The Effect And Mechanism Of FKBP51 On The Migration And Invasion Of Thyroid Papillary Carcinoma

Objectives:Thyroid cancer is the most common cancer in the endocrine system,with PTC(papillary thyroid carcinoma,PTC)being the most common.In recent years,the incidence of thyroid cancer has been increased rapidly,becoming one of major diseases threatened to human life and health.FKBP51(K506 Binding Protein 51,FKBP51)is a FK506 binding protein with a molecular weight of 51 kDa and belongs to the immunophilin family.Clinically it is used to reduce the activation of T lymphocytes or enhance lymphocyte to glucocorticoids sensitivity by combined with immune inhibitors,such as FK506 and rapamycin,to treat some autoimmune diseases and to prevent rejection after organ transplantation.Numerous studies have shown that FKBP51 is not only involved in the regulation of androgen and progesterone and other steroid hormones in vivo,but also is closely related to the occurrence and development of tumors.The increase or decrease of FKBP51 expression has been successively found in many tumors,especially hormone-dependent tumors,such as prostate cancer and breast cancer.However,the study of FKBP51 and papillary thyroid carcinoma has not been found.Considering that the incidence of PTC in women is much higher than that of males,it may be related to sex hormones.Therefore,we speculate that FKBP51 may play an important biological role in PTC.This study aims to assess the expression of FKBP51 protein in PTC and the biological behaviors such as cell proliferation,migration and invasion as well as its molecular mechanism,indicating a new molecular marker for the diagnosis and prognosis of papillary thyroid carcinoma.Methods:1.Immunohistochemical:IHC was used to detect expression of FKBP51 in PTC and adjacent normal tissues,and the relationship between FKBP51 expression and clinical TNM stage.2.Lentivirus infection and plasmid transfection:PTC cell line K1 was infected by FKBP51-overexpressing lentivirus vector and TPC-1 was transfected by FKBP51-knockdown plasmid.CCK8 Kit was used to detect its growth and Transwell cambers were used to detect its migration and invasion capacities.3.Western blot:The changes of NF-?B pathway proteins and EMT related proteins were analysis by Western blot to explore molecular mechanism of FKBP51 on migration and invasion of PTC.4.Inhibition test:NF-?B pathway was used to inhibit by PDTC,and the effect of PDTC on migration and invasion ability as well as EMT related genes of FKBP51-overexpressing K1 cells was detected.5.Cytoskeleton immunofluorescence staining:In addition,we stained PTC cytoskeleton tubulin by immunofluorescence to investigate whether FKBP51 alters its migration and invasion ability by affecting cytoskeleton formation.Results:1.Analysis of FKBP51 expression in PTC and its correlation with clinicopathological features:The results of IHC analysis showed that FKBP51 was expressed both in papillary thyroid carcinoma tissues and in paracancerous tissues,but it was significantly higher in cancer tissues than in adjacent normal tissues(P<0.05).FKBP51 expression The expression level of FKBP51 was significantly correlated with clinical stage(P<0.05).The higher the expression of FKBP51 was,the worse the staging was,but the correlation with age was not statistically significant(P>0.05).2.The effect of FKBP51 on the biological characteristics of PTC:FKBP51 overexpression significantly promoted the migration and invasion ability of K1 cell line.FKBP51 knockdown could significantly inhibit the migration and invasion ability of TPC-1 cell lines(P<0.05),but FKBP51 had no significant effect on the proliferation of K1 and TPC-1 cells(P>0.05).3.FKBP51 promotes PTC migration and invasion through NF?B-EMT pathway:Further studies showed that FKBP51 could activate NF-?B pathway and EMT related proteins.NF-KB pathway inhibitor PDTC inhibited the ability of migration and invasion of FKBP51-overexpressing K1 cells and altered the expression of EMT related proteins.4.FKBP51 had no effect on tubulin formation of PTC:The red fluorescence-labeled anti-tubulin antibody stained the cells.Compared with the control group,FKBP51-overexpressing K1 cells and FKBP51-knockdown TPC-1 cells showed no significant difference in the cytoplasm distribution or fluorescence staining intensity of tubulin.difference.We also examined the effect of FKBP51 on tubulin formation in PTC cytoskeleton,with no statistically significant difference(P>0.05).Conclusion:The expression of FKBP51 in PTC was higher than that in normal tissues,and the expression level of FKBP51 was positively correlated with the clinical stage.FKBP51 had no significant effect on the proliferation of PTC,but it promoted its migration and invasion ability through NF-?B and EMT.