Activation of Rho GTPase Cdc42 promotes adhesion and invasion in colorectal cancer cells

BACKGROUND: The purpose of this study was to investigate the role of activated Rho GTPase cell division control protein 42 homolog (Cdc42) in colorectal cancer cell adhesion, migration, and invasion. MATERIAL/METHODS: The constitutively active form of Cdc42 (GFP-Cdc42L61) or control vector was overexpressed in the colorectal cancer cell line SW480. The localization of active Cdc42 was monitored by immunofluorescence staining, and the effects of active Cdc42 on cell migration and invasion were examined using an attachment assay, a wound healing assay, and a Matrigel migration assay in vitro. RESULTS: Immunofluorescence staining revealed that constitutively active Cdc42 predominately localized to the plasma membrane. Compared to SW480 cells transfected with the control vector, overexpression of constitutively active Cdc42 in SW480 cells promoted filopodia formation and cell stretch and dramatically enhanced cell adhesion to the coated plates. The wound healing assay revealed a significant increase of migration capability in SW480 cells expressing active Cdc42 compared to the control cells. Additionally, the Matrigel invasion assay demonstrated that active Cdc42 significantly promoted SW480 cell migration through the chamber. CONCLUSIONS: Our results suggest that active Rho GTPase Cdc42 can greatly enhance colorectal cancer cell SW480 to spread, migrate, and invade, which may contribute to colorectal cancer metastasis.