TY - JOUR
T1 - Relationship of sialyl-Lewisx/a underexpression and E-cadherin overexpression in the lymphovascular embolus of inflammatory breast carcinoma
AU - Alpaugh, Mary L.
AU - Tomlinson, James S.
AU - Ye, Yin
AU - Barsky, Sanford H.
N1 - Funding Information:
Supported by the California Breast Cancer Research Program (grant 6FB-0007 to M. L. A. and grant 5JB-0104 to S. H. B.), and by the Susan G. Komen Breast Cancer Foundation (grant 99-003173 to S. H. B.).
PY - 2002
Y1 - 2002
N2 - Inflammatory breast carcinoma (IBC) is characterized by florid tumor emboli within lymphovascular spaces called lymphovascular invasion. These emboli have a unique microscopic appearance of compact clumps of tumor cells retracted away from the surrounding endothelial cell layer. Using a human SCID model of IBC (MARY-X), we, in previous studies, demonstrated that the tumor cell embolus (IBC spheroid) forms on the basis of an intact and overexpressed E-cadherin/α,β-catenin axis that mediates tumor cell-tumor cell adhesion. In the present study we examine the mechanism behind the apparent lack of binding of the tumor embolus to the surrounding endothelium. We find that this lack of tumor cell binding is because of markedly decreased sialyl-Lewisx/a (sLex/a) carbohydrate ligand-binding epitopes on its overexpressed MUC1 and other surface molecules that bind endothelial E-selectin. Decreased sLex/a is because of decreased α3/4-fucosyltransferase activity in MARY-X. The decreased sLex/a fail to confer electrostatic repulsions between tumor cells, which further contributes to the compactness of the MARY-X spheroid by allowing the E-cadherin homodimeric interactions to go unopposed. MARY-X spheroids were retrovirally transfected with FucT-III cDNA, significantly raising their levels of fucosyltransferase activity and surface sLex/a. In parallel experiments, enzymatic transfers with a milk α1,3-fucosyltransferase and an α2,3-sialyltransferase (ST3GalIV) were performed on the MARY-X spheroids and increased surface sLex/a. The addition of SLex/a by either manipulation caused disadherence of the MARY-X spheroids and the disruption of the E-cadherin homodimers mediating cell adhesion. Our findings support the cooperative relationship of sLex/a underexpression and E-cadherin overexpression in the genesis of the lymphovascular embolus of IBC.
AB - Inflammatory breast carcinoma (IBC) is characterized by florid tumor emboli within lymphovascular spaces called lymphovascular invasion. These emboli have a unique microscopic appearance of compact clumps of tumor cells retracted away from the surrounding endothelial cell layer. Using a human SCID model of IBC (MARY-X), we, in previous studies, demonstrated that the tumor cell embolus (IBC spheroid) forms on the basis of an intact and overexpressed E-cadherin/α,β-catenin axis that mediates tumor cell-tumor cell adhesion. In the present study we examine the mechanism behind the apparent lack of binding of the tumor embolus to the surrounding endothelium. We find that this lack of tumor cell binding is because of markedly decreased sialyl-Lewisx/a (sLex/a) carbohydrate ligand-binding epitopes on its overexpressed MUC1 and other surface molecules that bind endothelial E-selectin. Decreased sLex/a is because of decreased α3/4-fucosyltransferase activity in MARY-X. The decreased sLex/a fail to confer electrostatic repulsions between tumor cells, which further contributes to the compactness of the MARY-X spheroid by allowing the E-cadherin homodimeric interactions to go unopposed. MARY-X spheroids were retrovirally transfected with FucT-III cDNA, significantly raising their levels of fucosyltransferase activity and surface sLex/a. In parallel experiments, enzymatic transfers with a milk α1,3-fucosyltransferase and an α2,3-sialyltransferase (ST3GalIV) were performed on the MARY-X spheroids and increased surface sLex/a. The addition of SLex/a by either manipulation caused disadherence of the MARY-X spheroids and the disruption of the E-cadherin homodimers mediating cell adhesion. Our findings support the cooperative relationship of sLex/a underexpression and E-cadherin overexpression in the genesis of the lymphovascular embolus of IBC.
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U2 - 10.1016/S0002-9440(10)64217-4
DO - 10.1016/S0002-9440(10)64217-4
M3 - Article
C2 - 12163386
AN - SCOPUS:0036966485
VL - 161
SP - 619
EP - 628
JO - American Journal of Pathology
JF - American Journal of Pathology
SN - 0002-9440
IS - 2
ER -