Ho Y K, Preisler H D, Bardos T J
Cancer Res. 1979 Aug;39(8):3163-6.
The effect of partially thiolated polycytidylic acid (MPC) on the colony-forming ability of the progenitor cells (CFUC) of RF/Un leukemic mice was investigated using the plasma clot method in order to study the mode of action of the modified polynucleotide. The results showed that MPC inhibited the CFUC in a dose-dependent and time-dependent manner. Once a maximum level of inhibition of CFUC (approximately 40%) was observed, no further inhibition occurred whether the concentration of MPC was increased or whether the duration of incubation was lengthened. High-specific-activity [3H]thymidine, an S-phase-specific agent, showed a similar inhibition profile on the CFUC as did MPC. When MPC and high-specific-activity [3H]thymidine were incubated together with the bone marrow cells, there was no additive or synergistic inhibitory effect on the CFUC. Thus, it appears that MPC is an S-phase-specific agent. When injected i.v. into the mice, MPC decreased the number of CFUC of both the bone marrow and the spleen significantly.
为研究修饰多核苷酸的作用方式，采用血浆凝块法研究了部分硫醇化聚胞苷酸（MPC）对RF/Un白血病小鼠祖细胞（CFUC）集落形成能力的影响。结果表明，MPC以剂量和时间依赖性方式抑制CFUC。一旦观察到CFUC的最大抑制水平（约40%），无论MPC浓度增加还是孵育时间延长，均未出现进一步抑制。高比活度[3H]胸苷是一种S期特异性试剂，对CFUC的抑制谱与MPC相似。当MPC和高比活度[3H]胸苷与骨髓细胞一起孵育时，对CFUC没有相加或协同抑制作用。因此，MPC似乎是一种S期特异性试剂。当静脉注射到小鼠体内时，MPC显著降低了骨髓和脾脏中CFUC的数量。
