Mercer W E, Avignolo C, Galanti N, Rose K M, Hyland J K, Jacob S T, Baserga R
Exp Cell Res. 1984 Jan;150(1):118-30. doi: 10.1016/0014-4827(84)90707-9.
We have used an antibody against RNA polymerase I to investigate the role of rRNA synthesis and/or accumulation in the control of cell proliferation. The antibody was microinjected directly into the nuclei of quiescent Swiss 3T3 cells that were subsequently stimulated with serum. Under the experimental conditions used, the microinjection of the antibody against RNA polymerase I (RNA pol I) caused a 50-70% decrease in nucleolar RNA synthesis that lasted for at least 17 h, a greater than 90% inhibition in the accumulation of nucleolar RNA, and a 70% inhibition in the accumulation of total cellular RNA. A control IgG, similarly microinjected into Swiss 3T3 cells had no inhibitory effect on either the synthesis or accumulation of nucleolar and cellular RNA. Despite the dramatic effect on the synthesis and accumulation of ribosomal RNA (rRNA) the antibody against RNA (rRNA) the antibody against RNA pol I was totally ineffective in inhibiting the entry into S phase of serum-stimulated Swiss 3T3 cells. Cells depleted of cellular RNA by metaphase arrest also entered S phase with subnormal amounts of cellular RNA. The results of these experiments clearly indicate that a normal rate of nucleolar RNA synthesis, and a normal rate of accumulation of total cellular RNA are not a prerequisite for the entry of cells into S phase.
我们使用了一种针对RNA聚合酶I的抗体，以研究核糖体RNA（rRNA）合成和/或积累在细胞增殖控制中的作用。将该抗体直接显微注射到静止的瑞士3T3细胞的细胞核中，随后用血清刺激这些细胞。在所使用的实验条件下，显微注射针对RNA聚合酶I（RNA pol I）的抗体导致核仁RNA合成减少50 - 70%，持续至少17小时，核仁RNA积累的抑制率超过90%，以及总细胞RNA积累的抑制率为70%。同样显微注射到瑞士3T3细胞中的对照IgG对核仁RNA和细胞RNA的合成或积累均无抑制作用。尽管对核糖体RNA（rRNA）的合成和积累有显著影响，但针对RNA pol I的抗体在抑制血清刺激的瑞士3T3细胞进入S期方面完全无效。通过中期阻滞使细胞RNA耗尽的细胞也能以低于正常量的细胞RNA进入S期。这些实验结果清楚地表明，核仁RNA的正常合成速率和总细胞RNA的正常积累速率并非细胞进入S期的先决条件。
