Juvenile nasopharyngeal angiofibroma contain an angiogenic growth factor: Basic FGF

Abstract

The presence of an angiogenic protein basic fibroblast growth factor (FGF) was established in juvenile nasopharyngeal angiofibroma (JNF). Extracts of these tumors have the capacity to stimulate endothelial cell proliferation. This activity is indistinguishable from basic FGF. The biological activity contained in the extracts binds to heparin-Sepharose columns and is eluted with a characteristic 2 mol sodium chloride. The exact fraction of the biological activity corresponds to the location where an immunoreactive basic FGF can be detected by radioimmunoassay. These same fractions contain an 18,000-d molecule which is identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting with an antibody to basic FGF. Indeed, immunohistochemical studies localize the growth factor to the endothelium of JNF. Although these findings do not establish that basic FGF mediates the development of this angiofibroma, they do support the possibility that the pathogenesis of JNF is associated with the presence of angiogenic factors like basic FGF. If this is the case, a comprehensive study of the etiology of JNF may lead to a better understanding of how locally produced growth factors mediate proliferative disease and how its modification might lead to better treatment on a biological basis.

Update on Select Benign Mesenchymal and Meningothelial Sinonasal Tract Lesions

“…Another study identified that GSTM1 (null genotype) is linked to the development of JNA [69]. SYK protein kinase (tyrosine kinase) is differentially expression in low and high stage JNA, suggesting a possible molecular treatment target, along with angiogenic protein basic fibroblast growth factor [70,71].…”

Biomolecular Analysis of Juvenile Nasopharyngeal Angiofibroma

“…Therefore, vascular endothelial growth factor (VEGF), nerve growth factor (NGF), insulin-like growth factor (IGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), and transforming growth factor (TGF) were assessed in many studies [2,5,6,10,12,[14][15][16]23,[25][26][27]. The levels of TGF-β1 [10,25,27,29], basic fibroblast growth factor (bFGF) [6,15,25,26], NGF (2), and VEGF [5,6,10,12,14,16,23,25] were found to be elevated in JNA. The most notable of which are TGF-β1 and VEGF.…”

Angiofibroma nasofaríngeo: revisão de literatura

“…Porém, há indícios de que o comportamento tumoral varie com alterações dos níveis séricos hormonais. Schiff 34 , em sua tese sobre a patogênese do angiofibroma, descreveu em detalhes a presença de fibroblastos imaturos e células endoteliais, típicas do tumor e ressaltou que o quadro é revertido drasticamente pela ação estrogênica, que causa maturação histológica do tecido conjuntivo e das células endoteliais. Porém, Schiff não identificou a potencial origem do tumor.…”

“…Se de um lado a presença de receptores androgênicos é considerada um fato confirmado 12 , diferentes trabalhos da literatura acusam a ausência de receptores estrogênicos 9,35,36 , sugerindo uma ação indireta desse hormônio. Schiff 34 sugeriu um duplo mecanismo de ação dos estrógenos: redução da permeabilidade do tecido conjuntivo, reduzindo o número de vasos; e redução da produção de andrógenos por feedback negativo. Os achados desses autores apontam para a possibilidade de utilização de antiandrogênicos puros (flutamida, ciproterona) como uma alternativa aos tratamentos radioterápico e quimioterápico.…”