Regeneration of secretory epithelium in the human endocervix

Biopsies of hum endocervix were obtained from healthy women at day 5, 15, and 25 of the menstrual cycle, and immediately incubated with 3H-thymidine in a culture medium for 1 to 2 h. A few labelled nuclei were found in thick, semi-thin, and ultra-thin sections and indicated that gland cells of the columnar epithelium of the endocervix were capable of DNA synthesis and hence mitosis, independent of the menstrual cycle. As basal or "reserve" cells were less frequently labelled than differentiated epithelial cells, the findings suggested renewal of the secretory epithelium of the endocervix without cell replacement by basal or "reserve" cells. We discuss the implications of the results for the understanding of normal and neoplastic regeneration and for the treatment of cancer.