Brick1 is an essential regulator of actin cytoskeleton required for embryonic development and cell transformation

Cancer Res. 2010 Nov 15;70(22):9349-59. doi: 10.1158/0008-5472.CAN-09-4491. Epub 2010 Sep 22.


Brick1 (Brk1) is the less-studied component of the Wave/Scar pathway involved in the branched nucleation of actin fibers. The clinical relevance of Brk1 is emphasized by correlative data showing that Von Hippel-Lindau (VHL) patients that also lose the BRK1 gene are protected against the development of tumors. This contrasts with recent evidence suggesting that the Wave complex may function as an invasion suppressor in epithelial cancers. Here, we show that the downregulation of Brk1 results in abnormal actin stress fiber formation and vinculin distribution and loss of Arp2/3 and Wave proteins at the cellular protrusions. Brk1 is required for cell proliferation and cell transformation by oncogenes. In addition, Brk1 downregulation results in defective directional migration and invasive growth in renal cell carcinoma cells as well as in other tumor cell types. Finally, genetic ablation of Brk1 results in dramatic defects in embryo compaction and development, suggesting an essential role for this protein in actin dynamics. Thus, genetic loss or inhibition of BRK1 is likely to be protective against tumor development due to proliferation and motility defects in affected cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Animals
  • Carcinoma, Renal Cell / genetics
  • Carcinoma, Renal Cell / metabolism
  • Carcinoma, Renal Cell / pathology
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Movement / physiology
  • Cell Proliferation
  • Cell Transformation, Neoplastic*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Cytoskeletal Proteins / physiology*
  • Cytoskeleton / metabolism*
  • Down-Regulation
  • Embryo, Mammalian / embryology
  • Embryo, Mammalian / metabolism
  • Embryonic Development / genetics
  • Embryonic Development / physiology*
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Kaplan-Meier Estimate
  • Kidney Neoplasms / genetics
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / secondary
  • Melanoma, Experimental / genetics
  • Melanoma, Experimental / metabolism
  • Melanoma, Experimental / pathology
  • Mice
  • Mice, Knockout
  • Mice, SCID
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction


  • Actins
  • BRK1 protein, human
  • Brick1 protein, mouse
  • Cytoskeletal Proteins