circRIP2 accelerates bladder cancer progression via miR-1305/Tgf-β2/smad3 pathway
Authors: Jian Huang
Juanyi Shi
Tianxin Lin
Weilian Feng
Luping Chen
Yinjie Su
Journal: Molecular cancer (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Bladder cancer; EMT; Tgf-β2; circRIP2; miR-1305.
Affiliations: The Department of Urology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China., The Department of Endocrinology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China., The Department of Pediatric Surgery, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China., The Department of Urology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China. .

Abstract:  Background: Increasing evidences indicate that circular RNAs exert critical function in regulating bladder cancer progression. However, the expressive patterns and roles of circular RNAs in bladder cancer remain less investigated. Methods: circRIP2 was identified and evaluated by RNA-sequencing and qPCR; in vitro effects of circRIP2 were determined by CCK8, clone forming, wound healing and trans-well assays; while mice subcutaneous tumor model was designed for in vivo analysis. Western blot, RNA pulldown assay, miRNA capture and dual luciferase assessment were applied for mechanistic studies. Results: circRIP2 was identified as a conserved and dramatically repressed circular RNA in bladder cancer. Patients that displayed higher circRIP2 expression negatively associate with the grade, stage, metastasis as well as outcome of bladder cancer. In vitro and in vivo studies suggest that circRIP2 enables to promote bladder cancer progression via inducing EMT. Regarding the mechanism, we performed RNA-sequencing analysis, RNA pulldown with biotin-labeled circRIP2-specific probe, dual luciferase reporter assay. It was found that circRIP2 enables to sponge miR-1305 to elevate Tgf-β2 in bladder cancer, and inducing EMT via Tgf-β2/smad3 pathway. Blocking Tgf-β2 in bladder cancer deprives circRIP2 induced cancer progression and EMT. Conclusions: Taken together, our study provides the first evidence that circRIP2 expresses differentially in bladder cancer and negatively along with the cancer progression; effective circRIP2 activity accelerates bladder cancer progression via inducing EMT by activating miR-1305/Tgf-β2/smad3 pathway. The research implies that circRIP2 might be a potential biomarker and therapeutic target for bladder cancer patients. 

Retracted: No

PubPeer comments:
 Figure 1A. Brought to my attention by a reader. * Red boxes: The 5637 panel looks unexpectedly similar to the U3 panel. The exposures appear to be slightly different, but the background dots in the gel appear to all be in the same positions. ![file] , 
 Figure 2. * Green boxes: In Figure 2I, the si-1 and si-2 Migration panels appear to show an area of overlap * Orange boxes: In Figure 2K, the si-1 Migration panel appears to be a mirror image of the si-2 Invasion panel * Pink boxes: In Figure 2K, the si-1 Invasion panel appears to look similar to the si-2 Migration panel ![file] , 
 #2 Dear Dr. Elisabeth M Bik: Thank you very much for raising the concerns regarding the figures in our recently published paper. We are going to go through all the original data carefully and will response your comment soon. Best Regards, Tianxin Lin , 
 #1 #2 Dear Dr. Bik: We do appreciate you for pointing out the errors in our publication and we are sorry for the confusion to the readers. Here are our responses to your comments. Regarding the Fig 1A After checking the original data, we found that the longer exposure picture of 5637 cells was mislabeled as U3 cells. The error has been corrected in the revised Fig 1A attached below, which now includes a picture of the correct U3. ![file] Regarding the Figs 2I and 2K. In Fig 2I, the other area of picture of si#1 cells was mistakably reused as si#2 cells. So it was confused the overlap of si1 and si2. In Fig 2K, the mistake of repeated picture was caused by incaution of compose type by the first author. These errors have been corrected in the revised Fig 2I and 2K attached below. In addition, the original data of three repeated experiments from Figs 2I and 2k were also attached below. ![file] ![file] ![file] ![file] ![file] We re preparing a correction request that will be submitted to the Molecular Cancer journal shortly. We apologize to our readers for any confusion that these unintentional errors might have caused. Best regardsuff01 Tianxin Lin , 
 Correction, 2 January 2021: https: molecular-cancer.biomedcentral.com articles 10.1186 s12943-020-01284-5  *Following the publication of the original paper [1], the authors found two errors in the figures caused by incaution of compose type.* *In Fig. 1a, the band of 5637 is similar to U3. After checking the original data, authors found that the pictures of 5637 and U3 cells were saved in the same file. When they disposed the pictures in Photoshop, the longer exposure picture of 5637 cells was mislabeled as U3 cells.* *In Fig. 2i, it was confused the overlap of si1 and si2. After checking the original data, authors found the problem happened in the data acquisition. In the transwell assay, they took 10 pictures for each sample, but mislabeled the No.10 of si#1 as No.1 of si#2, resulting in other area of picture of si#1 cells was mistakenly reused as si#2 cells. In Fig. 2k, the mistake of repeated picture was caused by incaution of compose type. These errors have been corrected in the revised Fig. 2i andu2009k as shown below.* *The unintentional errors might cause misunderstand to the editor, reviewers and readers. The authors take full responsibility for this unintentional error. To better reduce the effect of these mistakes, several corrections were made as above. Since these errors do not originate from original experiments, and all the experiments have been repeated at least 3 times, there is no effect on the interpretation or conclusion of this work. Authors truly apologize for our overlook in this matter. They apologize to the editors, reviewers and readers for any confusion that was caused by this unintentional error.* Could the authors please care to explain the statement  Since these errors do not originate from original experiments ? Are these not original experiments? How do we know if the remaining 2 experiments have also not been switched? I am just worried that if four sets of visible panels have been switched, how many panels not shown in the paper might have been switched too. There are a lot of errors in this paper. ,