MiR-4299 Mediates The Invasive Properties Of Human Follicular Thyroid Carcinoma By Targeting ST6GALNAC4

Objective: The objective of this study is to analyze the differential expression of 6 sialyltransferase genes in the both human follicular thyroid carcinoma(FTC)cell lines and tissue specimens of FTC patients,and to clarify the mechanism of based on miR-4299 probe in modulating the invasion of follicular thyroid carcinoma cell by targeting ST6GALNAC4.To further diagnose human follicular thyroid carcinoma(FTC),and provide a new target point of FTC.Methods:(1)Using real-time PCR for quantification of ST6 GALNAC genes,we compared the differential expression(i.e.,>3-fold higher)of ST6 GALNAC genes in the two pairs of FTC cell lines and tissue specimens of FTC patients.(2)Manipulating the differentially expressed ST6 GALNAC genes,to detect the invasive ability of FTC cell lines in vitro and in vivo.(3)q RT–PCR showed the differential expressional profiles of miR-4299 and ST6 GALNAC family in three kinds of thyroid cell lines(FTC-133,FTC-238,Nthy-ori 3-1)and tissue specimens(malignant and borderline).Mimics,agomir,antagomir and negative control oligonucleotides for hsa-miR-4299 were obtained.It indicated miR-4299 directly targeted ST6GALNAC4.Target molecule ST6GALNAC4 of miR-4299 was confirmed by Transfection and luciferase activity assay..(4)Manipulating the differentially expressed miR-4299,to detect the invasive ability of FTC cell lines in vitro and in vivo,and the expression of ST6GALNAC genes in cell.Results:(1)Differential expression of ST6 GALNAC gene family in three kinds of thyroid cell lines and tissue samples.(2)The silencing of ST6GALNAC4 in FTC-238 cells resulted in decreased the invasive ability in vitro and in vivo(*P ﹤ 0.05).The overexpression of ST6GALNAC4 in FTC-133 cells resulted in increased in vitro and in vivo(*P﹤0.05).(3)miR-4299 was differentially expressed in FTC-238 cell lines,FTC-133 cell lines and tissue samples of FTC patients.The miR-4299 directly targeted ST6GALNAC4 and ST6GALNAC4 was the target gene of miR-4299.(4)Forced expression of miR-4299 led to decreased the invasive ability and the expression of ST6GALNAC4 in FTC-238 cells;Decreased expression of miR-4299 led to increased the invasive ability and the expression of ST6GALNAC4 in FTC-133 cells.Conclusion:(1)The expression of ST6 GALNAC genes was significant difference in FTC-238 cell lines,FTC-133 cell lines and tissue specimens of FTC patients.These characteristic alterations are associated with the invasive ability in FTC.(2)miR-4299 mediates the invasive properties of human follicular thyroid carcinoma cells probably through targeted regulating ST6GALNAC4 expression.