Long Noncoding RNA Promotes the Progression of Breast Cancer by Regulating miR-138-5p/ Axis.

Growing evidence demonstrated that long noncoding RNAs (lncRNAs) were involved in the progression of diverse cancers, including breast cancer (BC). Recent studies indicated that lncRNA nuclear enriched abundant transcript 1 () was overexpressed and facilitated tumor processes in many cancers. Nevertheless, the underlying mechanism of in regulating BC progression is still largely unknown. The abundance of , microRNA-138-5p (miR-138-5p), and zinc finger protein X-linked () was assessed by quantitative real-time polymerase chain reaction. Cell Counting Kit-8 (CCK-8) assay, flow cytometry, and transwell assay were utilized to evaluate cell proliferation, apoptosis, migration, and invasion, respectively. Western blot analysis was applied to detect the protein expression of CyclinD1, Bax, E-cadherin, and . The interaction between miR-138-5p and or was predicted by starBase v3.0 and validated by dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation assays. The mice xenograft model was established to investigate the roles of . was highly expressed and miR-138-5p was lowly expressed in BC tissues and cells. interference or miR-138-5p restoration repressed cell proliferation, migration, and invasion but accelerated apoptosis in BC cells. Moreover, miR-138-5p directly interacted with and its knockdown reversed the suppressive impact of downregulation on the progression of BC cells. In addition, was a downstream target of miR-138-5p and its upregulation attenuated the antitumor role of miR-138-5p in BC cells. Besides, expression was positively regulated by and inversely modulated by miR-138-5p. Furthermore, interference of inhibited tumor growth by upregulating miR-138-5p and downregulating . affected BC progression through modulating miR-138-5p/ axis, providing a vital theoretical basis for BC treatment.