AUTHOR=Ji Yong , Zhang Guoqing , Zhang Xingyi 

TITLE=Identification of LncRNA CARD8-AS1 as a Potential Prognostic Biomarker Associated With Progression of Lung Adenocarcinoma

JOURNAL=British Journal of Biomedical Science

VOLUME=Volume 79 - 2022

YEAR=2022

URL=https://www.frontierspartnerships.org/journals/british-journal-of-biomedical-science/articles/10.3389/bjbs.2022.10498

DOI=10.3389/bjbs.2022.10498

ISSN=2474-0896

ABSTRACT=Background: Long non-coding RNAs (lncRNAs) exhibit crucial roles in human tumors. lncRNA CARD8-AS1 (CARD8-AS1) is abnormally expressed in several cancers. However, the role of CARD8-AS1 in lung adenocarcinoma remains elusive. This study aimed to investigate the role of CARD8-AS1 in lung adenocarcinoma. 
Methods: The expression of CARD8-AS1 was detected by RT-qPCR analysis and confirmed using an online database. The clinical prognostic value of CARD8-AS1 was evaluated using the Kaplan-Meier curve and multivariate Cox regression analyses. The effects of CARD8-AS1 on cancer cell proliferation, migration, and invasion potential were assessed through CCK-8 assay and Transwell migration and invasion assays. Western blot assay was used to measure Bcl-2 and Bax protein levels. The interaction between CARD8-AS1 and miR-650, as well as miR-650 and Bax, was assessed using a dual-luciferase reporter assay. 
Results: The expression of CARD8-AS1 was decreased significantly in lung adenocarcinoma tissues and cell lines. Low expression of CARD8-AS1 was related to tumor size, TNM stage, lymph node metastasis, and poor overall survival. Elevated expression of CARD8-AS1 could suppress cellular viability, migration potential, and invasion ability. The Bcl-2 protein levels were decreased while Bax levels were increased by overexpression of CARD8-AS1. miR-650 may thus be a direct target of CARD8-AS1 and Bax may be a direct target of miR-650.
Conclusion: These findings revealed that CARD8-AS1 expression was downregulated in lung adenocarcinoma and significantly associated with several clinical parameters. CARD8-AS1 exerted tumor-suppressive effects by targeting the miR-650 and then regulating Bax expression. CARD8-AS1/miR-650 may serve as novel prognostic biomarkers and potential therapeutic targets for the treatment of lung adenocarcinoma.