The pro-metastasis tyrosine phosphatase, PRL-3 (PTP4A3), is a novel mediator of oncogenic function of BCR-ABL in human chronic myeloid leukemia
1 Cancer Science Institute of Singapore, Singapore, Singapore
2 Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
3 Department of Hematology-Oncology, National University Hospital, Singapore, Singapore
4 Institute of Molecular and Cell Biology (IMCB), A*Star, Singapore, Singapore
Molecular Cancer 2012, 11:72 doi:10.1186/1476-4598-11-72Published: 21 September 2012
Resistance to tyrosine kinase inhibitors (TKIs) remains a challenge in management of patients with chronic myeloid leukemia (CML). A better understanding of the BCR-ABL signalling network may lead to better therapy.
Here we report the discovery of a novel downstream target of BCR-ABL signalling, PRL-3 (PTP4A3), an oncogenic tyrosine phosphatase. Analysis of CML cancer cell lines and CML patient samples reveals the upregulation of PRL-3. Inhibition of BCR-ABL signalling either by Imatinib or by RNAi silencing BCR-ABL reduces PRL-3 and increases cleavage of PARP. In contrast, the amount of PRL-3 protein remains constant or even increased in response to Imatinib treatment in drug resistant cells expressing P210 T315I. Finally, analysis with specific shRNA shows PRL-3 involvement in the proliferation and self-renewal of CML cells.
These data support a role for PRL-3 in BCR-ABL signalling and CML biology and may be a potential therapeutic target downstream of BCR-ABL in TKI resistant mutant cells.