Poster Presentation Lowy Cancer Symposium 2015

Stathmin mediates neuroblastoma metastasis in a tubulin-independent manner via RhoA activation and transendothelial migration (#114)

Christopher M Fife 1 2 , Sharon M Sagnella 1 2 , Frances L Byrne 3 , Dominic Ng 4 , Thomas P Davis 5 , Joshua A McCarroll 1 2 , Maria Kavallaris 1 2
  1. Australian Centre for Nanomedicine, University of New South Wales, Sydney, New South Wales, Australia
  2. Tumour Biology and Targeting Program, Children's Cancer Institute Australia, Sydney, NSW, Australia
  3. Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
  4. Cytoskeleton Regulation and Signal Transduction Group, University of Melbourne, Melbourne, Victoria, Australia
  5. ARC Centre for Convergent Bio-Nano Science and Technology, Monash University, Melbourne, Victoria, Australia

Neuroblastoma is an aggressive childhood cancer with dismal 5-year survival rates, primarily due to metastatic disease1,2. Metastasis, the movement of cancer cells from one site to another, involves cell cytoskeletal remodelling3. The microtubule destabilising protein, stathmin, has recently been shown to mediate neuroblastoma metastasis4. In this study we investigated stathmin’s contribution to specific steps in the metastatic cascade and the potential mechanism by which it exerts these effects.

Stathmin suppression significantly reduced neuroblastoma cell (SK-N-BE(2) and SH-SY5Y) migration and invasion (through transwell inserts), and invasion into an extracellular matrix from 3D tumour spheroids, without influencing anoikis. Moreover, stathmin suppression significantly reduced SK-N-BE(2) and SH-SY5Y cell in vitro transendothelial migration. In vivo transendothelial migration was examined using an experimental metastasis tail vein model using shRNA-expressing SK-N-BE(2) neuroblastoma cells. In this model, stathmin suppression significantly reduced whole body, lung, kidney and liver metastasis. To examine how stathmin may exert these effects, SK-N-BE(2) and SH-SY5Y neuroblastoma cells were treated with the ROCK inhibitors Y-27632 and H-1152, resulting in transendothelial migration levels of stathmin suppressed cells being returned to control levels - highlighting that stathmin regulates transendothelial migration through ROCK signalling. Furthermore, stathmin suppression in SK-N-BE(2) cells significantly increased the activation of upstream RhoA, whilst not influencing Rac1 or Cdc42. Interestingly, restoration of stathmin levels with either wild-type stathmin or 4E:mutant stathmin (defective tubulin-binding ability) returned SK-N-BE(2) cell migration back to control levels indicating that stathmin influences migration in neuroblastoma cells independently of tubulin binding.

In conclusion, stathmin suppression interferes with key metastatic events via RhoA/ROCK signalling in neuroblastoma. Furthermore, stathmin’s influence on cell migration is independent of tubulin binding. Further investigation is required to determine how stathmin is regulating these phenotypes in a microtubule-independent manner. Targeting stathmin signalling pathways may provide a novel treatment approach for metastatic neuroblastoma.

  1. Maris, J. M., Hogarty, M. D., Bagatell, R., Cohn, S. (2007) “Neuroblastoma” Lancet 369, 2106-2120.
  2. Gutierrez, J. C., Fischer, A. C., Sola, J. E., Perez, E. A. & Koniaris, L. G. (2007). "Markedly improving survival of neuroblastoma: a 30-year analysis of 1,646 patients." Pediatric Surgery International 23, 637-646.
  3. Fife, C. M., McCarroll, J. M., Kavallaris, M. (2014).“Movers and shakers: cell cytoskeleton in cancer metastasis.” British Journal of Pharmacology 171, 5507- 5523.
  4. Byrne, F. L., Yang, L., Phillips, P. A., Hansford, L. M., Fletcher, J. I., Ormandy, C. J., McCarroll, J. A. & Kavallaris, M. (2013). “RNAi-mediated stathmin suppression reduces lung metastasis in an orthotopic neuroblastoma mouse model.” Oncogene 33, 882-890.