The Long Intergenic Noncoding RNA 00707 Promotes Lung Adenocarcinoma Cell Proliferation and Migration by Regulating Cdc42.

BACKGROUND/AIMS: Lung cancer (LC) is a serious disease with high morbidity and mortality. Long noncoding RNAs (lncRNAs) have garnered attention because they participate in diverse human disorders, including cancer. Our study examined the long intergenic noncoding RNA 00707 (LINC00707). The effects of LINC00707 on lung adenocarcinoma (LAD) and molecular mechanisms are unclear. This study is aimed to investigate the role of LINC00707 in the malignant processes of LAD.

METHODS: Quantitative reverse transcription PCR (qRT-PCR) was used to examine the expression level of LINC00707 in tissues and cell lines. The association of LINC00707 expression and postoperative prognosis was analyzed by the Kaplan-Meier method and log-rank test. Cell proliferation was evaluated in vitro and in vivo. Transwell assays were performed to examine cell migration. Cell cycle and apoptosis was determined by flow -cytometric and western blot analyses. Microarray analysis was conducted to screen for the downstream target gene Cdc42 of LINC00707, which was identified by qRT-PCR, functional analysis, and rescue experiment.

RESULTS: The expression level of LINC00707 was clearly upregulated in LAD tissues compared to that in corresponding normal tissues. Its overexpression was related to advanced TNM stage, larger tumor size, lymphatic metastasis, and poor prognosis. Functional assays revealed that LINC00707 knockdown repressed LAD cell proliferation both in vitro and in vivo. This process may involve the inducing of G1 arrest and apoptosis. Moreover, cell migration was impaired after LINC00707 inhibition. Microarray analysis and rescue assays suggested that Cdc42 is an important target gene involved in the carcinogenesis of LINC00707.

CONCLUSIONS: In summary, LINC00707 is a noncoding oncogene that exerts important regulatory functions in LAD, suggesting its potential as a biomarker in the prognosis and treatment of LAD.