Phenotypic and genetic analysis of acute megakaryoblastic leukemia in young children with WT1, MLL-PTD and EVI1 genes / 中华医学遗传学杂志

OBJECTIVE@#To explore the phenotypic and genetic characteristics of acute megakaryoblastic leukemia (AMKL) in young children accompany by WT1, MLL-PTD and EVI1, in order to improve the diagnosis level of AMKL.@*METHODS@#EDTA-K@*RESULTS@#White blood cell count was 12.3× 10@*CONCLUSION@#Acute megakaryocytic leukemia has unique and complex phenotypic and genetics characteristics.

Clinical and genetic features of a patient with myeloid neoplasm in association with PDGFRA and EVI1 gene rearrangements / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Todelineate the clinical and genetic features of a patient with myeloproliferative neoplasm (MPN) in association with PDGFRA and EVI1 genes rearrangements.</p><p><b>METHODS</b>Clinical data of the patient was collected. Conventional cytogenetics, fluorescence in situ hybridization (FISH) and nested PCR were carried out for the patient.</p><p><b>RESULTS</b>The patient has featured recurrent rash, joint pain, and intermittent fever. Laboratory tests showed hyperleukocytosis and marked eosinophilia. Physical examination revealed splenomegaly. His karyotype was 46,XY,t(3;5)(q26;q15)[6]/46,XY[10]. FISH assay showed that both PDGFRA and EVI1 genes were rearranged. Molecular studies of the mRNA suggested that there was a in-frame fusion between exon 12 of the PDGFRA gene and exon 9 of the FIP1L1 gene. Imatinib was initiated at a dosage of 200 mg, and after 10 months, the signal of the FIP1L1-PDGFRA fusion gene was undetectable in bone marrow sample. However, the expression of EVI1 mRNA was stable, with no significant difference found between the patient and 10 healthy controls.</p><p><b>CONCLUSION</b>MPN in association with PDGFRA and EVI1 genes rearrangements have unique clinical and genetic features. Genetic testing is helpful for early diagnosis. Imatinib may be effective for the treatment.</p>

Clinical and biological characteristics of childhood acute myeloid leukemia with EVI1 gene positive expression / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the expression of ecotropic viral integration site (EVI1) gene in childhood acute myeloid leukemia (AML) and the clinical features of EVI1-positive children with AML.</p><p><b>METHODS</b>The clinical data of EVI1-positive children with AML were collected and analyzed. RT-PCR and real-time quantitative PCR were used for qualitative and quantitative analysis of expression of EVI1. Flow cytometry (FCM) was used for determining the immunophenotypes of bone marrow cells. Multiparameter FCM was used for monitoring minimal residual disease. The karyotypes were determined.</p><p><b>RESULTS</b>Of 241 children with AML, 33 (13.7%) were positive for EVI1 expression. There were no significant differences in age at first visit as well as the white blood cell count, hemoglobin level, and platelet count in peripheral blood between EVI1-positive and EVI1-negative children with AML (P>0.05), but EVI1-positive children had a significantly increased proportion of females compared with EVI1-negative children (P<0.05). The change in EVI1 expression was not synchronous with clinical remission and the change of MRD: some children had clinical remission or negative conversion of MRD before negative conversion of EVI1, while some had negative conversion of EVI1 before clinical remission or while MRD showed positive. EVI1 gene was usually co-expressed with other fusion genes. CD33 (100%), CD38 (88%), and HLADR (76%) were highly expressed in EVI1-positive children with AML. Abnormal chromosome structure or number was found in 15 patients. Compared with EVI1-negative children, EVI1-positive children had significantly lower complete remission rates after the first course of treatment (P<0.05).</p><p><b>CONCLUSIONS</b>EVI1-positive children with AML have a poor short-term prognosis. In the development of AML, the activation of EVI1 gene is not isolated, but the result of interactions with other genes or chromosome abnormalities, and the mechanism of activation and its function need further study.</p>

