Overexpression of bone morphogenetic protein 4 enhances the invasiveness of Smad4-deficient human colorectal cancer cells

Cancer Lett. 2009 Aug 28;281(2):220-31. doi: 10.1016/j.canlet.2009.02.046. Epub 2009 Mar 24.


Bone morphogenetic proteins (BMP), a member of the TGF-beta superfamily, have broad activities in regulating various kinds of cellular behaviors. Previously, we have demonstrated that BMP-4 is up-regulated in human colonic adenocarcinoma and promotes the invasive phenotypes of human colorectal cancer HCT116 cells. Smad4 is a central mediator in BMP signaling pathway and it is frequently mutated in metastatic colorectal cancers. To address whether Smad4 was required for enhancing metastatic potentials by BMP-4 in colorectal cancer, we generated BMP-4 overexpressing clones from Smad4-deficient SW480 cells. The growth rate of BMP-4 overexpressing cells was slightly higher than that of empty-vector controls. Overexpression of BMP-4 resulted in an increased expression of vimentin, a marker of epithelial-mesenchymal transition, and caused the changes of cell morphology, spreading and formation of focal adhesions. BMP-4 overexpressing cells increased cell adhesion on fibronectin and collagen, and augmented cell migration and invasion potentials in comparison to empty-vector controls. The induction of cell migration by BMP-4 overexpression was inhibited by BMP-4 siRNA. To further identify the target genes of the elevated BMP-4 signaling in SW480 cells, an oligonucleotide microarray was performed. Among 46,000 genes, 91 genes (65 up-regulated and 26 down-regulated) with 2-fold difference have been identified between BMP-4 overexpressing and empty-vector cells. This study demonstrates that Smad4 is dispensable for enhanced invasiveness of human colorectal cancer cells due to BMP-4 overexpression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Bone Morphogenetic Protein 4 / biosynthesis*
  • Bone Morphogenetic Protein 4 / genetics
  • Cell Adhesion / physiology
  • Cell Line, Tumor
  • Cell Movement / physiology
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism*
  • Colorectal Neoplasms / pathology*
  • Fluorescent Antibody Technique
  • Gene Expression
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Neoplasm Invasiveness / genetics*
  • Oligonucleotide Array Sequence Analysis
  • RNA, Small Interfering
  • Reverse Transcriptase Polymerase Chain Reaction
  • Smad4 Protein / deficiency*
  • Vimentin / biosynthesis


  • BMP4 protein, human
  • Bone Morphogenetic Protein 4
  • RNA, Small Interfering
  • SMAD4 protein, human
  • Smad4 Protein
  • Vimentin