Oncolytic activity of a new group of non-classified rotavirus of Reoviridae family on human epidermoid carcinoma A431 growth.

Abstract

e15272 Background: Significant increase of malignant tumors` incidence all over the world in spite of vast arsenal of anticancer drugs and their combinations challenges the oncologists to develop new approaches to tumor treatment. Application of oncolytic virus is considered to be rather promising. Here we studied two strains of the new group of non-classified rotavirus of Reoviridae family (RVK): 100 and 228 ( http://jbks.ru/archive/issue-10/article-6 ). RVK are attenuated non-pathogenic virus growing on pig embryo kidney cell culture with concentration 5·109 per 1 ml. The aim of the study was to assess the effect of two RVK strains (100 and 228) on the growth of human epidermoid carcinoma A431 transplanted to nude mice in vivo. Methods: Mice Balb/cNude 22-24 g body weight (n = 13) were injected with 4х106 cells of human epidermoid carcinoma A431 subcutaneously in SPF-area of vivarium. After formation of palpable tumors (1 week after transplantation) administration of alive RVK strains 100 and 228 was performed. The 3rd group was the control one and received 0.85% NaCl. The injections were performed once a week 0.3 ml. Tumor growth rate and its` volume were measured. 1 week after the completion of the course mice were sacrificed, tumors were weighted and their morphology was studied. Results: In mice injected with RVK tumor growth inhibition developed in early date after the injection and was statistically significant within 30 - 40 days of monitoring only after the administration of strain 100. In these animals tumor weight was 2.6 times lower than in control mice (6.3±3.0 и 16.6±2.3 g respectively, р < 0.05), in mice having received strain 228 it was 1.7 times less tan in controls. Layers of high-grade sqamous carcinoma cells without keratinization with inflammatory and necrotic foci were observed in tumors of control mice while in tumors inhibited by RVK dystrophic changes and fragmentation, inflammation in places severe and necrotic foci were seen. Implication of the strain 100 resulted in 2-3 time reduction of tumor size, decrease of tumor cells` layers, mononuclear infiltration. Conclusions: In the in vivo model of human epidermoid carcinoma A431 transplanted to nude mice the inhibition of tumor growth under RVK administration was established. Our results confirm the oncolytic activity in RVK, particularly in strain 100.