['As we previously observed that bovine liposomal Cu/Zn SOD (LipSOD) reduces cutaneous radiation-induced fibrosis (RIF) in human therapeutic assays the mechanisms involved were investigated here by an in vitro study of the LipSOD effects on cellular antioxidant metabolism and regulation of matrix degradation.', 'Primary cultures of human fibroblasts harvested from normal or RIF skin were treated with various doses of LipSOD. Catalase, Cu/Zn and Mn SOD endogenous cell enzyme activities and protein amounts were assayed by polyacrylamide gel electrophoresis and western blotting. Gene expressions of tissue inhibitor of metalloproteinases (TIMP) and TGF-beta1 was investigated by northern blot analysis.', 'A deficiency of endogenous Mn SOD, considered to favour cell proliferation, was observed in cultured RIF cell. The present study showed that bovine Cu/Zn SOD entered the cells. Exposure to LipSOD (a) enhanced endogenous Mn SOD activity and protein level, without changes of endogenous Cu/Zn SOD and catalase, and (b) significantly reduced TIMP and TGF-beta1 gene expression, in RIF cells. No changes in these parameters were noted in treated control skin fibroblasts.'] Does cu/Zn superoxide dismutase modulate phenotypic changes in cultured fibroblasts from human skin with chronic radiotherapy damage?