[Mutation and expression of PAX5 gene in adult acute lymphoblastic leukemia]

PAX5 is an important transcription factor of paired-box(PAX) family. The aim of this study was to investigate the mutations and expression of PAX5 and its clinical significance in adult patients with acute lymphoblastic leukemia (ALL). Reverse transcription polymerase chain reaction (RT-PCR) and genomic PCR were performed to detect the deletions of PAX5 and point mutations of PAX5 exon 2-10 in 101 cases of adult ALL and were confirmed by cloning and sequencing. In addition, quantitative PCR (qPCR) was performed to evaluate the expression of PAX5. Furthermore, the correlations of mutations and expression of PAX5 with clinical parameters were analyzed, and the prognostic significance was evaluated as well. The results showed that PAX5 mutations were observed in 8 of 101 (7.9%) patients with B-ALL. A total of 9 types of mutations were detected, including 4 types of deletions, 4 types of point mutations and 1 insertion mutation; percentage of patients with age ≥ 50 years was higher in PAX5 mutation group than in wide-type group (62.5% vs 21.5%,P = 0.031) . The statistical differences were observed in B-cell subtype, initial platelet count and immunophenotypes between high and low expression of PAX5 (P < 0.05) . In addition, patients with high expression of PAX5 had higher first complete remission rate (86.7% vs 62.5%, P = 0.030) and 6-month overall survival rate (75.0% vs 50.0%, P = 0.034) compared with patients with low expression of PAX5. It is concluded that deletion/insertion/point mutations and aberrant expression of PAX5 can be observed in adult patients with B-ALL. Mutations and aberrant expression of PAX5 correlated with clinical parameters and have important clinical significance.