ISSN:
1573-7217
Keywords:
monoclonal antibody
;
breast cancer
;
estrogen-induced protein
;
immunohistochemistry
;
secretory protein
;
ultrastructure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary We have previously reported the production of monoclonal antibodies which detect, by immunohistochemistry, an estrogen-induced protein of molecular weight 24,000 daltons (24K). This protein, of unknown function, has been detected in: a) estrogen receptor-positive breast cancer cell lines but not in receptornegative lines; b) several human normal estrogen target organs; and c) certain human carcinomas, including breast tumors. To examine the subcellular localization of this 24K estrogen-induced protein, we have done immunohistochemical studies at light and electron microscopic levels using a human breast tumor cell line (MCF-7) grownin vitro and also in nude micein vivo. MCF-7 cells grown in the ascites fluid of nude mice and processed for paraffin sections showed a defined polarity, and the 24K protein was localized in the apical cytoplasm of the cells. After cytocentrifugation, MCF-7 cells grownin vitro displayed 24K protein mainly confined to large cytoplasmic granules. The presence of 24K protein in cytoplasmic granules was also seen by immunoelectronmicroscopy in MCF-7 cells grown bothin vitro andin vivo. The granules had different sizes, shapes, and 24K immunostaining intensity. The morphological evidence suggests that the 24K estrogeninduced protein is secreted from the cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01806037
Permalink
