表皮生长因子（ＥＧＦ）对纯化的鼠胚成纤维细胞（Ｃ_３Ｈ_１０Ｔ_１／２Ｃ１８）胞核~３Ｈ－ＵＴＰ掺入有明显的促进作用。这一作用在ＥＧＦ与细胞核共同培养９０ｍｉｎ时达到高峰。该作用是ＥＧＦ浓度依赖性的。ＥＧＦ对β射线转化的上述细胞的纯化细胞核，亦同样有促进转录作用。本实验所用的细胞核经光镜，电子显微镜观察，细胞膜、细胞浆标志酶检测及放射性同位素示踪法鉴定，未检出有核外成份的污染。本实验结果为膜受体信号传递途径以外的ＥＧＦ对核直接作用途径的存在提供了证据。

EGF is a mitogen. We have investigated nuclear effects and mechanisms of EGF in normal C,H mouse embryo fibroblasts C3H10 T1/2 C18 (designated NC,H10) and 3HTdR transformaed C3H10T1/2 C18 (designated TC3H10).EGF exerted a direct effects on transcription activity of the isolated nuclei of NC3H10 and TC3H10. EGF (sng/mL) increased 3H-UTP incorporation into RNA of NC3H10 by 49. 7% and that of TC3H10 by 71. 8%.These results are consistent with the possibility that in addition to the classical pathway of signal transduction, EGF may play a role in regulatory control of gene transcription on nuclei directly.