Qianyin Li

The Journal retracts the article “Blockade of Y177 and Nuclear Translocation of Bcr-Abl Inhibits Proliferation and Promotes Apoptosis in Chronic Myeloid Leukemia Cells”

The gradual emerging of resistance to imatinib urgently calls for the development of new therapy for chronic myeloid leukemia (CML). The fusion protein Bcr-Abl, which promotes the malignant transformation of CML cells, is mainly located in the cytoplasm, while the c-Abl protein which is expressed in the nucleus can induce apoptosis. Based on the hetero-dimerization of FKBP (the 12-kDa FK506- and rapamycin-binding protein) and FRB (the FKBP-rapamycin binding domain of the protein kinase, mTOR) mediated by AP21967, we constructed a nuclear transport system to induce cytoplasmic Bcr-Abl into nuclear. In this study, we reported the construction of the nuclear transport system, and we demonstrated that FN3R (three nuclear localization signals were fused to FRBT2098L with a FLAG tag), HF2S (two FKBP domains were in tandem and fused to the SH2 domain of Grb2 with an HA tag) and Bcr-Abl form a complexus upon AP21967. Bcr-Abl was imported into the nucleus successfully by the nuclear transport system. The nuclear transport system inhibited CML cell proliferation through mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 5 (STAT5) pathways mainly by HF2S. It was proven that nuclear located Bcr-Abl induced CML cell (including imatinib-resistant K562G01 cells) apoptosis by activation of p73 and its downstream molecules. In summary, our study provides a new targeted therapy for the CML patients even with Tyrosine Kinase Inhibitor (TKI)-resistance.

Accumulating evidence demonstrated that miRNAs are highly involved in kidney fibrosis and Epithelial-Eesenchymal Transition (EMT), however, the mechanisms of miRNAs in kidney fibrosis are poorly understood. In this work, we identified that miR542-3p could promote EMT through down-regulating bone morphogenetic protein 7 (BMP7) expression by targeting BMP7 3′UTR. Firstly, real-time PCR results showed that miR542-3p was significantly up-regulated in kidney fibrosis in vitro and in vivo. Moreover, Western blot results demonstrated that miR542-3p may promote EMT in the NRK52e cell line. In addition, we confirmed that BMP7, which played a crucial role in anti-kidney fibrosis and suppressed the progression of EMT, was a target of miR542-3p through Dual-Luciferase reporter assay, as did Western blot analysis. The effects of miR542-3p on regulating EMT could also be suppressed by transiently overexpressing BMP7 in NRK52e cells. Taken together, miR542-3p may be a critical mediator of the induction of EMT via directly targeting BMP7.