We found that the development of oral SCC cells was inhibited specifically in through and vitro the inhibition of angiogenesis in vivo by the treatment with Crizotinib ALK inhibitor. We speculate that antiangiogenic treatment using TNP 470 is useful for oral cancer. TNP 470 was received from Takeda Chemical Industries. This agent was dissolved in 99% ethanol and suspended in saline containing 500 gum arabic. Dulbeccos modied Eagles medium was obtained from Sigma Chemical Co.. Eagles minimal essential medium and phosphate bu. ered saline were purchased from Nissui Pharmaceutical Co.. Fetal calf serum was obtained from Boehringer Mannheim Biochemica. Rat anti mouse CD31 monoclonal antibody was purchased from Caltag Laboratories Co.. Biotinylated rabbit anti rat serum, typical rabbit serum and avidin biotinylated horseradish peroxidase complex reagent was obtained from Vector Laboratories. The industrial stable diet, CL 2, and scid mice at 8 weeks of age, were purchased from CLEA Japan, Inc.. All cells were cultured at 37_C in a humidied atmosphere of five hundred CO2 in air. The human vulval epidermal cell line A431 and the six human oral SCC cell lines, HSC 2, HOC119, HOC512, HOC519, HOC621 and HOC1208 were preserved withDMEMcontaining 10% FCS. The human gingival SCC cell line, Ca9 22, was preserved with Eagles MEM containing 10% FCS. These cell lines were previously defined and HOC621 and HOC1208 Lymphatic system were recently founded from tongue and gingival SCC, respectively. Human umbilical vein endothelial cells were cultured in DMEM containing two decades FCS, l0 ng/ml standard broblast expansion factor, and 5 unit/ml heparin on gelatin precoated plates. HSC 2 cells were collected, trypsinized and suspended at 1. 0_106 cells in 100 ml DMEM with 10 % FCS. Cells were subcutaneously inoculated to the right dorsal section of rats. After the bearing resulting cancers were conrmed to 5_10 mm of the longest length, 30 rats were randomly separated in to three groups. Mice in each group were treated subcutaneously with: saline, 10 mg/kg of TNP 470, 50 mg/kg of TNP 470, everyday from Day 1 to Day 14. Growth bearing rats were anesthetized with ether, and then sacriced by dislocating the cervical vertebrae. Growth tissue specimens were xed in 10% neutralbu. ered formalin, inserted in para?n, sectioned at 5 mm and stained with hematoxylin and eosin. For ATP-competitive ALK inhibitor the immunohistochemical studies, tissue specimens were embedded in optimum cutting temperature compound, freezing, sectioned at 5 mm and xed at four to five paraformaldehyde. A standard ABC approach was used to spot tumorsurrounding microvessels. The specimens were incubated with 10 % normal rabbit serum in PBS for 30 min at 4_C accompanied by rat anti mouse PECAM 1 monoclonal antibody for 2 h at room temperature, then reacted with biotinylated rabbit anti rat serum for 45 min and with ABC reagents for 2 h at room temperature.