Özdaş, SibelCanatar, İpekÖzdaş, Talih2025-01-062025-01-0620220023-852X10.1002/lary.297872-s2.0-85111505181https://doi.org/10.1002/lary.29787https://hdl.handle.net/20.500.14669/1416Objectives/Hypothesis: Dysregulated expression of microRNAs (miRNAs) and dysregulation of the mechanisms that regulate them are associated with carcinogenesis. Exportin-5 (XPO5), a member of the Karyopherin family, is responsible for the transfer of pre-miRNAs from the nucleus to the cytoplasm. Despite the high oncogenic potential of XPO5 as a critical regulator of the biogenesis of miRNAs, its role in head and neck squamous cell carcinoma (HNSCC) biology has not been explained yet. Study Design: In-vitro translational. Methods: The expression of XPO5 at the mRNA, protein, and intracellular level in SCC-9, FaDu SCC-90, and Detroit-562 cell lines were evaluated with quantitative reverse transcription polymerase chain reaction, Western-blot analysis, and immunofluorescence staining, respectively. The functional role of XPO5 in HNSCC was analyzed by silencing the gene expression with XPO5-small interfering RNA (siRNA) in the in vitro model. Cell proliferation, migration capacity, and apoptosis in XPO5 knockdown HNSCC cell lines were evaluated by MTT, wound-healing, and caspase-3 assay, respectively. Results: Expression of XPO5 was determined to be upregulated at mRNA, protein, and intracellular level in metastatic cells compared to primary cells in HNSCC. XPO5 gene expression was knockdown by XPO5-siRNA transfection, verifying that it was suppressed at the mRNA, protein, and intracellular level. Silencing XPO5 caused a decrease in cell proliferation, delay in wound healing, and increase in Caspase-3 enzyme activity in HNSCC cell lines compared to control. Conclusions: This report is the first to describe the oncogenic role of XPO5 in HNSCC biology by in vitro experiments. Consequently, XPO5 can be used as a potential biomarker and therapeutic target molecule against the disease in the diagnosis-treatment-follow-up of HNSCC. Level of Evidence: NA Laryngoscope, 132:569–577, 2022. © 2021 The American Laryngological, Rhinological and Otological Society, Inc.eninfo:eu-repo/semantics/closedAccessHead and neck squamous cell carcinoma (HNSCC)metastasisnuclear exportsiRNAXPO5Article577334328643Q1569132