Beclin-1 knockdown decreases proliferation, invasion and migration of Ewing sarcoma SK-ES-1 cells via inhibition of MMP-9
Authors: Conglin Ye
Min Dai
Xiaolong Yu
Runsheng Guo
Tao Nie
Hucheng Liu
Bin Zhang
Xuqiang Liu
Ping Zhan
Journal: Oncology Letters (2017)
Discipline: CLINICAL MEDICINE
Keywords: Beclin-1; Ewing sarcoma; autophagy; invasion; matric metalloproteinase-9
Affiliations: Department of Orthopedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi, Nanchang, Jiangxi 330006, P.R. China.

Abstract:  Although Beclin-1, a well-known key regulator of autophagy, has been demonstrated to serve a function in a number of disorders, including cancer, aging and degenerative diseases, its biological function in Ewing sarcoma (ES) remains unresolved. The objective of the present study was to determine the in vitro effect of Beclin-1 knockdown on the growth and malignant phenotype of ES SK-ES-1 cells, which have increased endogenous expression of Beclin-1 compared with RD-ES cells, and to investigate the underlying molecular mechanism. Cell proliferation, invasion and migration were investigated using CCK-8, Boyden chamber Transwell, and wound healing assays, respectively. Western blot analysis was used to detect expression levels of matrix metalloproteinase (MMP)-2 and MMP-9, which are associated with the malignant phenotype. Beclin-1 knockdown significantly inhibited proliferation, invasion and migration of SK-ES-1 cells. Western blot analysis revealed that Beclin-1 knockdown caused a significant reduction in the expression of MMP-9; no marked changes in MMP-2 expression were observed in the si-Beclin-1 group compared with the control group. The results of the present study suggest that Beclin-1 serves a function in proliferation, tumor progression and inhibition of autophagy in ES, and demonstrates it's potential as a target to increase the efficacy of anticancer agents. 

Retracted: No

PubPeer comments:
 Image concerns in this paper were found during a systematic search of papers in Spandidos journals for possible duplicated images. Figure 2C. * Red boxes: The 0h Con and 0h si-con panels appear to show an overlap. ![file] , 
 Figure 1A and 3A: * Blue boxes: The b-actin panel in Figure 1A looks very similar to two lanes in the b-actin panel of Figure 3A, where the lanes represent different experiments. Note the presence of some dark dots under the right-most band. Images made darker to bring out more details. ![file] , 
 #1 Dear professor, Thank you for reading my ariticle. Although the 0h Con and 0h si-con panels were similar, they were not an overlap. Best wishes. , 
 #3 Dear professor, Thank you for reading. Though the b-actin panel in Figure 1A were similar to two lanes in the b-actin panel of Figure 3A, they were not an overlap. Maybe you will have another opinion if you compare the two figures carefully. Best wishes. , 
 #1 #3 I would agree with Dr. Bik s concern. I superimposed the 2 questioned images and they do look almost perfectly overlapped, with a bit shift or even plus a twist of 1 deg, perhaps. I would suggest Dr. Dai provide original (or raw) images to substantiate your affirmation that  they were not an overlap . ![] , 
 Despite the statement by an author that these images were merely similar, but not overlapping, the journal issued a Corrigendum, December 2020: https: www.spandidos-publications.com 10.3892 ol.2020.12372  The authors drew to our attention that they had noticed that Fig. 2 in the above published article contained an error: Essentially, the same data panel had been selected for the 0 h Con and 0 h si-con experiments in Fig. 2C on p. 3224. Furthermore, an interested reader drew to our attention that a pairing of control u03b2-actin bands used in Figs. 1 and 3 may have been derived from the same original source. After having re-examined their data, the authors were able to identify the correct images for the 0 h Con and 0 h si-con experiments, and the corrected version of Fig. 2, including the correct data for Fig. 2C, is shown opposite. Furthermore, alternative data are also shown for Figs. 1 and 3, as presented below and opposite. Note that the alterations made to these Figures do not affect the results or the conclusions reported in this paper, and all the authors agree to this Corrigendum. The authors thank the Editor for presenting them with the opportunity to publish this Corrigendum, and apologize to the Editor and to the readership of the Journal for any inconvenience caused. ,