Abstract
BACKGROUND: RET/PTC rearrangement, RAS, and BRAF mutations are considered to be mutually exclusive in papillary thyroid carcinoma (PTC). However, although concomitant mutations of RET/PTC, RAS, or BRAF have been reported recently, their significance for tumor progression and survival remains unclear. We sought to examine the prognostic value of concomitant mutations in PTC.
METHODS: We investigated 88 PTC for concomitant mutations. Mutation in BRAF exon 15, KRAS, NRAS, and HRAS were studied by polymerase chain reaction (PCR)-sequencing of tumor DNA; RET/PTC rearrangement was determined by reverse transcription (RT)-PCR-sequencing of tumor cDNA.
RESULTS: BRAF(V600E) was detected in 39 of 82 classic PTC (CPTC) and in all three tall-cell variants (49%, 42/85). KRAS mutation (p.Q61R and p.S65N) was detected in two CPTC (2%, 2/88) and NRAS(Q61R) in one CPTC and two follicular variant PTC (FVPTC; 3%, 3/88). KRAS(S65N) was identified for the first time in thyroid cancer and could activate mitogen-associated protein kinase (MAPK). RET/PTC-1 was detected in nine CPTC, one tall-cell variant, and two FVPTC. Concomitant BRAF(V600E) and KRAS, or BRAF(V600E) and RET/PTC-1 mutations were found in two CPTC, and six CPTC and one tall-cell variant, respectively. In total, 11 concomitant mutations were found in 88 PTC samples (13%), and most of them were in the advanced stage of disease (8/11, 73%; p<0.01).
CONCLUSIONS: Our data show that concomitant mutations are a frequent event in advanced PTC and are associated with poor prognosis. The concomitant mutations may represent intratumor heterogeneity and could exert a gene dosage effect to promote disease progression. KRAS(S65N) can constitutively activate the MAPK pathway.
Original language | English |
---|---|
Pages (from-to) | 1256-66 |
Number of pages | 11 |
Journal | Thyroid |
Volume | 24 |
Issue number | 8 |
DOIs | |
Publication status | Published - 1 Aug 2014 |
Externally published | Yes |
Keywords
- Adolescent
- Adult
- Carcinoma/genetics
- Carcinoma, Papillary
- Cell Proliferation
- Cloning, Molecular
- DNA Mutational Analysis
- Disease Progression
- Female
- Gene Rearrangement
- Genes, ras/genetics
- Humans
- Kaplan-Meier Estimate
- MAP Kinase Signaling System
- Male
- Middle Aged
- Mutation
- PAX8 Transcription Factor
- Paired Box Transcription Factors/genetics
- Prognosis
- Proto-Oncogene Proteins B-raf/genetics
- Proto-Oncogene Proteins c-ret/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Thyroid Cancer, Papillary
- Thyroid Neoplasms/genetics
- Young Adult
- ras Proteins/genetics