Intravenously administered 2'-deoxycytidine suppresses mouse myeloma tumor growth.

We examined the in vivo effects of intravenously administered 2'-deoxycytidine (dCyd) on tumor growth and survival time in mice bearing SP2/0-Ag14 (SP2/0) myeloma tumors. Administration of dCyd tended to decrease the tumor volume and significantly decreased the tumor weight. A single intravenous administration of dCyd significantly increased survival time of the tumor-bearing mice. The effect of dCyd on tumor growth was maintained for at least 1 week after the final administration. The net amount of dCyd in the kidney, liver, and spleen of the tumor-bearing mice increased 2.5 to 5.3 fold compared with the amount in non-tumor-bearing mice. Our results suggest that the increase in dCyd in the mice inoculated SP2/0 myeloma cells plays an important role for the growth suppression of the tumor.