The Role of SOD2 in Migration and Anchorage-Independent Growth of SKOV3 Ovarian Cancer Cells

The 5-year survival rates for ovarian cancer are 93%, 75%, and 30% for localized, regional, and distant tumors, respectively. These vast differences in survival rates underscore the need to identify novel therapeutic targets that are effective at different stages of tumor progression to better treat all patients diagnosed with this deadly disease.  Manganese superoxide dismutase (SOD2) is a mitochondrial antioxidant enzyme responsible for eliminating superoxide and preventing oxidative damage to the mitochondria. Recent studies have implicated changes in SOD2 expression levels in multiple cancers, including breast, colorectal, prostate, and head and neck. While studies have begun to unravel the role of SOD2 in ovarian cancer, no one has looked at the specific role SOD2 plays in distinct stages of tumor progression of ovarian cancer. Here, we report SOD2 deficiency (accomplished through utilizing shRNA techniques) results in increased invasive and migratory ability of SKOV3 cells, a commonly used ovarian adenocarcinoma cell line. In contrast, SOD2-deficient SKOV3 cells display abrogated anchorage-independent growth in soft agar. These studies in SKOV3 cells indicate that SOD2 expression hampers invasion and migration critical for early tumor initiation but helps maintain anchorage-independent growth necessary for ovarian cancer metastases. In aggregate, SOD2 plays a context-dependent role in ovarian cancer progression and its utility as a therapeutic target for later-stage anchorage-independent ovarian cancer cells should be further explored. (First online: March 1, 2022)