A continuous cell line (HBL-100) was obtained from primary cultures of cells derived from an early lactation sample of human milk. There was no evidence of a breast lesion in the milk donor. Karyotype analysis showed that all metaphases contained human chromosomes including a large acrocentric marker chromosome. Both desmosomes and cytoplasmic tonofibrils were observed during early passage. HBL-100 cells exhibited several characteristics of transformation including the ability to form colonies in soft agar, an aneuploid chromosome complement, and continuous growth.
This study traced the origin of cells observed in human breast secretion samples obtained during lactation and describes the appearance of these cells following prolonged maintenance in vitro. Human milk contains a large number of single vacuolated foam celsl and a small proportion of non-vacuolated epithelial cells in clusters. Foam cells are identified by their large size, the polarity of their cytoplasmic organelles, the variation in number and size of lipid vacuoles and the condensed chromatin of their eccentrically located nucleus. Both cell types originate by exfoliation from the mammary gland. This was established by comparing the structural characteristics of cells isolated from milk with those of the cuboidal cell linings of ducts and alveoli in lactating mammary tissue. Relatively pure populations of foam cells could be established from early lactation samples (3-7 days post/partum) while non-vacuolated epithelial cell clusters were more frequently cultured from late lactation specimens (1-10 days postweaning). Foam cells did not divide and lost cytoplasmic organization during prolonged culture. In contrast, non-vacuolated epithelium in clusters proliferated to form colonies of polygonal cells. These results, which imply that foam cells are an active form of the non-vacuolated mammary cells in clusters, call attention to one system for the study of the complex hormonal interactions necessary to induce and maintain lactation.
Several cultured human squamous cell carcinoma cell lines (SCC-4, SCC-12B2, SCC-12F2, EC-GI-10, and BEN) and one normal keratinocyte line (Epy-1) were investigated for the production of bone resorption-stimulating activity (BRSA). Conditioned medium (CM) from each of the six cell lines stimulated bone resorption in neonatal mouse calvariae in culture. The BRSA of SCC-12F2 and EC-GI-10 was inhibited completely by antibody to interleukin-1 alpha (IL-1 alpha), whereas the BRSA in CM from the BEN, SCC-4, SCC-12B2, and Epy-1 cell lines was only partially inhibited by anti-IL-1 alpha. Addition of indomethacin to the calvarial cultures also partially inhibited the BRSA from EC-GI-10, SCC-4, SCC-12B2, and Epy-1 cells; the BRSA from BEN and SCC-12F2 cells was inhibited completely by indomethacin. cAMP production by calvariae was determined after a 60-min incubation with CM. CM from EC-GI-10, BEN, SCC-4, and Epy-1 stimulated cAMP production by bone. Preincubation of CM from BEN, EC-GI-10, SCC-4, and Epy-1 cells with two antisera against PTH-related protein [PTHrP; one specific for two PTHrP-(1-141), the other recognizing both PTHrP-(1-40) and PTHrP-(1-141)] completely inhibited the cAMP-stimulating activity. Using specific enzyme-linked immunosorbent assays for IL-1 alpha and IL-1 beta, IL-1 alpha was measured in CM of the SCC-4, SCC-12B2, SCC-12F2, and Epy-1 cell lines. IL-1 beta was undetectable (less than 0.1 ng/ml) in CM from all cell lines. Our findings indicate that the BRSA secreted by SCC-12F2 cells can be accounted for largely or entirely by IL-1 alpha, while the activity produced by SCC-12B2 includes IL-1 alpha and another unknown factor(s). The BRSA produced by EC-GI-10, BEN, SCC-4, and Epy-1 cells includes both IL-1 alpha and PTHrP. We conclude that IL-1 alpha may be a more prevalent and biologically significant component of the BRSA produced by SCCs than previously recognized.
Contamination of Strain L cell cultures by pleuropneumonia-like organismtis (PPLO) resulted in a complete inhibition of the incorporation of tritiated thymnidine and uridine. Contanminated cultures were characterized by a concentration of PPLO along the margins of the cells and in the intercellular-spaces of the cultures. Autoracliograins of PPLO-contaminated cultures were characterized by exposed silver grains over the margins of the cells. Kanamnycin was efjective in the elimination of PPLO and the restoration of nucleoside incorporation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.