Abstract
PURPOSE: Abnormal expression of PINCH-1 has been observed in various types of human cancers. However, the clinical importance and mechanism underlying its role in head and neck squamous cell carcinoma (HNSCC) is yet to be fully elucidated. METHODS: This study evaluated the expression of PINCH-1 in HNSCC samples through immunohistochemical staining and Western blotting. AMC-HN-8, Cal27, and SCC7 cell lines were utilized for cellular function experiments, both in vivo and in vitro. CCK8, colony-formation assay, flow cytometry, wound-healing assay, and transwell assay were employed to investigate the effects of alterations in target proteins on the growth and metastasis of cancer cells. Mito-Tracker Deep Red FM was used to track mitochondrial morphology. RESULTS: PINCH-1 was found to be overexpressed in HNSCC and closely associated with lymph node metastasis and poor pathologic differentiation. Its upregulation promoted proliferation, inhibited apoptosis, and enhanced migration and invasion in HNSCC cells. It also promoted mitochondrial fission. We conducted a mechanism analysis, which showed that PINCH-1 knockdown inhibited mitochondrial fission by reducing the expression of DRP1. Furthermore, inhibition of mitochondrial fission could impede the proliferation and metastasis of HNSCC cells. Re-expression of DRP1 reversed the inhibitory effect of PINCH-1 knockdown on mitochondrial fission, cell proliferation, and metastasis in HNSCC cells. CONCLUSIONS: PINCH-1 plays a critical oncogenic role in HNSCC by enhancing DRP1-mediated mitochondrial fission, which may serve as a novel therapeutic target for HNSCC.