RETRACTED ARTICLE: Upregulation of the long non-coding RNA AFAP1-AS1 affects the proliferation, invasion and survival of tongue squamous cell carcinoma via the Wnt/β-catenin signaling pathway
Authors: Shan-Shan Zhang
Jing Xiong
Shuai Zhang
Min Hu
Min-Hui Dai
Ze-You Wang
Han-Jiang Wu
Zhao-Jian Gong
Journal: Molecular Cancer (2018)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: AFAP1-AS1; Long non-coding RNA; Proliferation; TSCC; Wnt/β-catenin signaling.
Affiliations: Department of Laboratory Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China., Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China., Department of Clinical Medicine, Fujian Medical University, Fuzhou, Fujian, 350100, China., Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China., Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China. ., Department of Stomatology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China. .

Abstract:  Background: Long non-coding RNA (lncRNA) actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) is oriented in an antisense direction to the protein-coding gene AFAP1 in the opposite strand. Previous studies showed that lncRNA AFAP1-AS1 was upregulated and acted as an oncogene in a variety of tumors. However, the expression and biological functions of lncRNA AFAP1-AS1 in tongue squamous cell carcinoma (TSCC) are still unknown. Methods: The expression level of AFAP1-AS1 was measured in 103 pairs of human TSCC tissues and corresponding adjacent normal tongue mucous tissues. The correlation between AFAP1-AS1 and the clinicopathological features was evaluated using the chi-square test. The effects of AFAP1-AS1 on TSCC cells were determined via a CCK-8 assay, clone formation assay, flow cytometry, wound healing assay and transwell assay. Furthermore, the effect of AFAP1-AS1 knockdown on the activation of the Wnt/β-catenin signaling pathway was investigated. Finally, CAL-27 cells with AFAP1-AS1 knockdown were subcutaneously injected into nude mice to evaluate the effect of AFAP1-AS1 on tumor growth in vivo. Results: In this study, we found that lncRNA AFAP1-AS1 was increased in TSCC tissues and that patients with high AFAP1-AS1 expression had a shorter overall survival. Short hairpin RNA (shRNA)-mediated AFAP1-AS1 knockdown significantly decreased the proliferation of TSCC cells. Furthermore, AFAP1-AS1 silencing partly inhibited cell migration and invasion. Inhibition of AFAP1-AS1 decreased the activity of the Wnt/β-catenin pathway and suppressed the expression of EMT-related genes (SLUG, SNAIL1, VIM, CADN, ZEB1, ZEB2, SMAD2 and TWIST1) in TSCC cells. In addition, CAL-27 cells with AFAP1-AS1 knockdown were injected into nude mice to investigate the effect of AFAP1-AS1 on tumorigenesis in vivo. Downregulation of AFAP1-AS1 suppressed tumor growth and inhibited the expression of EMT-related genes (SLUG, SNIAL1, VIM, ZEB1, NANOG, SMAD2, NESTIN and SOX2) in vivo. Conclusions: Taken together, our findings present a road map for targeting the newly identified lncRNA AFAP1-AS1 to suppress TSCC progression, and these results elucidate a novel potential therapeutic strategy for TSCC. 

Retracted: Yes

PubPeer comments:
 In Fig. 4, pictures in a were obviously same to pitures in b, just moved a little: ![file] ![file] ![file] ![file] , 
 Thank you for doing the right thing. , 
 Thanks for your comment. Certainly, we made a serious error in preparing figures, certain images were inappropriately processed: images in figure 4a and figure 4b wereu00a0wronglyu00a0processed. Several images might be collected from one experimental group. We have checked the raw figures carefully, and found that there was severe confusion in the collection of images. We have contacted to the journal editor to retract the article. Meanwhile we will repeat the two experiments as soon as possible to verify those results. Thanks for your reminder again. , 
 Thank you. This issue have brought our attention, we will seriously go through our date and response soon and take further actions. , 
 2019 retraction. https: molecular-cancer.biomedcentral.com articles 10.1186 s12943-019-1026-y The authors have retracted this article [1] because there are errors in Figures 4a and 4b. In these figures a number of cell field views are replicated between experimental groups: In Figure 4b the Scc-9 Mock panel replicates the Scc-9 shR-NC panel in Figure 4a In Figure 4b the CAL-27 Mock panel replicates the CAL-27 Mock panel in Figure 4a In Figure 4b the CAL-27 sHR-Nc panel replicates the CAL-27 sHR-Nc panel in Figure 4a In Figure 4b the CAL-27 shR-AFAP1-AS1 panel replicates the CAL-27 shR-AFAP1-AS1 panel in Figure 4a The conclusions of this study are therefore not reliable. Zhaojian Gong, Hanjiang Wu, Shanshan Zhang, and Shuai Zhang agree with this retraction. Ze-you Wang, Min Hu, Min-hui Dai, and Jing Xiong agree with the retraction but did not respond to further correspondence about the retraction notice. ,