Effect of intratumoral OK-432 administration on thymidine phosphorylase expression in human gastric carcinoma

It is known that thymidine phosphorylase (dThdPase) is increased in various types of malignant tumors and is induced by cytokines. In this study, we h ave investigated the effects of OK-432 which induces multiple cytokines, on dThdPase expression and angiogenesis in human gastric carcinomas. We exami ned 25 patients who underwent gastrectomy for gastric carcinoma. OK- 432 wa s directly injected in tumors in 16 (OK group) of 25 patients via endoscopy before operation and the other 9 patients were not treated (control group) . The dThdPase activity in carcinoma tissues of the OK group was significan tly higher than that of the control group (P <0.05). The amounts of IL-1 al pha, IFN-alpha, and IFN-gamma in carcinomas in the OK group were significan tly higher than in the controls (P <0.05), and these were significantly cor related with the dThdPase activity. Intratumoral OK-432 administration enh ances the expression of dThdPase in gastric carcinoma cells by inducing var ious cytokines.