<p>Long Non-Coding RNA LINC00239 Functions as a Competitive Endogenous RNA by Sponging microRNA-484 and Enhancing KLF12 Expression to Promote the Oncogenicity of Colorectal Cancer</p>
Authors: Chenguang Li
Xiaofan Luo
Lei Wang
Meng Yue
Di Sun
Journal: OncoTargets and Therapy (2020)
Discipline: CLINICAL MEDICINE
Keywords: CRC; kruppel-like factor 12; long intergenic non-protein coding RNA 239; miRNA sponge.
Affiliations: Department of Colorectal and Anal Surgery, First Hospital of Jilin University, Changchun, Jilin 130021, People's Republic of China.

Abstract:  Background: Long intergenic non-protein coding RNA 239 (LINC00239) is an oncogenic long non-coding RNA in acute myeloid leukemia. We aimed to determine LINC00239 expression in colorectal cancer (CRC) and examine the influences of LINC00239 on tumor behaviors of CRC cells. Furthermore, the mechanism underlying the actions of LINC00239 in CRC was unveiled in detail. Materials and methods: Quantitative real-time polymerase chain reaction was used to detect LINC00239 expression in CRC tissues and cell lines. CRC cell proliferation, apoptosis, migration, and invasion were investigated by cell counting kit-8 assays, flow cytometry, and cell migration and invasion assays, respectively. Tumor xenograft experiments were performed to evaluate the tumor growth of CRC cells in vivo. The interactions among LINC00239, microRNA-484 (miR-484), and kruppel-like factor 12 (KLF12) were analyzed by bioinformatics prediction, RNA immunoprecipitation and luciferase reporter assay. Results: LINC00239 was upregulated in CRC tissues and cell lines. LINC00239 knockdown impaired CRC cell proliferation, migration, and invasion and promoted apoptosis in vitro. Additionally, LINC00239 deficiency inhibited CRC growth in vivo. Mechanistically, LINC00239 functioned as a competing endogenous RNA by directly sponging miR-484, thereby enhancing KLF12 expression. Rescue experiments further corroborated that miR-484 inhibition or KLF12 overexpression reversed the inhibitory actions of LINC00239 knockdown in CRC cells. Conclusion: The LINC00239/miR-484/KLF12 pathway executed critical roles in CRC oncogenicity and may provide potential targets for CRC treatments. 

Retracted: No

PubPeer comments:
 Here are multiple appearances of what seems to be the same well-traveled ruler, marked by a distinctive scratch just to the right of 2 . Different teams of researchers from six different institutions somehow used it to provide scale for the xenograft tumors in their studies. There would be no problem if all the images had been recorded at a single lab, but the papers do not mention outsourcing any of the experiments to an outside contractor. Upper row: - Fig 7B from [Chen et al (2021)] .  Representative images of subcutaneous tumours collected from the sh-USP30-AS1 and sh-NC groups. Rotated through 90 deg for ease of comparison. - **Fig 8A from [Luo et al (2020)] **.  Representative images of tumor xenografts originating from SW480 cells stably expressing sh-LINC00239 or sh-NC. Rotated through 90 deg. - Fig 7A from [Liu et al (2020)] .  Representative images of tumor xenografts that originated from SW480 cells stably overexpressing sh-VPS9D1-AS1 or sh-NC . ![file] Middle row: - Fig 7B from [He et al (2021)] .  At 31 days following cell injection, all mice were euthanized and tumor xenografts were resected and imaged . - Fig 6B from [Liu et al (2020)] .  All mice were euthanized at the end of the experiment, and the tumor xenografts were harvested and imaged . Rotated through 90 deg. - Fig 8A from [Yang, Yang Wang (2020)] .  Tumor growth curves were plotted according to the tumor volumes measured weekly . ![file] Lower row: - Fig 7B from [Li et al (2020)] .  Representative images of tumor xenografts collected from short hairpin RNA (sh)-LINC00525 and control (sh-NC) groups . - Fig 6A from [Dai et al (2020)] .  After 28 days post-inoculation, mice were euthanized and tumor xenografts were dissected and photographed . ![file] , 
 Dear Editor Thank you for your comments on our paper. The in vivo study was performed by a third party, which was dedicated to animal experiments. Thus, the same ruler might be used in images of tumors. , 
 #2 Thank you. That is very helpful. Could you provide the name of that third party as you did for the sources of your cell lines, kitu2019s, etc.? I was not able to identify this information in the methods section of this paper. , 
 Expression of Interest, [20 October 2021] . --------------------- The Editor and Publisher of *OncoTargets and Therapy* wish to publish an Expression of Concern for the published article. Following publication, concerns were raised about the scientific integrity of the articles content. We reached out to the authors requesting they supply information that would confirm the integrity of the data. The authors provided several files in response to our queries but they did not satisfy our requirements to confirm the authenticity of some types of data. In addition, there were unexplained similarities between some of the figures presented in this article, and figures presented in articles by different authors groups. As yet, the authors have not provided a satisfactory explanation for this. 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. , 
 As the authors and the journal seem to be having difficulty identifying the source of the material published in this paper, I will add another potential clue. It seems that at least one image in this paper overlaps with an image in another Dove Press paper. Careful readers will notice that the field of view is different in each paper, suggesting that the two figures were prepared by the same person who had access to a larger original. I believe there may be other cross-paper overlaps. There is an overlap of author affiliations between the two papers, but I did not see an overlap among the authors. Figure 6D OncoTargets and Therapy (2020) doi: 10.2147 ott.s278582 https: pubpeer.com publications 0FA6780247E4D254B36177D09C2C03#4 Figure 5D Cancer Management and Research (2020) doi: 10.2147 cmar.s271021 https: pubpeer.com publications 6151F1D7C9E66F6611DFDE78C99763 *** ![file] , 
 Retracted [5 August 2022] . ---------------------------- The Editor and Publisher of OncoTargets and Therapy wish to retract the published article. Following publication of the Expression of Concern for this article, concerns were raised regarding the alleged duplication of images in Figure 6D with those from Figure 5D from Fan et al (2020) . Specifically, - Figure 6D, SW480, left hand panel, appears to have been duplicated with a similar image in Figure 5D, PC-3, #1, from Fan et al, 2020. The authors were unable to provide an explanation for the duplicated images and the decision was made to retract the article. Our decision-making was informed by our policy on publishing ethics and integrity and the COPE guidelines on retraction. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. , 
 - *[left]* Fig 1F from  Long Noncoding RNA LINC00525 Promotes the Aggressive Phenotype of Chordoma Through Acting as a microRNA-505-3p Sponge and Consequently Raising HMGB1 Expression ([Li et al 2020] ). - *[right]* **Fig 7D**. ![file] , 
 I m truly amazed by the number of papers originating from China in which questionable data were provided by mysterious third-party companies, never disclosed in the *acknowledgments* section. ,