The Correlationship Between GLUT1Expression And BRAF V600E Mutation In Papillary Thyroid Carcinoma

Background:The glucose transporter1(GLUT1) is a key protein that facilitates the extensive glucose uptake of cancer cells, and its overexpression is associated with more aggressive tumor phenotypes. In cases of BRAF V600E mutations, GLUT1seems to be a target of the constitutive activation of the RAF/MEK/ERK pathway. In this study, we hypothesized that the common BRAF V600E mutation was associated with GLUT1overexpression and proliferation in papillary thyroid carcinoma.Objective:To find the correlationship between GLUT1expression and BRAF V600E mutation in papillary thyroid carcinoma. Methods:The BRAF V600E mutation were analysed by direct sequencing of genomic DNA which was isolated from paraffin-embedded tumor tissues in46cases of PTC after polymerase chain reaction (PCR).38cases were detected successful. Then they were investigated using immunohistochemistry (IHC) with antibodies against GLUT1protein. GLUT1expression was found in two types:cytoplasm expression and membrane expression. They were both assessed using the Remmele immunoreactive score. Statistical analysis was performed using SPSS18.0.Results:38cases (38/46,82.6%) were positive for BRAF V600E mutation, including24(63.2%,24/38) of PTC with the BRAF V600E mutation and14(37.8%,14/38) of PTC with BRAF wild type. In the immunohistochemical results, GLUT1cytoplasmic expression was found in25of38cases (65.8%).In these GLUT1cytoplasmic expression cases,16were with the BRAF V600E mutation and9were with BRAF wild type. Spearman correlation test showed that there was no correlation between GLUT1cytoplasmic expression and BRAF V600E mutation. GLUT1membrane expression wasfound in10cases (26.3%,10/38), among which, all were positive for BRAF V600E mutant (41.7%,10/24). Spearman correlation test found that the GLUT1membrane expression was significantly correlated with BRAF V600E mutation (P=0.004).Conclusions:GLUT1expression was found both in cytoplasm and membrane in papillary thyroid carcinoma. The membrane expression of GLUT1and BRAF V600E mutation was significantly correlated. This suggested that BRAF V600E mutation may play an important role in the beginning of glycolysis, and give the growth advantage of cancer cells.