Cancer Science & Therapy

Anastrozole Reduce Cell Proliferation and Induce Apoptosis in Glioblastoma Multiforme Xenograft Mouse Model

Abstract

Irene G Aguilar-García, María de la Galván-Ramírez, Sergio H Dueñas-Jiménez, Rolando Castañeda-Arellano, Jorge D. Rivas-Carrillo, Erika P. Domínguez-Rangel, and Judith M Dueñas-Jiménez

Objective: Glioblastoma multiforme is the most aggressive form of primary brain tumors, characterized by a high molecular heterogeneity hinder its treatment. Glioblastoma multiforme cells synthesize steroids through the enzyme aromatase and express estrogen receptors. Anastrozole, a specific aromatase inhibitor, plays an important role in endocrine therapy for breast cancer treatment. However, it is unknown whether this inhibitor is useful for treating glioblastoma multiforme. The aim of this work was evaluated the anastrozole effects in the viability and proliferation of malignant cells C6 in vitro as well as apoptosis, cell division, aromatase and estrogen receptor alpha expression in a GBM model in vivo. Methods: C6 cells viability under anastrozole treatment (25, 50, 75 μg/ml) was measured by MTT method and their proliferation was determinate by immunohitofluorescence. In the tumor tissue, the proliferation was evaluated using ki-67 antibody by immunohistofluorescence. ER alpha, aromatase, caspase 8 and 9 protein expression was analyzed using western-blotting. Furthermore, GPR-30, SOX2, CD133 and GFAP were evaluated by immunohistofluorescence. Results: Anastrozole produced a reduction in the viability and proliferation of the C6 cells in culture when was used at 50 μg/ml. It reduces the number of Ki67 immunofluorescent cells in approximately 50%. The aromatase expression decreased in 95%. The estrogen receptor alpha expression increased by a 20% approximately. Caspase 8 expression increased in the treated tumor tissue, although it was undetectable in the not treated group. Caspase 9 increased in approximately 95% in the treated group. All data expressed in these experimental quantifications have a statistically significant difference (p<0.05). G protein coupled receptor-30 was observed in the tumor specimens exhibiting an expression reduction in the anastrozole treated group. Conclusion: The present study demonstrates that anastrozole reduces viability and proliferation in vitro, induces apoptosis and reduces proliferation and aromatase expression in the glioblastoma Xenograft mouse model.