Long Non-Coding RNA AC022306.2 Promotes Cell Proliferation, Migration, and Invasion by Mediating GALK2 in Epithelial Ovarian Cancer

BackgroundLong non-coding RNA (LncRNA) has been exhibited to exert significant function among human cancers. AC022306.2, as a newly discovered lncRNA, has an unclear function in ovarian cancer (OC). This study aims to uncover the functional role of AC022306.2 in OC and discover its possible mechanism. MethodsThe expression of AC022306.2 and Galactokinase 2 (GALK2) in OC tissues and adjacent non-tumor tissues was detected via qRT-PCR. The CCK-8 assay, cell clonogenesis assay, scratch healing assay and trans-well assay were used to reveal the function of AC022306.2 and GALK2 in ovarian cancer cell lines. Mice xenografts experiment was performed. Bioinformatics predicted the microRNA (miRNA) that bond with AC022306.2 and GALK2, and dual luciferase reporter system confirmed it. Rescue experiments of miRNA mimics and siGALK2 transfection on the basis of AC022306.2 over-expression were carried out to uncover the mechanism by which AC022306.2 played cancer-promoting roles in ovarian cancer.ResultsIt was found that AC022306.2 was up-regulated in EOC tissues compared with adjacent non-tumor tissues. The elevated expression of AC022306.2 was related to the FIGO stage of OC. Functional experiments showed that AC022306.2 overexpression accelerated proliferation and aggression of OC cells in vitro and accelerated tumor growth in vivo. We also found that GALK2 was up-regulated in OC tissues. The expression of GALK2 mRNA in OC tissue was positively associated with the expression of AC022306.2. After AC022306.2 was knocked down, the expression of GALK2 was down-regulated. In addition, GALK2 depletion restored the proliferation and aggression capabilities of OC cells after AC022306.2 overexpression. Mechanically, AC022306.2 acted as a competitive endogenous RNA (ceRNA) of miR-369-3p to modulate the expression of GALK2. The up-regulating of miR-369-3p or the down-regulating of GALK2 partially reversed the effect of AC022306.2 overexpressed on cell propagation and aggression in OC. ConclusionsAC022306.2 is a new oncogene in the carcinogenesis and development of OC. AC022306.2 improves the development of OC by regulating the miR-369-3p / GALK2 axis, indicating that AC022306.2 may have the potential to become a new molecular target for the treatment of OC.