P72R TP53 VARIANT AS A POTENTIAL MARKER FOR ACUTE MYELOID LEUKEMIA FROM AMAZONAS STATE, BRAZIL

Abstract

Background: Acute Myeloid Leukemia (AML) a cancer of the white blood cells, characterized by infiltration of leukemic blasts in the bone marrow (BM), affects the proliferation and maturation of the cells in the BM. Genetic variants are related in the AML, as in the gene encodes a tumor suppressor protein TP53, associated with adverse prognostic of the disease, related with lower survival of the AML patients. Objective: We evaluated the presence of genetic variants in the TP53 exome in patients with AML, also investigated possible association of the TP53 variants with clinical and laboratory data. Methods: Study population was composed of 10 AML patients, the nucleotide sequencing was performed in BM samples, the presence of variants was investigated in the TP53 2 – 11 exons. Results: Among the patients, three (30%) are male and seven (70%) females, being six patients with primary AML, one secondary AML and three patients with relapsed. Variants different were observed in the TP53 exome, as more prevalent those located in the 4 exon, as P72R. Variants missense identified: L32K (exon 3), M44K, P72R, W91G and A119D (exon 4), E271D and P278L (exon 8), K357M (exon 10) and no sense variant c.1069 A>T* (exon 10). According to number of variants identified in each patient, we define as Group 1 that with 1-2 variants, >2 variants as Group 2. The white blood cell count was higher in the group 2 when compared to group 1 [10.680 (1.1215 - 86.030) vs 9.770 (4.760 - 149.900)]. As well as the red blood cell count was high in the group 2 [3.21 (2.89 - 3.59) vs 2.95 (2.57 - 3.09)], also to platelet count [44.000 (16.000 - 71.000) vs 35.000 (16.000 - 44.000)]. Discussion: Previous studies have shown low frequency of variants in the TP53 gene, approximately 5-10% of the AML cases and 30% related in the AML-t, the variants are prevalent in the 4 to exon, however, we identified variants in all patients. The P72R variant was common between patients, most variants occur mainly in the exon 4. Conclusion: Variants in the TP53 are frequently observed in AML patients, the number of variants may be associated with change hematological. We highlight the P72R variant as possible marker for disease, however, further studies are needed to evaluate the effect of this variants with outcome of the disease.