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Doctoral Thesis
DOI
https://doi.org/10.11606/T.5.2023.tde-03012024-162846
Document
Author
Full name
Jose Artur Medina
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2023
Supervisor
Committee
Maria, Durvanei Augusto (President)
Kubrusly, Marcia Saldanha
Veras, Mariana Matera
Gomes, Ligia Ferreira
Title in Portuguese
Efeitos das interações farmacológicas do composto 2 - amino etil dihidrogeno fosfato (2-AEH2F) em linhagens tumorais de glioblastoma humano
Keywords in Portuguese
2 Aminoetil Dihidrogeno Fosfato
Fosfatase alcalina
Glioblastoma
Abstract in Portuguese
As fosfatases alcalinas são enzimas calcificantes ubíquas cuja concentração e funcionalidade são aumentadas no microambiente tumoral inflamatório sendo essenciais para a absorção celular de nutrientes fisiologicamente importantes, como precursores fosfolipídicos e vitamina B6. As fosfatases alcalinas são marcadores celulares de recorrência, indiferenciação e resistência em glioblastomas. A Temozolamida, o quimiterápico mais empregado, é tão tóxico às células neoplásicas quanto aos astrócitos do hospedeiro. Desta forma, descrevemos a função enzimática de fosfatases do sobrenadante de linhagens de GBM SF295, como um possível alvo molecular para drogas fosfatadas anticâncer. O 2-AEH2F, o pró-fármaco candidato, é um substrato natural para as fosfatases alcalinas, nutriente para formação de membranas, cujo produto etanolamina, favorece a redução da relação fosfatidilcolina/fosfatidiletanolamina, e hidrólise das fosfatidiletanolaminas, que gerariam as N acil etanolaminas após ação de outras fosfolipases, via liberação de anandamidas, deflagadoras de apoptose em gliomas e, resistência á apoptose em astrócitos, via receptores canabinoides 1 e 2. Este estudo descreve a atividade catalítica de fosfatases alcalinas coletadas do sobrenadante de glioblastomas SF-295 sobre o nitrofenil fosfato na presença de 2-AEH2F, realizados na presença de inibidores ou de cofatores enzimáticos. A presença de inibidores competitivos diminui a função enzimática das fosfatases alcalinas do GBM, enquanto os cofatores minerais, geralmente presentes no microambiente tumoral, aumentam a atividade enzimática sobre o substrato 2-AEH2F, Km: 4,669 mM, V max: 60 uM/min/L. Astrócitos são menos resistêntes á Temozolamida que linhagens de glioblastoma U138 e o 2-AEH2F estimula a proliferação de astrócitos conforme teste de carboxifluoresceína. Proteínas vinculadas á apoptose como caspase 3, á indiferenciação como o CD90, e á supressão tumoral como a p53, foram mensuradas após exposição ao 2-AEH2F e á Temozolamida em astrócitos e U138. O 2-AEH2F se comportou como substrato mostrando potencial para atingir seletivamente células-tronco de GBM e proteger os astrócitos do hospedeiro
Title in English
Effect of pharmacological interactions of 2 aminoethyl dihydrogen phosphate intumor lines of Human gliobastoma
Keywords in English
2-Aminoethyl Dihydrogen Phosphate
Alkaline phosphatase
Glioblastoma
Glioma
Abstract in English
Alkaline phosphatases are ubiquitous calcifying enzymes whose concentration and functionality are increased in the inflammatory tumor microenvironment and are essential for cellular uptake of physiologically important nutrients such as phospholipids and B6 vitamins. Alkaline phosphatases are cellular markers of recurrence, undifferentiation and resistance in glioblastomas. Temozolamide, the most used chemotherapeutic, is as toxic to neoplasms as to host astrocytes. Thus, we describe the enzymatic function of phosphatases from the supernatant of GBM SF295 strains, as a possible molecular target for phosphate-containing anticancer drugs. 2-AEH2F, the candidate prodrug, is a natural substrate for alkaline phosphatases, nutrient for the formation of membranes, whose ethanolamine product, favors the reduction of the phosphatidylcholine/phosphatidylethanolamine ratio, and perhaps the hydrolysis of phosphatidylethanolamines, which would generate N acyl ethanolamines after the action of other phospholipases, via the release of anandamides, triggers of apoptosis in gliomas and, resistance to apoptosis, in astrocytes, via CB1/2 receptors. This study describes the catalytic activity of alkaline phosphatases collected from the supernatant of SF-295 glioblastomas on nitrophenyl phosphate in the presence of 2-AEH2F, carried out in the presence of enzyme inhibitors or cofactors. The presence of competitive inhibitors decreases the enzymatic function of GBM alkaline phosphatases, while mineral cofactors, usually present in the tumor microenvironment, increase enzymatic activity on the 2-AEH2F substrate, Km: 4.669 mM, V max: 60 uM/min/ L. Astrocytes were as sensitive to Temozolamide as glioblastoma cell lines and 2-AEH2F inhibited apoptosis in astrocytes. Proteins linked to apoptosis such as caspase 3, undifferentiation, such as CD90, and p53, the universal oncogenic suppressor, were also measured after exposure to 2-AEH2F and Temozolamide. 2-AEH2F behaved as a substrate showing potential to selectively target GBM stem cells and protect host astrocytes from Temozolomide
 
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Publishing Date
2024-01-08
 
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