Long non-coding RNA DLEU1 contributes to the development of endometrial cancer by sponging miR-490 to regulate SP1 expression.

This study aimed to investigate the role of long non-coding RNA DLEU1 in endometrial cancer (EC) development. The DLEU1 expression in EC tissues and cells (HHUA, KLE, Ishikawa, and ECC-1) were detected. The expression of DLEU1 was suppressed by transfection with sh-DLEU1 and the effects of DLEU1 suppression on the malignant behaviors of Ishikawa cells, including cell viability, apoptosis, migration and migration were then detected. In addition, the interaction of DLEU1 and miR-490 as well as between miR-490 and SP1 in EC were investigated. Furthermore, the regulatory relationship between DLEU1 and PI3K/AKT/GSK-3β pathway was explored. DLEU1 was upregulated in EC tissues and cells. Suppression of DLEU1 significantly inhibited Ishikawa cell viability, promoted cell apoptosis, decreased BCL-2 expression and increased the expression of Bax, cleaved-caspase-3 and cleaved-caspase-3, suppressed cell migration and invasion, and inhibited EMT via increasing the expression of E-cadherin and decreasing the expression of N-cadherin, Snail and Vimentin. In addition, DLEU1 could sponge miR-490 and miR-490 inhibition significantly reversed the effects of DLEU1 suppression on the malignant behaviors of Ishikawa cells. Furthermore, SP1 was verified as a target of miR-490, and SP1 knockdown could reverse the effects of miR-490 inhibition on the malignant behaviors of Ishikawa cells. Besides, suppression of DLEU1 inhibited PI3K/AKT/GSK-3β pathway, while miR-490 inhibition activated this pathway that could be neutralized by SP1 knockdown. Our findings indicate that DLEU1 contributes to EC development by sponging miR-490 to regulate SP1 expression. DLEU1/miR-490/SP1 axis may provide a new strategy for EC therapy.