Faulkner L, Katz D R, Brickell P M
Department of Biochemistry and Molecular Biology, Bland Sutton Institute, University College and Middlesex School of Medicine, London, United Kingdom.
Immunobiology. 1993 Aug;188(4-5):460-8. doi: 10.1016/S0171-2985(11)80227-5.
The c-fgr proto-oncogene is expressed in Burkitt's lymphoma (BL) cell and cell lines derived from them. When Epstein-Barr virus (EBV)-negative BL cell lines that contain low levels of c-fgr mRNA are infected with EBV, transcription of the c-fgr gene is further induced. In this paper we show that treatment of EBV-negative and EBV-positive BL cell lines with all-trans retinoic acid also stimulates an increase in c-fgr mRNA levels, varying between 2- and 13-fold depending on the cell line. An increase is detectable 12 to 48 h after treatment, depending on the cell line, suggesting that the c-fgr gene is not regulated directly by retinoic acid but responds to other retinoic acid-induced changes in the cell. We also show that treatment of BL cell lines with all-trans retinoic acid either results in a dose-dependent decrease in growth rate, or has no effect on growth, depending on the cell line. It has previously been suggested that the c-fgr gene product might have a role in regulating the growth of BL cells, since treatment of the EBV-positive BL cell line Daudi with alpha-interferon results in a decrease in c-fgr mRNA levels followed by a decrease in growth rate. Our data indicate that there is no general correlation between c-fgr mRNA levels and growth rate in BL cells and so argue against a role for the c-fgr gene product in growth regulation in these cells.
原癌基因c-fgr在伯基特淋巴瘤（BL）细胞及其衍生的细胞系中表达。当含有低水平c-fgr mRNA的爱泼斯坦-巴尔病毒（EBV）阴性BL细胞系被EBV感染时，c-fgr基因的转录会进一步被诱导。在本文中，我们表明用全反式维甲酸处理EBV阴性和EBV阳性BL细胞系也会刺激c-fgr mRNA水平升高，升高幅度在2至13倍之间，具体取决于细胞系。处理后12至48小时可检测到升高，具体取决于细胞系，这表明c-fgr基因不是直接受维甲酸调控，而是对细胞中其他维甲酸诱导的变化做出反应。我们还表明，用全反式维甲酸处理BL细胞系，要么导致生长速率呈剂量依赖性下降，要么对生长没有影响，具体取决于细胞系。此前有人提出，c-fgr基因产物可能在调节BL细胞生长中起作用，因为用α-干扰素处理EBV阳性BL细胞系Daudi会导致c-fgr mRNA水平下降，随后生长速率降低。我们的数据表明，BL细胞中c-fgr mRNA水平与生长速率之间没有普遍的相关性，因此反对c-fgr基因产物在这些细胞生长调节中起作用的观点。
