In recent years, the intracellular reactive oxygen species (ROS) levels have gained increasing attention as a critical regulator of cellular proliferation. We investigated the hypothesis that manganese superoxide dismutase (MnSOD) activity regulates proliferative and quiescent growth by modulating cellular ROS levels. Decreasing MnSOD activity favored proliferation in mouse embryonic fibroblast...

Excess fat storage in adipocytes is associated with increased generation of reactive oxygen species (ROS) and impaired activity of antioxidant mechanisms. Manganese superoxide dismutase (MnSOD) is a mitochondrial enzyme involved in detoxification of ROS, and objective of the current study is to analyze expression and regulation of MnSOD in obesity. MnSOD is increased in visceral but not subcuta...

PURPOSE Although the etiology of breast cancer is multifactorial, oxidative stress plays an important role in carcinogenesis. In this study, manganese superoxide dismutase (MnSOD) gene polymorphism and activity were evaluated in benign and breast cancer tissue. METHODS One hundred and one females were enrolled in this study, 65 who were histopathologically diagnosed with breast cancer and 46 ...

Endothelial function is impaired by oxidative stress in chronic heart failure (HF). Mechanisms that protect against increases in oxidative stress in HF are not clear. The goal of this study was to determine whether manganese superoxide dismutase (MnSOD) plays a key role in protecting against endothelial dysfunction in HF. Endothelial function and gene expression were examined in aorta from wild...

Two polymorphic variants of manganese superoxide dismutase (MnSOD), with either Ile or Thr at amino acid 58, (Ile58MnSOD or Thr58MnSOD), have been found in the human population. The MnSOD activity of these two variants and their effects on the malignant phenotype of human breast cancer MCF-7 cells were compared. It was demonstrated that MnSOD-overexpressing clones obtained from transfection of ...

To determine whether overexpression of antioxidant enzymes in lung epithelial cells prevents damage from oxidant injury, stable cell lines were generated with complementary DNAs encoding manganese superoxide dismutase (MnSOD) and/or catalase (CAT). Cell lines overexpressing MnSOD, CAT, or MnSOD + CAT were assessed for tolerance to hyperoxia or paraquat. After exposure to 95% O(2) for 10 d, 44 t...

Since it was first observed in late 1970s that human cancers often had decreased manganese superoxide dismutase (MnSOD) protein expression and activity, extensive studies have been conducted to verify the association between MnSOD and cancer. Significance of MnSOD as a primary mitochondrial antioxidant enzyme is unquestionable; results from in vitro, in vivo and epidemiological studies are in h...

BACKGROUND Manganese superoxide dismutase (MnSOD) is a mitochondrial antioxidant enzyme that is down-regulated in a majority of cancers. Due to this observation, as well as MnSOD's potent antioxidant enzymatic activity, MnSOD has been suggested as a tumor suppressor for over 30 years. However, testing this postulate has proven difficult due to the early post-natal lethality of the MnSOD constit...

Manganese superoxide dismutase plasmid liposomes (MnSOD-PL) confer organ-specific in vivo ionizing irradiation protection. To prepare for potential intravenous clinical trials of systemic MnSOD-PL for radioprotection in humans, plasmid and bacterial sequences were removed and a new minicircle construct was tested. Minicircle MnSOD was purified and then cotransfected into 32D cl 3 murine interle...

Manganese Superoxide disimilase (MnSOD) is a member of a family of meta lloenz) mes that catalyze the dismutation of the Superoxide aniÃ3n to I !;<>;. It has been shown that MnSOD activity in tumor cells is lower than that in their normal counterparts. To investigate the molecular basis for the reduced level of MnSOD activity in human tumor cells, the primary structure of human MnSOD has been d...