Functional Analysis of the Putative Tumor Suppressor PTPRD in Neuroblastoma Cells

Abstract

The gene encoding PTPδ is mutated or downregulated in human cancers including neuroblastoma. Here, we functionally tested the tumor-suppressive potential of PTPδ in neuroblastoma cell lines by reconstitution of both short and long PTPδ isoforms. We did not observe any significant difference in colony forming ability between cells expressing wild-type or catalytically inactive PTPδ. Although endogenous PTPδ expression was very low in neuroblastoma cells, it was also low in mouse embryo adrenal glands, suggesting that PTPδ may have little developmental function in early adrenal neuroblasts. This study, therefore, questions the significance of PTPδ as a tumor suppressor protein in neuroblastoma.

Keywords: :

• Gene expression
• Neuroblastoma
• Tumor suppressors
• Tumor cell biology
• Signal transduction
• Tyrosine Phosphatase

ACKNOWLEDGMENTS

The authors thank to Francesca Menghi and Simon Picker for supplying the human cDNA samples, to Candy Kumps, Chris Jones, and Jenni Jayalapan for generously providing us with cell lines, and to John Bixby for providing the full-length PTPRD clone. The authors are also grateful to Owen Williams for feedback on the paper.

The research was funded by a Child Health Research Appeal Trust studentship (OC), Cancer Research UK (CHC) and the European Commission Training Network Grant MRTN-CT-2006-035830.