MicroRNA-503 suppresses cell proliferation and invasion in osteosarcoma via targeting insulin-like growth factor 1 receptor
Authors: Zili Wang
Kunqi Jiang
Chenhuang Zheng
Jinshen He
Xu Cao
Song Wu
Journal: Experimental and Therapeutic Medicine (2017)
Discipline: CLINICAL MEDICINE
Keywords: insulin-like growth factor 1 receptor; invasion; microRNA; osteosarcoma; proliferation.
Affiliations: Department of Orthopedics, Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China.

Abstract:  MicroRNAs (miRs) are a class of small non-coding RNAs and have key roles in various cancer types. Recently, miR-503 has been reported to act as a tumor suppressor in osteosarcoma. However, the detailed mechanism of the regulatory role of miR-503 in osteosarcoma cell proliferation and invasion has largely remained elusive. The present study found that miR-503 was significantly downregulated in osteosarcoma tissues compared to that in matched adjacent non-tumorous tissues. In addition, the expression of miR-503 in osteosarcoma of T3-T4 stage was significantly lower when compared with that in T1-T2 stage samples. miR-503 was also downregulated in osteosarcoma cell lines (Saos-2, MG63, U2OS and SW1353), when compared with that in the normal osteoblast cell line hFOB. Overexpression of miR-503 significantly inhibited the proliferation and invasion of U2OS cells and decreased the protein levels of insulin-like growth factor 1 receptor (IGF-1R), which was further identified as a novel target of miR-503 by a luciferase reporter assay. Moreover, overexpression of IGF-1R eliminated the suppressive effects of miR-503 on the proliferation and invasion of U2OS cells, suggesting that miR-503 inhibits osteosarcoma cell proliferation and invasion by directly targeting IGF-1R. Furthermore, IGF-1R was significantly upregulated in osteosarcoma tissues compared with that in adjacent non-tumor tissues, as well as in osteosarcoma cell lines compared with that in hFOB cells. In addition, the expression levels of IGF-1R were inversely correlated to the miR-503 levels in osteosarcoma tissues, suggesting that the increased IGF-1R expression may be caused by the reduced expression of miR-503. In conclusion, the present study demonstrated that miR-503 suppresses cell proliferation and invasion in osteosarcoma via targeting IGF-1R and thus highlights the importance of miR-503/IGF-1R signaling in the malignant progression of osteosarcoma. 

Retracted: Yes

PubPeer comments:
 Fig 2C,  Transwell assay were then performed to examine the cell proliferation and invasion ; and 4C,  Transwell assay were used to examine cell proliferation and invasion . ![file] For comparison: Fig 3 C D from [Zhang et al (2016)] .  Transwell assay were performed to examine the migratory and invasive capacities of Saos-2 and U2OS cells transfected with miR-205 mimic or miR-negative control (NC) mimic , and Fig 7C D,  Transwell assay were performed to examine cell migration and invasion of MG63 or U2OS cells transfected with miR-205 mimic, or co-transfected with miR-205 mimic and RUNX2 plasmid . ![] Also *[above]* Fig 4C from [Lai, Chen Li (2015)] .  a Transwell assay were performed to examine the cell proliferation of AGS cells transfected with miR-133a mimics, miR-133a inhibitor, or co-transfected with miR-133a mimics and FSCN1 plasmid. Control: AGS cells without any transfection. *[below]* Figs 3(B), 6(B) from [Shi et al (2015)] .  Transwell assay was performed to determine the invasive capacity of the Saos-2 and U-2 OS cells transfected with NC scramble miRNA or miR-204 mimics, respectively. Control, Saos-2 and U-2 OS cells without any transfection ...  Transwell assay was performed to determine the invasive capacity of the Saos-2 and U-2 OS cells transfected with Sirt1 siRNA or co-transfected with miR-204 mimics and the Sirt1 plasmid, respectively. Control, Saos-2 and U-2 OS cells without any transfection . ![file] , 
 Retracted [6 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 Fig. 2C 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. ,