Long Noncoding RNA FOXD2-AS1 Promotes the Malignancy of Cervical Cancer by Sponging MicroRNA-760 and Upregulating Hepatoma-Derived Growth Factor
Authors: Mingxiao Wen
Yingping Zhu
Jiangyan Xu
Xiaoqing Dou
Shuzhen Zhang
Xianli Xu
Qun Zhou
Journal: Frontiers in Pharmacology (2020)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: FOXD2 adjacent opposite strand RNA 1; FOXD2-AS1; cervical cancer; hepatoma-derived growth factor; microRNA-760.
Affiliations: Department of Gynecology, The First Affiliated Hospital of Zhejiang Chinese Medical University, Zhejiang Provincial Hospital of Traditional Chinese Medicine, Hangzhou, China., Department of Clinical Laboratory, The First Affiliated Hospital of Zhejiang Chinese Medical University, Zhejiang Provincial Hospital of Traditional Chinese Medicine, Hangzhou, China.

Abstract:  Although the functions of long noncoding RNA (lncRNA) called FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) have been well studied in multiple human cancer types, its expression status and detailed roles in cervical cancer remain unknown and merit investigation. This study was aimed at assessing FOXD2-AS1 expression in cervical cancer and at determining its effects on the aggressive behavior of cervical cancer in vitro and in vivo. Expression of FOXD2-AS1 in cervical cancer tissues and cell lines was determined via reverse-transcription quantitative PCR. The effects of FOXD2-AS1 on cervical cancer cells were examined by a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, flow-cytometric analysis, migration and invasion assays, and an in vivo tumorigenicity assay. FOXD2-AS1 was found to be significantly upregulated in cervical cancer tissues and cell lines. High FOXD2-AS1 expression was notably linked with the Federation of Gynecology and Obstetrics (FIGO) stage, lymph node metastasis, and depth of cervical invasion in patients with cervical cancer. Kaplan-Meier survival analysis revealed significantly shorter overall survival of patients when the tumor expression of FOXD2-AS1 was higher in comparison with those in patients with lower FOXD2-AS1 expression. In vitro functional assays revealed that downregulation of FOXD2-AS1 led to suppression of proliferation, migration, and invasiveness as well as to the induction of apoptosis of cervical cancer cells. In addition, FOXD2-AS1 silencing hindered tumor growth in vivo. Mechanism investigation revealed that FOXD2-AS1 functioned as a molecular sponge of microRNA-760 (miR-760). Furthermore, hepatoma-derived growth factor (HDGF) was validated as a direct target gene of miR-760 in cervical cancer cells. Moreover, an miR-760 knockdown reversed the effects of FOXD2-AS1 silencing on cervical cancer cells. FOXD2-AS1 possesses significant oncogenic activity in cervical cancer progression; this activity is mediated by sponging of miR-760 with consequent upregulation of HDGF. The FOXD2-AS1-miR-760-HDGF axis might harbor promising targets for novel treatment strategies of cervical cancer. 

Retracted: No

PubPeer comments:
 Figure 2C and 7E. * Green and blue boxes highlight two panels that look unexpectedly similar to each other, yet representing different experiments and cell lines. Could the authors please check?  , 
 Please admire this montage of xenograft tumor images. Green, red, orange, blue boxes mark various pairs that appear to be the same tumors, rotated slightly and viewed from different angles.  Upper row: - **Fig 8A from [Dou et al (2020)] **. A representative image of tumor xenografts from groups u201csi-FOXD2-AS1u201d and u201csi-NC.u201d Rotated through 90 deg to facilitate comparison. - Fig 8B from [Wang et al (2019)] .  Representative images of tumor xenografts excised from nude mice obtained 4 weeks after subcutaneous injection of Y79 cells transfected with miR-665 mimics or miR-NC. - Fig 7B from [Jiao, Liu Tian (2019)] .  Photograph of tumor xenograft derived from the nude mice injected with miR-493 mimics or miR-NC-transfected Tca8113 cells. Lower row: - Fig 7A from [Ren et al (2019)] .  Representative images of the [HOS] tumor xenografts in miR-758 mimics and miR-NC groups. - Fig 6A from [Zhou Li (2019)] .  Photographs of tumor xenografts were obtained from nude mice that were injected with miR-605 mimics or miR-NC transfected H460 cells . Rotated through 90 deg. - Fig 8B from [Yang et al (2019)] .  Photographs of [U251] tumor xenografts from the agomiR-652 and agomiR-NC groups. Rotated through 90 deg. , 
 #1 Two flow-cytometry plots share most of their points in common, suggesting that they come from the same raw data file (differently gated and filtered). I have adjusted contrast and aspect ratios for ease of comparison.  Here in context. Righthand panel is from Figs 2C, 4B, 6C, 7E.  Lefthand panel is from Figs 2C, 4B, 6C from [Li et al (2019)]  , 
 Two flow-cytometry plots share most of their points in common, suggesting that they come from the same raw data file (differently gated and filtered). I have adjusted contrast and aspect ratios for ease of comparison.  Here in context. Left-hand panel is from Fig 6C again.  Right-hand panel is from Figs 2C, 4C, 5E, 6C of [Deng et al (2010)] .  --------------------------------------------------   In each line-up, left-hand panel is from Fig 4B again.  Second panels are both from Fig 4C of [Han, Huang Han (2020)] .  There may be other matches. , 
 *[above]* Fig 7e f from  Long non-coding RNA GAS6-AS1 acts as a ceRNA for microRNA-585, thereby increasing EIF5A2 expression and facilitating hepatocellular carcinoma oncogenicity ([Ai et al 2020] ). *[lower left]* Fig 5d from  TRG-AS1 is a potent driver of oncogenicity of tongue squamous cell carcinoma through microRNA-543 Yes-associated protein 1 axis regulation ([He et al 2020] ) **[expression of concern]**. *[lower right]* **Fig 7G**.  , 
 - *[left]* Fig 3A B from  microRNA-944 inhibits the malignancy of hepatocellular carcinoma by directly targeting IGF-1R and deactivating the PI3K Akt signaling pathway ([Lv et al 2019] ). - *[right]* **Fig 2D E**.  Two panels overlap. , 
 Fig 4C D overlaps with figures from three retracted papers:  Fig 5D E from  MicroRNA-559 plays an inhibitory role in the malignant progression of glioblastoma cells by directly targeting metadherin ([Yang et al 2019] ).  Fig 3A B from  microRNA-944 inhibits the malignancy of hepatocellular carcinoma by directly targeting IGF-1R and deactivating the PI3K Akt signaling pathway ([Lv et al 2019] ).  Fig 6C D from  Long Noncoding RNA em RGMB-AS1 em Acts as a microRNA-574 Sponge Thereby Enhancing the Aggressiveness of Gastric Cancer via HDAC4 Upregulation ([Wang et al 2020] ).  , 
 - *[above]* Fig 6D E. - *[below]* Fig 5D E from  Long Noncoding RNA LINC00173 Promotes the Malignancy of Melanoma by Promoting the Expression of IRS4 Through Competitive Binding to microRNA-493 ([Yang et al 2020] ).  , 
 #5 - *[left]* Fig 7G again. - *[right]* Fig 2E from  Long Noncoding RNA KCNMB2-AS1 Increases ROCK1 Expression by Sponging microRNA-374a3p to Facilitate the Progression of Nonu2013Small-Cell Lung Cancer ([Yang et al 2020] ).  ,