The Expression And Regulation Of FOXP3 In Thyroid Papillary Carcinoma And Lymphocytic Thyroiditis

Purpose:Regulatory T cells have become popular in research for participating the development of cancer and auto-immmune diseases. Both papillary thyroid carcinoma(PTC) and Lymphocytic Thyroiditis(LT) show high incidence in all over the world and also in China. However it is still unclear that the function of regulatory T cells in the development of these two diseases. Forkhead box protein3(FoxP3) is well-known Treg cell marker. This study mainly focus on the distribution and corresponding expression of FOXP3 in lymphocyte infiltration PTC, LT, and PTC coexisting with LT, furthermore explore the immune regulation mechanism of FOXP3 in tumor and autoimmune diseases, therefore providing guidance for better clinical management of thyroid diseases. Methods:In this study, there were totally 98 specimens from thyroid patients in thyroid surgical department of China-Japan Friendship Hospital Affiliated Jilin University between January,2013 and September,2014. The selection criteria included that the patients haven’t accepted any preoperative treatments, including chemotherapy, radiotherapy and other surgical managements. Among these cases, there were 30 cases of thyroid papillary carcinoma, 23 cases of lymphocytic thyroiditis, 25 cases of thyroid papillary carcinoma with lymphocytic thyroiditis, as well as 20 cases of other relative normal thyroid tissues around nodular goiter as a comparison group. All the specimens were processed by sequential fixation by 10% Neutral buffered formalin, dehydration, transparency, paraffin-embedding, slicing, and immunohistochemistry SPⅡ staining. The frequency and extent of FOXP3 expression were evaluated among all of the groups. Results:1. The thyroid papillary carcinoma tumor infiltrating of lymphocytes FOXP3+ in the positive expression rate is 70% than the control group(relatively normal thyroid tissue) 5% significantly increased, the difference was statistically significant.2. The lymphocytic thyroiditis infiltrating of lymphocytes FOXP3+ in the positive expression rate is 78% than the control group(relatively normal thyroid tissue) 5% significantly increased, the difference was statistically significant.3. The PTC accompanied with LT infiltrating of lymphocytes FOXP3+ in the positive expression rate is 83% than the control group(relatively normal thyroid tissue) 5% significantly increased, the difference was statistically significant.4. The PTC accompanied with LT infiltrating of lymphocytes FOXP3+ in the positive expression rate is more than the pure PTC significantly increased, the difference was statistically significant.5. The PTC accompanied with LT infiltrating of lymphocytes FOXP3+ in the positive expression have a rising trend than the pure PTC significantly increased, but the difference was not statistically significant.6. PTC and LT compared to FOXP3 in the infiltration of lymphocytes there was no statistically significant difference in the positive expression. Conclusion:1. The high expression of FOXP3+ in PTC promote the onset and progress of thyroid papillary carcinoma and participated in the tumor immune escape.2. The high expression of FOXP3+ in LT have some influence factors of autoimmune thyroid diseases.3. The expression proportion of FOXP3+ in PTC accompanied with LT is significantly higher than that of PTC only patients. The difference is supporting the hypothesis that regulatory T cells take part in the regulating tumor cells escape from the immune system as well as inducing anti-tumor immunity, furthermore causing the occurrence of autoimmune diseases.4. FOXP3 in microenvironment of PTC accompanied with LT coexisting group shows a tendency of higher ratio compared to that of pure LT group, even though there was no statistically significant difference.