Molecular Pathogenesis of Juvenile Nasopharyngeal Angiofibroma in Brazilian Patients

Abstract

Juvenile nasopharyngeal angiofibroma (JNA) is a vascular tumor of the nasopharynx that accounts for 0.5% of all cancers of the head and neck. It primarily affects males aged 14-25 years. Of the many genes that mediate the development of JNA, GSTM1 has been most frequently associated with this vascular tumor. The loss of expression of GSTM1 (null genotype) is linked to the development of these tumors. The aim of this cross-sectional case study was to examine the prevalence of the GSTM1-null genotype in Brazilian patients with JNA. DNA was extracted from the leukocytes of blood samples from 10 patients. GSTM1 genotypes were analyzed using a PCR-based assay that was designed to identify the wild-type allele of GSTM1. All 10 patients (100%) were males, with a mean age of 17.8 years. The null genotype for GSTM1 was noted in 4 patients (40%)-1 (10%) at Fisch stage I, 1 (10%) at stage III, and 2 (20%) at stage II. No patient with this genotype had stage IV disease. There was no correlation between Fisch classification and GSTM1 genotype (P = .5695). The correlation between age at diagnosis and GSTM1 genotype was not significant (P = .728). The present findings indicate that there is evidence of an association between the GSTM1-null genotype and JNA in this studied Brazilian population.

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].…”

Juvenile Nasopharyngeal Angiofibroma Presenting with Acute Airway Obstruction

“…They typically present as insidious onset nasal obstruction (80–90%), epistaxis (45–60%), headache (25%), and facial swelling (10–18%) and are most often associated with a history of chronic sinusitis [ 2 – 4 ]. There are various genetic etiologies that have been proposed; however, none of these have been directly linked to nasopharyngeal angiofibromas so that a causal link is yet to be established [ 5 ]. In this case report, we present an unusual case of a nasopharyngeal angiofibroma causing obstruction acutely in an adult male.…”

Biomolecular Analysis of Juvenile Nasopharyngeal Angiofibroma

“…When this is not expressed there is an increased risk of developing some malignancies [17,42]. Two studies performed on GSTM1-null genotype [17,33]. In both studies, the GSTM1-null genotype was associated with the formation of JNA.…”

“…Among these, c-Myc [6,7,28], c-Kit (2,6,7), FLI-1 [5], endoglin [5,11], TNC [9], PCNA [10,12], Ki-67 [16], GSTM1 [17,33], AURKA and MDM2 (34) were shown to be associated with JNA. Among these, GSTM1-null genotype gene seems important.…”

“…protooncogenes, including p53, c-Myc, H-Ras, Ki-Ras, c-Kit, p130Cas, Friend leukemia integration-1 (FLI-1), endoglin, podoplanin, stromelysin-3 (ST3), tenascin-C (TNC), syndecan-2, proliferating cell nuclear antigen (PCNA), Bcl-2, Ki-67, S-100, c-Fos, GSTM1 gene, AURKA, MDM2, Her-2/neu, and Hif-1 [2,[5][6][7][9][10][11][12][13][15][16][17]25,27,28,[32][33][34][35], in the etiology of JNA have been investigated. Among these, c-Myc [6,7,28], c-Kit (2,6,7), FLI-1 [5], endoglin [5,11], TNC [9], PCNA [10,12], Ki-67 [16], GSTM1 [17,33], AURKA and MDM2 (34) were shown to be associated with JNA.…”