asta-z-7557 and Lymphoma--Large-B-Cell--Diffuse

Oxazaphosphorines belong to a group of alkylating agents. Mafosfamide cyclohexylamine salt (D-17272), 4-hydro-peroxy-cyclophosphamide (D-18864) and glufosfamide (D-19575, beta-D-glucose-isophosphoramide mustard) are new generation oxazaphosphorines. The objective of the present study was to compare the cytotoxic action of these oxazaphosphorine compounds against human histiocytic lymphoma U937 cells. The chemical structures of the oxazaphosphorines were responsible for the different responses of U937 cells. The cytotoxic effects of D-17272, D-18864, and D-19575 on U937 cells depended on the agent tested, its dose, and the time intervals after the oxazaphosphorine application. Among the oxazaphosphorine agents, D-18864 appeared to be the most cytotoxic, and D-19575 was characterized by the lowest cytotoxicity. The in vitro cytotoxic activities of the oxazaphosphorines were strongly associated with their cell death inducing potential.

Topics: Antineoplastic Agents, Alkylating; Apoptosis; Cell Proliferation; Cyclophosphamide; Flow Cytometry; Glucose; Humans; Ifosfamide; Lymphoma, Large B-Cell, Diffuse; Membrane Potential, Mitochondrial; Necrosis; Phosphoramide Mustards; Tumor Cells, Cultured

The antitumor activity of mafosfamide (MFA), and its parent compound cyclophosphamide (CTX), was investigated against an ovarian reticular cell sarcoma growing i.m. in C57BI/6 mice (M5), which is very sensitive to CTX, and against a subline of this tumor (R16) resistant to CTX. MFA is the prototype of a class of oxazaphosphorines which do not require metabolic activation since under physiologic conditions they undergo rapid spontaneous hydrolyzation to the activated 4-hydroxyoxazaphosphorine and retain a spectrum of activity very similar to the parent compound. After a single dose (300 mg/kg X 1) or repeated low doses (100 mg/kg X 6) the antitumoral activity of MFA on the M5 tumor appeared comparable to or only slightly lower than CTX; the highest T/C value for median survival times was 167% in MFA-treated mice vs. 176% in the CTX group. MFA showed no activity against the R16 subline, thus indicating cross-resistance between the two drugs. Marked thickening of the glissonian capsule with compression of the lobular area of the liver, observed on i.p. administration of MFA, did not result in histopathologic abnormalities of the hepatic parenchyma. The therapeutic efficacy of MFA was similar with i.p. and the i.v. route. MFA may represent a good candidate to replace CTX in cases in which a compound acting per se, and not through metabolites, is preferred.

Topics: Animals; Cyclophosphamide; Drug Resistance; Female; Liver; Lymphoma, Large B-Cell, Diffuse; Mice; Mice, Inbred C57BL; Ovarian Neoplasms