miR-663b promotes tumor cell proliferation, migration and invasion in nasopharyngeal carcinoma through targeting TUSC2
Authors: Ning Zhang
Weijun Luo
Zhiqian Lv
Tao Xu
Yanming Deng
Yang Zhang
Shaoen Li
Shaoqiang Liang
Zhenhe Zheng
Lusi Chen
Journal: Experimental and Therapeutic Medicine (2017)
Discipline: CLINICAL MEDICINE
Keywords: TUSC2; invasion; microRNA; migration; nasopharyngeal carcinoma
Affiliations: Department of Radiotherapy, Tumor Hospital of First People's Hospital of Foshan, Foshan, Guangdong 528041, P.R. China.

Abstract:  The authors' previous study revealed that the serum levels of microRNA (miR)-663b are significantly increased in patients with nasopharyngeal carcinoma (NPC), and are associated with NPC progression and poor prognosis. However, the molecular mechanism of underlying NPC growth and metastasis remains unclear. In the present study, quantitative polymerase chain reaction and western blot analyses were performed to examine changes to mRNA and protein expression, respectively. MTT, wound healing and Transwell assays were used to examine cell proliferation, migration and invasion, respectively. Luciferase reporter gene assays were performed to identify target genes of miR-663b. It was demonstrated that miR-663b was significantly upregulated in NPC tissue compared with non-tumor nasopharyngeal epithelial tissue samples. Furthermore, miR-663b expression gradually increased with advancing stages of NPC, with the highest expression being observed in the latest stage IV. The increased expression of miR-663b was associated with advanced clinical stage and lymph node metastasis. In addition, miR-663b expression was increased in NPC cell lines compared with normal nasopharyngeal epithelial NP69 cells. Knockdown of miR-663b resulted in a significant reduction in the proliferation, migration and invasion of NPC CNE1 cells. Tumor suppressor candidate 2 (TUSC2) was identified as a novel target gene of miR-663b. It was further demonstrated that TUSC2 was significantly downregulated in NPC tissue samples and cell lines. miR-663b negatively regulated the expression of TUSC2 at the post-transcriptional level in CNE1 cells. Additionally, inhibition of TUSC2 expression attenuated the suppressive effects of miR-663b downregulation on the proliferation, migration and invasion of CNE1 cells. To the best of our knowledge, this is the first study to demonstrate that miR-663b, which is upregulated in NPC, promotes the proliferation, migration and invasion of NPC cells, partially through the inhibition of TUSC2 expression. Therefore, it is suggested that miR-663b is a promising therapeutic target for the treatment of patients with NPC. 

Retracted: Yes

PubPeer comments:
 Figs 2D, 5E. Transwell assays. ![file] Colors mark similarities to Figs 2D, 5E of [Yang et al (2017)] . ![file] Figs 3C, 4D, 5D from [Hu et al (2016)] ... ![file] ...Figs 3 C,D and 8 C,D from [Liu et al (2017)] . ![file] Other manifestations are linked in those threads. , 
 Retracted, [14 October 2021] . ------------------------------------ Following the publication of this paper, it was drawn to the Editorsu2019 attention by a concerned reader that the Transwell cell migration assay data shown in Figs. 2D and 5E were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to *Experimental and Therapeutic Medicine*, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. , 
 We want to explain the similarity in the transwell assays. The transwell experiments were finished in a public laboratory, and many other research groups also conducted their studies there. All images captured by the photograph system were stored in a public computer. One laboratory technician in our study group misused several images. We deeply apologize for the adverse influence it has brought. We are repeating this assay again, and we hope we could re-submit it again.u00a0 ,