CRISPR/Cas9-Mediated OC-2 Editing Inhibits the Tumor Growth and Angiogenesis of Ovarian Cancer
Authors: Simin Zhang
Binhua Wu
Ning Deng
Ligang Zhang
Wenhui Zhu
Yinmei Zhang
Tongyi Lu
Journal: Frontiers in Oncology (2020)
Discipline: CLINICAL MEDICINE
Keywords: CRISPR/Cas9; OC-2; apoptosis; ovarian cancer; tumor angiogenesis.
Affiliations: Guangdong Province Engineering Research Center for Antibody Drug and Immunoassay, Department of Biology, Jinan University, Guangzhou, China.

Abstract:  Ovarian cancer is the leading cancer-related cause of death in women worldwide. It is of great relevance to understand the mechanism responsible for tumor progression and identify unique oncogenesis markers for a higher chance of preventing this malignant disease. The high-expression OC-2 gene has been shown to be a potential candidate for regulating oncogenesis and angiogenesis in ovarian cancer. Hence, we wished to investigate the impact of OC-2 gene on ovarian cancer aggressiveness. CRISPR/Cas9, a gene editing tool, allows for direct ablation of OC-2 at the genomic level, and we successfully generated OC-2 KO cell lines from SKOV3 and CAOV3 cells. In an apoptosis assay, OC-2 KO induced the apoptosis activation of tumor cells, with the up-regulation of Bax/Caspase-8 and the down-regulation of Bcl-2. Consequently, the proliferation, migration, and invasion of OC-2 KO cell lines were significantly inhibited. Assays of qRT-PCR and Western blotting showed that the expression levels of pro-angiogenic growth factors VEGFA, FGF2, HGF, and HIF-1Œ± and the activation of Akt/ERK pathways were significantly down-regulated at the loss of OC-2. In the xenograft model, OC-2 KO potently suppressed the subcutaneous tumor growth, with the inhibition exceeding 56%. The down-regulation of CD31 and relevant pro-angiogenic growth factors were observed in OC-2 KO tumor tissues. Taken together, OC-2 depletion negatively regulated the ovarian cancer progression possibly by apoptosis activation and angiogenesis inhibition. This work revealed a pivotal regulator of apoptosis and angiogenesis networks in ovarian cancer, and we applied the CRISPR/Cas9 system to the transcription factor pathway for developing a broad-acting anti-tumor gene therapy. 

