. Author manuscript; available in PMC: 2010 Sep 3.

Published in final edited form as: Integr Biol (Camb). 2008 Nov 12;1(1):70–79. doi: 10.1039/b816472j

Table 1.

Summary of conditions that have functional consequences in mammary progenitors

Signaling proteins that also exist in vivo	Cell fate	ECM	BrdU incorporation	Antagonists	Proposed function for progenitors
Laminin1	Dependent on partner		Decrease	None identified	Maintains quiescence suppresses growth
Jagged1	^aK14⁺/K19⁺ progenitor	Collagen4-rich Laminin1-rich (e.g. Matrigel)	Dependent on partner	GSI, AG, LY anti-β1, α6 integrins anti-EGFR	Maintains the progenitor cell pool
P-Cadherin	K14⁺/K19⁻/K8⁻ MEP	All	Decrease	GSI, LY, anti-α6,-β4,-β1 integrins	Guides differentiation into MEP
E-Cadherin (or a cell–cell contact)	K14⁻/K19⁺/K8⁺ GATA3⁺ LEP	Collagen1	ND	^bEGTA ^bCa⁺⁺-free media	Facilitates differentiation into LEP

MEP = myoepithelial, LEP = luminal epithelial, GSI = γ-secretase inhibitor, AG = AG1478, LY = LY294002, ND = no data.

Paired with collagen1, Jagged1 induced an K14⁺/K19⁻/K8⁻ MEP- or basal-like phenotype that was not consistently growth suppressed.

5 mM EGTA for 24 h or Ca ⁺⁺ -free media prevented generation of the K14⁻/K8 ⁺. LEP cells under conditions where cell–cell contact was permitted (data not shown).