Circular RNA circ-SMAD7 is downregulated in colorectal cancer and suppresses tumor metastasis by regulating epithelial mesenchymal transition
Authors: B-L Song
R-F Chong
D-K Wang
K-F Fan
Y-F Liu
Journal: European review for medical and pharmacological sciences (2020)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Circular RNAs; Colorectal cancer; circ-SMAD7; RT-qPCR; Overall survival time
Affiliations: Department of General Surgery, Qingdao Chengyang District People's Hospital, Qingdao, China. .

Abstract:  Objective: Recently, circular RNAs play a vital role in many diseases including tumor progression. Colorectal cancer (CRC) is one of the most ordinary malignant tumors. The purpose of our study is to detect the potential function of circ-SMAD7 in CRC. Patients and methods: The level of circ-SMAD7 was detected by Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) in CRC tissue samples. The circ-SMAD7 expression level and the patients' overall survival time were analyzed. Functional experiments were conducted to identify the changes of the biological behaviors in CRC cells after the overexpression of circ-SMAD7. The transwell assay, the Matrigel assay, and the Wound healing assay were conducted. The Western blot assay was performed to analyze the effect of circ-SMAD7 on the epithelial-to-mesenchymal transition (EMT) process. Results: In the research, the expression level of circ-SMAD7 was significantly decreased in CRC tissues compared with that in the adjacent samples. Circ-SMAD7 expression was positively associated to patients' overall survival time. The expression of circ-SMAD7 was also decreased in CRC cell lines. The upregulation of circ-SMAD7 led to the inhibition of cell migration and invasion in CRC. In addition, the results of further experiments revealed that the EMT-related proteins were regulated via overexpression of circ-SMAD7 in CRC. Conclusions: These results suggest that circ-SMAD7 could inhibit cell migration and invasion of CRC by suppressing the EMT process, which might offer a potential therapeutic target for CRC. 

Retracted: Yes

PubPeer comments:
 This paper is one of a set of 121 papers that all contain images from the same library of about 100 photos and plots. This is unexpected, because each paper has different authors and different affiliations, with little to no overlap, and describes different cancer types and molecules. It would be very hard to explain how authors from different labs would all obtain the same photo. Therefore, the papers might have all be derived from the same source, such as a paper mill that sells ready-to-be-published papers. This  Stock Photo paper set has been described in more detail on my blog post, https: scienceintegritydigest.com 2020 07 05 the-stock-photo-paper-mill and in a Wall Street Journal article by Eva Xiao (currently behind a paywall): https: www.wsj.com articles chinese-research-papers-raise-doubts-fueling-global-questions-about-scientific-integrity-11593939600 The vast majority (113 121) of the papers were published in the same journal, European Review for Medical and Pharmacological Sciences (ERMPS). A link to the full set of papers can be found here: https: docs.google.com spreadsheets d 172RWS18w1lTNJ9Nnj80fuXXTqTm4fGkoK0sdYyvKE3g edit?usp=sharing All papers have been reported to the journal editors on July 2, 2020. , 
 Withdrawn. https: www.europeanreview.org article 23002 *Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, u201cCircular RNA circ-SMAD7 is downregulated in colorectal cancer and suppresses tumor metastasis by regulating epithelial mesenchymal transition, by D.-K. Wang, R.-F. Chong, B.-L. Song, K.-F. Fan, Y.-F. Liu, published in Eur Rev Med Pharmacol Sci 2020; 24 (4): 1736-1742u2013DOI: 10.26355 eurrev_202002_20350u2013PMID: 32141541u201d has been withdrawn.* *The Publisher apologizes for any inconvenience this may cause.* ,