Correlation between sodium iodine transporter expression and BRAF^V600E mutation in thyroid papillary carcinoma

Objective To explore the relationship between BRAF^V600E mutation and sodium iodide transporter(NIS) in common genetic events in thyroid papillary carcinoma(PTC).

Methods A total of 104 PTC patients who underwent surgical treatment PTC were selected. Fresh PTC tissue and normal tissue adjacent to carcinoma specimens were collected. The contents of NIS mRNA were detected by fluorescence quantitative PCR. NIS protein expressions in paraffin blocks were detected by immunohistochemistry, at the same time BRAF^V600E gene mutation was tested.

Results In 104 cases of PTC, there were 70 cases of BRAF^V600E gene mutation(67.3%), which was significantly higher than that in the normal tissue adjacent to carcinoma(0 case)(P < 0.01). The expression of NIS mRNA in PTC tissues was significantly lower than that in the normal tissues adjacent to carcimoma(P < 0.01), but the expression of NIS protein was significantly higher than that in the normal tissues adjacent to carcimoma(P < 0.01). The proportion of NIS mRNA expression in the PTC tissues was lower and the increase of NIS protein expression was significantly higher than that in the normal tissues adjacent to carcimoma(P < 0.01). The expression of NIS mRNA in patients with gene mutation of PTC BRAF^V600E was significantly lower than that in the wild type(P < 0.01), but there was no significant difference in NIS protein(P>0.05).

Conclusions BRAF^V600E mutation only exists in the cancer tissue, which may be associated with the low expression of NIS mRNA in cancer tissue and high expression of the NIS protein. NIS protein in PTC may be mainly expressed in the cytoplasm, which affects the normal function of transportation and causes patients to be unable to gather iodine.