Rapid apoptosis in the pulmonary vasculature distinguishes non-metastatic from metastatic melanoma cells.

The presence of metastases indicates an ominous prognosis in patients with malignancies, yet the factors that distinguish metastatic from non-metastatic tumors remain poorly understood. Here we pursued the hypothesis that apoptosis in vivo would distinguish metastatic cells from non-metastatic cells and developed a novel method for observation of apoptosis induction in living cells. One hour after the infusion of metastatic or non-metastatic human melanoma or transformed rat embryo fibroblasts, arrest of tumor cells in the pulmonary vasculature was equivalent.