Activated ras oncogenes in human thyroid cancers.
Human thyroid epithelial (follicular) cells give rise to two malignant tumors--"follicular" carcinomas, which metastasize almost exclusively via the bloodstream, and "papillary" carcinomas, which metastasize predominantly via lymphatics (Williams, E. D. In: W. Duncan (ed.), Recent Results in Cancer Research: Thyroid Cancer, pp. 47-55. Berlin: Springer-Verlag, 1980). We have investigated whether this contrast in biological behavior might be associated with different patterns of oncogene activation. DNA transfection analysis of five follicular and ten papillary cancers indeed showed a statistically significant difference in the pattern of genes responsible, activated ras oncogenes being found in 80% of follicular tumors but only 20% of papillary tumors. In addition, in follicular cancers we have found activation of all three ras oncogenes (H-ras, K-ras, and N-ras), the first time that this has been demonstrated in a primary human tumor type (as opposed to cell lines). We suggest therefore that ras activation may be an important determinant of metastatic capability in these epithelial cancers.
Lemoine
N R
NR
Department of Pathology, University of Wales College of Medicine, Heath Park, Cardiff, United Kingdom.
Mayall
E S
ES
Wyllie
F S
FS
Farr
C J
CJ
Hughes
D
D
Padua
R A
RA
Thurston
V
V
Williams
E D
ED
Wynford-Thomas
D
D
D000818:Animals; D011905:Genes, ras; D006801:Humans; D051379:Mice; D009154:Mutation; D009362:Neoplasm Metastasis; D013964:Thyroid Neoplasms / Q000235:genetics*; D014162:Transfection