Long non-coding RNA FOXP4-AS1 acts as an adverse prognostic factor and regulates proliferation and apoptosis in nasopharyngeal carcinoma.

Zhong, L-K; Zhou, J; He, X; He, B-F; Zhou, X-W; Zhu, J-L; Liu, J; Qiu, Y-H

OBJECTIVE Nasopharyngeal carcinoma (NPC) is one of the most common malignancies worldwide. In The Cancer Genome Atlas (TCGA) database, the expression level of lncRNA forkhead box P4 antisense RNA 1 (FOXP4-AS1) is higher in NPC samples than in normal samples. PATIENTS AND METHODS Quantitative Real-time PCR and Western blotting were performed to detect the expression level of RNA and protein. Luciferase reporter assay ran to test the interactions between FOXP4-AS1 and miR-423-5p and STMN1. Subcellular fractionation assay was used to determine the subcellular localization of FOXP4-AS1. The tumor-promotion functions of FOXP4-AS1 were determined by both in vitro and in vivo assays. RESULTS The expression of FOXP4-AS1 was up-regulated in 80 cases with NPC, and these patients with a poor prognosis. Functionally, high expression of FOXP4-AS1 in NPC was connected with promoted cell proliferation and inhibited apoptosis. Moreover, FOXP4-AS1 is located in the cytoplasm of CNE1 (NPC cell lines). Mechanistically, FOXP4-AS1 up-regulated STMN1 on post-transcriptional regulation by means of miR-423-5p. CONCLUSIONS Our present study demonstrated that high expression of FOXP4-AS1 in NPC portended poor outcomes. FOXP4-AS1upregulated STMN1 by interacting with miR-423-5p as a competing endogenous RNA (ceRNA) to promote NPC progression.