Modifying Effect of 1-β-D-arabinofuranosylcytosine on the Growth of the Solid Tumor Ehrlich Carcinoma in Mice under In Vivo and Ex Vivo Proton Irradiation of Cells

In this work, we study the modifying effect of the 1-β-D-arabinofuranosylcytosine (AraC) on tumor induction and growth in mice under the proton irradiation of Ehrlich ascites carcinoma (EAC) cells in vivo and ex vivo. A decrease in tumor growth rate after proton irradiation in the presence of AraC, both in vivo and ex vivo, has been shown. The most expressed antitumor effects of AraC in combination with proton irradiation have been revealed during the ex vivo irradiation of ascites cells. This may indicate a difference in the effect of AraC on cells irradiated in vivo and ex vivo, both at the stage of primary oncogenesis and during the development of an established neoplasm. The impact of incubation conditions, irradiation, and AraC concentration on the magnitude of radiosensitizing effect of AraC is discussed.