Rockwell G A, Johnson G, Sibatani A
CSIRO Division of Molecular Biology, North Ryde, NSW, Australia.
Cell Struct Funct. 1987 Dec;12(6):539-48. doi: 10.1247/csf.12.539.
Human keratinocytes have been serially cultivated in low (0.015 mM) and high (1.8 mM) calcium containing medium. The calcium concentration of the growth medium significantly influenced the cell growth period in vitro. Cells grown in low calcium medium underwent 35-40 population doublings over 16-17 passages, while cells grown in high calcium medium ceased to proliferate after 20 population doublings over 7 passages. Changing the keratinocytes from one in vitro environment to the other drastically altered the lifespan in culture of populations derived from the same primary tissue. The degree of DNA methylation of human keratinocytes was shown to decrease with age in both high and low calcium culture conditions but does not appear to be associated with differentiation.
人角质形成细胞已在含低钙（0.015 mM）和高钙（1.8 mM）的培养基中连续培养。生长培养基中的钙浓度显著影响体外细胞生长周期。在低钙培养基中生长的细胞在16 - 17代中经历了35 - 40次群体倍增，而在高钙培养基中生长的细胞在7代中经历20次群体倍增后停止增殖。将角质形成细胞从一种体外环境转变为另一种体外环境，会极大地改变源自同一原代组织的细胞群体在培养中的寿命。在高钙和低钙培养条件下，人角质形成细胞的DNA甲基化程度均随年龄增长而降低，但似乎与分化无关。
