Open Access Research

Metastasis of aggressive amoeboid sarcoma cells is dependent on Rho/ROCK/MLC signaling

Jan Kosla2, Daniela Paňková1, Jiří Plachý2, Ondřej Tolde1, Kristýna Bicanová1, Michal Dvořák2, Daniel Rösel1 and Jan Brábek1*

Author Affiliations

1 Department of Cell Biology, Faculty of Science, Charles University in Prague, Viničná 7, 12843, Prague 2, Czech Republic

2 Laboratory of Molecular Virology or Cellular and Viral Genetics, Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 14220, Prague 4, Czech Republic

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Cell Communication and Signaling 2013, 11:51  doi:10.1186/1478-811X-11-51

Published: 30 July 2013

Abstract

Background

Although there is extensive evidence for the amoeboid invasiveness of cancer cells in vitro, much less is known about the role of amoeboid invasiveness in metastasis and the importance of Rho/ROCK/MLC signaling in this process.

Results

We analyzed the dependence of amoeboid invasiveness of rat and chicken sarcoma cells and the metastatic activity of chicken cells on individual elements of the Rho/ROCK/MLC pathway. In both animal models, inhibition of Rho, ROCK or MLC resulted in greatly decreased cell invasiveness in vitro, while inhibition of extracellular proteases using a broad spectrum inhibitor did not have a significant effect. The inhibition of both Rho activity and MLC phosphorylation by dominant negative mutants led to a decreased capability of chicken sarcoma cells to metastasize. Moreover, the overexpression of RhoA in non-metastatic chicken cells resulted in the rescue of both invasiveness and metastatic capability. Rho and ROCK, unlike MLC, appeared to be directly involved in the maintenance of the amoeboid phenotype, as their inhibition resulted in the amoeboid-mesenchymal transition in analyzed cell lines.

Conclusion

Taken together, these results suggest that protease-independent invasion controlled by elements of the Rho/ROCK/MLC pathway can be frequently exploited by metastatic sarcoma cells.

Keywords:
Metastasis; Sarcoma; RhoA; ROCK; MLC; Amoeboid invasiveness; 3D environment; Chicken model