Intracellular superoxide dismutase activity defines invasiveness of the murine T-lymphoma cell line L5187Y-ML25 in vitro and in vivo.

Superoxide anion in the tumor microenvironment promotes a malignant phenotype. Here, we examined superoxide in a murine T-lymphoma cell line L5187Y-ML25. Clones with high and low intracellular superoxide dismutase (SOD) activities were obtained from parental L5187Y-ML25 cells and were subjected to assays determining cell invasiveness, motility, and in vivo dissemination. Cells with lower SOD activity exhibited higher invasiveness in vitro and in vivo. NADPH oxidase inhibitor suppressed intracellular free radical levels and cell motility, suggesting NADPH oxidase as a source of superoxides that stimulates cell motility. These results implicate superoxide as a potential anti-metastatic therapy for hematopoietic cell malignancies.