Clinical characteristics of childhood leukemia with EVI1 gene and BCR/ABL gene co-expression / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the clinical characteristics of ecotopic viral integration site-1 (EVI1) and BCR/ABL positive childhood leukemia.</p><p><b>METHODS</b>Clinical data of four children with EVI1 and BCR/ABL positive leukemia and eight children with BCR/ABL positive but EVI1 negative chronic myeloid leukemia (CML) were retrospectively analyzed.</p><p><b>RESULTS</b>In the four children with EVI1 and BCR/ABL positive leukemia, two were initially diagnosed with chronic phase of CML, one with accelerated phase of CML and one with high-risk acute lymphoblastic leukemia (ALL). There were no significant differences in clinical characteristics at diagnosis between the patients with EVI1 and BCR/ABL positive leukemia and BCR/ABL positive but EVI1 negative leukemia. CD33 and CD38 were highly expressed and t(9;22) abnormality was present in all patients with EVI1 and BCR/ABL positive leukemia. Two of the 3 children with EVI1 and BCR/ABL positive CML achieved complete remission one or three months after treatment. Acquired negative status conversion occurred for EVI1 but not BCR/ABL in one CML case. The 3 children with EVI1 and BCR/ABL positive CML survived 20, 13 and 14 months, respectively, without recurrence. The child with EVI1 and BCR/ABL positive ALL failed to achieve complete remission after the first course of treatment and discontinued further treatment.</p><p><b>CONCLUSIONS</b>Co-expression of EVI1 and BCR/ABL fusion gene can be found in childhood CML and ALL. The relatively rare leukemia has not significant difference respect to clinical characteristics. Prognosis of the disease needs to be determined by clinical studies with a larger sample size.</p>

Inhibition of evi1 expression by siRNA in HEL cell line / 中国实验血液学杂志

The aim of study was to investigate the inhibitory effect of small interfering RNA on evi1 gene expression and biological characteristics in HEL cells and its mechanism. 3 siRNA (siRNA-1, siRNA-2, siRNA-3) specific for evi1 gene were synthesized and transfected into HEL cells in vitro. Experiments were divided into test and control groups. MTT method was used to assay the inhibitory effect of siRNA on cell proliferation; semiquantitative RT-PCR was used to detect the expression of evi1 gene mRNA; the cell viability was determined by trypan blue dye test; the change of cell cycle and apoptosis of cells were analyzed by flow cytometry. The results showed that siRNA-1 had strongest effect, and inhibitory effect was most obvious at 48 hours after transfection. When the concentration of siRNA raised to 120 nmol/L, the inhibitory rate reached to the peak. The inhibitory rate of siRNA-1 on proliferation of HEL cells, relative expression level of evi1 mRNA and cell viability at 48 hours after transfection were 72.22 ± 2.80%, 27.31 ± 1.11% and 26.05 ± 2.49%, which had significant difference from other groups (p < 0.001). The siRNA resulted in arrest of cell cycle at G(0)/G(1) phase, the cell amount at S phase obviously decreased, the apoptotic rate of HEL cells obviously increased (p < 0.01). It is concluded that the siRNA specific for evi1 gene can suppress the proliferation of HEL cells, reduce the expression of evi1 mRNA, decrease the cell viability, arrest the cell cycle at G(0)/G(1) phase, suppress cell mitosis, and promote cell apoptosis.

Study of genes involved in chronic myeloid leukemia with t (3; 21) (q26; q22) in blastic crisis / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore genes involved in chronic myeloid leukemia (CML) with t (3; 21) (q26; q22) chromosome translocation in blastic crisis.</p><p><b>METHODS</b>A case of CML patient with t (3; 21) (q26; q22) in blastic crisis was reported. AML1 and bcr/abl genes were detected by FISH in interphase and metaphase cells. Genes involved in t (3; 21) (q26; q22) were analysed by RT-PCR and sequencing.</p><p><b>RESULTS</b>AML1 gene hybridization signal was detected in der (3) and der (21) chromosomes. AML1-Evi1, AML1-MDS1-Evi1, AML1-EAP fusion transcripts and Evi1 gene were detected in mRNA level, but no AML1-Evi1 fusion transcript. The mRNA expression level of AML1-MDS1-Evi1 fusion gene was 1.58 and 1.54 times higher than that of AML1-MDS1 and AML1-EAP, respectively. The mRNA expression level of Evi1 gene of the patient was 2.71 times higher than that of HEL cell line.</p><p><b>CONCLUSION</b>t (3; 21) (q26; q22) resulted in the AML1-MDS1-Evi1, AML1-MDS1, AML1-EAP fusion transcripts, and Evi1 gene was also activated by the translocation. These secondary aberrations should be the molecular basis of CML patient with t (3; 21) (q26; q22) in blastic crisis.</p>