Molecular Biological Study On BRAF Gene And Clinical Character And Prognosis Of Thyroid Carcinoma

Objective:Recently studies found that a new gene, BRAF, and the mutant of which was an important genetic event in occurring of thyroid carcinoma and had played important role in early stage of development in this kind of carcinoma. So,it is important to investigate the mechanism of thyroid carcinoma and explore the relationship between the molecular genetic transformation and the clinical pathological character. Meanwhile,maybe a wonderfur objective evidence can be found to serve as molecular diagnosis and evaluation of prognosis and treatment in targeted-gene. At the same time, To detect the frequency of BRAFV600E mutation efficiently so as to explore a kind of efficient, sensitive and specific method of detection mutation, RFLP-PCR and MASA-PCR were performed in paraffin-embedded biopsy samples from thyroid lesion.Method: We collected 86 cases of paraffin embed tissue of PTC and 42 cases of benign and malignant thyroid lesion as control(including 7 cases of FTC, 2 cases of medullary thyroid carcinoma, 2 cases of anaplastic thyroid carcinoma, 15 cases of thyroid adenoma, 15 cases of nodular goiter and 1 case of normal tissue beside carcinoma). All of the samples were taken from the department of pathology of the first affiliated hospital, medical college of Shi he zi University from 1983 to 2005 and all were diagnosed and classified by more than two pathological professors referring to WHO standard. we inspected the BRAFV600E mutation in 97 thyroid carcinoma with RFLP-PCR and MASA-PCR after researching their clinical pathology and immunohistochemistry, then, we Analysed the association between BRAFV600E mutation and its clinicial character.Results: The result showed BRAFV600E mutation was detected only in 67.4% PTC(58/86)and 1 case of anaplastic thyroid cancer. The mutation was especially highly prevalent and almost restricted to conventional PTC and microcarcinoma and the frequency was respectively 73.0%(54/74)and 2/3. However, other kinds of thyroid carcinoma and benign thyroid lesions in control were negative for BRAFV600E mutation. Since BRAFV600E mutation and RET/PTC rearrangement are both the common genetic alterations in PTC, we compared the results of BRAFV600E mutation to RET/PTC rearrangement which was completed by xiaoming zhou by means of RT-PCR. The result indicated BRAF mutation and RET/PTC rearrangement were mutually exclusive in PTC and were only restricted in PTC, their etipathogenesis may be different. Therefore, although thyroid tumor was caused by these different...