MEG3 Induces Cervical Carcinoma Cells' Apoptosis Through Endoplasmic Reticulum Stress by miR-7-5p/STC1 Axis.

Background: Many patients with advanced cervical cancer (CC) have a poor prognosis and their mortality rank the first among women with malignant tumors. It's essential to explore the molecular mechanism of CC in clinical practice. Long noncoding RNA maternally expressed gene 3 (MEG3) has been reported to downregulate in CC tissues. However, the underlying mechanism of MEG3 in CC remains poorly elaborated. The current study aimed to explore the potential mechanism of MEG3 inducing endoplasmic reticulum stress (ERs)-mediated apoptosis of CC cells. Methods: The expression of MEG3 and miR-7-5p in CC tissues and cell lines was verified by quantitative reverse transcription/polymerase chain reaction (qRT-PCR). The vector of MEG3, miR-7-5p inhibitor, and sh-SCT1 were transfected into CC cell lines, and their expression was tested by qRT-PCR. Flow cytometry was used to detect apoptosis, and ERs-related protein expression was performed by Western blot. The regulatory relationship between MEG3/SCT1 and miR-7-5p was validated by Dual luciferase reporter assay. Results: CC tissues and cell lines showed downregulated MEG3 and STC1, and upregulated miR-7-5p. Overexpression of MEG3 or miR-7-5p inhibition induced ERs-triggered apoptosis of CC cells. In addition, sh-STC1 can reverse the effects of overexpressing MEG3 on CC cell apoptosis. In addition, dual luciferase reporter assay revealed that miR-7-5p can directly target to MEG3 and STC1. Conclusion: MEG3, act as a competing endogenous RNA of miR-7-5p, accelerates ERs-mediated apoptosis of CC cells through regulating SCT1 expression.