Circular RNA circ-SMAD7 promoted ovarian cancer cell proliferation and metastasis by suppressing KLF6
Authors: Y-P Lang
X-P Qin
Y Zhao
Z-W Shao
D Kou
Journal: European review for medical and pharmacological sciences (2019)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: Circular RNAs; circ-SMAD7; ovarian cancer; cell proliferation; metastasis
Affiliations: Department of Gynecology, Shanxian Central Hospital, Heze, China. .

Abstract:  Objective: Recently, the roles of circular RNAs (circRNAs) in tumor progression have attracted much attention. Currently, circ-SMAD7 has been identified as an oncogene in cancers. The aim of this study was to investigate the function of circ-SMAD7 in the progression of ovarian cancer. Patients and methods: Circ-SMAD7 expression in both ovarian cancer cells and tissue samples was detected by quantitative Real Time-Polymerase Chain reaction (qRT-PCR). Circ-SMAD7 shRNA was constructed and transfected into the ovarian cancer cells. To identify the function of circ-SMAD7 in ovarian cancer, cell proliferation assay, colony formation assay, transwell assay, and Matrigel assay were conducted, respectively. In addition, qRT-PCR and Western blot assays were performed to elucidate the underlying mechanism and, then, it was analyzed. Results: Circ-SMAD7 expression was remarkably higher in ovarian cancer tissue samples than in corresponding normal tissues. The proliferation of the ovarian cancer cells was significantly inhibited after circ-SMAD7 downregulation. Meanwhile, the migration and invasion of ovarian cancer cells were significantly inhibited after circ-SMAD7 downregulation in vitro. Both the mRNA and the protein expressions of the Kr√ºppel-like factor 6 (KLF6) were remarkably promoted after circ-SMAD7 was knocked down in ovarian cancer cells. Furthermore, the KLF6 expression level was negatively correlated with circ-SMAD7 expression level in ovarian cancer samples. Conclusions: Our study suggests that circ-SMAD7 promotes the progression of ovarian cancer and enhances cell metastasis and proliferation via suppressing KLF6. In addition, circ-SMAD7 may be a novel therapeutic strategy in ovarian cancer. 

Retracted: Yes

PubPeer comments:
 #2 Both the blots are different but of the same protein .But if you carefully observe you can see some background in figure 5 a third lane which is not there in figure 4 a. About Gapdh they are also different which due to high exposure looks similar and moreover the proteins are of same panel an extensive evaluation of the further. , 
 Both the blots are different but of same protein so it can develop in a particular way moreover if observed carefully you can find some background in figure 5a third lane which is not there is figure 4a.Regarding Gapdh it looks similar might be due to it s high exposure . , 
 #1 Indeed. The example boxed in red (DR5) is particularly notable for representing **five** lanes in Fig 4a but only **four** lanes in Fig 5a. Apparently it is an all-purpose blot! , 
 This is a paper from the group that recently published a paper claiming to have shown that homeopathy is working, please see https: www.ncbi.nlm.nih.gov pubmed 30202036 I am, like many others, questioning their results due to many serious errors in the paper. This has been discussed in Nature recently: https: www.nature.com articles d41586-018-06967-0 In order to check the quality and the trustworthiness of the work coming from the Kundu lab in India, I started analysing the published litterature. In this paper there is not much trust left. Two cases of data duplication was detected after a quick look.  , 
 #4 No, there is duplication here and it s quite obvious. T. Rosea has been wrong before, but s he s absolutely right in this instance. , 
 #4 *if observed carefully you can find some background in figure 5a third lane which is not there is figure 4a* It may be that the commenter has mistaken the different trimming of the two bands for actual substantive differences. , 
 Only a fool or one of the authors of this paper would questioning these obvious duplications. , 
 Some more unexpected similarities between panels in different figures, some of which represent different experiments.  ,