RESUMO
Objective:To study the effect of astrocyte elevated gene-1 (AEG-1) on proliferation and metastasis of papillary thyroid cancer (PTC) by regulating cell autophagy and epithelial-mesenchymal transition (EMT).Methods:Normal thyroid cells Nthy-ori3-1 and PTC cells TPC-1, FTC-133, B-CPAP and SW579 were cultured in vitro. Real time fluorescent quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of AEG-1 in PTC cells. The PTC cells with the highest AEG-1 expression were selected for AEG-1 shRNA infection, and then divided into sh-NC group and sh-AEG-1 group. Cell counting kit-8 (CCK8) and EdU (5-ethynyl-2 ′- deoxyuridine) experiments were used to detect the effect of AEG-1 on the proliferation of PTC cells; Transwell test was used to detect the effect of AEG-1 on the metastasis of PTC cells; subcutaneous tumorigenesis test in nude mice was used to detect the effect of AEG-1 on the expression of autophagy related proteins and EMT related proteins. PTC cells in sh-NC group and sh-AEG-1 group were treated with rapamycin and transforming growth factor-β (TGF-β), respectively. CCK8 and transwell assay were used to detect the cell proliferation and metastasis ability of each group of cells, respectively. Results:Compared with normal thyroid cells Nthy-ori3-1, the expression level of AEG-1 in PTC cells was increased, with the highest expression in TPC-1 cells. After AEG-1 shRNA was transfected into TPC-1 cells, cell proliferation, metastasis and tumorigenicity in vivo were reduced ( P<0.05). Compared with the sh-NC group, the expression of autophagy-related proteins P62 and Beclin1 were increased and the expression of LC3B protein was decreased, and EMT-related proteins E-cadherin expression were increased and N-cadherin and Vimentin protein expression were decreased in the sh-AEG-1 group ( P<0.05). CCK8 and Transwell experiments showed that treatment with autophagy inducer Rapamycin and EMT inducer TGF-β attenuated the inhibitory effect of sh-AEG-1 on proliferation and metastasis ability of PTC cell ( P<0.05). Conclusions:AEG-1 promotes the proliferation and metastasis of PTC cells by inducing cell autophagy and EMT.