Adams J C, Watt F M
Keratinocyte Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, England.
J Cell Biol. 1988 Nov;107(5):1927-38. doi: 10.1083/jcb.107.5.1927.
We have characterized an unusual cell phenotype in third passage cultures of a human keratinocyte strain derived from newborn foreskin epidermis. The cells had the same DNA fingerprint pattern as the second passage, morphologically normal, keratinocytes; they formed desmosomes and expressed the keratin profile characteristic of normal keratinocytes in culture. However, unlike normal keratinocytes, the cells did not grow as compact colonies and did not stratify or undergo terminal differentiation, even after TPA treatment or suspension culture. For these reasons we named them ndk for "nondifferentiating keratinocytes." The ndk cells also differed from normal keratinocytes in that they did not require a feeder layer and were not stimulated by cholera toxin to proliferate. The ndk cells had an absolute requirement for hydrocortisone and their growth rate was increased when epidermal growth factor was added to the medium. Although ndk failed to undergo terminal differentiation in culture, they were not transformed, since they were still sensitive to contact inhibition of growth, did not proliferate in soft agar, and had a limited lifespan in culture. The appearance of the ndk phenotype was correlated with a doubling of chromosome number and the presence of a lp marker chromosome. We suggest that these cells are a useful experimental adjunct to cultures of normal keratinocytes, in which proliferation and terminal differentiation are tightly coordinated, because in ndk cells there appears to be a block in terminal differentiation.
我们已对源自新生儿包皮表皮的人角质形成细胞系第三代培养物中的一种异常细胞表型进行了表征。这些细胞具有与第二代形态正常的角质形成细胞相同的DNA指纹图谱；它们形成桥粒，并表达培养中正常角质形成细胞特有的角蛋白谱。然而，与正常角质形成细胞不同，这些细胞不会形成紧密的集落生长，即使在经佛波酯（TPA）处理或悬浮培养后也不会分层或进行终末分化。基于这些原因，我们将它们命名为ndk，即“未分化角质形成细胞”。ndk细胞与正常角质形成细胞的不同之处还在于它们不需要饲养层，并且不受霍乱毒素刺激而增殖。ndk细胞绝对需要氢化可的松，当向培养基中添加表皮生长因子时，其生长速率会增加。尽管ndk在培养中未能进行终末分化，但它们并未发生转化，因为它们仍对生长接触抑制敏感，不在软琼脂中增殖，并且在培养中的寿命有限。ndk表型的出现与染色体数目加倍以及一条1p标记染色体的存在相关。我们认为，这些细胞对于正常角质形成细胞培养是一种有用的实验辅助，在正常角质形成细胞培养中增殖和终末分化紧密协调，因为在ndk细胞中似乎存在终末分化障碍。
