Diabetes may increase risk for oral cancer through the insulin receptor substrate-1 and focal adhesion kinase pathway

Oral Oncol. 2007 Feb;43(2):165-73. doi: 10.1016/j.oraloncology.2006.02.004. Epub 2006 Jul 24.


In light of recent epidemiological studies that associate diabetes mellitus with increased risk for oral cancer, we investigated in diabetic (type I) and normal rats with induced oral squamous cell carcinoma whether the molecular basis for that putative association involves insulin receptor substrate-1 (IRS-1) and focal adhesion kinase (FAK). Fourteen diabetic and 12 normal rats developed cancer after 4-nitroquinoline-N-oxide treatment, while six diabetic and six normal animals were used as controls. Oral sections were studied using monoclonal antibodies against IRS-1 and FAK proteins. Expression of IRS-1 was significantly higher in diabetic than normal rats, but it decreased in diabetic animals with tumor, especially in more advanced stages. FAK expression was significantly higher in rats with cancer in comparison to the ones without it, regardless the diabetes status. These data suggest that the IRS-1/FAK pathway is altered by diabetes resulting in reduced cell adhesion and possibly increasing risk for oral cancer.

MeSH terms

  • Animals
  • Cell Transformation, Neoplastic / metabolism
  • Cell Transformation, Neoplastic / pathology
  • Diabetes Mellitus, Experimental / complications*
  • Diabetes Mellitus, Experimental / metabolism
  • Disease Progression
  • Disease Susceptibility
  • Female
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism
  • Focal Adhesion Protein-Tyrosine Kinases / physiology*
  • Image Processing, Computer-Assisted / methods
  • Insulin Receptor Substrate Proteins
  • Mouth Neoplasms / etiology*
  • Mouth Neoplasms / metabolism
  • Mouth Neoplasms / pathology
  • Neoplasm Invasiveness
  • Phosphoproteins / metabolism
  • Phosphoproteins / physiology*
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction


  • Insulin Receptor Substrate Proteins
  • Irs1 protein, rat
  • Phosphoproteins
  • Focal Adhesion Protein-Tyrosine Kinases