Transcription factors c-Myc and CDX2 mediate E-selectin ligand expression in colon cancer cells undergoing EGF/bFGF-induced epithelial-mesenchymal transition.

Abstract

Sialyl Lewis x (sLe(x)) and sialyl Lewis a (sLe(a)) glycans are expressed on highly metastatic colon cancer cells. They promote extravasation of cancer cells and tumor angiogenesis via interacting with E-selectin on endothelial cells. Recently, epithelial-mesenchymal transition (EMT) has been noted as a critical phenotypic alteration in metastatic cancer cells. To address the association between sLe(x/a) expression and EMT, we assessed whether sLe(x/a) are highly expressed on colon cancer cells undergoing EMT. Treatment of HT29 and DLD-1 cells with EGF and/or basic FGF (bFGF) induced EMT and significantly increased sLe(x/a) expression resulting in enhanced E-selectin binding activity. The transcript levels of the glycosyltransferase genes ST3GAL1/3/4 and FUT3 were significantly elevated and that of FUT2 was significantly suppressed by the treatment. We provide evidence that ST3GAL1/3/4 and FUT3 are transcriptionally up-regulated by c-Myc with probable involvement of Ser62 phosphorylation, and that FUT2 is transcriptionally down-regulated through the attenuation of CDX2. The contribution of c-Myc and CDX2 to the sLe(x/a) induction was proved to be significant by knockdown or forced expression experiments. Interestingly, the cells undergoing EMT exhibited significantly increased VEGF secretion, which can promote tumor angiogenesis in cooperation with sLe(x/a). Finally, immunohistological study indicated high E-selectin ligand expression on cancer cells undergoing EMT in vivo, supporting their coexistence observed in vitro. These results suggest a significant link between sLe(x/a) expression and EMT in colon cancer cells and a pivotal role of c-Myc and CDX2 in regulating sLe(x/a) expression during EMT.

• Authors: Keiichiro Sakuma, Masahiro Aoki, Reiji Kannagi
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 109 Issue 20 Pg. 7776-81 (May 15 2012) ISSN: 1091-6490 [Electronic] United States
• PMID: 22547830 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Monoclonal
• CA-19-9 Antigen
• CDX2 Transcription Factor
• CDX2 protein, human
• DNA Primers
• E-Selectin
• Homeodomain Proteins
• MYC protein, human
• Oligosaccharides
• Proto-Oncogene Proteins c-myc
• Sialyl Lewis X Antigen
• fibroblast growth factor 13
• Fibroblast Growth Factors

Topics

• Antibodies, Monoclonal
• Blotting, Western
• CA-19-9 Antigen
• CDX2 Transcription Factor
• Cell Line, Tumor
• Chromatin Immunoprecipitation
• Colonic Neoplasms (physiopathology)
• DNA Primers (genetics)
• E-Selectin (metabolism)
• Enzyme-Linked Immunosorbent Assay
• Epithelial-Mesenchymal Transition (physiology)
• Fibroblast Growth Factors (metabolism)
• Flow Cytometry
• Gene Expression Regulation, Neoplastic (genetics, physiology)
• Homeodomain Proteins (metabolism)
• Humans
• Immunohistochemistry
• Oligosaccharides (metabolism)
• Proto-Oncogene Proteins c-myc (metabolism)
• Real-Time Polymerase Chain Reaction
• Sialyl Lewis X Antigen