This study was aimed to detect the expression of AML1 fusion genes in the patients with adult acute myeloid leukemia (AML) and further to investigate their association with the progression and prognosis of AML. Bone marrow samples were collected from 168 patients with de novo adult AML, and the expression of AML1 ETO, AML1-EVI1, AML1-MDS1, AML1-MTG16, AML1-PRDM16, AML1-LRP16, AML1-CLCA2 and AML1-PRDX4 was analyzed by a novel multiplex nested RT-PCR. Positive samples and minimal residual disease were further examined by real-time fluorescent quantitative PCR. The results showed that the AML1 fusion genes were found in 10.7% (18/168) patients. Among them, AML1-ETO in 12 (7.1%) cases were detected, AML1-EVI1 in 2 cases (1.2%), and AML1-MDS1, AML1-MTG16, AML1-PRDM16, and AML1-CLCA2 in 1 case (0.6%) each were detected. Among the patients with AML1-ETO, 10 patients (10/12, 83.33%) achieved complete remission (CR) after one cycle of chemotherapy, while 2 patients achieved CR after 2 cycles of chemotherapy. The 2 patients with AML1-EVI1 failed to achieve CR after one cycle of chemotherapy. Patients with AML1-MDS1, AML1-MTG16, AML1-PRDM16, or AML1-CACL2 did not achieve CR after one cycle of chemotherapy. It is concluded that AML1 fusion genes are more frequent and can provide the molecular markers for diagnostics and prognosis evaluation of AML and for monitoring MRD.

This study aimed to develop a novel multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) assay to accurately and effectively detect 10 common gene rearrangements in adult acute lymphoblastic leukemia (ALL) and to examine the clinicopathologic characteristics and other genetic aberrations of patients with ALL expressing different fusion genes. Our RT-nPCR assay had a positive detection rate of 35.15% (90/256) for the 10 fusion genes. BCR-ABL1, FUS-ERG, MLL-AF4, ETV6-RUNX1, E2A-PBX1, dupMLL, MLL-AF10, MLL-ENL, SET-NUP214 and SIL-TAL1 were detected in 36 (14.06%), 14 (5.47%), 14 (5.47%), four (1.56%), four (1.56%), five (1.95%), four (1.56%), two (0.78%), two (0.78%) and five patients (1.95%), respectively. The RT-nPCR results were further confirmed by split-out PCR, and cytogenetic and fluorescence in situ hybridization (FISH) analysis revealed corresponding translocations and fusions in 63 and 74 cases, respectively. JAK2 and IKZF1 mutations were commonly detected in patients with BCR-ABL1 ALL, and HOX overexpression was highly correlated with MLL fusions and SET-NUP214. This study demonstrates that RT-nPCR is an effective method for identifying 10 gene rearrangements in adult ALL, and it could potentially be developed for diagnostic use and prognostic studies of ALL.