抄録
Effect of an anti-tumor compound, 1-(2-methylbutyl)-3-methyl-6, 7-methylenedioxyisoquinoline·HCl (B-15) on nucleic acids and protein synthesis of Sarcina lutea and synchronized HeLa cells was investigated ; the following results were obtained. A selective inhibitory activity against the incorporation of 3H-thymidine into DNA of Sarcina lutea was observed with B-15 at concentrations which were not, or only slightly, inhibitory in the bacterial viability test. On the other hand, the rapidly labeled DNA in the nucleus of Sarcina lutea was not degraded. In synchronized HeLa cells, the incorporation of 3H-thymidine into DNA was inhibited immediately after addition of B-15 and the extent of inhibition was greater than in the case of the incorporation of 3H-uridine into RNA or 14C-leucine into proteins. Moreover, if added at the stage of DNA synthesis, B-15 inhibited both the incorporation of 3H-thymidine into DNA and division of the cells. However, the inhibition of DNA synthesis was rapidly reversed when B-15 was removed from the culture medium. From these results, it seems that the primary action of B-15 on the intact cells is a selective inhibition of DNA synthesis.
