LncRNA RP11-116G8.5 promotes the progression of lung squamous cell carcinoma through sponging miR-3150b-3p/miR-6870-5p to upregulate PHF12/FOXP4

Background: Lung squamous cell carcinoma (LUSC) is one of the commonest malignancies worldwide. Long noncoding RNAs (lncRNAs) have been revealed to engage in cancer development. LncRNA RP11-116G8.5 is a new founded lncRNA that has not been clearly elucidated in LUSC. Materials and methods: Expression levels of RNAs in LUSC cells were measured through qRT-PCR. To identify the functions of RP11-116G8.5, CCK-8 assay, colony formation assay and EdU assay were conducted in indicated LUSC cells. Mechanism experiments, including RNA pull down assay, Agog-RIP assay and luciferase reporter assay were performed to demonstrate the interaction between RP11-116G8.5 and miR-3150b-3p/miR-6870-5p. Meanwhile, the interaction between miR-3150b-3p/miR-6870-5p and their downstream targets PHD finger protein 12 (PHF12), and forkhead box P4 (FOXP4) were also proven in the same methods. Results: RP11-116G8.5 was expressed at high level in LUSC cell lines. Down-regulated RP11-11-6G8.5 repressed cell proliferation, migration and invasion, but accelerated apoptosis. Furthermore, it was proven that RP11-116G8.5 could act as sponges for miR-3150b-3p and miR-6870-5p these miRNAs were found to act as cancer suppressors in LUSC cells. PHF12 and FOXP4 were verified as the target gene of miR-3150b-3p and miR-6870-5p separately. Overexpression of PHF12 and FOXP4 could reverse the repressive effect of RP11-116G8.5 knockdown on LUSC progression. Additionally, Paired Box 5 (PAX-5) was proven to be the transcription factor for RP11-116G8.5 in LUSC cells. Conclusions: LncRNA RP11-116G8.5 promotes malignant behaviors of LUSC through sponging miR-3150b-3p/miR-6870-5p to upregulate PHF12/FOXP4 expression.