A Research About The Effect Of MicroRNA130a And Iodine In The Onset Of Papillary Thyroid Carcinoma

Objective: The aim of this study was to investigate the expression of microRNA130 a in benign and malignant thyroid tissue,validation the effect of microRNA130 a on the pathogenesis of papillary thyroid carcinoma.Preliminary study the role of iodine on papillary thyroid carcinoma.Method:(1)Tissues from 47 cases of nodular goiter or papillary thyroid carcinoma(PTC)patients in pathology department of Huangdao Affiliated Hospital of Qingdao University were collected.MicroRNA was extracted from the fresh tissues.The Real Time-qPCR experiment was performed to detect the expression of microRNA130 a in nodular goiter and PTC tissues with U6 as a reference.And protein of the fresh tissue was extracted and determined by Western Blot assay.The expression of the positive target gene SMAD4 of microRNA130 a was detected in nodular goiter and PTC tissues with β-actin as reference.Simultaneously,the frozen sections of the tissues were stained by immunohistochemistry.The expression of the positive target gene SMAD4 of microRNA130 a in different tissues was compared.(2)Data in the epidemiological survey of endocrinology department of Affiliated Hospital of Qingdao University in 2014 were sorted.The relations between urine iodine and thyroglobulin antibody(TGAb),thyroid peroxidase antibody(TPOAb)and thyroid stimulating hormone(TSH)were analyzed by Empower Stats software.Thyroid carcinoma cell line TPC-1was treated with potassium iodide(KI)of 0 μM,20 μM,40 μM and 80 μM,respectively.After 48 hours,the intracellular ROS was labeled with DCFH DA.And the intracellular ROS levels were detected by flow cytometry.Results:(1)The results of Real Time-qPCR assays showed that the expression of microRNA130 a in nodular goiter tissues was 3.31 times of that in PTC tissues.The expression of microRNA130 a in PTC group was significantly lower than that in nodular goiter group(p<0.05).The results of Western Blot assays showed that the expression level of the positive target gene SMAD4 of microRNA130 a in nodular goiter tissues was obviously higher than that in PTC tissues.The immunohistochemistry experiment showed that the expression of SMAD4 in PTC group was significantly lower than that in nodular goiter group(p<0.05) (2)Analysis on the epidemiological data showed that with the increase of urinary iodine,the level of TGAb ascended,and the level of TPOAb descended.After 48 hours of treatment with potassium iodide,the expression level of intracellular ROS of TPC-1 cells in 20 M,40 M,80 M KI treatment groups increased significantly.The expression level of intracellular ROS in 80 M KI treatment group was obviously higher than that of 20 M and 40 M KI treatment groups.Conclusion: The expression of microRNA130 a in human thyroid papillary carcinoma tissue was obviously lower compared with that in nodular goiter tissue.As same as our previous studies through gene chip assay,microRNA130 a can inhibit the proliferation of thyroid cancer cells by increasing their apoptosis and suppressing the invasion and migration processes.Therefore,we think that microRNA130 a can inhibit the occurrence of thyroid papillary carcinoma.Iodine rich diet can influence the antibody level of thyroid gland.And high concentration of iodine may lead to cell death by affecting the oxidative stress in thyroid cancer cells,and then increase the incidence of papillary thyroid carcinoma.