PIM3 Proto-Oncogene Kinase Is a Common Transcriptional Target of Divergent EWS/ETS Oncoproteins

Abstract

Despite significant structural diversity, present evidence suggests that EWS/ETS fusion proteins promote oncogenesis by transcriptionally modulating a common set of target genes. In order to identify these genes, microarray expression analyses were performed on NIH 3T3 polyclonal populations expressing one of three EWS/ETS fusion genes. The majority of these genes can be grouped into seven functional categories, including cellular metabolism and signal transduction. The biologic significance of these target genes was pursued. The effects of modulating genes involved in metabolism were assessed by flux studies and demonstrated shifts in glucose utilization and lactate production as a result of EWS/FLI1 expression. The proto-oncogene coding for serine/threonine kinase PIM3 was found to one of several genes encoding signal transduction proteins that were up-regulated by EWS/ETS fusions. PIM3 was found to be expressed in a panel of human Ewing's family tumor cell lines. Forced expression of PIM3 promoted anchorage-independent growth. Coexpression of a kinase-deficient PIM3 mutant attenuated EWS/FLI1-mediated NIH 3T3 tumorigenesis in immunodeficent mice.

ACKNOWLEDGMENTS

We thank Harvey Herschman for providing the anti-KID1 (PIM3) antibodies and cDNA, Elliot Landaw for insight and assistance with statistical analysis, and Iris Williams for assistance with the FACS analysis and sorting.

This work was supported by NCI grant CA87771 from the National Institutes of Health.

B.D. and S.M.W. contributed equally to this work.