RETRACTED ARTICLE: The value of <i>FGF9</i> as a novel biomarker in the diagnosis of prostate cancer

We, the Editors and Publisher of the journal Artificial Cells, Nanomedicine, and Biotechnology, have retracted the following article: Genggang Cui, Mingming Shao, Xingzhou Gu, Hongbo Guo, Shiqing Zhang, Jianlei Lu & Hongbin Ma (2019) The value of FGF9 as a novel biomarker in the diagnosis of prostate cancer. Artificial Cells, Nanomedicine, and Biotechnology, 47:1, 2241–2245, DOI: 10.1080/21691401.2019.1620250 It has come to our attention that the full authorship list and affiliations for this manuscript, including the study site and ethics committee, were changed after the article was submitted. We have contacted the authors for an explanation, but we have not received a response within the requested timeframe. As determining authorship and the location of where the research was conducted is core to the integrity of published work, we are therefore retracting the article. The authors listed in this publication have been sent notification. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.</p

Both endogenous and exogenous Osx are ubiquitinated.

<p>A. Saos-2 cells treated with or without MG-132 (20 µM) for 6 h were lysed, the cell lysates were immunoprecipitated with an anti-Ub antibody, and then blotted with an anti-Osx antibody. B. Saos-2 cells treated with or without MG-132 (20 µM) for 6 h were lysed, the cell lysates were immunoprecipitated with an anti-Osx antibody, and then blotted with an anti-Ub antibody. C. HEK 293T cells were transiently co-transfected with Flag-tagged hOsx and HA-tagged ubiquitin plasmids, and then treated with or without MG-132 (20 µM) for 6 h. The cell lysates were immunoprecipitated with an anti-Flag antibody, and then blotted with an anti-HA antibody. Results are shown for one of three independent experiments.</p

MDM2 upregulates MMP9 expression.

<p>(A) MCF-7 cells were transfected with MMP9-Luc reporter plasmids and pcmv-MDM2 expression plasmids for 24 h. Whole-cell lysates were utilized to detect luciferase activities, and β-galactosidase activities were used as an internal control for transfection efficiency. The results were obtained from three independent experiments. Data are expressed as the mean ± SD. (B) Total RNA was isolated from MCF-7 cells transfected with pcmv-MDM2 expression plasmids or pcmv vectors to assay MMP9 mRNA levels using RT-PCR, normalized against β-actin. Images are representative of three independent experiments. (C) MMP9 activity was detected using gelatin zymography in MDA-MB-231 cells that over- or under-expressed MDM2 (plasmid or siRNA transfection) and control cells. (D) The levels of MDM2 protein were detected using Western blot analysis in MDF-7 cells transfected with MDM2 expression plasmids and control vectors. β-actin levels served as internal control. (E) The levels of MDM2 protein were detected using Western blot analysis in MDA-MB-231 cells that over- or under-expressed MDM2 (plasmid or siRNA transfection) and control cells. β-actin levels served as internal control.</p

Univariate analysis using Cox proportional risk modeling in patients with IDC.

<p>HR: hazard ratio; 95%CI: 95% confidence interval; ER: estrogen receptor; PR: progesterone receptor; HER2: human epidermal growth factor receptor 2.</p

The Osx K58R and K230R mutations enhance the mRNA expression of osteoblast differentiation marker genes.

<p>C2C12 cells were transiently transfected with the WT Flag-hOsx plasmid or the K58R and K230R mutants, and 24 h later total RNA was extracted and <i>ALP</i>, <i>Col I</i> and <i>Ocn</i> mRNA were quantified by real-time PCR analysis and normalized to β-actin. Results are mean ± SD of three independent experiments performed in triplicate; *<i>p</i><0.05, **<i>p</i><0.01 and ***<i>p</i><0.001.</p

Both endogenous and exogenous Osx are increased by proteasome inhibitor treatment.

<p>A. Saos-2 cells were treated with MG-132 (20 µM) for various periods of time. Endogenous Osx protein was detected by Western blot analysis with an anti-Osx antibody. B. HEK 293T cells were transfected with Flag-hOsx plasmids and then treated with MG-132 (20 µM) for various periods of time. Exogenous Osx protein was detected by Western blot analysis with an anti-Flag antibody. C. Saos-2 cells were treated with lactacystin (10 µM) for various periods of time. Endogenous Osx protein was detected by Western blot analysis with an anti-Osx antibody. D. HEK 293T cells were transfected with Flag-hOsx plasmids and then treated with lactacystin (10 µM) for various periods of time. Exogenous Osx protein was detected by Western blot analysis with an anti-Flag antibody. β-actin served as a loading control. Results are shown for one of three independent experiments.</p

Identification of the ubiquitination sites in Osx.

<p>A. Osx primary sequence, with the lysine residues indicated. B. HEK 293T cells were co-transfected with Ocn-Luc reporter, control Renilla luciferase reporter vector, and the WT Flag-hOsx plasmid or Lys-to-Arg mutants. Relative luciferase activity was measured 24 h after transfection and normalized to the Renilla activity. Results were obtained from three independent experiments performed in triplicate. Data are expressed as mean ± SD. C. HEK 293T cells were co-transfected with HA-Ub expression plasmids and the WT Flag-hOsx plasmid or K26R, K41R, K45R, K46R, K58R and K230R mutants. Cell lysates were immunoprecipitated using an anti-Flag antibody and blotted with an anti-HA antibody. Results are shown for one of three independent experiments.</p

The Osx K58R and K230R mutations enhance ALP activity and mineralized matrix formation.

<p>C2C12 cells were transiently transfected with pcDNA3.1, the WT Flag-hOsx plasmid or the K58R and K230R mutants. At 24 h after transfection, the cells were incubated with rhBMP-2 (100 ng/ml). ALP activity was examined by ALP staining 5–7 days later, or mineralization was assessed using Alizarin Red staining 10–12 days later. A. Representative images of three independent experiments are shown. B. Quantification of ALP activity and mineralization shown in A. Results are mean ± SD of three independent experiments; **<i>p</i><0.01 and ***<i>p</i><0.001.</p

Screening for suitable cell models.

<p>Whole cell extracts of HEK 293T, A549, SW1990, MG-63 and Saos-2 cells were isolated and analyzed by Western blotting with an anti-Osx antibody. β-actin served as a loading control.</p

MDM2 promotes the migration of MCF-7 cells.

<p>MCF-7 cells were transfected with pcmv-MDM2 expression plasmids and pcmv vectors or siRNAs against MDM2 and non-specific siRNA (controls); after 24 h, the cells were scraped with a sterile pipette tip to create a wound. (A) Wound closure was observed by phase-contrast microscopy and photographed at 0 and 24 h. (B) The wound area was measured by the Adobe Photoshop software. Wound closure was quantified as the mean ± standard deviation of three independent experiments. The control wound closure was set at 100%, and the MDM2 treatments are represented as the percent of the control. (C) The levels of MDM2 protein were detected using Western blot analysis in MCF-7 cells that over- or under-expressed MDM2 (plasmid or siRNA transfection) and control cells. β-actin levels served as internal control.</p