Telomere Dynamics, Gene Expression and Genetic Instability in Glioblastoma Cells Treated with Reversine

Author(s): Fábio Morato de Oliveira, Aline Monezi Montel, Wagner Gouvêa dos Santos, Fermino Sanches Neto, Cristina Mores Junta, Ubirajara Lanza Júnior, Sabine Mai

Background: In the present study, we analyzed the cytotoxic effect of reversine, a small molecule used for stem cell dedifferentiation and potential to selectively induce cell death, on two human glioblastoma cell lines. The AURKA and AURKB gene expression were quantified in both cell lines following the exposure to different concentrations of reversine, and the effect of reversine on telomere dynamics, in a 3D scale was analyzed. AURKA and AURKB genes express mitotic kinases with an important role in the regulation of several mitotic events. Hyperexpression of these genes are found in patients with cytogenetic abnormalities presenting an unfavorable prognosis.

Methods and Results: Our results indicate that reversine was able to inhibit the cell growth of both cell lines in a time and concentration-dependent fashion. A comparative analysis showed that reversine induced apoptosis of U138 cells more significantly than in U87 cells at the same dosage. Reversine was able to decrease the expression levels of AURKA and AURKB mRNA in both cell lines after 24 hours exposure. The total number of telomeres in both glioblastoma cells was determined after 48 h exposure and compared (not treated vs. treated cells) using TeloView®™ software. Two distinct subgroups of the same cell line were identified, based on treatment status (reversine+/-). Microscopy Fluorescence analysis showed glioblastoma cells exhibiting nuclei with low relative fluorescent intensities suggestive of short telomeres and nuclei with intermediate relative fluorescent intensity indicating intermediate length of telomeres.

Conclusions: Our results have demonstrated that reversine can act as an important antiproliferative agent in glioblastoma cells and possibly promote redifferentiation of glioblastoma cell lines by genetic reprogramming and changing the genomic instability status, as suggested by decreased gene expression profile, and two distinct telomere signatures. Aurora kinase inhibitors such as reversine may have potential therapeutic value when combined with radiation therapy.