Insulinlike growth factor-I-mediated migration and invasion of human colon carcinoma cells requires activation of c-Met and urokinase plasminogen activator receptor

Ann Surg. 2005 May;241(5):748-56; discussion 756-8. doi: 10.1097/01.sla.0000160699.59061.92.


Objective: To determine whether insulinlike growth factor-I (IGF-I) and hepatocyte growth factor (HGF) cooperate to induce migration and invasion of human colorectal carcinoma (CRC) cells and whether the effects of IGF-I and/or HGF are mediated through activation of the urokinase plasminogen activator (uPA)/uPA receptor (uPAR) system, a central mediator of tumor-cell migration and invasion.

Summary background data: CRC cells must invade through the basement membrane of the colon and migrate to form metastases. CRC cells are known to overexpress IGF-I receptor (IGF-IR), c-Met, and uPAR, 3 cell-surface receptors known to mediate cell migration and invasion. We hypothesized that IGF-IR and c-Met cooperate to induce migration and invasion in CRC cells and that this signaling is dependent on uPAR.

Methods: KM12L4 human CRC cells were treated with IGF-I, HGF, or IGF-I + HGF in transwell migration and invasion chambers; cells that had migrated or invaded were counted. To determine the role of c-Met in IGF-I-induced migration and invasion, c-Met was inhibited by infection of cells with an adenovirus containing a c-Met ribozyme; transwell assays were then repeated. To determine the role of the uPA/uPAR system in IGF-I-induced CRC cell migration and invasion, transwell assays were repeated after pretreating cells with the uPA inhibitor amiloride or with neutralizing antibodies to uPA and uPAR.

Results: IGF-I and HGF, alone or in combination, increased cell migration and invasion. The c-Met ribozyme inhibited IGF-I- and HGF-mediated migration and invasion, indicating that c-Met is essential for these processes. uPA and uPAR inhibition blocked IGF-I- and HGF-mediated migration and invasion, suggesting that uPAR is downstream of IGF/IGF-IR and HGF/c-Met in the signaling pathways that mediate cell migration and invasion.

Conclusions: IGF-I and HGF cooperate to induce migration and invasion of CRC cells, and c-Met and uPA/uPAR are required for IGF-I-mediated migration and invasion. In our in vitro model of CRC migration and invasion, uPA and uPAR appear to be downstream of IGF-IR and c-Met and are required for migration and invasion. Elucidation of the pathways that contribute to tumor progression and metastasis should provide a foundation for the rational development and use of targeted therapies for CRC.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Line, Tumor
  • Cell Movement / physiology*
  • Colorectal Neoplasms / pathology*
  • Hepatocyte Growth Factor / physiology
  • Humans
  • Insulin-Like Growth Factor I / physiology*
  • Neoplasm Invasiveness*
  • Proto-Oncogene Proteins c-met / physiology*
  • Receptors, Cell Surface / physiology*
  • Receptors, Urokinase Plasminogen Activator
  • Signal Transduction / physiology
  • Urokinase-Type Plasminogen Activator / physiology


  • PLAUR protein, human
  • Receptors, Cell Surface
  • Receptors, Urokinase Plasminogen Activator
  • Hepatocyte Growth Factor
  • Insulin-Like Growth Factor I
  • Proto-Oncogene Proteins c-met
  • Urokinase-Type Plasminogen Activator