Abstract 594: AGT mutations as a prognosis factor in patients with astrocytoma

Background: Astrocytomas are the most common and lethal brain tumors. The median survival of patients is 15 months. The study of genetic alterations may help to understand the mechanisms of development and behavior of the disease and thus understand the risk factors and prognostic factors. AGT gene and its peptide derivatives, are involved in cell proliferation and neoangiogenesis and resistance to apoptosis, hence the pathogenesis of astrocytomas. Objective: To identify somatic and germinal AGT gene variations in from patients with astrocytoma. Material and methods: 155 randomly selected files from patients diagnosed with astrocytoma between 2008-2014 were revised to determined clinical prognosis factor in Mexican population. In 25 patients, the molecular analysis of the whole codification region, 5´UTR and 3´UTR of the gene AGT was done in tumors biopsy and blood. Each amplified region had a depth of minimum 1500x. IonReporter software was utilize to analyze the genetic variants and using Integrative Genomic Viewer we confirmed that each variant had a Phred higher than 25. Genotypic frequencies were compared with HapMapMex. Results The clinical variants associated with prognosis were age (OR 0.01 IC 95% 1.02-1.07, p = 0.000), Grade IV (OR 17.11, IC 95% 1.89-132.13 p = 0.011), location of tumor (OR 1.17, IC 1.2-6.3, p = 0.016), total resection (OR = .186, IC 95% .098-.622, p = 0.003, Karnofsky (OR = .05, IC 95% 0.024-0.24, p = 0.003), motor deficiency (OR = 3.5, IC = 1.1-10.5, p = 0.025). In blood were found 11 genetic variants. rs4049, rs2148582, rs699, rs4762 and rs1926723 were associated with risk of tumor in the codominant model. rs5050 (- A20C) was statistically associated with the prognosis (OR 10.8, IC 1.16-100.51 p = 0.036). These variant it is part of a haplotype related to low expression of angiotensinogen. In biopsies of 2 patients missense mutations were found p.Arg477His in one patient and Gly226Ala -Pro165Ser in another one. Conclusion: In 8% of the tumors samples new somatic mutations were found. The genetic variant rs5050 of AGT is a prognosis biomarker in patients with astrocytoma. Citation Format: Talia Wegman-Ostrosky, Ernesto Soto-Reyes, Silvia Vidal-Millan, Sonia Mejia, Jose Sanchez-Corona, Luis A. Herrera. AGT mutations as a prognosis factor in patients with astrocytoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 594. doi:10.1158/1538-7445.AM2015-594