Wnt/β-catenin pathway regulates ABCB1 transcription in chronic myeloid leukemia

BMC Cancer

Research Article

Renata Binato¹  Luciana Pizzatti¹  Bárbara Du Rocher¹  Eliana Abdelhay²  Stephany Corrêa²  Morgana TL Castelo-Branco³ 

[1] Divisão de Laboratórios CEMO, INCA, Rio de Janeiro, Brazil;Divisão de Laboratórios CEMO, INCA, Rio de Janeiro, Brazil;Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;

关键词: Chronic Myeloid Leukemia;    K562 Cell;    Electrophoretic Mobility Shift Assay;    Blastic Crisis;    Chronic Myeloid Leukemia Cell;   

DOI  :  10.1186/1471-2407-12-303

 received in 2011-10-27, accepted in 2012-07-23,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe advanced phases of chronic myeloid leukemia (CML) are known to be more resistant to therapy. This resistance has been associated with the overexpression of ABCB1, which gives rise to the multidrug resistance (MDR) phenomenon. MDR is characterized by resistance to nonrelated drugs, and P-glycoprotein (encoded by ABCB1) has been implicated as the major cause of its emergence. Wnt signaling has been demonstrated to be important in several aspects of CML. Recently, Wnt signaling was linked to ABCB1 regulation through its canonical pathway, which is mediated by β-catenin, in other types of cancer. In this study, we investigated the involvement of the Wnt/β-catenin pathway in the regulation of ABCB1 transcription in CML, as the basal promoter of ABCB1 has several β-catenin binding sites. β-catenin is the mediator of canonical Wnt signaling, which is important for CML progression.MethodsIn this work we used the K562 cell line and its derived MDR-resistant cell line Lucena (K562/VCR) as CML study models. Real time PCR (RT-qPCR), electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), flow cytometry (FACS), western blot, immunofluorescence, RNA knockdown (siRNA) and Luciferase reporter approaches were used.Resultsβ-catenin was present in the protein complex on the basal promoter of ABCB1 in both cell lines in vitro, but its binding was more pronounced in the resistant cell line in vivo. Lucena cells also exhibited higher β-catenin levels compared to its parental cell line. Wnt1 and β-catenin depletion and overexpression of nuclear β-catenin, together with TCF binding sites activation demonstrated that ABCB1 is positively regulated by the canonical pathway of Wnt signaling.ConclusionsThese results suggest, for the first time, that the Wnt/β-catenin pathway regulates ABCB1 in CML.

【 授权许可】

Unknown   
© Correa et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.