The POU2F1/miR-4490/USP22 axis regulates cell proliferation and metastasis in gastric cancer
Authors: Zhizhao Lin
Xiaosheng Wu
Huiqiong Zhu
Weiyu Dai
Side Liu
Aimin Li
Qiong Yang
Yuyang Liu
Yaying Chen
Jing Xiong
Li Xiang
Jiaying Li
Yizhi Xiao
Jing Wang
Wenjing Zhang
Jianjiao Lin
Weimei Tang
Tianming Chen
Jide Wang
Yusi Wang
Yong Sun
Guangnan Liu
Journal: Cellular Oncology (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Epithelial-mesenchymal transition; Gastric cancer; Metastasis; MiR-4490; POU2F1.
Affiliations: Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Department of Digestive Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China., Department of Gastroenterology, Longgang District People's Hospital, Shenzhen, 518172, China., Department of Medical Oncology, the First people's Hospital of Yunnan Province, Medical School of Kunming University of Science and Technology, Kunming, 650032, China., The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, 510515, People's Republic of China., Department of Gastroenterology, The third affiliated hospital of Guangzhou medical university, Guangzhou, 510150, China., The Second Affiliated Hospital of University of South China, Hengyang, 421001, China., Guangdong Provincial Key Laboratory of Gastroenterology, Department of Gastroenterology, Department of Digestive Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong Province, China. ., Department of Gastroenterology, Longgang District People's Hospital, Shenzhen, 518172, China. .

Abstract:  Purpose: Growing evidence indicates that aberrant expression of microRNAs contributes to tumor development. However, the biological role of microRNA-4490 (miR-4490) in gastric cancer (GC) remains to be clarified. Methods: To explore the function of miR-4490 in GC, we performed colony formation, EdU incorporation, qRT-PCR, Western blotting, in situ hybridization (ISH), immunohistochemistry (IHC), flow cytometry, ChIP and dual-luciferase reporter assays. In addition, the growth, migration and invasion capacities of GC cells were evaluated. Results: We found that miR-4490 was significantly downregulated in primary GC samples and in GC-derived cell lines compared with normal controls, and that this expression level was negatively correlated with GC malignancy. Exogenous miR-4490 expression not only reduced cell cycle progression and proliferation, but also significantly inhibited GC cell migration, invasion and epithelial-mesenchymal transition (EMT) in vitro. Mechanistically, we found that miR-4490 directly targets USP22, which mediates inhibition of GC cell proliferation and EMT-induced metastasis in vitro and in vivo. Moreover, we found through luciferase and ChIP assays that transcription factor POU2F1 can directly bind to POU2F1 binding sites within the miR-4490 and USP22 promoters and, by doing so, modulate their transcription. Spearman's correlation analysis revealed a positive correlation between USP22 and POU2F1 expression and negative correlations between miR-4490 and USP22 as well as miR-4490 and POU2F1 expression in primary GC tissues. Conclusion: Based on our results we conclude that miR-4490 acts as a tumor suppressor, and that the POU2F1/miR-4490/USP22 axis plays an important role in the regulation of growth, invasion and EMT of GC cells. 

Retracted: No

PubPeer comments:
 Figure 3A appears to have a repeated image. *** ![file] , 
 Figure 4F appears to have 2 images which overlap. Thanks to Dr. Bik for the help. *** ![file] , 
 #2 For the transwell assay in Fig.4f, we also re-checked our original data, and provided as follows: ![file] The first three pictures in each group conducted in three individual repeated experiments were chosen for statistical analysis. We apologized that we brought inconvenience to editors and readers because of our carelessness in choosing and organizing our figure in Fig.4f. The previous figure in miR USP22 of BGC-823 was mistakenly chosen from the group miR USP22 of AGS. Here, we provided a new picture marked in red as the new represented figure in miR USP22 group of BGC-823. Thank you for your carefulness. We are deeply sorry again for causing the confusion and inconvenience. And we will contact the publisher to correct our mistakes as soon as possible. #1 Dear editor-in-chief and readers: First of all, thank you very much for your careful correction. Due to our carelessness, we were very sorry for the mistakes in the picture when analyzing the data. In order to verify this matter, we immediately checked the original record and found that the error is due to the fact that each group is placed in the same folder, and the pictures of the same group were misrepresented when uploading. For proof, we provided the original data of the experiment and made changes to the figures. Express regret for this mistake once again! For the wound healing experiment in Fig.3a, we provided the original data as follows: ![file] The first three pictures in each group conducted in three individual repeated experiments were chosen for statistical analysis. We are deeply sorry that when we puzzling our figure, we mistook a figure in m-NC group of AGS in 24 h for i-NC group, causing the overlapping of figure. Here, we provided a new picture marked in red from the original data as the represented figure in i-NC group of AGS in 24 h. ,