Y-27632 Suppresses the Growth and Migration of Oral Squamous Cell Carcinoma, but Upregulates Autophagy by Suppressing mTOR Effectors.

BACKGROUND: The Rho-associated protein kinase (ROCK) inhibitor Y-27632 is a potential immunotherapeutic agent for cancer treatment. Y-27632 blocks the growth and migration of oral squamous cell carcinoma (OSCC) CAL-27 cells. However, detailed studies on the underlying mechanisms have not yet been reported. METHODS: We investigated the effects of Y-27632 on the proliferation, migration, and invasion of OSCC cells (CAL-27, SCC-4, and SCC-9) using the Cell Counting Kit-8 assay, ethynyl-2'-deoxyuridine staining, cell scratch, and transwell assay in vitro. Next, ROCK1/2 was knocked down using siRNA to confirm that the effects of Y-27632 were mediated by the inhibition of ROCK activity. A xenograft mouse model was used to verify the effects of Y-27632 in vivo. The mechanisms underlying Y-27632-induced tumor suppression were detected using western blotting and qRT-PCR. RESULTS: Our data demonstrated that Y-27632 potently inhibited OSCC cells (CAL-27, SCC-4, and SCC-9) by inhibiting ROCK activity. In vivo assays confirmed that Y-27632 suppressed OSCC growth by reducing cell proliferation. Biochemical assays demonstrated that Y-27632 inactivated the AKT pathway, and treatment with SC79, an AKT activator, rescued the cell growth and migration inhibition elicited by Y-27632. Further investigation revealed that Y-27632 enhanced autophagy by suppressing the AKT/mTOR pathway. CONCLUSION: Our study demonstrated that Y-27632 significantly suppressed the growth and migration of OSCC cells and upregulated autophagy via the AKT/mTOR pathway, thus providing a potential therapeutic drug for patients with OSCC.