RETRACTED: Effects of long noncoding RNA SPRY4-IT1-mediated EZH2 on the invasion and migration of lung adenocarcinoma (Retracted article. See vol. 122, 2021)

We aim to investigate the interaction between the EZH2 and the long noncoding RNA (lncRNA) SPRY4-IT1. We also explore their respective effects on human lung adenocarcinoma (LA) cell invasion and migration. Both LA and adjacent normal tissues were obtained from 256 LA patients. SPTY4-IT expression and EZH2 mRNA expressions in tissues and cells were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The siRNAs against SPRY4-IT1 and EZH2 were co-transfected into A549 and H1975 cells. The interaction between SPRY4-IT1 and EZH2 was determined using a RNA pull-down assay and a RNA immunoprecipitation (RIP) assay. A Transwell assay and scratch assay were used to evaluate the cell migration and invasion abilities. The expressions of E-cadherin and Vimentin in the epithelial-mesenchymal transition (EMT) and EZH2 protein expression were detected through western blotting. SPRY4-IT1 expression was observed to be significantly lower, while the expression of EZH2 was higher in the LA tissues than in the adjacent normal tissues. Compared with the HBE cell line, expressions of SPRY4-IT1 in each human LA cell line had decreased, with the lowest observed reduction in the A549 cell line, while EZH2 mRNA and protein expression increased in each human LA cell lines. After SPRY4-IT1-siRNA was transfected into A549 and H1975 cells, invasion and migration abilities were enhanced, in addition to a reduction in the expression of E-cadherin, while expressions of Vimentin exhibited an increased rate. Consequently, we find that EZH2 promotes LA cell invasion and metastasis by inhibiting SPRY4-IT1 expression.