Effects of 5-Hydroxypyrimidine Derivatives on Tumor Growth and Lifespan of C57BL/6 Mice with Epidermoid Lung Carcinoma

The effects of 5-hydroxypyrimidine derivatives SNK-411 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine) and SNK-578 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine chlorohydrate) on the tumor growth and survival of male C57BL/6 mice with transplanted Lewis lung epidermoid carcinoma (LLC) were studied in animals receiving intraperitoneal treatment on days 2-15 of tumor development. Compound SNK-578 in a dose of 10 mg/kg significantly inhibited tumor growth (by 3.6 times; 72.2%) in 7 days after the treatment was discontinued, while compound SNK-411 in a dose of 25 mg/kg only negligibly reduced tumor volume (by 41.7%). A combination of course of SNK-411 (25 mg/kg) and single intraperitoneal dose of doxorubicin (4 mg/kg) significantly inhibited the tumor growth (by 2.2 times; 55.2%), while the combination of SNK-578 (10 mg/kg) with doxorubicin (4 mg/kg) was in fact ineffective. The median survival of animals with untreated LLC was 28 days. Median survival of mice injected with SNK-578 (10 mg/kg) was 43 days, hence, the lifespan of mice with LLC was by 38.6% longer after the treatment. Two of ten mice in this group developed no tumors.