ANGIOGENESIS AND APOPTOSIS ARE CELLULAR-PARAMETERS OF NEOPLASTIC PROGRESSION IN TRANSGENIC MOUSE MODELS OF TUMORIGENESIS

The epidemiology and histopathology of human cancers and studies of an imal models of tumorigenesis have led to a widely-accepted notion that multiple genetic and epigenetic changes have to accrue for the succes sful development of a malignant phenotype. Tumor growth and expansion requires an ability not only to proliferate, but also to down-modulate cell death (apoptosis) and activate angiogenesis to produce a tumor n eovasculature. This review will describe the interplay between apoptos is and proliferation, as well as the characteristics of the angiogenic phenotype in two transgenic mouse models of multi-step tumorigenesis, namely, pancreatic islet cell carcinomas and squamous cell carcinomas of the skin.