[Retracted] MicroRNA­432 inhibits the aggressiveness of glioblastoma multiforme by directly targeting IGF­1R.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the flow cytometric assay data shown for the cell invasion assays in Figs. 2C, 4C and 5D, and the tumour images shown in Fig. 6A, were strikingly similar to data appearing in different form in other articles by different authors. Moreover, it appeared as if certain of the same data may have reappeared on more than one occasion in the flow cytometric plots shown in Figs. 2, 4 and 5. 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 International Journal of Molecular 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 a reply. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Molecular Medicine 45: 597­606, 2020; DOI: 10.3892/ijmm.2019.4429].

MicroRNA­432 inhibits the aggressiveness of glioblastoma multiforme by directly targeting IGF­1R.

MicroRNA­432 (miR­432) has been studied in multiple tumors, but the expression status, biological functions and the mechanism of action of miR­432 in glioblastoma multiforme (GBM) are yet to be elucidated. In the present study, miR­432 expression in GBM was determined and its clinical significance was evaluated among patients with GBM. The effects on the malignancy of GBM in vitro and in vivo were examined in detail and the interactions between miR­432 and insulin­like growth factor 1 receptor (IGF­1R) mRNA were then explored. miR­432 expression in GBM tissue samples and cell lines was measured by reverse transcription­quantitative (RT­q)PCR. GBM cell proliferation, apoptosis, migration and invasion in vitro and tumor growth in vivo were evaluated by a Cell Counting Kit­8 assay, flow­cytometric analysis, Transwell migration and invasion assays, and a tumor xenograft experiment, respectively. Bioinformatic analysis followed by a luciferase reporter assay, RT­qPCR and western blotting was applied to demonstrate that IGF­1R is a direct target gene of miR­432 in GBM cells. It was found that miR­432 is downregulated in GBM tumors and cell lines. miR­432 under expression obviously correlated with the Karnofsky Performance Status score and shorter overall survival among patients with GBM. Exogenous miR­432 expression significantly reduced proliferation and induced apoptosis of GBM cells. In addition, miR­432 overexpression impaired the migratory and invasive abilities of GBM cells in vitro and decreased their tumor growth in vivo. Furthermore, IGF­1R was validated as a direct target gene of miR­432 in GBM cells. IGF­1R knockdown imitated the tumor­suppressive actions of miR­432 overexpression in GBM cells. Rescue experiments proved IGF­1R downregulation to be essential for the effects of miR­432 on GBM cells. The results of the present study revealed a tumor­suppressive role of the miR­432­IGF­1R axis in GBM cells and this axis may have implications for GBM therapy.