miR-622 suppresses tumor formation by directly targeting VEGFA in papillary thyroid carcinoma
Authors: Linlin Ji
Yue Yao
Qingjie Ma
Renjie Wang
Mengshi Ma
Qiang Wen
Journal: OncoTargets and Therapy (2018)
Discipline: CLINICAL MEDICINE
Keywords: VEGFA; invasion; miR-622; proliferation; thyroid cancer.
Affiliations: Department of Nuclear Medicine, China-Japan Union Hospital of Jilin University, Changchun, People's Republic of China.

Abstract:  Background: MicroRNAs (miRNAs) were reportedly to play crucial roles in papillary thyroid carcinoma (PTC) tumorigenesis and development. Therefore, the discovery of miRNAs may provide a new and powerful tool for diagnosis and treatment of PTC. Purpose: The aim of this study was to investigate the biological function and underlying mechanism of miR-622 in PTC. Materials and methods: The expression levels of miR-622 in PTC patient tissues and cell lines were determined by quantitative RT-PCR (qRT-PCR). The biological function including cell proliferation, colony formation, migration and invasion, as well as underling mechanism of miR-622 in PTC, were also evaluated by a series of in vitro and in vivo experiments. Results: miR-622 expression level was significantly downregulated in PTC tissues and cell lines. Decreased miR-622 expression was associated with advanced clinical stage and lymph node metastasis (P&lt;0.01). The overexpression of miR-622 in TPC-1 cells inhibited cell proliferation, migration and invasion in vitro, as well as suppress tumor growth in vivo. Moreover, we also demonstrated that miR-622 specifically targeted the 3'-UTR regions of vascular endothelial growth factor A (VEGFA) and inhibited its expression both mRNA level and protein levels. Overexpression of VEGFA reversed miR-622-mediated inhibition effect on cell proliferation, migration and invasion in thyroid cancer cells. More importantly, VEGFA expression was significantly increased and inversely correlated with the levels of miR-622 in PTC tissues. Conclusion: These results show that miR-622 acts as a tumor suppressor in thyroid cancer, at least in part, via targeting VEGFA, and suggest that miR-622 may serves as a potential target for treatment of thyroid cancer patients. 

Retracted: Yes

PubPeer comments:
 Fig 3B.  Cell invasion was determined in TPC-1 cells transfected miR-622 mimic or miR-NC mimic by transwell invasion assay. ![file] The miR-NC panel appears to be based on Fig 7B from [Wang et al (2017)] , but with additional cells. Here rotated through 180 deg for ease of comparison. ![file] , 
 Retracted [3 June 2021] . ------------------------------------ The Editor and Publisher of OncoTargets and Therapy wish to retract the published article. The journal was notified of alleged image manipulation relating to Figure 3B. Specifically: Figure 3B panel miR-NC appears to be a duplication, but with more cells added, of Figure 7B panel si-CON group published in Wang et al, 2017 . The same image has also been observed in other publications, including Figure 11a panel miR-708 mimic, published in Song et al, 2019 and in Figure 8B published in Pan et al, 2018 (RETRACTED) . The authors were unable to provide a satisfactory explanation for the duplication and the decision was made to retract the paper. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. , 
 Fig 6B.  Representative images of tumor tissues . ![file] The absence of a consistent direction of lighting or shadowing raises a concern that the juxtaposition of the xenograft tumors occurred in the digital realm rather than on a physical table-top, with the image of the ruler as a separate addition to the composition. This in turn undermines any evidence about the relative scale of the tumors. ,