Differential influence of pentoxifylline on murine colon adenocarcinoma- and melanoma-derived metastatic tumor development in lungs.

Pentoxifylline (PTX), a methylxanthine derivative, is commonly and in most cases chronically used in patients suffering from peripheral vascular diseases. It increases erythrocyte flexibility, reduces blood viscosity and improves microcirculatory flow. Moreover, PTX has been found to enhance anticancer activity of some chemotherapeutic agents and ionizing irradiation. On the other hand, PTX has been recently shown to inhibit anticancer response and promote murine tumor growth in liver. In this study we show that PTX facilitates development of murine colon adenocarcinoma- but not melanoma-derived tumors also in lungs. It could suggest that tumor-promoting PTX activity is tissue-independent, although, it might depend on the cancer cell line.