TY - JOUR
T1 - A role for dystroglycan in epithelial polarization
T2 - Loss of function in breast tumor cells
AU - Muschler, John
AU - Levy, Dinah
AU - Boudreau, Roseanne
AU - Henry, Michael
AU - Campbell, Kevin
AU - Bissell, Mina J.
PY - 2002/12/1
Y1 - 2002/12/1
N2 - Receptors mediating cell-basement membrane interactions are potent regulators of epithelial architecture and function, and alterations in signals from the basement membrane are implicated in the aberrant behavior of carcinoma cells. In this study, we have investigated the role of the basement membrane receptor dystroglycan (DG) in mammary epithelial cell function, and the significance of loss of DG function in breast tumor cell lines. Nonmalignant mammary epithelial cells express a functional DG. Analysis of multiple breast carcinoma cell lines revealed that DG is expressed in all of the cell lines examined, as evidenced by β-DG expression, but that α-DG is functionally diminished in the majority. High levels of α-DG correlated strongly with the ability of cells to polarize in the presence of the basement membrane. Overexpression of the DG cDNA in HMT-3522-T4-2 cells elevated α-DG levels and altered responsiveness to the basement membrane; DG overexpression restored the ability of the cells to undergo cytoskeletal changes, to polarize, and to restrict growth in response to basement membrane proteins. Moreover, restoration of DG function to these cells greatly reduced their tumorigenic potential in nude mice. These data point to DG as an important mediator of normal cell responses to the basement membrane, and as a significant variable in carcinoma cells, in which its frequent loss can contribute to aberrant cell behavior.
AB - Receptors mediating cell-basement membrane interactions are potent regulators of epithelial architecture and function, and alterations in signals from the basement membrane are implicated in the aberrant behavior of carcinoma cells. In this study, we have investigated the role of the basement membrane receptor dystroglycan (DG) in mammary epithelial cell function, and the significance of loss of DG function in breast tumor cell lines. Nonmalignant mammary epithelial cells express a functional DG. Analysis of multiple breast carcinoma cell lines revealed that DG is expressed in all of the cell lines examined, as evidenced by β-DG expression, but that α-DG is functionally diminished in the majority. High levels of α-DG correlated strongly with the ability of cells to polarize in the presence of the basement membrane. Overexpression of the DG cDNA in HMT-3522-T4-2 cells elevated α-DG levels and altered responsiveness to the basement membrane; DG overexpression restored the ability of the cells to undergo cytoskeletal changes, to polarize, and to restrict growth in response to basement membrane proteins. Moreover, restoration of DG function to these cells greatly reduced their tumorigenic potential in nude mice. These data point to DG as an important mediator of normal cell responses to the basement membrane, and as a significant variable in carcinoma cells, in which its frequent loss can contribute to aberrant cell behavior.
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M3 - Article
C2 - 12460932
AN - SCOPUS:0036894605
SN - 0008-5472
VL - 62
SP - 7102
EP - 7109
JO - Cancer Research
JF - Cancer Research
IS - 23
ER -