Abstract
OBJECTIVES: Lung adenocarcinoma (LUAD) exhibits a higher fatality rate among all cancer types worldwide, yet the precise mechanisms underlying its initiation and progression remain unknown. Mounting evidence suggests that long non-coding RNAs (lncRNAs) exert significant regulatory roles in cancer development and progression. Nevertheless, the precise involvement of lncRNA CYP4A22-AS1 in LUAD remains incompletely comprehended. METHODS: Bioinformatics analyses evaluated the expression level of CYP4A22-AS1 in lung adenocarcinoma and paracancer. The LUAD cell line with a high expression of CYP4A22-AS1 was constructed to evaluate the role of CYP4A22-AS1 in the proliferation and metastasis of LUAD by CCK8, scratch healing, transwell assays, and animal experiments. We applied transcriptome and microRNA sequencing to examine the mechanism of CYP4A22-AS1 enhancing the proliferation and metastasis of LUAD. Luciferase reporter gene analyses, west-blotting, and qRT-PCR were carried out to reveal the interaction between CYP4A22-AS1, miR-205-5p/EREG, and miR-34c-5p/BCL-2 axes. RESULTS: CYP4A22-AS1 expression was significantly higher in LUAD tissues than in the adjacent tissues. Furthermore, we constructed a LUAD cell line with a high expression of CYP4A22-AS1 and noted that the high expression of CYP4A22-AS1 significantly enhanced the proliferation and metastasis of LUAD. We applied transcriptome and microRNA sequencing to examine the mechanism of CYP4A22-AS1 enhancing the proliferation and metastasis of LUAD. CYP4A22-AS1 increased the expression of EREG and BCL-2 by reducing the expression of miR-205-5p and miR-34-5p and activating the downstream signaling pathway of EGFR and the anti-apoptotic signaling pathway of BCL-2, thereby triggering the proliferation and metastasis of LUAD. The transfection of miR-205-5p and miR-34-5p mimics inhibited the role of CYP4A22-AS1 in enhancing tumor progression. CONCLUSION: This study elucidates the molecular mechanism whereby CYP4A22-AS1 overexpression promotes LUAD progression through the miR-205-5p/EREG and miR-34c-5p/BCL-2 axes.