RETRACTED: Inhibition of miR-140-3p or miR-155-5p by antagomir treatment sensitize chordoma cells to chemotherapy drug treatment by increasing PTEN expression.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the authors and the Editor-in-Chief as the validity of the data cannot be guaranteed. The journal was initially contacted by the corresponding author to report that, when the authors verified post publication PTEN as their former target of miR-140-3p, they found that treatment with miR-140-3p or miR-155-5p antagomir increased PTEN protein levels in patient-derived chordoma cells without having a significant effect on the malignancy of the tumor cells. The journal further requested the author to provide more information about their post publication findings with regard to this article. However, the author was not able to fulfil this request.