p210 ^bcr‐abl induces amoeboid motility by recruiting ADF/destrin through RhoA/ROCK1

Abstract

We previously demonstrated that the Bcr-Abl oncogene, p210(bcr-abl), through its unique GEF domain, specifically activates RhoA and induces spontaneous amoeboid motility. We intend to study the pathways downstream RhoA controlling amoeboid motility. Mouse prolymphoblastic cells (Ba/F3 cell line) expressing different forms of Bcr-Abl were embedded in 3-dimensional (3D) Matrigel to study motility and explore the effects of inhibiting Rho pathway (inhibitors and siRNAs). The phosphorylation levels of cofilin-1 and destrin were analyzed by 2-dimensional electrophoresis. Composition of Bcr-Abl signalplex in different conditions was determined by coimmunoprecipitation. Ba/F3p190 and Ba/F3 expressing a mutant form of p210(bcr-abl) (unable to activate RhoA) cells presented a spontaneous motility, but not an amoeboid type. p210(bcr-abl)-induced amoeboid motility in a 3D matrix requires isoform-specific RhoA/ROCK-1/destrin signaling. Next to the conventional Rho/ROCK/MLC/myosin pathway, this pathway is a crucial determinant for amoeboid motility, specific for the destrin isoform (and not its coexpressed homologue cofilin-1). Also, the presence of destrin (and not cofilin-1) in the p210(bcr-abl) complex is dependent on ROCK1, and this signalplex is required for amoeboid motility. This underscores isoform-specific function within the ADF/cofilin family and provides new insight into Bcr-Abl signaling to amoeboid motility and possible impact on understanding chronic myeloid leukemia progression.

Non-overlapping activities of ADF and cofilin-1 during the migration of metastatic breast tumor cells

“…It should be pointed out that our analysis has been restricted to migration on a two dimensional substrate. Cells traversing through a 3 dimensional network in which adhesions are not formed in a distinct plane may show additional differences in behavior depending on their relative amounts and activities of ADF and cofilin [69]. …”

Novel Insights into the Roles of Rho Kinase in Cancer

“…In tumor cells, ROCK1 and ROCK2 have recently been reported to have functional differences in regulating adhesion, migration, proliferation, and gene expression, but the underlying mechanisms are not fully understood (Inaba et al 2010 ; Mertsch and Thanos 2014 ; Montalvo et al 2013 ; Rochelle et al 2013 ; Vega et al 2011 ; Vigil et al 2012 ; Wang et al 2014 ). In non-small cell lung carcinoma, suppression of ROCK1 or ROCK2 expression alone was sufficient to impair anchorage-independent growth (Vigil et al 2012 ).…”

In Vitro Modeling of Tissue-Specific 3D Microenvironments and Possibile Application to Pediatric Cancer Research

“…Cellular invasion was scored by evaluating the number of cells at different positions in the 3D matrices, by using an inverted microscope and a digital depth meter [167,168]. A more complex 3D model for testing cell motility was developed by de Silva and collaborators [169], where they have fabricated an Inverted Colloidal Crystals (ICC) scaffold, with a 3D honeycomb-like structure from colloidal crystal templates.…”