Superoxide dismutase in SAS human tongue carcinoma cell line is a factor defining invasiveness and cell motility

This article describes an apparent inverse relationship between cell motility and intracellular Cu-Zn superoxide dismutase (SOD) activity of two human squamous carcinoma-derived clones, SAS-H1 with high invasiveness and SAS-L1 with low invasiveness. Clone SAS-H1 exhibited significantly greater motility than SAS-L1 but had significantly lower levels of intracellular Cu-ZnSOD than SAS-L1 cells. We then transfected Cu-ZnSOD antisense cDNA into SAS-L1 to reduce the intracellular Cu-ZnSOD activity. Antisense cDNA transfected SAS-L-AS clones had lower Cu-ZnSOD activity than control vector-transfected SAS-L-Neo clones, and this was associated with increased motility. Invasiveness of SAS-H1 and SAS-L-AS1 was enhanced by superoxide treatment, while the invasiveness of SAS-L1 was unaffected. These findings indicate that intracellular SOD is involved in cell motility by virtue of its action in scavenging superoxide in the cells.