LAUSR

e15008 Background: Lung cancer is the most common cancer worldwide. The efficacy of chemotherapy for this tumor does not exceed 40%. Moreover, all cytotoxic agents cause many side effects. The search for new substances with an antitumor effect seems to be relevant. Tropolone alkaloids, which are seven-membered non-benzenoid aromatic compounds, are promising inhibitors of tumor growth. The purpose of the study was to evaluate the antitumor efficacy of 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone in subcutaneous xenografts of lung cancer A549 cells in immunodeficient Balb/c Nude mice. Methods: The study was performed on a PDX model of lung cancer created by subcutaneous injection of A549 cell suspension, 5x106 cells in 0.2 ml of a solution of serum-free nutrient medium 199 and Matrigel (1:1). Animals were equally divided into 5 groups (each n = 5). Experimental groups 1, 2, 3 and 4 received 2-(6,8-dimethyl-5-nitro-4-chloroquinoline-2-yl)-5,6,7-trichloro-1,3-tropolone at doses of 0.0055, 0.055, 0.55 and 2.75 mg/g, respectively; the control group received 1% starch gel. The dynamics of the growth of a subcutaneous xenograft was evaluated by measuring tumor nodes. The volumes of tumor nodes were calculated using the Shrek’s formula for the ellipsoid: V = a×b×c×p/6, where V is the tumor volume (mm3), and a, b, c are the maximum dimensions of the ellipsoid in three planes (mm). The data were statistically analyzed using the Exel and Medstatistic progams. Results: The dynamics of subcutaneous xenograft growth in groups 1, 2, 3 and 4 significantly differed from the control group (p = 0.023). The average tumor volumes on the 39th day after the implantation in the control group and in experimental groups 1, 2, 3 and 4 were 1159.2, 895.3, 565.8, 80.7 and 76.7 mm3, respectively. The inhibition of tumor growth (ITG) was in direct proportion to the dose of the administered substance. Lower ITG(%) (32.4, 23.2 and 10.3% in experimental groups 2, 3 and 4, respectively) was associated with lower concentrations of О154 (0.55 mg/g, 0.055 mg/g and 0.0055 mg/g, respectively). Conclusions: The study demonstrated statistically significant differences in xenograft volume indices in all experimental groups compared to the control group.