<p>Long Noncoding RNA LINC00525 Promotes the Aggressive Phenotype of Chordoma Through Acting as a microRNA-505-3p Sponge and Consequently Raising HMGB1 Expression</p>
Authors: Hong Ma
Lei Li
Guohua Lv
Bing Wang
Journal: OncoTargets and Therapy (2020)
Discipline: CLINICAL MEDICINE
Keywords: HMGB1; LINC00525; chordoma; miR-505-3p; oncogenicity.
Affiliations: Department of Spine Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, People's Republic of China.

Abstract:  Purposes: Long intergenic non-protein coding RNA 525 (LINC00525), a long noncoding RNA, has been implicated in the carcinogenesis and progression of many human cancer types. However, the detailed roles of LINC00525 in chordoma and the underlying mechanisms are not fully understood. Here, we aimed to determine whether LINC00525 could modulate the oncogenicity of chordoma cells and to elucidate in detail the molecular events underlying these tumor-promoting activities. Methods: Reverse-transcription quantitative polymerase chain reactions were performed to assess LINC00525 expression in chordoma. The effects of LINC00525 silencing on chordoma cell proliferation, apoptosis, migration, and invasiveness in vitro and tumor growth in vivo were respectively tested using CCK-8 assay, flow cytometry, migration and invasion assays, and xenograft experiments. Results: High LINC00525 expression levels were detected in chordoma tissues. The proliferative, migratory, and invasive abilities of chordoma cells in vitro and their tumor growth in vivo were suppressed by the LINC00525 knockdown, whereas apoptosis was induced by it. Mechanistically, LINC00525 acted as a molecular sponge of microRNA-505-3p (miR-505-3p) and upregulated the expression of high mobility group box 1 (HMGB1), which is directly targeted by miR-505-3p. Rescue assays indicated that increasing the output of miR-505-3p-HMGB1 axis attenuated the effects of LINC00525 depletion on chordoma cells. Conclusion: LINC00525, a pro-oncogenic long noncoding RNA, promotes chordoma progression by regulating the miR-505-3p-HMGB1 axis. The LINC00525-miR-505-3p-HMGB1 pathway may be a novel therapeutic target in chordoma. 

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] , 
 Expression of Concern, [15 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. , 
 - *[left]* Fig 1F. - *[right]* Fig 7D from  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 ([Luo et al 2020] ) **[retracted]**. ![file] --------------------------- - *[left]* Fig 3D. - *[right]* Fig 4E from  Long Non-Coding RNA DARS-AS1 Contributes to Prostate Cancer Progression Through Regulating the MicroRNA-628-5p MTDH Axis ([Fan et al 2020] ) **[retracted]**. ![file] , 
 Retracted [16 September 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 subsequently raised regarding the alleged duplication of images in Figures 1 and 3 with those from unrelated articles. Specifically, - Figure 1F, panel U-CH2 si-NC, appears to have been duplicated with the same image from Figure 7D, panel HCT116, si-NC in Luo et al, 2020 . - Figure 3D, panel U-CH1, miR-505-3p mimic, appears to have been duplicated with the same images from Figure 4E, panel PC-3, si-DARS-AS1+inhibitor control in Fan et al, 2020 . The authors did not respond to our queries and were unable to provide an explanation for the duplicated images. The Editor requested to retract the article and the authors were notified of this. 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. ,