Superoxide dismutase (SOD1) and Lactate dehydrogenase (LDH)
activities in breast cancer tissue
The antioxidant enzyme superoxide dismutase (SOD) activity was found to
be higher in the tumor as compared to its surrounding (Fig-1a, SOD1). In
essence, lactate dehydrogenase (LDH) is an enzyme necessary for the
conversion of sugar into cellular energy. An elevated total serum SOD
level is a predictor of tissue damage and inflammation (29). Another
study has shown loss of LDH-B expression as an early and frequent event
in human breast cancer (30). In our current study, we found the loss of
LDH 3, 4 and 5 in breast cancer as compared to the surrounding whereas
LDH 2 seems to be equally expressed both in the surrounding and the
tumor. LDH has 2 subunits, subunit A and subunit B in different
proportion in each type of LDH. In this study, we found that the
expression of Subunit A is reduced or almost lacking in breast tumor.
Therefore, the less is the expression of LDH 3, 4 and 5 in tumor tissue
(Fig-1a).