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Early Detection and Diagnosis
Expression of the putative tumor suppressor gene PTPN13/PTPL1 is an independent prognostic marker for overall survival in breast cancer
Article first published online: 9 SEP 2008
Copyright © 2008 Wiley-Liss, Inc.
International Journal of Cancer
Volume 124, Issue 3, pages 638–643, 1 February 2009
How to Cite
Révillion, F., Puech, C., Rabenoelina, F., Chalbos, D., Peyrat, J.-P. and Freiss, G. (2009), Expression of the putative tumor suppressor gene PTPN13/PTPL1 is an independent prognostic marker for overall survival in breast cancer. Int. J. Cancer, 124: 638–643. doi: 10.1002/ijc.23989
- Issue published online: 18 NOV 2008
- Article first published online: 9 SEP 2008
- Accepted manuscript online: 9 SEP 2008 12:00AM EST
- Manuscript Accepted: 1 AUG 2008
- Manuscript Received: 3 JUN 2008
- Ligue Régionale Contre le Cancer Languedoc Roussillon
- INCa (Institut National du Cancer). Grant Numbers: 0611-3D1019-34/Valo, 0610-3D1616-118/PL2006
- breast cancer;
Although it is well established that some protein tyrosine kinases have a prognostic value in breast cancer, the involvement of protein tyrosine phosphatases (PTPs) is poorly substantiated for breast tumors. Three of these enzymes (PTP-gamma, LAR, and PTPL1) are already known to be regulated by estrogens or their antagonists in human breast cancer cells. We used a real-time reverse transcriptase polymerase chain reaction method to test the expression levels of PTP-gamma, LAR and its neuronal isoform, and PTPL1 in a training set of RNA from 59 breast tumors. We sought correlations between levels of these molecular markers, current tumor markers, and survival. We then quantified the expression level of the selected phosphatase in 232 additional samples, resulting in a testing set of 291 breast tumor RNAs from patients with a median follow-up of 6.4 years. The Spearman nonparametric test revealed correlations between PTPL1 expression and differentiation markers. Cox univariate analysis of the overall survival studies demonstrated that PTPL1 is a prognostic factor [risk ratio (RR) = 0.45], together with the progesterone receptor (PR) (RR = 0.52) and node involvement (RR = 1.58). In multivariate analyses, PTPL1 and PR retained their prognostic value (RRs of 0.48 and 0.55, respectively). This study demonstrates for the first time that PTPL1 expression level is an independent prognostic indicator of favorable outcome for patients with breast cancer. In conjunction with our mechanistic studies, this finding identifies PTPL1 as an important regulatory element of human breast tumor aggressiveness and sensitivity to treatments such as antiestrogens and antiaromatase. © 2008 Wiley-Liss, Inc.