[Correction of serum prooncogenic cytokines and metastases by 5-hydroxypyrimidine derivatives and doxorubicin after removal of a primary tumor node in mice with the Lewis lung epidermoid carcinoma].

The effect of a single injection of doxorubicin, 8-day administration of two 5-hydroxypyrimidine derivatives, SNK-411 (2-Isobutyl-4,6-dimethyl-5-hydroxypyrimidine) and SNK-578 (hydrochloride of 2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine), on metastases, lifespan and serum cytokines has been investigated in С57ВL/6 mice after removal of a primary tumor node of Lewis lung carcinoma (LLC). LLC cells (1×106) were injected in the footpad of right hind feet of mice in control and experimental groups; after 14 days of tumor development the hind feet with the tumor were amputated at the ankle level. One hour before the amputation mice received a single injection of doxorubicin (4 mg/kg) and 8-day therapy with the 5-hydroxypyrimidine derivatives started. SNK-578 monotherapy was performed at a dose of 10 mg/kg administered intraperitoneally (i.p.). SNK-411 was administered per os at a dose of 25 mg/kg. In the case of combined therapy mice also received a single injection of doxorubicin (4 mg/kg; i.p.). The metastasis inhibition index in mice-treated with SNK-411 and SNK-578 were 53.3% as compared with control mice (with removed tumor). The mice-treated with SNK-411, doxorubicin, and the combination SNK-578 + doxorubicin had lifespan increased by 60.2%, 53.9%, and 42.9%, respectively. A single injection of doxorubicin, the course administration of the 5-hydroxypyrimidine derivative alone and in combination with single injection of doxorubicin completely decreased serum levels of the prooncogenic Th2-cytokines IL-4, and IL-6 and significantly decreased the level of the Th2-cytokine IL-5. Administration of doxorubicin, SNK-411 and SNK-578 did not influence serum concentration of Th1-cytokine interferon gamma (IFN-γ). These data confirm our previous findings that administration of the compounds studied decreased concentrations of prooncogenic IL-4 and IL-6 in tumor-bearing mice with LLC and had no effect on concentrations of the Th1-cytokine IFN-γ.