beta4 integrin-dependent formation of polarized three-dimensional architecture confers resistance to apoptosis in normal and malignant mammary epithelium.
Tumor cells can evade chemotherapy by acquiring resistance to apoptosis. We investigated the molecular mechanism whereby malignant and nonmalignant mammary epithelial cells become insensitive to apoptosis. We show that regardless of growth status, formation of polarized, three-dimensional structures driven by basement membrane confers protection to apoptosis in both nonmalignant and malignant mammary epithelial cells. By contrast, irrespective of their malignant status, nonpolarized structures are sensitive to induction of apoptosis. Resistance to apoptosis requires ligation of beta4 integrins, which regulates tissue polarity, hemidesmosome formation, and NFkappaB activation. Expression of beta4 integrin that lacks the hemidesmosome targeting domain interferes with tissue polarity and NFkappaB activation and permits apoptosis. These results indicate that integrin-induced polarity may drive tumor cell resistance to apoptosis-inducing agents via effects on NFkappaB.
Weaver
Valerie M
VM
Department of Pathology and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA. wmweaver@mail.med.upenn.edu
Lelièvre
Sophie
S
Lakins
Johnathon N
JN
Chrenek
Micah A
MA
Jones
Jonathan C R
JC
Giancotti
Filippo
F
Werb
Zena
Z
Bissell
Mina J
MJ
D017209:Apoptosis / Q000502:physiology*; D001485:Basement Membrane / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D016764:Cell Polarity; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D039663:Integrin beta4 / Q000378:metabolism* / Q000648:ultrastructure; D016328:NF-kappa B / Q000378:metabolism; D014407:Tumor Cells, Cultured
D039663:Integrin beta4; D016328:NF-kappa B