Stein G H
Exp Cell Res. 1983 Apr 1;144(2):468-71. doi: 10.1016/0014-4827(83)90426-3.
HeLa cells in S phase induce DNA synthesis in cycling cells, serum-deprived quiescent cells, and non-replicative senescent cells following cell fusion. In contrast normal human diploid fibroblasts (HDF) do not induce DNA synthesis in either quiescent cells or senescent cells. Instead, the replicative HDF nuclei are inhibited from entering S phase in heterokaryons formed with these two types of non-replicative cells. These differences in the inducing capabilities of normal HDF and HeLa cells raise the question whether normal HDF in S phase can induce DNA synthesis in cycling cells. This paper demonstrates that young HDF in S phase can induce DNA synthesis in cycling HDF. Thus, the hypothesis that initiation of DNA synthesis in cycling cells is positively controlled by inducer molecules appears to be valid for normal HDF as well as for transformed cells such as HeLa.
处于S期的HeLa细胞在细胞融合后，可诱导周期细胞、血清饥饿静止细胞以及非复制性衰老细胞进行DNA合成。相比之下，正常人类二倍体成纤维细胞（HDF）在静止细胞或衰老细胞中均不诱导DNA合成。相反，在与这两种非复制性细胞形成的异核体中，增殖性HDF细胞核进入S期受到抑制。正常HDF和HeLa细胞诱导能力的这些差异引发了一个问题，即处于S期的正常HDF是否能诱导周期细胞进行DNA合成。本文证明处于S期的年轻HDF可诱导周期HDF进行DNA合成。因此，周期细胞中DNA合成的起始由诱导分子正向调控这一假说，似乎对正常HDF以及HeLa等转化细胞同样有效。
