[CAS NO. 6055-19-2]  Cyclophosphamide (NSC-26271) Monohydrate

Cyclophosphamide (CY) is a chemotherapeutic agent with a dose-dependent, bimodal effect on the immune system. Cyclophosphamide treatment enhances apoptosis and decreases homeostatic proliferation of regulatory T cells. Cyclophosphamide downregulates the expression of GITR and FoxP3, which are involved in the suppressive activity of T(REGs).Cyclophosphamide increases CYP3A4, CYP2C8, and CYP2C9 protein levels in primary human hepatocyte cultures, which thereby enhances their own rates of 4-hydroxylation in the cultured hepatocytes. Cyclophosphamide has produced mutations in base-pair substituting strains of Salmonella tryphimurium in the presence of metabolic activation, but it has been shown to be negative in the E. coli chromotest. Cyclophosphamide has been shown to produce gene mutations, chromosome aberrations, micronuclei and sister chromatid exchanges in a variety of cultured cells in the presence of metabolic activation as well as sister chromatid exchanges without metabolic activation.