shRNA-mediated EMMPRIN silencing inhibits human leukemic monocyte lymphoma U937 cell proliferation and increases chemosensitivity to adriamycin
Authors: Jianjun Peng
Hui Gao
Chunbo Wang
Qixiao Jiang
Yantao Han
Journal: Cell biochemistry and biophysics (2015)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: EMMPRIN; tumor progression; chemotherapeutic drugs; acute myeloid leukemia; U937 cell line
Affiliations: Department of Pharmacology, Medical College, Qingdao University, Qingdao, 266021, Shandong, China.

Abstract:  EMMPRIN is a widely distributed cell surface glycoprotein, which plays an important role in tumor progression and confers resistance to some chemotherapeutic drugs. Recent studies have shown that EMMPRIN overexpression indicates poor prognosis in acute myeloid leukemia (AML). However, little was known on the role of EMMPRIN in leukemia. Human leukemia cell line U937 was stably transfected with a EMMPRIN-targeted shRNA-containing vector to investigate the effect of EMMPRIN on cellular functions. EMMPRIN expression was monitored by qRT-PCR and Western blotting. Cell viability and proliferation were determined by trypan blue exclusion and BrdU labeling, respectively. Cell cycle and apoptosis were analyzed by flow cytometry. Cytotoxicity of chemotherapeutic agent adriamycin on cells was assessed by MTT assay. Knockdown of EMMPRIN gene significantly inhibited cell viability and decreased cell proliferation. Fluorescence-activated cell-sorting analysis revealed that the reduced EMMPRIN expression resulted in cell cycle arrest at G1 phase and induced apoptosis. Meanwhile, western blotting analysis showed that EMMPRIN knockdown was associated with downregulation of cell cycle- and apoptosis-related molecules including cyclin D1, cyclin E, as well as increase in cleavage of caspase-3 and PARP. This study also showed that silencing of EMMPRIN sensitized U937 cells to Adriamycin. EMMPRIN is involved in proliferation, growth, and chemosensitivity of human AML line U937, indicating that EMMPRIN may be a promising therapeutic target for AML. 

Retracted: Yes

PubPeer comments:
 Left:  Fig. 4 EMMPRIN knockdown induced apoptosis in U937 cells. a Cell apoptosis was determined with fluorescence-activated cell sorting (FACS) analysis. Right:  Fig. 3 u2013 Effect of hispidulin on ... cell viability and apoptosis (B)... in the cells stably transfected with HIF-1u03b1. The cells were incubated with 50 u03bcM of hispidulin for 48 h before conducting the analyses. From [Gao et al (2015)] . Unrelated experiments, identical FACS results. ![file] , 
 Fig 3(b):  EMMPRIN arrested U937 cell cycle at G0 G1 phase. ... b Levels of cyclin D1 and cyclin E were assessed with western blotting . Below, Fig 3C from [Gao et al (2015)] :  Effect of hispidulin on ... expression of Bcl-2 and Bax and caspase-3 activity (C) in the cells stably transfected with HIF-1u03b1. ![file] Beta-actin loading controls are the same. 3 4 of Cyclin E and Bax are the same. , 
 Retracted, [15 January 2022] . ----------------------------- The Editor-in-Chief has retracted this article. After publication concerns were raised about overlap of Fig. 3B with Fig. 3C in [1] and of Fig. 4A with Fig. 3 in [1]. None of the authors has responded to correspondence about this retraction. - [1]. Gao, H., Xie, J., Peng, J., Han, Y., Jiang, Q., Han, M. Wang, C. (2015). Hispidulin inhibits proliferation and enhances chemosensitivity of gallbladder cancer cells by targeting HIF-1u03b1. Experimental Cell Research, 332, 236u2013246. ,