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|Type:||Artigo de periódico|
|Title:||Knocking Down Low Molecular Weight Protein Tyrosine Phosphatase (LMW-PTP) Reverts Chemoresistance through Inactivation of Src and Bcr-Abl Proteins|
|Author:||Ferreira, Paula A.|
Ruela-de-Sousa, Roberta R.
Queiroz, Karla C. S.
Souza, Ana Carolina S.
Pilli, Ronaldo Aloise
Peppelenbosch, Maikel P.
den Hertog, Jeroen
Ferreira, Carmen V.
|Abstract:||The development of multidrug resistance (MDR) limits the efficacy of continuous chemotherapeutic treatment in chronic myelogenous leukemia (CML). Low molecular weight protein tyrosine phosphatase (LMW-PTP) is up-regulated in several cancers and has been associated to poor prognosis. This prompted us to investigate the involvement of LMW-PTP in MDR. In this study, we investigated the role of LMW-PTP in a chemoresistant CML cell line, Lucena-1. Our results showed that LMW-PTP is highly expressed and 7-fold more active in Lucena-1 cells compared to K562 cells, the non-resistant cell line. Knocking down LMW-PTP in Lucena-1 cells reverted chemoresistance to vincristine and imatinib mesylate, followed by a decrease of Src and Bcr-Abl phosphorylation at the activating sites, inactivating both kinases. On the other hand, overexpression of LMW-PTP in K562 cells led to chemoresistance to vincristine. Our findings describe, for the first time, that LMW-PTP cooperates with MDR phenotype, at least in part, through maintaining Src and Bcr-Abl kinases in more active statuses. These findings suggest that inhibition of LMW-PTP may be a useful strategy for the development of therapies for multidrug resistant CML.|
|Editor:||Public Library Science|
|Citation:||Plos ONE. Public Library Science, v.7, n.9, 2012|
|Appears in Collections:||IB - Artigos e Outros Documentos|
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