use of computer-aided drug design, de novo synthesis, and high-throughput screening to identify the novel antitumour agent YL529 . In this study, we investigated the anticancer effect and mechanism of action of YL529 in vitro and in vivo. Our results show that YL529, an inhibitor of VEGFR1, VEGFR2, VEGFR3, RAF, Fms and c-Kit, can inhibit VEGF-induced angiogenesis and induce tumour regression. YL529 will be studied in phase I clinical testing in patients with advanced solid malignancies. The nomenclature used for receptors conforms to BJP’s Guide to Receptors and Channels. Methods Synthesis and preparation of YL529 YL529 benzamido ) phenoxy)picolinamide4-methylbenzenesulfonate) was synthesized in the State Key Laboratory of Biotherapy, Sichuan University and its structural formula is shown in Materials Cell count kit-8 was MedChemExpress AMI-1 purchased from Dojindo. DMSO and CMC-Na were purchased from Sigma Chemical Company. Human recombinant VEGF165, human basic fibroblast growth factor, anti-CD31 and Matrigel were purchased from BD Biosciences. The primary antibodies for detection of VEGFR2, phospho VEGFR2, p44/42MAPK, p-p44/42MAPK, RAF, p-RAF, MEK, p-MEK, phospho-histone H3, as well as the HRP-conjugated secondary antibody, were purchased from Cell Signaling Technology. Anti–actin was purchased from Santa Cruz Biotechnology. Anti-Ki67 was purchased from Neomarkers. The TUNEL assay kit was purchased from Promega and Q Tracker Red cell labelling kit from Invitrogen. The EDU detection kit was purchased from Borui Biological. Human umbilical cord w
