Effects of maturational agents on expression and secretion of two partially characterized high molecular weight milk-related glycoproteins in MCF-7 breast carcinoma cells
✍ Scribed by Miyako Abe; Donald Kufe
- Publisher
- John Wiley and Sons
- Year
- 1986
- Tongue
- English
- Weight
- 811 KB
- Volume
- 126
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
We have previously defined a human mammary epithelial antigen using a murine monoclonal antibody (MAb), designated DF3, prepared against a membrane-enriched fraction of a h u m a n breast carcinoma. MAb DF3 detects a cell surface antigen with a molecular weight (mw) of approximately 300 Kd and a higher mw species also detectable in h u m a n milk. These findings and the demonstration that butyric acid (BA) increases DF3 antigen expression suggested that MAb DF3 reacts with a differentiation antigen detectable in h u m a n breast carcinoma cells. The results of the present study demonstrate that MAb DF3 reacts with two mucin-like high mw glycoproteins (330 and 450 Kd) present in MCF-7 breast carcinoma cells. The results also demonstrate that t h e intracellular content and secretion of DF3 antigen is increased by 12-0-tetradecanoylphorbol-13-acetate (TPA) and I-0-D-arabinofuranosylcytosine (ara-C). Other known inducers of differentiation including retinoic acid (RA), hexamethylene bisacetamide (HMBA), 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) and certain polar solvents decrease DF3 antigen expression. Furthermore, the results demonstrate that DF3 antigen is secreted and that the extent coincides with changes in intracellular content. Finally, actinomycin D and cycloheximide inhibit the increases in DF3 antigen expression following TPA treatment thus suggesting that newly synthesized RNA and protein are required for induction of this antigen. Thus, the monitoring of DF3 antigen expression may provide a marker for studying maturation of h u m a n breast cancer cells.