Nras loss induces metastatic conversion of Rb1-deficient neuroendocrine thyroid tumor Academic Article uri icon


MeSH Major

  • Genes, ras
  • Neuroendocrine Tumors
  • Retinoblastoma Protein
  • Thyroid Neoplasms


  • Mutations in the gene encoding the retinoblastoma tumor suppressor predispose humans and mice to tumor development. Here we have assessed the effect of Nras loss on tumor development in Rb1 heterozygous mice. Loss of one or two Nras alleles is shown to significantly reduce the severity of pituitary tumors arising in Rb1(+/-) animals by enhancing their differentiation. By contrast, C-cell thyroid adenomas occurring in Rb1(+/-) mice progress to metastatic medullary carcinomas after loss of Nras. In Rb1(+/-)Nras(+/-) animals, distant medullary thyroid carcinoma metastases are associated with loss of the remaining wild-type Nras allele. Loss of Nras in Rb1-deficient C cells results in elevated Ras homolog family A (RhoA) activity, and this is causally linked to the invasiveness and metastatic behavior of these cells. These findings suggest that the loss of the proto-oncogene Nras in certain cellular contexts can promote malignant tumor progression.

publication date

  • January 2006



  • Academic Article



  • eng

Digital Object Identifier (DOI)

  • 10.1038/ng1703

PubMed ID

  • 16369533

Additional Document Info

start page

  • 118

end page

  • 23


  • 38


  • 1