SERUM-FREE CULTURE OF TRANSFORMED AND UNTRANSFORMED MOUSE KERATINOCYTES

一种化学定义的组织培养系统，为 用BALB/MK上皮细胞系研究(1) 激活的病毒癌基因的引入改变了细胞系的 增长因素要求，以及(2)什么增长因素会导致 该细胞系的有丝分裂反应以及这些生长因子是如何 彼此互动。 在该培养体系中，未感染的BALB/MK角质形成细胞 生长只需要两种生长因子--胰岛素和 表皮生长因子(EGF)。肿瘤病毒感染的BALB/MK 展示了生长因子需求的四种模式：(1) 亲本系未改变的要求(v-raf)；(2)部分 逃避EGF要求(v-mos、v-fms、v-erbB)；(3) 完全摆脱EGF要求(v-K-ras、v-H-ras)；以及 (4)逃避所有生长因子要求(v-FGR)。 其中三种病毒感染剂，v-K-ras，v-FGR和v-fms， 展示了在EGF样活性介质中的释放， 推测是转化生长因子α。没有病毒感染剂产生胰岛素样物质 活动。 在确定的有丝分裂试验中，下列生长因子 被发现是BALB/MK有丝分裂原，按降序排列 效力：酸性成纤维细胞生长因子、碱性成纤维细胞生长因子、表皮生长因子、 还有胰岛素。胰岛素和EGF之间有协同作用。 胰岛素和基础成纤维细胞生长因子。

A chemically-defined tissue culture system developed for the BALB/MK epithelial cell line was used to study (1) how the introduction of activated viral oncogenes alters the cell line's growth factor requirements, and (2) what growth factors elicit a mitogenic response in this cell line and how these growth factors interact with each other. In this defined media system, uninfected BALB/MK keratinocytes required only two growth factors for growth--insulin and epidermal growth factor (EGF). Oncovirally infected BALB/MK demonstrated four patterns of growth factor requirements: (1) requirements unaltered from parental line (v-raf); (2) partial escape from EGF requirement (v-mos, v-fms, v-erbB); (3) complete escape from EGF requirement (v-K-ras, v-H-ras); and (4) escape from all growth factor requirements (v-fgr). Three of these viral infectants, v-K-ras, v-fgr, and v-fms, demonstrated release into the medium of EGF-like activity, presumably TGF alpha. No viral infectants produced insulin-like activity. In defined medium mitogenic assays, the following growth factors were found to be BALB/MK mitogens, in descending order of potency: acidic fibroblast growth factor (FGF), basic FGF, EGF, and insulin. Synergism was noted between insulin and EGF or insulin and basic FGF.