Cheng Wen Li

[Acute myeloid leukemia with t(11;12)(p15;q13) translocation: two cases report and literature review].

OBJECTIVE To investigate the clinical and laboratory features of acute myeloid leukemia (AML) with t(11;12)(p15;q13) translocation. METHODS Two cases of AML with t(11;12)(p15;q13) translocation were reported and the related literatures were reviewed. RESULTS The diagnosis of AML-M3 was supported by morphological, cytochemical staining and electron microscope tests. A rare t(11;12)(p15;q13) translocation, but not classical t(15;17)(q22;q12) translocation and PML- RARα fusion gene, was detected in both cases. Both of the patients were refractory to differentiation induction therapy such as retinoic acid and arsenic trioxide. CONCLUSION AML is a group of heterogeneous disease derived from hematopoietic stem cell. Cytogenetic characteristic is important for diagnosis, prognosis stratification and therapy selection. Because of the heterogeneity of clinical and molecular features, it is unsuitable to classify AML with t(11;12)(p15;q13) as AML with recurrent cytogenetic aberration. This group of disease may benefit from allogeneic hematopoietic stem cell transplantation.

[Detection of heterogeneity and evolution of subclones in t(8;21) AML by QM-FISH].

OBJECTIVE To explore the heterogeneous subclones in acute myeloid leukemia (AML) with t(8;21) by quantitative multicolor- fluorescence in situ hybridization (QM-FISH), and to figure out whether there is putative ancestral relationship among different subclones. METHODS Bacterial artificial chromosomes (BAC) clones that contain the targeted genes including AML1, ETO, WT1, p27 and c-kit were searched in the data base UCSC Genome Bioinformatics. Multicolor FISH probes were prepared by linking fluorescein labeled dUTP or dCTP to targeted genes by nick translation. Bone marrow mononuclear cells from t (8;21) AML patients are dropped on to the wet surface of glass slides after hypotonic treatment and fixation. After hybridization, the fluorescence signals were captured by Zeiss fluorescence microscope. The copy number of AML1, ETO, WT1, p27, c- kit and the AML1-ETO fusion gene in AML1-ETO positive cells was counted. The cells with same signals were defined as a subclone. Various subclones were recorded and their proportions were calculated, and their evolutionary relationship was deduced. The subclones in matched primary and relapsed samples were compared, the evolution of dominant clones were figured out and the genomic abnormality that is associated with relapse and drug resistance were speculated. RESULTS In this study, 36 primary AML with t(8;21) cases and 1 relapsed case paired with the primary case were detected. In these 36 primary cases, 4 cases (11.1%) acquired additional AML1-ETO fusion signal, 3(8.3%) had additional AML1 signal, 4(11.1%) had additional ETO signal, 20(55.6%) had additional WT1 signal, 15(41.7%) had additional p27 signal and 14(38.9%) had additional c-kit signal. In addition, 10(27.8%) displayed AML1 signal deletion, and such an aberration represents statistic significance in male patients. It seems that male patients usually accompany AML1 signal deletion. Of 36 cases, 28(77.8 %) harbored at least 2 subclones (ranged from 2 to 10). According to the genetic signature of subclones, we can assemble a putative ancestral tree, and the genetic architecture is linear or branching. In particular, the clonal architecture of the relapsed sample exhibited significant clonal evolution compared to its paired sample at diagnosis, including proportion changes in dominant clone, subclone disappearance and appearance of new dominant clones. CONCLUSION Genomic abnormality is very diverse in t(8;21) AML. Subclones have linear or complex branching evolutionary histories, and clonal architecture is dynamic.

Characteristics of karyotypes and gene mutations for elder acute myeloid leukemia

OBJECTIVE To investigate the incidence of karyotypes and gene mutations for elder acute myeloid leukemia and to explore the relationship between each other. METHODS Clinical data and bone marrow samples of elder AML patients were collected. Karyotype and gene mutation (FLT3, NPM1, C-Kit, CEBPα, DNMT3A) test were performed, characteristics of karyotypes and gene mutations were analysed. RESULTS The incidence of better risk karyotype was 16.6%, in which the incidences of t(15;17), t(8;21) and inv (16)/t(16;16) were 3.90%, 10.73%, and 1.95% respectively; the incidence of intermediate risk karyotype was 72.2%, in which the incidence of normal karyotype was 57.86%; the incidence of poor risk karyotype was 11.20%, in which the incidence of of MLL/11q23, complex karyotype and monosomal karyotype were 1.95%, 6.34%, 5.85% respectively; the incidences of FLT3, NPM1, C-Kit, CEBPα, DNMT3A mutation were 12.57%, 22.06%, 2.16%, 14.71%, 15.71% respectively. Compared with patients older than 60 years, patients with age of 55-60 years were with less complex karyotype (1.09% vs 10.62%)(P=0.003) and monosomal karyotype (2.17% vs 8.85%)(P=0.032), and more t(8;21)(17.39% vs 5.31%)(P=0.008) and inv (16)/t(16;16)(4.35% vs 0.00%)(P=0.045). CONCLUSION For older AML patients, great difference in the distribution of karyotyes was found between the patients older than 60 years and patients with age of 55-60 years, while no such characteristics was found for gene mutations. Good elucidation of karyotypes and gene mutations are key for the treatment of older acute myeloid leukemia patients.

[Clinical and laboratory investigation of patients with hematologic malignancies harboring der(1;7)(q10;p10)].

OBJECTIVE To investigate the clinical and laboratory characteristics of patients with various hematological malignancies harboring der(1;7)(q10;p10). METHODS Bone marrow samples were collected and undergone short-time unstimulated culture and R-banding, and karyotyped by conventional cytogenetic assay (CCA). Megalokaryocytes were detected by streptavidin-AKP (SAP). Retrospective analyses including the clinical and laboratory data were performed. RESULTS Nineteen of the 21 patients were male. Most of the patients are of older age. Thirteen cases (61.9%) were der(1;7)(q10;p10) without additional aberrations, 8(38.1%) patients had additional aberrations. Sixteen out of the 18 cases (88.9%) who underwent SAP analysis had diminutive megalokaryocyte, and lymphoid megalokaryocyte was found in 10 cases (55.6%). The der(1;7) patients manifested poor response to treatment. CONCLUSION The der(1;7) patients demonstrated distinct male predominance, older age at diagnosis, and some clinically distinctive features. These patients showed poor prognosis. The cytogenetic abnormality, i.e., der(1;7)(q10;p10), can be used as a prognostic indicator.