P-138 - Redox status in breast tumor and associated adipose tissue - interplay between obesity and malignancy

Abstract

Evidence linking obesity to breast cancer in premenopausal women remains inconclusive. We aimed to reveal redox status related to malignant phenotype and its relationship with obesity. To this end, premenopausal women with breast tumors were divided into four groups: normal-weight (non-obese) with benign tumors, obese with benign tumors, non-obese with malignant tumors and obese with malignant tumors. We examined activity and protein expression of main antioxidant defense (AD) enzymes (copper, zinc- and manganese- superoxide dismutase, catalase and glutathione peroxidase) in breast tumor tissue and tumor-associated adipose tissue. Activity and protein expression of AD enzymes were generally increased in malignant tumors of non-obese and obese women, in comparison to their respective benign counterparts. In tumor-associated adipose tissue of non-obese women, activity and protein expression of AD enzymes were increased in subjects with malignant tumors in comparison to those with benign tumors. In conclusion, the effect of malignancy on the redox signature of tumor tissue is evident in both non-obese and obese subjects, while in adipose tissue the effect is pronounced mostly in non-obese subjects, suggesting redox sensitive interplay between obesity and cancer.