Mouse lymphosarcomas sensitive and resistant to cyclophosphamide therapy: activity of cathepsins B, L, and D during various schemes of treatment with cyclophosphamide and SE-glycan

Abstract

We measured activities of cysteine (cathepsins B and L) and aspartyl proteinases (cathepsin D) in tumor tissue of mice with sensitive and resistant lymphosarcomas. In cyclophosphamide-resistant lymphosarcoma tissue activities of cathepsins B, L, and D were lower than in cyclophosphamide-sensitive lymphosarcoma. After treatment with cyclophosphamide in high doses enzyme activities in mice with cyclophosphamide-resistant lymphosarcoma increased more significantly than in animals with cyclophosphamide-sensitive lymphosarcoma. Sulfoethylated beta-1,3-D-glycan potentiated the effect of cyclophosphamide in mice with both forms of lymphosarcoma. This drug in the lowest dose (10 mg/kg) was most effective.