USP10 activates the FAK pathway by stabilizing RIOK3 in pancreatic ductal adenocarcinoma

Abstract Background The aberrant activation of FAK (Focal Adhesion Kinase) serves as a critical mechanism leading to heightened invasiveness and metastatic potential in pancreatic ductal adenocarcinoma (PDAC). FAK inhibitors have entered clinical trials, underscoring the significance of targeting FAK in treating PDAC. Further exploration of the regulation mechanism of FAK is crucial for advancing FAK inhibitors. Our previous study suggests that RIO Kinase 3 (RIOK3) facilitates the invasiveness and metastasis of PDAC cells by stabilizing FAK protein expression and upregulating its phosphorylation. Methods We used bioinformatics and IHC to measure Ubiquitin-specific protease 10 (USP10) mRNA and protein expression in PDAC based on TCGA and GTEx PDAC mRNA databases and two PDAC tissue chips from independent medical centers, and survival analysis was performed. Stable knockdown and overexpression experiments were performed on three different PDAC cells to elucidate the carcinogenic effect of USP10 through both in vivo and in vitro experiments. Co-IP and laser confocal experiments were carried out to confirm the interaction modes between USP10, FAK, and RIOK3. Deubiquitination experiments further validated the deubiquitination effect of USP10 on RIOK3. Finally, a prognostic model incorporating co-expression of USP10 and RIOK3 along with other factors influencing PDAC survival was established and validated using COX regression analysis. Results USP10 was associated with a poor prognosis in PDAC. In vitro experiments found that USP10 significantly promotes the proliferation, invasion, and migration of PDAC cells. Xenografted tumor and lung metastasis models in nude mice demonstrated that USP10 promoted the growth and metastasis of PDAC cells. Mechanically, USP10 interacts with FAK and RIOK3. RIOK3 acts as a bridge between USP10 and FAK. USP10 deubiquitinates and stabilizes RIOK3. In addition, RIOK3 overexpression can significantly compensate for the USP10 knockdown-mediated decline in FAK protein expression. Moreover, USP10 and RIOK3 co-expression is a significant factor associated with poor survival in the PDAC prognostic model. Conclusion USP10 deubiquitinates and stabilizes RIOK3 and activates the FAK signaling pathway, thereby inhibiting PDAC tumorigenesis, indicating that it may be a potential drug target for cancer treatment.