RhoA functionally collaborates with HSPA1A to promote the migratory phenotype of cancer cells

Abstract

RhoA, a member of the GTPase family, plays a pivotal role in attaining a migratory phenotype, mainly by regulating cytoskeleton dynamics, cell adhesion and membrane protrusions. Although many upstream regulators and downstream effectors of RhoA have been identified, the discovery of new interacting partners continues to expand its interactome, providing fresh insights into its regulation and function. Co-immunoprecipitation and fluorescence microscopy were used to study the interaction, localization and morphological effects of HSPA1A and RhoA. The interaction was validated by modulating the protein expression through transfections and silencing approaches. Cell proliferation, migration and viability were assessed using MTT, a Boyden chamber and FACS assays, respectively. Our study identified HSPA1A, as an unexplored interacting partner of RhoA under physiological conditions. Functional analyses showed that the interaction between HSPA1A and RhoA enhances the migratory potential of cancer cells, induces G0/G1 cell cycle arrest and promotes a rounded cell morphology. Under HSPA1A transfection, increased RhoA protein levels were observed, while the silencing of HSPA1A resulted in decreased RhoA levels. This study highlights the critical role of HSPA1A-RhoA interaction in regulating cancer cell migration, morphology and cell cycle progression. These findings lay the groundwork for future research into its potential clinical applications.