LncRNA OXCT1-AS1 promotes the proliferation of non-small cell lung cancer cells by targeting the miR-195/CCNE1 axis

BACKGROUND: Long non-coding RNAs (lncRNAs) are involved in various biological processes in non-small cell lung cancer (NSCLC). This study aimed to investigate the key lncRNA OXCT1-AS1/miR-195/CCNE1 axis in the development of NSCLC and its potential molecular mechanism. METHODS: LncRNA OXCT1-AS1 is considered to be a competitive endogenous RNA (ceRNA) and its potential targeting microRNAs (miRNAs) were predicted through LncBase predicted v.2. The expression of OXCT1-AS1 and miR-195 in NSCLC tissues and cells was detected by reverse transcription polymerase chain reaction (RT-PCR). The Cell Counting Kit-8 (CCK-8) and cell colony-forming test were used to detect the effect of cell proliferation. RT-PCR was used to detect the expression changes of CCND1 and CCNE1. Western Blot was used to detect the changes of the CCNE1 cell cycle protein. Dual luciferase activity was used to determine the potential mechanism of lncRNA OXCT1-AS1. RESULTS: LncRNA OXCT1-AS1 was highly expressed and miR-195 was lowly expressed in NSCLC tissues and cell lines. LncBase predicted v.2.0 reported a high-scoring binding between OXCT1-AS1 and miR-195. The luciferase reporter assay defined the regulatory relationship between OXTC1-AS1 and miR-195. In NSCLC cells, knockdown of OXCT1-AS1 significantly increased the expression of miR-195, decreased the proliferation and colony formation number of cancer cells, and reduced the expression of CCND1 and CCNE1. Meanwhile, overexpression of miR-195 significantly inhibited the cell proliferation and colony formation number, and reduced the expression of CCND1 and CCNE1. Furthermore, according to the results of the dual-luciferase activity assay, miR-195 targeted the 3' untranslated regions (3' UTRs) of CCNE1, validating that CCNE1 is a direct target of miR-195. Overexpression of CCNE1 restored the role of OXCR1-AS1 in NSCLC cells. CONCLUSIONS: LncRNA OXCT1-AS1 can regulate the proliferation of NSCLC cells via miR-195/CCNE1 signaling. Therefore, OXCT1-AS1 may act as a prospective biomarker and therapeutic target for patients with NSCLC.