Long non-coding RNA DUXAP9 promotes the proliferation and metastasis of head and neck squamous cell carcinoma

To investigate the role of long non-coding RNA double homeobox A pseudogene 9 (DUXAP9) in head and neck squamous cell carcinoma (HNSCC) and to evaluate the expression level, molecular function and mechanism of DUXAP9 in HNSCC cells.

Differential expression of lncRNAs between normal and tumor tissues in HNSCC tissues were screened using lncRNA microarray, the expression level of DUXAP9 in HNSCC tissues and its relationship with prognosis were analyzed in the TCGA database. The expression levels of DUXAP9 in HNSCC tissues and cell lines were detected using qRT-PCR. The function in HNSCC cells after DUXAP9 silencing was evaluated using the CCK-8 assay, wound healing assay, Transwell migration assay and subcutaneous xenograft assay in nude mice. Changes in the transcription and translation of epithelial-mesenchymal transition (EMT)-related proteins in head and neck squamous cell carcinoma cells after DUXAP9 silencing were detected using qRT-PCR and Western blot.

lncRNA microarray results showed that, compared to adjacent normal tissues, DUXAP9 was abnormally upregulated in HNSCC tissues. Analysis from TCGA database showed that, compared to HNSCC patients with low DUXAP9 expression, HNSCC patients with high DUXAP9 expression had poorer survival. The relative expression of DUXAP9 in HNSCC tissues and 4 HNSCC cell lines increased compared to paired adjacent normal tissues as detected using qRT-PCR. Silencing DUXAP9 significantly inhibited the proliferation, migration and expression of EMT-related genes in HNSCC cells. The silencing of DUXAP9 significantly inhibited subcutaneous tumorigenesis of the HNSCC cell line CAL27 in nude mice.

Silencing DUXAP9 significantly inhibited the proliferation of HNSCC cells and subcutaneous xenografts in nude mice. DUXAP9 may mediate the migration of head and neck squamous cell carcinoma cells via the EMT pathway.