The Bi-(AID-1-T) G-Quadruplex Has a Janus Effect on Primary and Recurrent Gliomas: Anti-Proliferation and Pro-Migration

Abstract

High-grade gliomas are considered an incurable disease. Despite all the various therapy options available, patient survival remains low, and the tumor usually returns. Tumor resistance to conventional therapy and stimulation of the migratory activity of surviving cells are the main factors that lead to recurrent tumors. When developing new treatment approaches, the effect is most often evaluated on standard and phenotypically depleted cancer cell lines. Moreover, there is much focus on the anti-proliferative effect of such therapies without considering the possible stimulation of migratory activity. In this paper, we studied how glioma cell migration changes after exposure to bi-(AID-1-T), an anti-proliferative aptamer. We investigated the effect of this aptamer on eight human glioma cell cultures (Grades III and IV) that were derived from patients' tumor tissue; the difference between primary and recurrent tumors was taken into account. Despite its strong anti-proliferative activity, bi-(AID-1-T) was shown to induce migration of recurrent tumor cells. This result shows the importance of studying the effect of therapeutic molecules on the invasive properties of glioma tumor cells in order to reduce the likelihood of inducing tumor recurrence.

Keywords: G-quadruplexes; anti-proliferative activity; glioma; migration; resistance; treatment.

Figure 1

Effect of G-quadruplexes (GQs) AID-1-T and its dimer bi-(AID-1-T) on Sus\fP2 (primary glioma), G-01, and G-23 (recurrent glioma) cell cultures. (A) Proliferative activity estimation (MTS assay) in Sus\fP2, G-01, and G-23 cultures when treated with AID-1-T at 5 μM, 10 μM, 20 μM, and 30 μM concentrations; data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (B) Proliferative activity estimation (MTS assay) in Sus\fP2, G-01, and G-23 when treated with bi-(AID-1-T) at 5 μM, 10 μM, 20 μM, and 30 μM concentrations; data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (C) Cell viability assessment (flow cytometry) in Sus\fP2 after treatment with 10 μM AID-1-T; data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (D) Cell viability assessment (flow cytometry) in Sus\fP2 after treatment with 10 μM bi-(AID-1-T); data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (E) immunocytochemical staining (ICC) of Sus\fP2 and G-01 cell cultures after treatment with 10 μM AID-1-T. (F) ICC staining of Sus\fP2 and G-01 cell cultures after treatment with 10 μM bi-(AID-1-T). CD133 (prominin-1)—stem cells marker; L1CAM—L1 cell adhesion molecule, stem cells, and adhesion marker; EGFR—epidermal growth factor receptor, malignancy marker; Casp3—caspase-3, apoptosis marker; p53—malignancy marker; Nestin-stem cells marker, β-III-tubulin-neuroblast marker, Sox2-stem cells marker, CD44-stem cells and migration marker. * p < 0.05, *** p < 0.001 and **** p < 0.0001. The red dashed line indicates the level of controls taken as 100%.

Figure 2

Estimation of FAM-labeled bi-(AID-1-T) localization in G-01 cell culture 1.5, 3, 24, and 72 h after treatment with the cryo-aptamer at a 1 μM concentration. Scale bar 50 µm.

Figure 3

Effect of G-quadruplex-based dimeric aptamer bi-(AID-1-T) (10 μM) on cell cultures derived from primary gliomas and cell cultures from recurrent gliomas. (A) Proliferative activity estimation (MTS assay) in cell cultures treated with bi-(AID-1-T) at a 10 μM concentration; data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (B) Cell viability assessment (flow cytometry) in cell cultures derived from primary gliomas after treatment with 10 μM bi-(AID-1-T); data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (C) Cell viability assessment (flow cytometry) in cell cultures derived from recurrent gliomas after treatment with 10 μM bi-(AID-1-T); data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (D) ICC staining of cell cultures derived from primary gliomas after treatment with 10 μM bi-(AID-1-T); data are presented as a percentage of the control, which was the corresponding non-treated cell culture. (E) ICC staining of cell cultures derived from recurrent gliomas after treatment with 10 μM bi-(AID-1-T); data are presented as a percentage of the control, which was the corresponding non-treated cell culture. CD133 (prominin-1)—stem cells marker; L1CAM—L1 cell adhesion molecule, stem cells, and adhesion marker; EGFR—epidermal growth factor receptor, malignancy marker; Casp3-caspase-3, apoptosis marker; p53-malignancy marker; Nestin-stem cells marker, β-III-tubulin-neuroblast marker, Sox2-stem cells marker, CD44-stem cells and migration marker. (F) Migration estimation in cell cultures after treatment with 10 μM bi-(AID-1-T). * p < 0.05, ** p < 0.01, *** p < 0.001 and **** p < 0.0001. The red dashed line indicates the level of controls taken as 100%.