Abstract
Selectin-mediated adhesion of tumor cells to platelets, leukocytes, and endothelial cells may regulate their hematogenous dissemination in the microvasculature. We recently identified CD44 variant isoforms (CD44v) as functional P-, but not E- or L-, selectin ligands on colon carcinoma cells. Moreover, an ∼180-kDa sialofucosylated glycoprotein(s) mediated selectin binding in CD44-knockdown cells. Using immunoaffinity chromatography and tandem mass spectrometry, we identify this glycoprotein as the carcinoembryonic antigen (CEA). Blot rolling assays and flow-based adhesion assays using microbeads coated with CEA immunopurified from LS174T colon carcinoma cells and selectins as substrate reveal that CEA possesses E- and L-, but not P-, selectin ligand activity. CEA on CD44-knockdown LS174T cells exhibits higher HECA-452 immunoreactivity than CEA on wild-type cells, suggesting that CEA functions as an alternative acceptor for selectin-binding glycans. The enhanced expression of HECA-452 reactive epitopes on CEA from CD44-knockdown cells correlates with the increased CEA avidity for E- but not L-selectin. Through the generation of stable knockdown cell lines, we demonstrate that CEA serves as an auxiliary L-selectin ligand, which stabilizes L-selectin-dependent cell rolling against fluid shear. Moreover, CEA and CD44v cooperate to mediate colon carcinoma cell adhesion to E- and L-selectin at elevated shear stresses. The novel finding that CEA is an E- and L-selectin ligand may explain the enhanced metastatic potential associated with tumor cell CEA overexpression and the supportive role of selectins in metastasis.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 15647-15655 |
| Number of pages | 9 |
| Journal | Journal of Biological Chemistry |
| Volume | 283 |
| Issue number | 23 |
| DOIs | |
| State | Published - Jun 6 2008 |
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ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Molecular Biology
Cite this
Carcinoembryonic antigen and CD44 variant isoforms cooperate to mediate colon carcinoma cell adhesion to E- and L-selectin in shear flow. / Thomas, Susan N.; Zhu, Fei; Schnaar, Ronald Lee; Alves, Christina S.; Konstantopoulos, K.
In: Journal of Biological Chemistry, Vol. 283, No. 23, 06.06.2008, p. 15647-15655.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Carcinoembryonic antigen and CD44 variant isoforms cooperate to mediate colon carcinoma cell adhesion to E- and L-selectin in shear flow
AU - Thomas, Susan N.
AU - Zhu, Fei
AU - Schnaar, Ronald Lee
AU - Alves, Christina S.
AU - Konstantopoulos, K
PY - 2008/6/6
Y1 - 2008/6/6
N2 - Selectin-mediated adhesion of tumor cells to platelets, leukocytes, and endothelial cells may regulate their hematogenous dissemination in the microvasculature. We recently identified CD44 variant isoforms (CD44v) as functional P-, but not E- or L-, selectin ligands on colon carcinoma cells. Moreover, an ∼180-kDa sialofucosylated glycoprotein(s) mediated selectin binding in CD44-knockdown cells. Using immunoaffinity chromatography and tandem mass spectrometry, we identify this glycoprotein as the carcinoembryonic antigen (CEA). Blot rolling assays and flow-based adhesion assays using microbeads coated with CEA immunopurified from LS174T colon carcinoma cells and selectins as substrate reveal that CEA possesses E- and L-, but not P-, selectin ligand activity. CEA on CD44-knockdown LS174T cells exhibits higher HECA-452 immunoreactivity than CEA on wild-type cells, suggesting that CEA functions as an alternative acceptor for selectin-binding glycans. The enhanced expression of HECA-452 reactive epitopes on CEA from CD44-knockdown cells correlates with the increased CEA avidity for E- but not L-selectin. Through the generation of stable knockdown cell lines, we demonstrate that CEA serves as an auxiliary L-selectin ligand, which stabilizes L-selectin-dependent cell rolling against fluid shear. Moreover, CEA and CD44v cooperate to mediate colon carcinoma cell adhesion to E- and L-selectin at elevated shear stresses. The novel finding that CEA is an E- and L-selectin ligand may explain the enhanced metastatic potential associated with tumor cell CEA overexpression and the supportive role of selectins in metastasis.
AB - Selectin-mediated adhesion of tumor cells to platelets, leukocytes, and endothelial cells may regulate their hematogenous dissemination in the microvasculature. We recently identified CD44 variant isoforms (CD44v) as functional P-, but not E- or L-, selectin ligands on colon carcinoma cells. Moreover, an ∼180-kDa sialofucosylated glycoprotein(s) mediated selectin binding in CD44-knockdown cells. Using immunoaffinity chromatography and tandem mass spectrometry, we identify this glycoprotein as the carcinoembryonic antigen (CEA). Blot rolling assays and flow-based adhesion assays using microbeads coated with CEA immunopurified from LS174T colon carcinoma cells and selectins as substrate reveal that CEA possesses E- and L-, but not P-, selectin ligand activity. CEA on CD44-knockdown LS174T cells exhibits higher HECA-452 immunoreactivity than CEA on wild-type cells, suggesting that CEA functions as an alternative acceptor for selectin-binding glycans. The enhanced expression of HECA-452 reactive epitopes on CEA from CD44-knockdown cells correlates with the increased CEA avidity for E- but not L-selectin. Through the generation of stable knockdown cell lines, we demonstrate that CEA serves as an auxiliary L-selectin ligand, which stabilizes L-selectin-dependent cell rolling against fluid shear. Moreover, CEA and CD44v cooperate to mediate colon carcinoma cell adhesion to E- and L-selectin at elevated shear stresses. The novel finding that CEA is an E- and L-selectin ligand may explain the enhanced metastatic potential associated with tumor cell CEA overexpression and the supportive role of selectins in metastasis.
UR - http://www.scopus.com/inward/record.url?scp=47049127247&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=47049127247&partnerID=8YFLogxK
U2 - 10.1074/jbc.M800543200
DO - 10.1074/jbc.M800543200
M3 - Article
C2 - 18375392
AN - SCOPUS:47049127247
VL - 283
SP - 15647
EP - 15655
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 23
ER -