title: Phosphatidylinositol 3-Kinase/AKT Pathway Inhibition by Doxazosin Promotes Glioblastoma Cells Death, Upregulation of p53 and Triggers Low Neurotoxicity.
abstract: Glioblastoma is the most frequent and malignant brain tumor. Treatment includes chemotherapy with temozolomide concomitant with surgical resection and/or irradiation. However, a number of cases are resistant to temozolomide, as well as the human glioblastoma cell line U138-MG. We investigated doxazosin's (an antihypertensive drug) activity against glioblastoma cells (C6 and U138-MG) and its neurotoxicity on primary astrocytes and organoptypic hippocampal cultures. For this study, the following methods were used: citotoxicity assays, flow cytometry, western-blotting and confocal microscopy. We showed that doxazosin induces cell death on C6 and U138-MG cells. We observed that doxazosin's effects on the PI3K/Akt pathway were similar as LY294002 (PI3K specific inhibitor). In glioblastoma cells treated with doxasozin, Akt levels were greatly reduced. Upon examination of activities of proteins downstream of Akt we observed upregulation of GSK-3β and p53. This led to cell proliferation inhibition, cell death induction via caspase-3 activation and cell cycle arrest at G0/G1 phase in glioblastoma cells. We used in this study Lapatinib, a tyrosine kinase inhibitor, as a comparison with doxazosin because they present similar chemical structure. We also tested the neurocitotoxicity of doxazosin in primary astrocytes and organotypic cultures and observed that doxazosin induced cell death on a small percentage of non-tumor cells. Aggressiveness of glioblastoma tumors and dismal prognosis require development of new treatment agents. This includes less toxic drugs, more selective towards tumor cells, causing less damage to the patient. Therefore, our results confirm the potential of doxazosin as an attractive therapeutic antiglioma agent.
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Mariana Maier
authors.initials: MM
authors.lastname: Gaelzer
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Bárbara Paranhos
authors.initials: BP
authors.lastname: Coelho
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Alice Hoffmann
authors.initials: AH
authors.lastname: de Quadros
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Juliana Bender
authors.initials: JB
authors.lastname: Hoppe
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Silvia Resende
authors.initials: SR
authors.lastname: Terra
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Maria Cristina Barea
authors.initials: MC
authors.lastname: Guerra
authors.affiliation: Departamento de Química Biológica, Facultad de Farmácia y Bioquímica, Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Vanina
authors.initials: V
authors.lastname: Usach
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.|Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Fátima Costa Rodrigues
authors.initials: FC
authors.lastname: Guma
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.|Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Carlos Alberto Saraiva
authors.initials: CA
authors.lastname: Gonçalves
authors.affiliation: Departamento de Química Biológica, Facultad de Farmácia y Bioquímica, Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Setton-Avruj
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.|Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Ana Maria Oliveira
authors.initials: AM
authors.lastname: Battastini
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.|Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brasil.
authors.forename: Christianne Gazzana
authors.initials: CG
authors.lastname: Salbego
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001253:Astrocytes / Q000187:drug effects; D001932:Brain Neoplasms / Q000188:drug therapy*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D017292:Doxazosin / Q000494:pharmacology* / Q000633:toxicity; D004789:Enzyme Activation / Q000187:drug effects; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D005909:Glioblastoma / Q000188:drug therapy*; D000071679:Glycogen Synthase Kinase 3 beta / Q000096:biosynthesis; D006624:Hippocampus / Q000187:drug effects; D006801:Humans; D000077341:Lapatinib; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
chemical_list: D000970:Antineoplastic Agents; D053148:Caspase 3; D002867:Chromones; D017292:Doxazosin; D000071679:Glycogen Synthase Kinase 3 beta; D000077341:Lapatinib; D009025:Morpholines; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; D011799:Quinazolines; D016159:Tumor Suppressor Protein p53; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one