Long Noncoding RNA XIST Contributes to Cervical Cancer Development Through Targeting miR-889-3p/SIX1 Axis

Cervical cancer (CC) is one of the most common cancers among women in the world. Long noncoding RNAs and microRNAs were identified as important regulators in many physiological processes. The objective of this study was to illuminate the mechanism of X-inactive-specific transcript (XIST)/miR-889-3p/Sine oculis homeobox 1 (SIX1) axis in CC. The expression levels of XIST, miR-889-3p, and SIX1 were detected by quantitative real-time polymerase chain reaction. Cell proliferation was assessed by cell counting Kit 8 assay. Cell migration and invasion were evaluated by transwell assay. Cell apoptosis was detected by flow cytometry assay. Murine model was established using transfected Me180 cell. The interaction among XIST, miR-889-3p, and SIX1 was tested by dual-luciferase reporter and RNA immunoprecipitation assays. Protein level of SIX1 was measured by Western blot. XIST was highly expressed in CC tissues and cells. Silenced XIST inhibited proliferation, migration, and invasion and induced apoptosis. Moreover, XIST silencing blocked tumor growth in vivo. XIST directly bound to miR-889-3p, and XIST promoted proliferation, migration, and invasion and hindered apoptosis by suppressing miR-889-3p expression. MiR-889-3p targeted SIX1 and negatively regulated SIX1 expression. Furthermore, miR-889-3p had a low expression and SIX1 had a high expression in CC tissues and cells. XIST knockdown reduced SIX1 level by targeting miR-889-3p. In addition, miR-889-3p inhibition abolished the effects of SIX silencing on proliferation, migration, invasion, and apoptosis. XIST knockdown restrained cell proliferation, migration, and invasion and promoted apoptosis by regulating miR-889-3p/SIX1 axis.