Welsh M, Welsh N, Nilsson T, Arkhammar P, Pepinsky R B, Steiner D F, Berggren P O
Department of Medical Cell Biology, Uppsala University, Sweden.
Proc Natl Acad Sci U S A. 1988 Jan;85(1):116-20. doi: 10.1073/pnas.85.1.116.
Although the growth potential of the pancreatic islet beta cells is limited, glucose, cAMP, and certain polypeptide growth factors have been reported by other workers to exert modest stimulatory effects on beta-cell replication. To further assess means through which beta-cell growth can be stimulated, selected oncogene constructs linked to a rat insulin promoter were introduced by means of electroporation into free islet cells prepared from fetal rats and adult hyperglycemic obese (ob/ob) mice. The uptake and expression of the added oncogenes were sufficiently efficient to exert effects on beta-cell physiology in short-term experiments (less than or equal to 4 days). Stimulation of islet cell [3H]thymidine incorporation was observed after transfection with src alone or the combination of myc and ras. The effect observed in the fetal islet cells with src was more pronounced than any effect previously reported. Transfection with the src oncogene resulted in phosphorylation of lipocortin I and was paralleled by an increased immunofluorescence against src-like immunoreactivity in a majority of the electroporated cells. It is concluded that electroporation can induce sufficiently efficient expression of added oncogene constructs to study their effects on cells that are not readily transformable into continuously growing cell lines. Furthermore, the results suggest that beta-cell replication might be manipulated extrinsically by inserting appropriate growth-promoting genes into these cells.
尽管胰岛β细胞的生长潜力有限，但其他研究人员报告称，葡萄糖、环磷酸腺苷（cAMP）和某些多肽生长因子对β细胞复制有适度的刺激作用。为了进一步评估刺激β细胞生长的方法，通过电穿孔将与大鼠胰岛素启动子相连的选定癌基因构建体导入从胎鼠和成年高血糖肥胖（ob/ob）小鼠制备的游离胰岛细胞中。在短期实验（小于或等于4天）中，添加的癌基因的摄取和表达效率足以对β细胞生理产生影响。单独用src或myc与ras的组合转染后，观察到胰岛细胞[3H]胸腺嘧啶核苷掺入增加。在胎胰岛细胞中观察到的src效应比以前报道的任何效应都更明显。用src癌基因转染导致脂质皮质素I磷酸化，并且在大多数电穿孔细胞中，针对src样免疫反应性的免疫荧光增加与之平行。得出的结论是，电穿孔可以诱导添加的癌基因构建体充分有效地表达，以研究它们对不易转化为连续生长细胞系的细胞的影响。此外，结果表明，通过将适当的促生长基因插入这些细胞中，可能从外部操纵β细胞复制。
