In vitro and in vivo biological activities of a novel nonpolyglutamable anti-folate, MX-68

• Published in: Immunopharmacology Vol. 35; no. 1; pp. 41 - 46
• Main Authors: Mihara, Masahiko, Urakawa, Kazumi, Takagi, Nobuhiro, Moriya, Yoichiro, Takeda, Yasuhisa
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.1996; Elsevier
• Subjects: 2-Aminoadipic Acid - analogs & derivatives; 2-Aminoadipic Acid - metabolism; Animals; Arthritis, Experimental - chemically induced; Biological and medical sciences; Bones, joints and connective tissue. Antiinflammatory agents; Cell Division - drug effects; Cell proliferation; Cells, Cultured; Collagen - toxicity; Collagen-induced arthritis; Endothelium, Vascular - cytology; Endothelium, Vascular - drug effects; Fibroblasts - drug effects; Folic Acid Antagonists - chemical synthesis; Folic Acid Antagonists - metabolism; Humans; Leukocytes, Mononuclear - drug effects; Medical sciences; Methotrexate - analogs & derivatives; Methotrexate - metabolism; Mice; Mouse; MTX; MX-68; Pharmacology. Drug treatments; Polyglutamation; Polyglutamic Acid - metabolism; Tetrahydrofolate Dehydrogenase - metabolism; Cell proliferation; MX-68; CII; IL; MTX-PGs; Collagen-induced arthritis; PHA; Polyglutamation; PBMC; TNF; RA; MTX; SC; DHFR; Mouse; CIA; AICAR; EC; TS; Endothelial cell; Diseases of the osteoarticular system; Autoimmune disease; Inflammatory joint disease; Arthritis; Antifolate; Mononuclear cell; Antirheumatic agent; Dihydrofolate reductase; Immunopathology; Enzyme; Rodentia; Enzyme inhibitor; Vertebrata; Chemotherapy; Mammalia; Treatment; Animal; Collagen; Rheumatoid arthritis; Oxidoreductases; Fibroblast; Comparative study
• ISSN: 0162-3109
• DOI: 10.1016/0162-3109(96)00117-8

MX-68 is a newly synthesized anti-folate, chemically designed not to undergo intracellular polyglutamation and to have increased affinity to dihydrofolate reductase (DHFR). In the present study, we examined the in vitro and in vivo biological activities of MX-68 compared with methotrexate (MTX) which forms several polyglutamates intracellularly. MX-68 dose-dependently inhibited the proliferation of PHA-, anti-CD3-, or PMA plus ionomycin-stimulated peripheral blood mononuclear cells (PBMC) and endothelial cells (EC) from normal subjects as well as IL-1β- or TNFα-stimulated synovial fibroblastic cells (SC) from rheumatoid arthritis (RA) patients. Coaddition of folinic acid completely reversed the anti-proliferative effects of both MX-68 and MTX. Although the anti-proliferative activities of MX-68 were almost comparable to those of MTX, the washout study clearly showed the characteristic nature of MX-68. When drugs were removed during culture, the suppressive effect of MX-68 completely disappeared, whereas suppression by MTX was merely weakened. MX-68 dramatically suppressed the onset of collagen-induced arthritis (CIA) in mice when the drug was orally administered three times a week, starting from the day of first immunization. In this model, 2 mg/kg of MX-68 was sufficient to completely suppress arthritis, whereas suppression by the same dose of MTX was partial. These lines of evidence suggest that polyglutamation is not always a prerequisite in the anti-rheumatic effects of anti-folate. In addition, since intracellular accumulation of polyglutamates is thought to have adverse effects, MX-68 may become a more potent and less toxic anti-rheumatic drug than MTX.