RAC1 induces nuclear alterations through the LINC complex to enhance melanoma invasiveness

© 2020 Colón-Bolea et al.RHO GTPases are key regulators of the cytoskeletal architecture, which impact a broad range of biological processes in malignant cells including motility, invasion, and metastasis, thereby affecting tumor progression. One of the constraints during cell migration is the diameter of the pores through which cells pass. In this respect, the size and shape of the nucleus pose a major limitation. Therefore, enhanced nuclear plasticity can promote cell migration. Nuclear morphology is determined in part through the cytoskeleton, which connects to the nucleoskeleton through the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex. Here, we unravel the role of RAC1 as an orchestrator of nuclear morphology in melanoma cells. We demonstrate that activated RAC1 promotes nuclear alterations through its effector PAK1 and the tubulin cytoskeleton, thereby enhancing migration and intravasation of melanoma cells. Disruption of the LINC complex prevented RAC1-induced nuclear alterations and the invasive properties of melanoma cells. Thus, RAC1 induces nuclear morphology alterations through microtubules and the LINC complex to promote an invasive phenotype in melanoma cells.B.C.’s laboratory is supported by a Retos Jóvenes Investigadores grant SAF2015-73364-JIN Ministerio de Ciencia, Innovación y Universidades (MICIU/AEI/FEDER, UE), a PIE grant from Consejo Superior de Investigaciones Científicas (CSIC)—MCIU, and the Ramón y Cajal Research Program (MICIU, RYC2018-024004-I). P.C is supported by grant SAF-2015 63638R (MINECO/FEDER, UE); by Red Temática de Investigación Cooperativa sobre el Cáncer (RTICC), RD/12/0036/0033, and by Asociación Española Contra el Cáncer (AECC) grant GCB141423113. X.R.B. is supported by grants from the Castilla-León Government (BIO/SA01/15, CSI049U16), MINECO (SAF2015-64556-R, RD12/0036/0002), Worldwide Cancer Research (14-1248), Ramón Areces Foundation, and AECC (GC16173472GARC). Spanish funding to B.C., P.C., and X.R.B. is partially supported by the European Regional Development Fund