[The correlation between BRAF mutations, RET/PTC rearrangements and platelet-derived growth factor B expression in papillary thyroid carcinomas].

Objective: To investigate the prevalence of BRAF T1799A mutation and RET/PTC rearrangement in Qingdao and detect the expression of platelet-derived growth factor B (PDGF-B) in order to investigate the correlation between gene mutation and PDGF-B.

Methods: Fresh tissue from 48 papillary thyroid carcinomas (PTC) patients was examined for BRAF mutation RET rearrangements (RET/PTC1 and RET/PTC3) by PCR, followed by direct-sequence analysis. The expression of PDGF was analyzed by immunohistochemistry.

Results: Among the 48 patients, 14 (29.2%) were micro PTC; 18 (37.5%) had BRAF T1799A mutations and 23(47.9%) had RET/PTC rearrangement. There were 17 (35.4%) cases of RET/PTC1 and 6 (12.5%) of RET/PTC3, with no multiple rearrangements. Both BRAF T1799A mutation and RET/PTC rearrangement were present in 6 (12.5%) cases of non-micro PTC. The level of PDGF-B expression in BRAF T1799A positive was higher than that in the negative, and the level of PDGF-B expression in RET/PTC3 was higher than that in RET/PTC1 (P < 0.05). The more advanced neoplasm stage was, the stranger PDGF-B expression was.

Conclusions: The incidence of BRAF T1799A mutation and RET/PTC rearrangement is higher in Qingdao. BRAF T1799A mutation and RET/PTC3 rearrangement in patients suggests a poorer prognosis than the negative one. The BRAF T1799A mutation and RET/PTC3 rearrangement may strengthen the expression of PDGF-B. Both variations suggest a poor prognosis.