AFAP-110 is required for actin stress fiber formation and cell adhesion in MDA-MB-231 breast cancer cells

J Cell Physiol. 2007 Dec;213(3):740-9. doi: 10.1002/jcp.21143.


Regulation of actin organization and dynamics is a highly complex process that involves a number of actin-binding proteins, including capping, branching, severing, sequestering, and cross-linking proteins. The actin-binding and cross-linking protein AFAP-110 is expressed in normal myoepithelial cells. Screening of different breast epithelial cell lines revealed high expression levels of AFAP-110 in the human breast cancer cell lines MDA-MB-231 and MDA-MB-435. Knockdown of AFAP-110 expression in MDA-MB-231 cells does not result in any changes in cell proliferation but did result in a loss of actin stress fiber cross-linking and decreased adhesion to fibronectin. An inducible knockdown approach confirms that MDA-MB-231 breast cancer cells require AFAP-110 expression for stress fiber formation and adhesion. Thus, AFAP-110 may provide cytoskeletal tension through stress fiber formation, which is required for focal adhesion formation. Indeed, we could not detect any focal contacts or focal adhesions in AFAP-110 knockdown cells after adhesion to fibronectin. Although expression levels of crucial focal adhesion components were not influenced by AFAP-110 expression levels, treatment of AFAP-110 knockdown cells with LPA did not result in induction of actin stress fibers and focal adhesions. In summary, AFAP-110 plays an important role in MDA-MB-231 breast cancer cell adhesion possibly by regulating stress filament cross-linking which would promote focal adhesion formation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism*
  • Amino Acid Motifs
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Cell Adhesion / physiology
  • Cell Line, Tumor
  • Cross-Linking Reagents / metabolism
  • Female
  • Fibronectins / metabolism
  • Humans
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Phosphoproteins / chemistry
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA, Small Interfering / metabolism
  • Stress Fibers / metabolism*


  • AFAP 110
  • Actins
  • Cross-Linking Reagents
  • Fibronectins
  • Microfilament Proteins
  • Phosphoproteins
  • RNA, Small Interfering