The PCR kit MutaGEL Oxstress II has been developed for the diagnosis of the variability in the human enzyme genes of superoxide dismutase 2 (alleles valine16alanine) and catalase (promotor alleles C-262T) responsible for protectivity against metabolic “oxidative stress” tested on isolated DNA.
Oxidative stress is defined as a pathological disequilibrium between the body’s molecules (e.g from food oxidation), which have free electrons and the reducing agents who normally react with them. The anions of superoxide and peroxide are mainly concerned and their surplus acts as aging cause and may especially generate diabetes or cancer. The protein superoxide dimutase 2 (manganese-dependent SOD2) catalyses radicals of superoxide (from many different metabolic sources) to peroxide; the protein catalase (CAT together with glutathion S-transferase) transforms peroxide to water and oxygen. The higher or lower serum concentration of reactive molecules – NO, ox-LDL, H2O2, and many others – as result of ecological agents (e.g. poor or well living conditions) is therefore “framed” by the heritated variation of their reducing enzymes. Firstly our test diagnoses the polymorphism Val16Ala of SOD2, which changes the enzymes recognition by mitochondria, in whom it acts on ROS (reactive oxygen species): diseased people with certain cancers have more often valine alleles of SOD2 than healthy people (the relative abundance of Val/Val homozygotes in lung cancer patients is 1,7x the number in healthy persons; in bladder cancer the deviation is still higher). Because valine alleles are 1/3 less active than alanine alleles, its reduced decomposition of oxidative stress molecules can generate cancer. The results are complicated by the fact, that the alanine allele of SOD2 may also act as pathogenic factor in breast cancer (in unfavourable circumstances like with women with high body mass index and with many menstruation years), and this may point on a neoplastic potential of ROS metabolites produced by the more active enzyme. Secondly we diagnose the promotor polymorphism C-262T of human catalase – the enzyme acts downstream of SOD2 (s.a.) -, which changes the protein’s concentration in erythrocytes and blood: each T allele of a person increases the activity. This is generating a protective effect of its counterpart with a C against breast or pancreas cancer and here also a mirror effect exists with a pathogenic effect for CC homozygotes in the pathogenesis of diabethic neuropathy.Thus the enzymes allelic variants in oxidative stress generate pathogenic or protective effects depending on the examined disease. Further influence on the reduction of oxidative stress comes from the null mutants of glutathion S-transferase M1 and T1 (see PCR kit Mutagel GST M1/T1) and sequence changes in the genes for endothelial NO synthase + NAD(P)H oxidase (see PCR kit Mutagel Oxstress I), (M.E.).