LASP1 facilitates bladder cancer progression through binding and downregulating MYH9 to inhibit mitochondrial ROS-induced apoptosis.

LIM and SH3 protein 1 (LASP1) plays a crucial role in tumorigenesis and metastasis, but its function in bladder cancer remains unclear. Here, we found that LASP1 was markedly upregulated in bladder cancer tissues and correlated with poor prognosis. Co-immunoprecipitation and mass spectrometry identified MYH9 as a direct LASP1-binding partner, with the interaction mediated by the SH3 domain of LASP1 and the M2 domain of MYH9. Functional assays revealed that LASP1 maintained mitochondrial morphology and function by regulating MYH9, thereby preventing mitochondrial damage-induced apoptosis and promoting cell proliferation and migration. In vitro and in vivo experiments consistently demonstrated that the LASP1-MYH9 axis enhances bladder cancer growth and metastasis. Overall, our findings reveal that LASP1 facilitates bladder cancer progression by interacting with MYH9 to inhibit mitochondria-mediated apoptosis, and provide a rationale for further exploring the LASP1-MYH9 axis in bladder cancer therapy.