Effect of chemotherapeutical agents on the structure and function of blood serum albumin in breast cancer

: Superoxide-removing activity, the number of sulfo-hydryl NH2-groups and groups, mean mass molecular concentration, free and antioxidant activity of albumin were determined in blood serum and its albumin fraction in 20 patients with breast cancer T3-4N1-2Mo, before and after incubation with cyclophosphamide, adriablastin, methotrexate and vincristine at concentrations used in clinic. Our data suggested that, following incubation with blood plasma, chemotherapeutic drugs bound to albumin fraction and protein fragmentation took place. Preincubation of blood plasma with the drugs and their immobilization on albumin molecules caused protein fragmentation to occur. Fragments having pro-oxidant properties might have been absorbed and fixed by both tumor tissues and any others thus creating a pool of fast-dividing cells and organs. Therefore, cytostatic drugs can exert enhanced antitumor action and, at the same time, a highly toxic effect when administered with autoplasma during chemotherapy.