Investigation Of BRAF^V600E Gene Mutation And NIS Promoter Methylation In The Papillary Thyroid Cancer

Objective:To investigate the relationship between positive expression of mutational BRAFV600E gene and promoter methylation of Thyroid sodium/iodide symporter (NIS) in papillary thyroid carcinoma(PTC), to provide the theoretic basis of clinical treatment for thyroid carcinoma.Methods:1.experimental subject:74Paraffin Sliced Specimens are obtained from pathology department of the third Xiangya hospital of central south university during January2012to December2012. These Specimens are divided into two groups,55in PTC group and19in control group.2. experimental approach:(1) extract DNA from the Paraffin Specimens,(2)PCR technique is employed to amplify the BRAFV600E gene, then the Specimens are detected by agarose gel electrophoresis, the positive bands are sent to sequencing,(3) the sequencing positive samples with gene mutation of BRAFV600E are treated by Methylation-specific PCR technique(MSP) to amplify the promoter of NIS, then the Specimens are detected by agarose gel electrophoresis, the positive bands are sent to sequencing, to investigate the distribution situation of NIS promoter methylation in Specimens with mutational BRAFV600E gene. To analyze the relativity between positive expression of mutational BRAFV600E gene and promoter methylation of NIS in PTC.Results:1.there are35Specimens show positive expression of mutational BRAFV600E gene in55PTC Specimens (63.64%).20Specimens show negative Results(36.36%). There is no positive expression of mutational BRAFV600E gene in19Specimens in control group. Using SPSS21.0statistical software and rank-sum test to analyze the data. There is Significant difference between both groups,(P<0.01);2. among35specimens with positive expression of mutational BRAFV600E gene, we find7specimens with promoter methylation of NIS(20%). There is no promoter methylation of NIS discovered in the remaining39specimens. The data is analyzed by SPSS21.0statistical software using rank-sum test. The results showed no significant difference,(P>0.05);3. Statistical analysis are done to figure out the relationships between mutational BRAFV600E gene expression and clinical data of the patients, promoter methylation of NIS and clinical data of the patients. Both show relativity with lymphatic metastasis. There are no supporting evidence for other clinical condition;4. The relativity between positive expression of mutational BRAF gene and promoter methylation of NIS is analyzed by using Fourfold table exact test, we discover Statistical difference between them,(x2=0, P<0.01)Conclusions:1. BRAFV600E gene mutation is a High-frequency event in gene mutations of PTC patients, and it is a High-frequency event in lymphatic metastasis.2. NIS promoter methylation is a Low-frequency event in gene mutations of PTC patients, But it is a High-frequency event in lymphatic metastasis.3. There is relationship between positive expression of mutational BRAFV600E gene and promoter methylation of NIS.