Table I.

Names and descriptions of cell lines and subclones used in the study.

Cell line	Description
HB2	Cell line established from human luminal mammary epithelial cells (14)
HB2/tnz34	HB2 cells stably transfected with the trk-neu hybrid receptor (5)
Tr-ep	HB2/tnz34 cells stably transfected with the tetracycline repressor; epithelial morphology
Tr-fib	Tr-ep cells having undergone EMT as a result of c-erbB2 signalling (NGF treatment); fibroblastoid morphology
TrE-ep1 TrE-ep5	Tr-ep cells stably expressing wild-type E-cadherin and GFP under the tetracycline operator; epithelial morphology
TrE-fib	Clone of TrE-ep1 cells having undergone EMT as a result of c-erbB2 signalling (NGF treatment) with concomitant ectopic E-cadherin expression (dox treatment); fibroblastoid morphology
TrEWV-ep	Tr-ep cells stably expressing the E-cadherin WV156-157AA mutant and GFP under the tetracycline operator; epithelial morphology
TrGFP-ep	Tr-ep cells stably expressing the ‘empty’ IRES-GFP construct under the tetracycline operator; epithelial morphology