Special Distribution of the EGF Receptor System in the Regulation of Breast Epithelia Cell Growth and Organization.
Annual rept. 15 May 95-14 May 96
UTAH UNIV SALT LAKE CITY
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184A1 human mammary epithelial cells HMECs form organotypic structures when plated on Matrigel however, after three weeks on matrigel l84Al cells do not form polarized, glandular epithelial structures, nor do they polarize if plated onto Transwell tissue culture inserts. Therefore, i84Ais can not he used to address the primary aim of my proposal to determine if the loss of the correct spatial organization or inappropriate expression of the EGF-R system provides a growth advantage, enhances motility, or changes the differentiated state of normal cells. MCF-7 cells do express a phenotype consistent with polarized epithelia when plated on Transwells, however, MCF-7 are so loosely adherent to transwells that they are refractory to typical experimental manipulation. HB2 cells are a normal, non-transformed mammary epithelial cell line that expresses high numbers of EGF-R, are tightly adherent to transwells, and polarize on transwells as determined by immunofluorescence localization of ZO-1, the EGF-R and Beta-1 integrin. HB2 may provide an experimental system with which to address the primary of my proposal. Preliminary experiments comparing 184A1s and HB2 have revealed an interesting and novel finding--rapid internalization of EGF-R can be uncoupled from the normal negative regulatory process of down-regulation.
- Anatomy and Physiology