Targeting endothelial cells that line tumor blood vessels forms the basis for metronomic therapy and is a promising new strategy for the treatment of cancer. Genetic and phenotypic differences between tumor derived and normal endothelial cells indicate that targeting tumor endothelial cells may be therapeutically useful. In the present study, we examined differences in responses to chemotherapy in microvascular endothelial cell lines from tumoral (T-EC) and normal (N-EC) mouse liver tissues. The identity of these cells was confirmed by immunocytochemistry for endothelial cell markers such as VE-Cadherin and CD31 for both types of endothelial cells, and the tumor-endothelial specific marker tumor endothelial marker-7 for T-EC. The involvement of Akt in NF-B dependent angiogenesis was different between N-EC and T-EC. Chemotherapeutic stress increased angiogenesis in T-EC, but not N-EC via an NF-kB- Akt -VEGF dependent manner. Both NF-B and Akt were involved in enhanced survival and migration in T-EC in response to chemotherapeutic stress. Moreover, Akt was involved in NF-B dependent VEGF expression and angiogenesis. These studies, showing differences in cellular responses to chemotherapy in tumor-derived endothelial cells, indicate that specific therapies targeting these cells may be therapeutically useful for liver cancers.