RETRACTED ARTICLE: Long non-coding RNA CCAT2 acts as an oncogene in osteosarcoma through regulation of miR-200b/VEGF
Authors: Dehai Kong
Jianmin Li
Juntao Liu
Deping Sun
Journal: Artificial Cells Nanomedicine and Biotechnology (2019)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: CCAT2; Osteosarcoma; VEGF; miR-200b; mobility
Affiliations: a Department of Orthopedics, Qilu Hospital of Shandong University , Jinan , PR China., b Department of Orthopedic Trauma, Yantai Affiliated Hospital of Binzhou Medical University , Yantai , PR China., c Department of Foot and Ankle Surgery, Binzhou Medical University Hospital , Binzhou , PR China.

Abstract:  Background/aim: Colon cancer-associated transcript 2 (CCAT2) is a new lncRNA, which is closely associated with risk of several cancers. The aim of this study was to explore the regulatory mechanism of CCAT2 in osteosarcoma (OSA). Methods: Cells were transfected with si-CCAT2, microRNA (miR)-200b inhibitor and the corresponding controls. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to measure the expression of CCAT2 and miR-200b in OSA tissues and cell lines. CCK8 and bromodeoxyuridine (BrdU) were conducted to examine cell proliferation. Apoptosis was detected by PI/FITC-Annexin V combining with flow cytometric analysis. Migration and invasion were respectively measured through transwell chambers assays. Western blot was used to examine expressions of relative proteins. Results: CCAT2 was highly expressed and miR-200b was lowly expressed in OSA tissues and cell lines. Knockdown of CCAT2 suppressed cell proliferation, migration and invasion but induced apoptosis and up-regulation of miR-200b. miR-200b inhibitor weakened the effect of si-CCAT2 on cell progression and cell mobility. Besides, knockdown of CCAT2 blocked the PI3K/Akt and AMPK pathways through up-regulating miR-200b. Conclusions: The CCAT2/miR-200b/vascular endothelial growth factor (VEGF) axis plays important regulating effect in OSA through the PI3K/Akt and AMPK pathways. 

Retracted: Yes

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 , 
 April 2021 retraction: https: www.tandfonline.com doi full 10.1080 21691401.2021.1899424 It reads:  Since publication, concerns have been raised about the integrity of the data in the article. When approached for an explanation, the authors checked their data and confirmed there are fundamental errors present. Therefore, they have agreed to the retraction of this article. The authors apologise for this oversight. ,