Expression and clinical significance of IKZF1 gene IK6 isoform in adult acute lymphoblastic leukemia

Abstract This study was aimed to detect the expression of IKZF1 gene isoforms in bone marrow cells of patients with adult acute lymphoblastic leukemia and to investigate the clinical characteristics and prognosis of patients with IK6 isoform. The expression of IKZF1 gene isoforms were measured by nested RT-PCR in 79 newly diagnosed ALL patients. The clinical characteristics of IK6 positive patients and overall survival, disease-free survival of the IK6 positive group and IK6 negative group were compared. The results showed that IK1 and IK2/3 were the functional isoform while the IK4, IK6, IK8 and IK9 were the dominant negative isoform in adult ALL. The dominant negative isoform IK6 accounted for 34.4% in B-ALL patients and accounted for 22.2% in T-ALL patients. The BCR/ABL1 positive rate and the percentage of high risk patients in IK6 positive group was higher than that of IK6 negtive group in B-ALL patients (P = 0.027, P = 0.048). The expression of IK6 isoform did not correlate with sex, age and WBC count of B-ALL and T-ALL patients. The overall survival and disease-free survival of IK6 positive group were both lower than that of IK6 negtive group in Ph negative B-ALL patients (P = 0.009, P = 0.002). It is concluded that IK6 is a main isoform of the expression of IKZF1 gene in adult ALL patients, and can be used as a prognostic factor for guiding treatment in Ph negative B-ALL patients.