Effect of non-steroidal anti-inflammatory drugs of Moloney sarcoma virus inoculated mice.

Chronic administration of phenylbutazone, flufenamic acid and a new, potent non-steroidal anti-inflammatory agent ITF (3-methyl-5-benzoyl-amino-isothiazole-4-carboxy-p-ethoxyphenylamine) to BALB/c mice inoculated with a Moloney sarcoma virus resulted in a stimulation of tumor growth and increased severity of disease. This treatment, however, had no effect on the spontaneous regression of tumors. Indomethacin in a dose of 5.0 or 2.5 mg per kg suppressed the MSV-induced tumor growth, but this effect was apparently connected with the high toxicity of this drug for mice.