NR2F1 contributes to cancer cell dormancy, invasion and metastasis of salivary adenoid cystic carcinoma by activating CXCL12/CXCR4 pathway
Authors: Min Zheng
Ya-Ling Tang
Mei Zhang
Xiang-Hua Yu
Xin Pang
Sha-Sha Wang
Jing-Biao Wu
Ya-Jie Tang
Xiao Yang
Lu-Ling Dai
Hao-Fan Wang
Xin-Hua Liang
Xiao-Lei Gao
Li Li
Journal: BMC Cancer (2019)
Discipline: CLINICAL MEDICINE
Keywords: Salivary adenoid cystic carcinoma (SACC); metastasis; nuclear receptor subfamily 2 group F member 1(NR2F1); tumor dormancy; tumor invasion.
Affiliations: State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Sec. 3, Renminnan Road, Chengdu, 610041, Sichuan, China., Department of Stomatology, Zhoushan Hospital, Wenzhou Medical University, No .739, Dingshen Road, Lincheng Street, Zhoushan, Zhejiang, 316021, China., State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China. ., Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan, 430068, China. ., State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No.14, Sec. 3, Renminnan Road, Chengdu, 610041, Sichuan, China. .

Abstract:  Background: Salivary adenoid cystic carcinoma (SACC) can recur after removal of the primary tumor and treatment, where they can keep no clinical symptoms and dormant state for 10-15 years. NR2F1 has been demonstrated to regulate the tumor cell dormancy in various malignant tumors and has a potential impact on recurrence and metastasis of carcinoma. However, the role and significance of NR2F1 in SACC dormancy still remain unknown. Methods: A total number of 59 patients with a diagnosis of SACC were included to detected expression of NR2F1, Ki-67 by immunohistochemical (IHC) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling (TUNEL). Fisher's exact test was used to examine the NR2F1 expression and clinicopathologic parameters of SACC. In vitro, SACC cell lines were transfected NR2F1 and knockdown NR2F1 respectively. CCK-8, flow cytometry, wound healing assay and transwell invasion determined SACC cell proliferation, apoptosis, cell cycle, migration and invasion respectively. Chromatin immunoprecipitation (ChIP) assays were utilized to demonstrate the potential role of NR2F1 in SACC invasion via CXCL12/CXCR4 axis. In vivo, xenografts of nude mice via subcutaneous injection or tail vein injection were used to testify the results in vitro. Results: Among the 59 patients with SACC, 23.73% (14/59) were positive to NR2F1 expression, a lower rate of expression compared with 60% (6/10) in normal salivary gland samples. NR2F1 was correlated with metastasis, relapse and dormancy of SACC. SACC cells with transfected NR2F1 remained dormant, as well as enhanced invasion and metastasis. Knockdown of NR2F1 via siRNA after NR2F1 overexpression restored the proliferation and the cell number in G2/M phases, and reduced the abilities of migration and invasion. In addition, NR2F1 promoted the expression of CXCL12 and CXCR4, and overexpression of CXCL12 at least partly rescued the proliferation, migration, and invasion activities induced by NR2F1 silencing. Conclusions: NR2F1 may be an underlying mechanism of SACC recurrence and metastasis via regulating tumor cell dormancy through CXCL12/CXCR4 pathway. 

Retracted: No

PubPeer comments:
 Figure 3, 4 and 6 are tainted with serious problems. Figure 3C: A part of the flow cytometry dot plot (Q4) at left is almost identical to another dot plot (Q4) at right. Figure 4D: In both micrograph panels, a micrograph has been duplicated and presented as something else. Figure 6C: Areas of a micrograph (0h, center and right) are duplicated and presented as something else. Figure 6D: A micrograph has been duplicated and presented as something else.  , 
 #1, I independently came across these while flipping through papers coauthored by the last author (I have not been making an exhaustive search) and have one to add to the pile. Unexpected similarities in Figure 3D. *** Contrast enhanced  , 
 Thanks so much for pointing out these for us. 1)tIn Figure 3C, although the plot of NR2F1hi SACC-83 and NR2F1hi SACC-83 groups were similar, the data were different, 64.7% and 46.1% respectively. And SACC-83 and SACC-LM had been observed to have no significant difference on apoptosis, which was in accord with other studies (Xie H, et al. CASC9 plays a role in salivary adenoid cystic carcinoma in vitro by upregulation of ACLY. Oral Dis. 2020 Dec 21. Qiu L, et al. C6-ceramide induces salivary adenoid cystic carcinoma cell apoptosis via IP3R-activated UPR and UPR-independent pathways. Biochem Biophys Res Commun. 2020;525(4):997-1003. Zhu X, et al. Pim-1 acts as an oncogene in human salivary gland adenoid cystic carcinoma. J Exp Clin Cancer Res. 2014;33(1):114.) 2)tAfter checking data carefully, we found that the images of Figure 3D were not the same and different. 3uff09We are not sure that the images of Figure 4D and Figure 6CD having been signed were different and not the same. Because the images were continuously taken, so there was some overlap between the two images, and it was easy to make a mistake. But we will contact the editor as soon as possible to replace these images, because we have the figures of the same and repeated experiments. Thanks again for your comment and we will pay attention to these in the future.   , 
 #3 Thank you for your reply. I am still concerned that the marked images are more similar than expected. Could the authors please provide a high resolution version of the original images for 3D? You may post those here or use a link to an external site (such as Imgur.com or Google Drive) for larger files. , 
 I have recommended that the journal investigate. This lab appears to have more than a [dozen papers] with similar concerns. , 
 Two sets of images in Figure 2A appear to overlap. ***  ,