Avaliação de fármacos anti-inflamatórios no crescimento de glioblastoma com foco na modulação adenosinérgica mediada pelo metotrexato

Abstract

Glioblastoma multiforme (GBM) is the most malignant tumor of central nervous system. The ecto-5′-nucleotidase (5’NT/CD73) is overexpressed in GBM microenvironment. The 5’NT/CD73 controls extracellular adenosine level, which has been described as immunosuppressive molecule. Studies have shown that anti-inflammatory drugs, such as indomethacin and dexamethasone have anti-proliferative effect by modulating 5’NT/CD73 expression in GBM cells. Methotrexate (MTX) is an antimetabolite drug, widely used in clinical for cancer and inflammatory diseases, which modulates 5’NT/CD73 expression in GBM cells. However, it is still unclear if the increase of 5’NT/CD73 expression and adenosine formation is related to the MTX antiproliferative effect in tumor cells. Considering the ability of some anti-inflammatory drugs to modulate the 5’NT/CD73 enzyme, one of the aims of the present work was to evaluate the effect of nonsteroidal anti-inflammatory drugs (NSAIDs): naproxen, piroxican, meloxicam, ibuprofen, diclofenac sodium, acetylsalicylic acid, acetaminophen, nimesulide and ketoprofen, on the expression of the 5’NT/CD73 enzyme in GBM cells and peripheral lymphocytes. In addition, we seek to increase the knowledge by which MTX inhibits the GBM cells growth. Cell viability and 5’NT/CD73 expression were evaluated in GBM cells and mesenteric lymphocytes after exposure to anti-inflammatory drugs. For analysis of the MTX mechanism, GBM cells were treated with APCP (5’NT/CD73 inhibitor), dipyridamole (inhibitor of adenosine uptake to the intracellular milieu), ABT-702 (inhibitor of adenosine kinase enzyme) and caffeine (non-selective antagonist of P1 adenosine receptors) before treatment with MTX and AMP. Only MTX increased expression of 5’NT/CD73 in GBM cells. Interventions on adenosinergic system did not change the antiproliferative effect of MTX. The cytotoxic effect of MTX is not associated with increased 5’NT/CD73 expression and adenosine levels in the extracellular environment under tested conditions. However, further studies are needed to confirm the results obtained and to understand the role of MTX in the GBM context.