The effect of local hrec TNF-alpha administration upon the spontaneous lung metastases in rats with Morris 5123 hepatoma.

The experiment used Morris hepatoma 5123 series growing in muscles of the right hind limb of Buffalo rats. The group I animals were given intratumor 4 doses of TNF-alpha and group II-8 doses of TNF-alpha (10 micrograms/day). Control groups (III and IV) consisted of rats with injected Morris hepatoma, which were given PBS solution instead of TNF-alpha. A decrease in the volume of neoplastic metastases was observed in groups I and II, compared with groups III and IV. At the same time an increase was found in the volume of metastatic tumors in group II (8 x TNF-alpha), compared with group I (4 x TNF-alpha). Histological and ultrastructural analysis of the pulmonary tissue revealed intensified fibrotic reactions and inflammatory infiltrations around the metastatic tumors. The change were much more enhanced in group II, which might affect the results of neoplastic metastatic volume measurements. We concluded that multiple human recombinant TNF-alpha, hrec TNF-alpha, local injections inhibited dissemination of tumor cells and prolonged the survival time of rats up to the 76th day of the follow-up.