Expression of VEGF-C in various cancer cell lines; sunitinib inhibited MDA-MB-231LN tumor growth. (a) VEGF expression levels were quantified in metastatic cancer cell lines under normoxic and hypoxic conditions. All cells were cultured overnight under normoxic or hypoxic (5% O2) conditions; subsequently, the amounts of VEGFs secreted in the conditioned medium were quantified with enzyme-linked immunosorbent assay (a). Columns indicate the values of four replicates; bars, SD. (b) Effects of sunitinib and of the anti-VEGFR-2 antibody, DC101, on the primary tumor growth. MDA-MB-231LN cells were transplanted into the m.f.p. of female mice, and the treatment was initiated on day 5 after the inoculation. Sunitinib was administered orally at 40 mg/kg once a day, and DC101 at 800 μg/mouse i.p. every 3 days for 2 weeks. Tumor volume was measured on the indicated days. Points indicate tumor volume; bars, SEM. *P < 0.05 as compared with control. m.f.p., mammary fat pad; N.D., not detected; VEGF, vascular endothelial growth factor; VEGFR, vascular endothelial growth factor receptor.