Heenen M, Thiriar S, Noël J C, Galand P
Department of Dermatology, Hôpital Académique Erasme, Bruxelles, Belgium.
Dermatology. 1998;197(2):123-6. doi: 10.1159/000017982.
The size of the germinative growth fraction (i.e. the number of actively proliferating germinative cells) of normal human epidermis is still a subject of debate. Ki-67 antigen and PCNA, an auxiliary protein of d-polymerase, are considered as markers of the growth fraction when used under optimal conditions.
In the present work, we have compared Ki-67 expression (detected with MIB1 antibody) with PCNA expression (detected with PC10 antibody) in biopsies of normal human epidermis fixed in neutral formalin and using antigen retrieval by microwave processing. To obtain additional information, such as the percentage of cells in S phase, biopsies were also incubated in 3H-thymidine before immunostaining.
Before microwave treatment, 8% of the basal cells were positive for MIB1 antibody and 7.8% were positive for PC10 antibody. The 3H-thymidine labelling index was 2.8%. The proportion of MIB1-positive cells rose to 19% after antigen retrieval by microwave processing. In the same way, the 3H labelling index rose to 9%. In contrast, PC10 became positive in all epidermal nuclei.
These results suggest that the growth fraction of the germinative cell population of normal human epidermis is not larger than 20% and is composed of cells with a short cell cycle time.
正常人类表皮生发层生长分数（即活跃增殖的生发细胞数量）的大小仍是一个有争议的话题。Ki-67抗原和增殖细胞核抗原（PCNA，一种DNA聚合酶的辅助蛋白）在最佳条件下使用时被视为生长分数的标志物。
在本研究中，我们比较了在中性福尔马林中固定并经微波处理进行抗原修复的正常人表皮活检组织中Ki-67表达（用MIB1抗体检测）与PCNA表达（用PC10抗体检测）。为了获得更多信息，如S期细胞百分比，活检组织在免疫染色前还进行了³H-胸腺嘧啶核苷孵育。
在微波处理前，8%的基底细胞MIB1抗体呈阳性，7.8%的基底细胞PC10抗体呈阳性。³H-胸腺嘧啶核苷标记指数为2.8%。经微波处理进行抗原修复后，MIB1阳性细胞比例升至19%。同样，³H标记指数升至9%。相比之下，PC10在所有表皮细胞核中均呈阳性。
这些结果表明，正常人类表皮生发细胞群体的生长分数不超过20%，且由细胞周期时间短的细胞组成。
