Circ_0026344 restrains metastasis of human colorectal cancer cells via miR-183
Authors: Hongtao Zhang
Xin Liu
Xuan Zhang
Dingguo Pan
Cuifeng Xia
Xianshuo Cheng
Yunfeng Li
Tao Shen
Journal: Artificial Cells Nanomedicine and Biotechnology (2019)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: CCL20; CXCL8; Chemokines; circRNA; epithelial-mesenchymal transition (EMT).
Affiliations: Department of Colorectal Surgery, The Third Affiliated Hospital of Kunming Medical University , Kunming , China., Tumor Institute, The Third Affiliated Hospital of Kunming Medical University , Kunming , China.

Abstract:  Background: CircRNA circ_0026344 was previously revealed as a tumour-suppressive gene in colorectal cancer (CRC) progression. The purpose of this research was to investigate the role of circ_0026344 in CRC cells metastasis induced by chemokines. Methods: Two human CRC cell lines SW480 and Caco-2 were treated by CCL20 and CXCL8. Cell proliferation, migration/invasion, expression of epithelial-mesenchymal transition (EMT) inducers and the expression of circ_0026344 were measured using sulforhodamine B assay, Transwell chamber, western blot and qRT-PCR, respectively. The effects of circ_0026344 on CRC cells migration/invasion and the expression of EMT inducers were evaluated. Moreover, the downstream miRNA and signalling pathways of circ_0026344 were studied. Results: CCL20 and CXCL8 synergized to facilitate the proliferation, migration and invasion of CRC cells. At the meantime, E-cadherin was downregulated, whereas N-cadherin, Vimentin and Snail were up-regulated by CCL20 and CXCL8 co-stimulation, which was accompanied by the mobilization of PI3K/AKT/ERK signalling. More interestingly, the expression of circ_0026344 was down-regulated by CCL20 and CXCL8 co-stimulation. Silence of circ_0026344 increased the migratory and invasive capacities of CRC cells and increased EMT process as well. Overexpression of circ_0026344 led to a contrary impact. miR-183 was negatively regulated by circ_0026344, and the inhibitory effects of circ_0026344 overexpression on Wnt/β-catenin pathway were reversed when miR-183 was overexpressed. Conclusion: Overexpression of circ_0026344 restrained CRC metastasis and EMT induced by CCL20 and CXCL8 synergistical treatment. miR-183 was a downstream effector of circ_0026344, and the anti-tumour function of circ_0026344 might be involved in the repressed Wnt/β-catenin signalling. Highlights CCL20 and CXCL8 synergize to decrease the expression of circ_0026344; Silence of circ_0026344 promotes CRC cells migration, invasion and EMT process; miR-183 is a downstream effector of circ_0026344. 

Retracted: No

PubPeer comments:
 This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels. Despite these similarities, these papers are authored by researchers from different departments and institutes, with almost no overlap in authors. The list of these papers is available here: https: docs.google.com spreadsheets d 1KXqTAyl4j-jVorFPMD2XRpr76LcIKJ0CVyIvRj0exYQ edit?usp=sharing A more detailed description of this set of papers, suspected to all be generated by a common source, a paper mill , can be found here: * https: forbetterscience.com 2020 01 24 the-full-service-paper-mill-and-its-chinese-customers (January 2020) * https: scienceintegritydigest.com 2020 02 21 the-tadpole-paper-mill (February 2020) The same paper mill has been described in these papers: * Jana Christopher - Systematic fabrication of scientific images revealed - FEBS Letters (2018) - https: febs.onlinelibrary.wiley.com doi full 10.1002 1873-3468.13201 * Jennifer A Byrne and Jana Christopher - Digital magic, or the dark arts of the 21st centuryu2014how can journals and peer reviewers detect manuscripts and publications from paper mills? - FEBS Letters (2020) - https: febs.onlinelibrary.wiley.com doi full 10.1002 1873-3468.13747 , 
 Expression of Concern, [3 February 2022] . ----------------------- We, the Publisher and Editor of Artificial Cells, Nanomedicine, and Biotechnology, are issuing an Expression of Concern for the following article: After publication of this article, questions about the scientific integrity of the article content were brought to the Publisher and Editoru2019s attention. We reached out to the authors requesting that they supply information that would confirm the articleu2019s integrity. The authors provided several files in response to our queries, but they were unable to provide the original data in a format which satisfies our requirements to confirm the authenticity of some types of data. In particular, they were unable to provide full western blots, where the molecular weight markers are indicated. Therefore, as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. The authors have been notified about this Expression of Concern. ,