LncRNA ZFAS1 promotes laryngeal cancer progression through RBFOX2-mediated MENA alternative splicing

Laryngeal cancer (LC) is the most common aggressive malignancy of the head and neck. LncRNA ZNFX1 antisense RNA 1 (ZFAS1) displays oncogenic properties in head and neck squamous cell carcinoma, but its regulatory role in laryngeal cancer progression remains obscure. Here, we found that ZFAS1 expression in laryngeal cancer tissues and cells was higher than that in adjacent normal tissues and normal nasopharyngeal epithelial cells. Highly expressed ZFAS1 was associated with advanced lymph node metastasis stages and clinical stages. ZFAS1 overexpression promoted LC cell proliferation, invasion, and N-cadherin and Vimentin expression, and suppressed E-cadherin expression. While ZFAS1 knockdown played an opposite role. Mechanistically, ZFAS1 stabilized RNA binding fox-1 homolog 2 (RBFOX2) protein expression by binding to RBFOX2, and RBFOX2 overexpression reversed the effect of ZFAS1 silence on cell functions. Moreover, highly expressed RBFOX2 led to skipping of MENA exon 11a and generating a pro-invasive isoform (MENA^INV ). MENA^INV overexpression effectively abolished the inhibitory effect of RBFOX2 knockdown on cell malignant progression. Furthermore, Hep2 cells infected with lentivirus-mediated ZFAS1 shRNA or negative control shRNA were subcutaneously injected into mice to assess the role of ZFAS1 in tumor growth. And the data showed that silencing ZFAS1 in vivo hindered xenograft tumor growth. In conclusion, silencing ZFAS1 alleviated malignant progression of laryngeal cancer cells and mouse xenograft tumor growth by regulating RBFOX2-mediated alternative splicing of MENA.