MiR-506 functions as a tumor suppressor in glioma by targeting STAT3
Authors: Ling Zuo
Yongxin Luan
Lixiang Zhou
Tao Peng
Journal: Oncology Reports (2016)
Discipline: CLINICAL MEDICINE
Keywords: MicroRNA-506; tumor suppressor; oncogenic; glioma; quantitative PCR
Affiliations: Department of Neurosurgery, First Bethune Hospital of Jilin University, Changchun, Jilin 130021, P.R. China., Department of Ophthalmology, Second Bethune Hospital of Jilin University, Changchun, Jilin 130041, P.R. China.

Abstract:  MicroRNA-506 (miR-506) has been reported to act as a tumor suppressive or an oncogenic miRNA in different types of tumors. However, the roles and underlying molecular mechanism of miR-506 in glioma remain unclear. In the present study, we performed quantitative PCR to investigate the level of miR-506 in 36 pairs of glioma tumor and matched adjacent tissues, and found that miR-506 was downregulated in the glioma tumors compared to the expression in the adjacent normal tissues. Furthermore, a functional assay found that ectopic expression of miR-506 in glioma cells markedly suppressed cell proliferation, colony formation, migration and invasion, and suppressed tumor growth in vivo. Moreover, signal transducer and activator of transcription 3 (STAT3) was identified as a direct target of miR-506. Western blot assay showed that overexpression of miR-506 not only induced changes in STAT3 expression but also altered expression of its downstream genes, including, Bcl2, cyclin D1 and matrix metalloproteinase 2 (MMP-2), in the human glioma cells. In addition, STAT3 mRNA expression was increased in the glioma tissues, and was inversely correlated with miR-506. Importantly, overexpression of STAT3 in glioma cells attenuated the suppressive effects of miR-506 on cell proliferation, colony formation, migration and invasion. These results showed that miR-506 functions as a tumor suppressor in glioma by targeting STAT3, suggesting that miR-506 may serve as a potential target in the treatment of human glioma. 

Retracted: Yes

PubPeer comments:
 Figs 4D, 6B, 7F from [Peng et al (2016)] Colored rectangles are to aid comparison with Fig 6 from [Wu et al (2015)] . ![file] UPDATE: More colored boxes added, to include Figs 4B, 6D from [Li, Li Zhang (2016)] in the mix. ![] , 
 *[right]* Fig 6B.  STAT3 protein was assessed by western blot analysis in U87 cells co-transfected with the STAT3 overexpression plasmid and miR-506 miR-NC. *[left]* Fig 5B from [Lin et al (2016)] .  Protein expression of ZEB2 was detected by western blotting in A549 cells transfected with pcDNA3.0-ZEB2 or blank vector . ![file] , 
 *[below]* Fig 2D.  Cell cycle arrest was determined in U87 cells transfected with the miR-506 mimic or miR-NC . *[above]* Fig 2D from [Zhang et al (2016)] .  Cell cycle distribution was determined in 786-O cells transfected with miR-22 mimic or miR-NC by FACS analysis. ![file] Could the authors of either paper explain the appearance of the same flow-cytometry plots in both (with different values for the phases)? , 
 Retracted [29 October 2021] . ---------------------- Following the publication of this paper, it was drawn to the Editor s attention by a concerned reader that certain of the western blot assay data shown in Figs. 4D, 6B and 7F were strikingly similar to data appearing in different form in other articles by different authors. Furthermore, an independent investigation of this paper conducted by the Editorial Office unveiled possible anomalies associated with the cyclin D1 data presented in Fig. 4D. Owing to the fact that the contentious data in the above article were already under consideration for publication, or had already been published, prior to its submission to *Oncology Reports*, the Editor has decided that this paper should be retracted from the Journal. The authors themselves requested that the paper be retracted. The Editor apologizes to the readership for any inconvenience caused. ,