Adaptations in the angiogenic microcirculation in a metastatic mammary tumor

摘要

Two murine mammary tumor transplant lines have been established at UC Davis. The Met-1 tumors, expressing the polyoma virus middle-T transgene, metastasized with 100% efficiency. The Db-7 tumors, expressing transgene mutation at positions 315 and 322, metastasized with <5% efficiency. Histology and computer-assisted intravital microscopy confirmed that the intratumoral/internal microcirculation in Met-1 tumors was more complex than in DB-7 tumors; the complexity occurred as an angiogenic adaptation to rapid growth in the Met-1 tumors. Met-1 tumors exhibited high vessel density and tortuosity. Also, the high microvascular complexity correlated with the high metastatic and growth rates in the Met-1 tumors. Met-1 tumors have been utilized successfully to study anti-angiogenic, anti-growth and anti-metastatic drug (SU5416) efficacy.