Annexin VII as a novel marker for invasive phenotype of malignant melanoma

Both F10 and BL6 sublines of B16 mouse melanoma cells are metastatic after intravenous injection, but only BL6 cells are metastatic after subcutaneous injection. While examining the genetic difference between the two sublines , we found a marked reduction of annexin VH expression in BL6 cells. In add ition, fusion cell clones of both sublines were as poorly metastatic as F10 cells after subcutaneous injection, and contained the annexin VII message as abundantly as F10 cells. Hence, we examined whether the annexin VII expr ession was correlated with the less malignant phenotype of clinical cases b y immunohistochemistry. Immunoreactivities to anti-annexin VII antibody in melanoma cells were evaluated quantitatively by using skin mast cells as an internal positive control. Eighteen patients with malignant melanoma were divided into two groups: lymph node metastasis-negative and positive groups . The ratio of numbers of patients positive versus negative to the antibody was significantly larger in the former than in the latter group. These res ults not only indicated that annexin VH serves as a marker for less invasiv e phenotype of malignant melanoma, but also suggested a possible role of an nexin VII in tumor suppression.