Low rate of ret proto-oncogene activation (PTC/retTPC) in papillary thyroid carcinomas from Saudi Arabia.
BACKGROUND
The ret proto-oncogene activation (PTC/retTPC oncogene) in thyroid papillary carcinoma has been reported in different populations with different frequencies. Thyroid papillary carcinoma appears to behave more aggressively in the Persian Gulf region than elsewhere. In the current study, the frequency of PTC/retTPC oncogene in thyroid tumors from Saudi Arabia was investigated.


METHODS
PTC/retTPC oncogene transcripts were analyzed by the polymerase chain reaction amplification of cDNA synthesized by treatment of total RNA with reverse transcriptase. Seven multinodular goiters, 1 follicular adenoma, 4 follicular carcinomas, 40 papillary carcinomas, and 5 anaplastic carcinomas were studied.


RESULTS
Only one papillary carcinoma specimen was found to have PTC/retTPC oncogene transcripts. The breakpoint of the rearranged PTC/retTPC oncogene is identical to that previously described. The PTC/retTPC-positive sample was also examined for p53 tumor suppressor gene mutations in exons 5-8. One transitional point mutation was detected at codon 161 (GCC to ACC), changing Ala to Thr.


CONCLUSIONS
This study questions the relevance of PTC/retTPC oncogene in the carcinogenesis of thyroid papillary carcinomas in the Saudi population. Genetic background among races may contribute to the different frequencies of PTC/retTPC oncogene in thyroid papillary carcinoma.
Zou
M
M
Molecular Endocrinology Laboratory, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
Shi
Y
Y
Farid
N R
NR
D002291:Carcinoma, Papillary / Q000235:genetics*; D003062:Codon / Q000235:genetics; D029721:Drosophila Proteins; D015972:Gene Expression Regulation, Neoplastic; D015321:Gene Rearrangement; D016158:Genes, p53 / Q000235:genetics; D006801:Humans; D009154:Mutation / Q000235:genetics; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051096:Proto-Oncogene Proteins c-ret; D011519:Proto-Oncogenes / Q000235:genetics*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*; D012529:Saudi Arabia; D013964:Thyroid Neoplasms / Q000235:genetics*; D014158:Transcription, Genetic
D003062:Codon; D029721:Drosophila Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D011505:Protein-Tyrosine Kinases; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila