Nutlin-3 suppresses tumorigenesis and progression of oral squamous cell carcinoma and enhances chemosensitivity to cisplatin

Oral squamous cell carcinoma (OSCC) is an epithelial malignant tumor with great challenges of tumor metastasis and drug resistance. Nutlin-3 is a MDM2 inhibitor that can potently activate tumor suppressor gene p53. However, the exact role of Nutlin-3 in OSCC has not been identified yet. SCC-9 cells were treated with 0, 2.5, 5, 10, 20 mu M Nutlin3. MDM2 and p53 protein levels were assessed using western blot analysis. Then, CCK8 assay, clone formation assay, TUNEL staining, wound healing and transwell assays were conducted to analyze the influences of Nutlin3 on the proliferation, apoptosis, migration, and invasion in SCC-9 cells. Moreover, SCC-9 cells were co-treated with 0, 0.5, 1, 2.5, 5 mu M cisplatin and Nutlin3 to determine the effect of Nutlin3 on cisplatin chemosensitivity in OSCC. As expected, Nutlin-3 inhibited MDM2 but restored p53 in OSCC in a concentration-dependent manner. Meanwhile, Nutlin-3 suppressed the proliferation, clone formation, migration, invasion and epithelial-mesenchymal transition of SCC-9 cells and both boosted the apoptosis. In addition, Nutlin-3 caused a reduced cell viability and an elevated cell apoptosis rate in cisplatin-treated SCC-9 cells, indicating that Nutlin-3 enhanced cisplatin chemosensitivity in OSCC cells. Taken together, Nutlin-3 may suppress tumorigenesis and progression of OSCC and enhance chemosensitivity to cisplatin in OSCC.