Retracted: Yes

PubPeer comments:
 In Fig.5B, single bands of the Western Blot image seem to be cut-copy-pasted:  , 
 Also in Fig.1 : The first two lanes of the Western Blot appear to be covered with a rectangular box  , 
 Figure 7 may have two images which overlap. ***  , 
 #1 Enhanced contrast helps illustrate the concern. ***  , 
 There is a provisionally accepted correction by the authors in Front Oncol: https: www.frontiersin.org articles 10.3389 fonc.2021.665737 full Quote:  In the original article, there was an error. **The Western Blot contains potentially cut and pasted bands**. , 
 Additional findings for Figure 5B, using Actinopolyspora Biskrensis s illustration from comment #4, and adding two concerns: * Purple arrows: Several more possible cuts appear to be visible * Orange boxes: In the ERK panel, lanes 1-2 look remarkably similar to lanes 5-6.  , 
 Figure 4B. * Yellow boxes: A panel appears to share an overlap with a panel in Figure 3B of Tongyi Lu et al, Cancer Science. (2018), DOI: 10.1111 cas.13633 - https: pubpeer.com publications CF66FB44DBC2B5CAB3F5F4A767AB38  , 
 Figure 7: Some panels look very similar to panels in Figure 7B of the Cancer Science (2018) paper, DOI: 10.1111 cas.13633 - https: pubpeer.com publications CF66FB44DBC2B5CAB3F5F4A767AB38 Marked using a well-trusted image duplication software tool.  , 
 Figure 6. * Pink and teal boxes: Some tumors look remarkably similar to tumors in Figure 7A of the above mentioned Tongyi Lu et al, Cancer Science. (2018), DOI: 10.1111 cas.13633 - https: pubpeer.com publications CF66FB44DBC2B5CAB3F5F4A767AB38  , 
 Finally RETRACTED: u201cFollowing publication, concerns were raised regarding manipulation in figures 5 and 7. An investigation was conducted in accordance with Frontiersu2019 guidelines and the authors failed to provide a satisfactory explanation. This retraction was approved by the Chief Editors of Frontiers in Oncology and the Editor-in-Chief of Frontiers. The authors agree to this retraction.u201d https: www.frontiersin.org articles 10.3389 fonc.2021.694036 full , 
 Dear Actinopolyspora Biskrensis, I am so sorry for late to reply it. When I get your feedbackuff0cwe actively contacted the journal editor department and applied for the retraction of the article Tongyi Lu et al., Front. Oncol. (2020), doi: 10.3389 fonc.2020.01529 -from the editorial department. I also said that we have applied the retraction of the article Tongyi Lu et al., Front. Oncol. (2020), doi: 10.3389 fonc.2020.01529 -from the editorial department when answering questions from another article ongyi Lu et al, Cancer Science. (2018), DOI: 10.1111 cas.13633 . I thought that you are the same unit, already knew our retraction application, so I didn t contact you in time and tell you it. Would you please withdraw the articles in WeChat official account? Our university has known about this and talk with me. The university will surely give us serious punishment. I don t want our university to be more influenced by this. Thank you! Yours, Ning Deng   , 
 --Retracted-- https: www.frontiersin.org articles 10.3389 fonc.2021.694036 full Retraction of the Original Article CRISPR Cas9-Mediated OC-2 Editing Inhibits the Tumor Growth and Angiogenesis of Ovarian Cancer By Lu T, Zhang L, Zhu W, Zhang Y, Zhang S, Wu B and Deng N (2020). Front. Oncol. 10:1529. doi: 10.3389 fonc.2020.01529 The journal retracts the September 2, 2020 article cited above for the following reasons: Following publication, concerns were raised regarding manipulation in Figures 5 and 7. An investigation was conducted in accordance with Frontiersu2019 guidelines and the authors failed to provide a satisfactory explanation. This retraction was approved by the Chief Editors of Frontiers in Oncology and the Editor-in-Chief of Frontiers. The authors agree to this retraction. , 
 Dear Heterochasta Lasioplaca, we have read the retraction which is approved by the Chief Editors of Frontiers in Oncology and the Editor-in-Chief of Frontiers. The authors agree to this retraction. It is very thankful for you and your team to figure out our mistakes in the manuscript. Because we had applied the retraction from the Journal before, we didn t reply and explain for those mistakes. We hope you could forgive us our fault this time and we can guarantee that we will avoid making such mistake again. , 
 #1 About the immunoblot band, the images of cell lines were exposed many times before and integrated for display. Due to negligence, we forget to replace the later result of the full picture. Beause we had applied the retraction from the journal, we did t reply before. Sorry for that deeply. , 
 #9 About the similarity of tumors, the tissues in two articles were stripped and saved in the refrigerator for some time. Because the size, number and name of tumors in the SKOV3 groups of Frontiers in Oncology were similar to those the SKOV3 groups of Cancer Science, the tumors were taken out without careful checking and photographed. Beause we had applied the retraction from the journal, we did t reply before. Sorry for that deeply. , 
 #8 About the microscope images, because the folder name of relevant methods and results in Frontiers in Oncology was very similar to the paper data of Cancer Science we saved before, the data was confused when we transfered the computer data file. , 
 #3 About the microscope images, because the folder name of relevant methods and results in Frontiers in Oncology was very similar to the paper data of Cancer Science we saved before, the data was confused when we transfered the computer data file. Beause we had applied the retraction from the journal, we did t reply before. Sorry for that deeply. , 
 Why can you not just admit that you falsified the damn paper?! ,