Okabe J, Honma Y, Hozumi M
Int J Cancer. 1977 Dec 15;20(6):933-40. doi: 10.1002/ijc.2910200617.
Treatment with ascitic fluid from animals bearing various tumors, can induce mouse myeloid leukemia line cells, M1, to differentiate in vitro into macrophages and granulocytes. Cells were isolated that were resistant to the ascitic fluid factor(s) stimulating differentiation (D-factor). The resistant cells became sensitive to the D-factor and differentiated after treatment with various inhibitors of RNA synthesis (actinomycin D, nogalamycin, chromomycin A3 or cordycepin) or protein synthesis (puromycin or cycloheximide). The cells could not be induced to differentiate by treatment with the inhibitors alone. The effective doses of the inhibitors of protein synthesis were toxic to the cells. Among these inhibitors actinomycin D (5 ng/ml) was the most effective for sensitizing the resistant cells. Inhibitors of DNA synthesis did not sensitize the resistant cells. Added actinomcyin D was mainly recovered in the nuclear fraction of the cells. The sensitizing effect of actinomycin D on the cells was roughly parallel to the extent of its inhibition of RNA synthesis in the cells. The effective concentration of actinomycin D (5 ng/ml) mainly inhibited it also inhibited alpha-amanitin-resistant RNA synthesis to some extent. These results suggest that alpha-amanitin-sensitive RNA synthesis may be involved in sensitization of the resistant cells to the D-factor.
用患有各种肿瘤的动物的腹水进行处理，可诱导小鼠髓系白血病细胞系M1在体外分化为巨噬细胞和粒细胞。分离出了对刺激分化的腹水因子（D因子）具有抗性的细胞。在用各种RNA合成抑制剂（放线菌素D、诺加霉素、色霉素A3或虫草素）或蛋白质合成抑制剂（嘌呤霉素或环己酰亚胺）处理后，抗性细胞对D因子变得敏感并发生分化。单独用抑制剂处理不能诱导细胞分化。蛋白质合成抑制剂的有效剂量对细胞有毒性。在这些抑制剂中，放线菌素D（5 ng/ml）对使抗性细胞敏感最为有效。DNA合成抑制剂不能使抗性细胞敏感。添加的放线菌素D主要在细胞的核部分中回收。放线菌素D对细胞的致敏作用与其对细胞RNA合成的抑制程度大致平行。放线菌素D的有效浓度（5 ng/ml）主要抑制它也在一定程度上抑制了对α-鹅膏蕈碱抗性的RNA合成。这些结果表明，对α-鹅膏蕈碱敏感的RNA合成可能参与了抗性细胞对D因子的致敏过程。
