Carcinostatic Effect of Extracts from Human Gastric Cancer

Abstract

Saline extracts from human gastric cancer divided into two parts, one of which was irradiated by X-ray of 2000 r, before homogenization, were fractionated with EtOH, in which S, was 30% vol. ppt., S, was 30-70% vol. ppt., and S₃ was supernatant. Further, S₁ and S₂ were fractionated with (NH₄)₂SO₄ into P₁ (30% sat. ppt.), P₂ (30-50% sat. ppt.), P₃ (50-700/ sat. ppt.), and P₄ (supernatant).
The S₂P₁ and S₂P₂ fractions non-irradiated inhibited the growth of subcutaneous solid Ehrlich ascites tumor in mice, which were respec tively significant at the level of 10% and 5%, but the same fractions irradiated lost the growth inhibitory activity.
The S₂P₃ fraction irradiated inhibited the growth of solid tumor at the level of 20%, and was different from the equivalent non-irradiated fraction having mitosis promoting activity at the significance of 0 .5%
These data may show that malignant tumor contains the growth inhibiting substance which is not species specific, and the carcinostatic effect of X-ray irradiation is due to the destruction of balance between growth promoting and inhibiting substances inside of the tumor tissue.