Tischler A S, Greene L A
Adv Biochem Psychopharmacol. 1980;25:61-8.
Much of the phenotypic plasticity exhibited by pheochromocytoma cells is shown by normal immature chromaffin cells. Considerable plasticity is also retained by human adrenal medullary cells and probably by adrenal medullary cells of other species in adult life. Many of the cells which exhibit this plasticity have or acquire characteristics of SIF cells. There are a number of unexplained differences among pheochromocytoma, immature and adult chromaffin cells in vivo and in vitro, particularly with regard to NGF requirements for cell survival and maintenance of processes, the role of endogenous NGF-like substances in promoting neurite outgrowth, glucocorticoid modulation of NGF responsiveness, and selective enzyme induction by NGF and steroids. Continued parallel studies of pheochromocytoma lines and normal chromaffin cells might help to clarify morphological and functional interrelationships within and between classes of sympathetic cells, and to elucidate mechanisms which regulate growth and phenotypic expression in these cells in normal and neoplastic states.
嗜铬细胞瘤细胞表现出的许多表型可塑性在正常未成熟嗜铬细胞中也有体现。人类肾上腺髓质细胞在成年期也保留了相当大的可塑性，其他物种的肾上腺髓质细胞可能也是如此。许多表现出这种可塑性的细胞具有或获得了SIF细胞的特征。嗜铬细胞瘤、未成熟和成年嗜铬细胞在体内和体外存在一些无法解释的差异，特别是在细胞存活和突起维持对神经生长因子（NGF）的需求、内源性NGF样物质在促进神经突生长中的作用、糖皮质激素对NGF反应性的调节以及NGF和类固醇对选择性酶的诱导方面。对嗜铬细胞瘤系和正常嗜铬细胞持续进行平行研究，可能有助于阐明交感细胞类别内部和之间的形态学和功能相互关系，并阐明在正常和肿瘤状态下调节这些细胞生长和表型表达的机制。
