Oncogene  1989 Feb;4(2):159-64 

High frequency of ras oncogene activation in all stages of human thyroid
tumorigenesis.

Lemoine NR, Mayall ES, Wyllie FS, Williams ED, Goyns M, Stringer B,
Wynford-Thomas D.

Department of Pathology, University of Wales College of Medicine, Health Park,
Cardiff, UK.

Using polymerase chain reaction amplification and oligonucleotide probing, the
activation of ras oncogenes in 24 benign and 20 malignant human thyroid
neoplasms was examined. The frequency of ras oncogene activation was similar at
all stages of tumorigenesis in this system, being found in 33% of adenomas
overall (50% of microfollicular tumours), 53% of differentiated follicular
carcinomas and 60% of undifferentiated carcinomas. This supports the contention
that mutation of these oncogenes occurs at an early step in tumorigenesis. The
predominant amino acid substitution in the differentiated tumours was glutamine
to arginine at position 61 of Ha-ras or N-ras, but this mutation was not found
in any of the undifferentiated tumours. It was noted that while transition
mutations predominated in differentiated tumours (both benign and malignant),
transversions were more common in the undifferentiated tumours.

PMID: 2648253 [PubMed - indexed for MEDLINE]