Abstract B021: Piezo1 and ROCK2 promote fast amoeboid migration in confined environments

Abstract

Cell migration through confined environments may induce a phenotypic transition to fast amoeboid (leader bleb-based) migration. However, the molecular mechanism(s) controlling this phenotypic transition remain poorly understood. Here, we show that regulation of intracellular calcium levels by the plasma membrane tension sensor, Piezo1, promotes the Leader Bleb-Based Migration (LBBM) of melanoma cells. Using a ratiometric assay, intracellular calcium is shown to rise with increasing levels of confinement. Chelation of extracellular and intracellular calcium by BAPTA and BAPTA-AM, respectively, inhibits LBBM. Moreover, in highly motile cells, we found intracellular calcium levels to be dramatically increased at the cell rear. Using the Piezo1 inhibitor, GsMTx4, and RNAi, we can inhibit the phenotypic transition to fast amoeboid (leader bleb-based) migration. Therefore, we wondered if Piezo1 through calcium/calmodulin activates Myosin Light Chain Kinase (MLCK) to promote actomyosin contractility and amoeboid migration. Using a microchannel based assay, we find that ROCK2 and not MLCK, promotes amoeboid migration. Altogether, our work reveals an unanticipated collaboration between Piezo1 and ROCK2 in amoeboid migrating melanoma cells. Citation Format: Alexa Caruso, Neelakshi Kar, Jeremy Logue. Piezo1 and ROCK2 promote fast amoeboid migration in confined environments [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B021.