The Effect Of Intrathyroidal Iodine Content And Extracellular Iodine Stimulation On Inhibitor Of Growth 4 Expression In Papillary Thyroid Carcinoma

ObjectiveTo study and clarify the expression of ING4 gene under the intrathyroidal iodine content and extracellular iodine stimulation;to explore the potential relationship between iodine,papillary thyroid carcinoma,and ING4,in order to further study the pathogenesis of iodine on papillary thyroid carcinoma To provide a basis for the impact.Methods1.Iodine content in papillary thyroid carcinoma and its adjacent tissues were determined by ICP-MS,and the differences in iodine content in papillary thyroid carcinoma and its adjacent tissues were compared and analyzed2.ING4 mRNA（RT-qPCR）and protein（Western-blot）expression in papillary thyroid carcinoma and its precancerous tissues were detected3.The CCK8 method was used to detect the cell viability changes of human papillary thyroid carcinoma TPC-1 cell line and human normal thyroid cell Nthy-ori 3-1cell line 24,48,72,96,and 120 hours after stimulating KIO₃solution with different concentrations.4.ING4 mRNA（RT-qPCR）and protein（Western-blot）expression of TPC-1 cell line of human papillary thyroid carcinoma and Nthy-ori 3-1 cell line of normal thyroid gland were detected after cultured with different concentrations of KIO₃solution for 24hours,respectively.Exposure to different KIO₃concentrations represented different iodine level stimuli.Results1.Baseline data of patients with papillary thyroid carcinoma and iodine content,the expression of ING4 mRNA and protein in papillary thyroid carcinoma and its adjacent tissuesA total of 62 pairs of papillary thyroid carcinoma and its adjacent tissues were collected in this study,including 25 males and 37 females,with an average age of43.307（43.307±15.519）years and an average tumor length of 2.203（2.203±0.70）cm.ICP-MS test results showed that the iodine content in papillary thyroid carcinoma tissue（median 29.647μg/g）was lower than the corresponding paracancerous tissue（median 869.610μg/g）,and the difference was statistically significant（P<0.001）.The results of RT-qPCR showed that the expression of ING4 mRNA in papillary thyroid carcinoma was all down-regulated to different degrees compared with the corresponding adjacent tissues,and the difference was statistically significant（P<0.001）.The Westem-Blot results showed that the expression of ING4 protein in papillary thyroid carcinoma tissues was lower than that in the corresponding adjacent tissues,and the difference was statistically significant（P<0.001）.2.Effects of different concentrations of KIO₃stimulation on cell viability,the expression of ING4 mRNA and protein in human papillary thyroid carcinoma TPC-1 cell line and human normal thyroid cell Nthy-ori 3-1 cell lineThe results of CCK8 method showed that under the same exposure time,the cell viability of Nthy-ori 3-1 cells and TPC-1 cells was only 10^-3M KIO₃treatment group,and the difference was statistically significant（P<0.05）.Under the same concentration of KIO₃exposure,the cell viability of Nthy-ori 3-1 cells and TPC-1 cells showed a trend of"rising first and then falling"to a certain extent with the prolonging of the exposure time,and under this trend,whether it is Both Nthy-ori 3-1 cells and TPC-1cells showed that the cell viability of the 10^-6M and 10^-10M KIO₃treatment groups was always enhanced.A further comparison of the two cell lines at the same concentration of KIO₃for different exposure times revealed that Nthy-ori 3-1 cells and TPC-1 cells had statistical differences in the cell viability of the two cell lines after 24 hours and 48hours of KIO3 exposure（P both<0.05）.RT-qPCR results showed that in Nthy-ori 3-1 cells,the expression of ING4 mRNA in the KIO₃treatment group at all concentrations was up-regulated to varying degrees compared with the control group,but the difference was not statistically significant（P>0.05）.However,TPC-1 cells were only down-regulated in the 10^-6M and 10^-10M KIO₃treatment groups compared with the control group ING4 mRNA expression,and the 10^-6M KIO₃treatment group was significantly different from the control group（P<0.05）.Regardless of the KIO₃exposure concentration,the expression of ING4 mRNA in Nthy-ori 3-1 cells was higher than that of ING4 mRNA in TPC-1 cells and there was a statistical difference（P<0.01）.Westem-Blot results showed that in Nthy-ori 3-1 cells,the expression of ING4protein in each treatment group exposed to different concentrations of KIO₃was higher than that of the control group,.The difference between the 10^-7M（suitable iodine level）and 10^-10M（lower iodine level）KIO₃treatment group and the control group was statistically significant（P<0.05）.There was no significant difference in the expression of ING4 protein in each KIO₃treatment group in TPC-1 cells compared with the control group（P>0.05）.Further comparison of the two cell lines in the same concentration of KIO₃treatment group found that the expression of ING4 protein in Nthy-ori 3-1 cells was not significantly different from TPC-1 cells（P>0.05）.Conclusion1.The results of this study showed that the internal iodine content,ING4 mRNA and protein expression in papillary thyroid carcinoma tissues were significantly lower than those in adjacent tissues.2.After 24 hours of potassium iodate exposure,10^-7（appropriate iodine level）and10^-10M（low iodine level）KIO₃can promote the expression of ING4 protein in human normal thyroid cells.3.Under the stimulation of different concentrations of KIO₃,the expression of ING4 mRNA in papillary thyroid cancer cells is lower than that of human normal thyroid cells,and most concentrations(except 10^-9,10^-10M)of human normal thyroid cells exposed to KIO_3.The expression level of ING4 protein is lower than that of papillary thyroid cancer cells.