This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by van Ginkel, P. R. Articles by Polans, A. S. Search for Related Content PubMed PubMed Citation Articles by van Ginkel, P. R. Articles by Polans, A. S.

Expression of the Receptor Tyrosine Kinase Axl Promotes Ocular Melanoma Cell Survival

¹Departments of Ophthalmology and Visual Sciences, ²Biomolecular Chemistry, and ³Population Health Sciences and the State Hygiene Laboratory, University of Wisconsin Medical School, Madison, Wisconsin, and ⁴Amgen Inc., Thousand Oaks, California

Metastatic tumor cells originating from cancers of a variety of tissues such as breast, skin, and prostate may remain dormant for long periods of time. In the case of uveal melanoma, the principal malignancy of the eye, complete removal of the primary tumor by enucleation can nonetheless be followed by metastatic tumor growth in distant organs months, years, or even decades later. This suggests that tumor cells have already spread to secondary sites at the time of treatment and remain dormant as micrometastases. Identifying factors that govern long-lived survival of metastatic tumor cells is therefore key to decreasing mortality associated with this and other diseases. While investigating factors differentially expressed in melanoma cells and normal melanocytes, we identified the receptor tyrosine kinase Axl and found up-regulation of Axl in uveal melanomas and melanoma cell lines by RNase protection, Western analysis, and immunohistochemistry. Axl has been shown to mediate cell growth and survival through its ligand Gas6 in non-transformed cells. To test whether stimulation of Axl can enhance survival of uveal melanoma cells, we assessed the degree of mitogenesis and cell survival by bromodeoxyuridine incorporation and trypan blue exclusion, respectively, upon stimulation of Mel 290 uveal melanoma cells with Gas6 in vitro. We show that Gas6 mediates mitogenesis and cell survival in Mel 290 cells. We further demonstrate that these effects occur specifically through the Axl receptor by modulating the expression of Axl with an antisense construct. cDNA microarray analysis of 12,687 genes then revealed that Gas6 stimulation of Axl in Mel 290 cells results primarily in the down-regulation of Cyr61, a member of the CCN protein family involved in tumor progression. These data show that the Axl pathway mediates increased survival of uveal melanoma cells, potentially advantageous during cancer dormancy, and that Axl may function in part through regulation of Cyr61.

This article has been cited by other articles:

				T. Revil, J. Toutant, L. Shkreta, D. Garneau, P. Cloutier, and B. Chabot Protein Kinase C-Dependent Control of Bcl-x Alternative Splicing Mol. Cell. Biol., December 15, 2007; 27(24): 8431 - 8441. [Abstract] [Full Text] [PDF]

				S. M. Nielsen-Preiss, M. P. Allen, M. Xu, D. A. Linseman, J. E. Pawlowski, R. J. Bouchard, B. C. Varnum, K. A. Heidenreich, and M. E. Wierman Adhesion-Related Kinase Induction of Migration Requires Phosphatidylinositol-3-Kinase and Ras Stimulation of Rac Activity in Immortalized Gonadotropin-Releasing Hormone Neuronal Cells Endocrinology, June 1, 2007; 148(6): 2806 - 2814. [Abstract] [Full Text] [PDF]

				P. Vajkoczy, P. Knyazev, A. Kunkel, H.-H. Capelle, S. Behrndt, H. von Tengg-Kobligk, F. Kiessling, U. Eichelsbacher, M. Essig, T.-A. Read, et al. Dominant-negative inhibition of the Axl receptor tyrosine kinase suppresses brain tumor cell growth and invasion and prolongs survival PNAS, April 11, 2006; 103(15): 5799 - 5804. [Abstract] [Full Text] [PDF]

				S. J. Holland, M. J. Powell, C. Franci, E. W. Chan, A. M. Friera, R. E. Atchison, J. McLaughlin, S. E. Swift, E. S. Pali, G. Yam, et al. Multiple Roles for the Receptor Tyrosine Kinase Axl in Tumor Formation Cancer Res., October 15, 2005; 65(20): 9294 - 9303. [Abstract] [Full Text] [PDF]