Analysis of Invasion Dynamics of Matrix-Embedded Cells in a Multisample Format.

In vitro tests of cancer cell invasion are the "first line" tools of preclinical researchers for screening the multitude of chemical compounds or cell perturbations that may aid in halting or treating cancer malignancy. In order to have predictive value or to contribute to designing personalized treatment regimes, these tests need to take into account the cancer cell environment and measure effects on invasion in sufficient detail. The in vitro invasion assays presented here are a trade-off between feasibility in a multisample format and mimicking the complexity of the tumor microenvironment.

CDC42 switches IRSp53 from inhibition of actin growth to elongation by clustering of VASP.

Filopodia explore the environment, sensing soluble and mechanical cues during directional motility and tissue morphogenesis. How filopodia are initiated and spatially restricted to specific sites on the plasma membrane is still unclear. Here, we show that the membrane deforming and curvature sensing IRSp53 (Insulin Receptor Substrate of 53 kDa) protein slows down actin filament barbed end growth.

Alphaherpesviral US3 kinase induces cofilin dephosphorylation to reorganize the actin cytoskeleton.

The conserved alphaherpesviral serine/threonine kinase US3 causes dramatic actin rearrangements, associated with increased viral spread. Here, we show that US3 of pseudorabies virus (PRV) leads to activation (dephosphorylation) of the central actin regulator cofilin. A mutation that impairs US3 kinase activity and the group I p21-activated kinase inhibitor IPA-3 inhibited US3-mediated cofilin activation.

p210bcr-abl induces amoeboid motility by recruiting ADF/destrin through RhoA/ROCK1.

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).

Cells lacking β-actin are genetically reprogrammed and maintain conditional migratory capacity.

Vertebrate nonmuscle cells express two actin isoforms: cytoplasmic β- and γ-actin. Because of the presence and localized translation of β-actin at the leading edge, this isoform is generally accepted to specifically generate protrusive forces for cell migration. Recent evidence also implicates β-actin in gene regulation.