Proliferation of aneuploid cells induced by CENP-E depletion is counteracted by the p14ARF tumor suppressor
The spindle assembly checkpoint (SAC) is a cellular surveillance mechanism that ensures the fidelity of chromosomes segregation. Reduced expression of some of its components weakens the SAC and induces chromosome instability and aneuploidy, which are both well-known hallmarks of cancer cells. Centromere protein-E (CENP-E) is a crucial component of the SAC and its function is to facilitate kinetochore microtubule attachment required to achieve and maintain chromosome alignment. The present study investigates the possible role of p14ARF as a controller of aneuploid cells proliferation. We used RNA interference to induce aneuploidy by partial depletion of CENP-E in human primary fibroblasts (IMR90) and in near diploid tumor cells (HCT116). In contrast to IMR90 aneuploid cell number, which was drastically reduced and leaned towards the WT condition, HCT116 aneuploid cell numbers were slightly decreased at later time points. This euploidy restoration was accompanied by increased p14ARF expression in IMR90 cells and followed ectopic p14ARF re-expression in p14ARF-null HCT116 cells. Collectively, our results suggest that hampering proliferation of aneuploid cells could be an additional role of the p14ARF tumor suppressor.
KeywordsAneuploidy CENP-E P14ARF HCT116 cells RNAi
This work was in part supported by Università degli Studi di Palermo, Italy: ATE-0255, and by Centro di Oncobiologia Sperimentale (COBS) to ADL. We want to thank Prof. S. Gazzeri, University J. Fourier, La Tronche, France, for providing us with the pcDNA3.1 plasmid harboring the p14ARF c-DNA. We are grateful to Prof. Floris Foijer, European Research Institute for the Biology of Ageing (ERIBA) University Medical Center Groningen (the Netherlands) and to Dr. Rosario Billetta, Abilita Bio, Inc. San Diego, CA (United States of America) and to Maha Mohammad Said, Institut Gustave Roussy, Villejuif (France) for their thoughtful reading of the manuscript.
LV did RNAi experiments, cell transfection, cytogenetics analysis, vector construction, RT-qPCR, analysed the data and helped to write the manuscript; VB did RNAi, cell transfection, cytogenetics analysis, RT-qPCR, analysed the data and helped to write the manuscript; DC did immunofluorescence microscopy, Western Blot and helped with vector construction; ADL designed the experiments, analysed the data and wrote the manuscript.
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Conflict of interest
The authors declare that they have no competing interests.