Abstract:

Objective To investigate the role and molecular mechanism of E2F7 in papillary thyroid carcinoma（PTC）. Methods The correlation between E2F7 and TC was predicted by bioinformatics analysis. The expression of E2F7 in PTC and adjacent tissues was detected by immunohistochemistry. Western blotting（WB） was used to detect the expression level of E2F7 in human PTC K1，TPC⁃1 and BCPAP cell lines and in normal human thyroid Nthy⁃ori3⁃1 cell line. The effect of silencing E2F7 on the proliferation and migration of K1 cells was detected by growth curve，clone formation assay and scratch assay. Flow cytometry was used to detect the effect of silencing E2F7 on K1 cell cycle and apoptosis. The transcription of cyclin cyclinD1，cyclinE1，EIF4A3 and cyclin⁃dependent kinase 4（CDK4）genes was detected by qRT⁃PCR，and the effect of E2F7 on cyclin and pathway proteins Akt，pAkt by WB. Results The expression level of E2F7 in PTC tissues is higher than that in adjacent tissues，clinical stage and lymph node metastasis were statistically significant with E2F7 expression level；The expression of E2F7 in K1 cells is significantly higher than that in normal thyroid cells；the protein expression level of K1 cells in the E2F7 silence group is compared with that in the control group compared with the control group； The proliferation and migration abilities were inhibited in the E2F7 silence group；The transcription and translation levels of cyclins in the E2F7 silence group were lower than the control group；The expression levels of key pathway proteins Akt and pAkt were down ⁃ regulated compared with the control group；The cycle progression was blocked and the rate of apoptosis increased. Conclusions The high expression of E2F7 in PTC tissue is related to the occurrence and development of PTC；E2F7 silencing causes K1 cell cycle arrest，promotes apoptosis and inhibits proliferation through Akt signaling pathway.

Key words:

papillary thyroid carcinoma, E2F transcription factor 7, cell cycle, apoptosis, Akt signaling pathway