OBJECTIVE: To investigate the cytotoxic effect and its mechanism of the micromolecule compound on the leukemia cells. METHODS: The cytotoxic effects of 28 Nilotinib derivatives on K562, KA, KG, HA and 32D cell lines were detected by MTT assays, and the compound Nilo 22 was screen out. Cell apoptosis and cell cycle on leukemia cells were detected by flow cytometry. The effect of compound screened out on leukemogenesis potential of MLL-AF9 leukemia mice GFP RESULTS: Nilo 22 serves as the most outstanding candidate out of 28 Nilotinib derivatives, which impairs leukemia cell lines, but spares normal hematopoietic cell line. Comparing with Nilotinib, Nilo 22 could induce the apoptosis of GFP CONCLUSION Nilo 22 shows a significant cytotoxic effect on mice and human leukemia cells, especially for drug resistance cells. Nilo 22 is a promising anti-leukemia agent to solve the common clinical problems of drug resistance and relapse of leukemia.
Animals ; Apoptosis/drug effects* ; Cell Cycle/drug effects* ; Cell Line, Tumor ; Humans ; Leukemia ; Mice ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Telomerase/metabolism* ; Telomere/metabolism*

MLL1 is a histone H3Lys4 methyltransferase and forms a complex with WDR5 and other components. It plays important roles in developmental events, transcriptional regulation, and leukemogenesis. MLL1-fusion proteins resulting from chromosomal translocations are molecular hallmarks of a special type of leukemia, which occurs in over 70% infant leukemia patients and often accompanies poor prognosis. Investigations in the past years on leukemogenesis and the MLL1-WDR5 histone H3Lys4 methyltransferase complex demonstrate that epigenetic regulation is one of the key steps in development and human diseases.
Animals ; DNA Methylation ; Epigenesis, Genetic ; Histone-Lysine N-Methyltransferase ; genetics ; metabolism ; Histones ; metabolism ; Humans ; Leukemia ; genetics ; metabolism ; Lysine ; metabolism ; Multiprotein Complexes ; genetics ; metabolism ; Myeloid-Lymphoid Leukemia Protein ; genetics ; metabolism ; Transcriptional Activation

In multiple types of acute leukemia,a portion of the MLL protein is fused to a variety of other unrelated proteins. The activity of leukemic MLL fusions is believed to be directly contributing to the conversion of normal bone marrow cells into leukemic cancer cells. However, the mechanism of this process has not been fully elucidated. We have recently found that the MLL leukemic fusions can abolish the activity of P53 tumor suppressor protein that actively guards against the appearance of cancer by instructing damaged cells to self-destruct. In contrast to the vast majority of cancers where p53 gene is mutated, very few p53 mutations have been found in leukemias. Our findings suggest that leukemic fusions contribute to disease progression, at least in part, by suppressing the function of P53, which,if proven,may present a novel opportunity to re-activating the P53 pathway in leukemic cells thereby identifying a rational therapeutic approach for managing leukemias where MLL fusions are detected.
Chromosomes, Human, Pair 11 ; genetics ; Histone-Lysine N-Methyltransferase ; Humans ; Leukemia ; etiology ; genetics ; Myeloid-Lymphoid Leukemia Protein ; genetics ; metabolism ; physiology ; Oncogene Proteins, Fusion ; metabolism ; physiology ; Tumor Suppressor Protein p53 ; genetics ; physiology

This study was aimed to investigate the effect of small interfering RNA (siRNA) on the expression of mll-af9 oncogene and the proliferation of human acute monocytic leukemia cell line THP-1. One group of siRNA was designed targeting mll-af9 mRNA and finally obtained by chemosynthesis. Then the obtained siRNA was transfected into cultured human acute monocytic leukemia cell line THP-1 by lipofectamine. Flow cytometry was used to detect siRNA transfection efficiency. The level of mll-af9 mRNA expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR). The cell proliferation rate was assayed by MTT. The change of cell cycles and apoptosis rate was detected by flow cytometry. The results showed that the siRNA transfection efficiency was 69.1%+/-1.8%. The level of mll-af9 mRNA expression was significantly inhibited in siRNA-transfected cells as compared with the controls. mll-af9-targeted siRNA inhibited the proliferation of THP-1 cells and induced cell apoptosis effectively after transfection. The percentage of G0/G1 phase cells significantly increased in siRNA-transfected cells in comparion with the control cells, but the percentage of S phase cells significantly decreased. It is concluded that the mll-af9-targeted siRNA can effectively inhibit the proliferation of human acute monocytic leukemia cell line THP-1.
Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Humans ; Leukemia, Monocytic, Acute ; genetics ; pathology ; Myeloid-Lymphoid Leukemia Protein ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

No abstract available.
Aged ; B-Lymphocytes/*cytology/metabolism ; Child ; *Chromosomes, Human, Pair 11 ; *Chromosomes, Human, Pair 9 ; Female ; Humans ; Immunophenotyping ; Infant ; Karyotyping ; Male ; Myeloid-Lymphoid Leukemia Protein/genetics/metabolism ; Oncogene Proteins, Fusion/genetics/metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/*diagnosis ; Translocation, Genetic

OBJECTIVETo explore the effect of MLL-AF9 fusion gene silence on p27 expression and transcription regulation in THP-1 cells.

METHODSSmall interference RNA (siRNA) fragments targeting THP-1 cells specific MLL-AF9 fusion gene were designed and constructed, and transfected into THP-1 by lipofectamine. Flow cytometry was used to detect siRNA transfection efficiency. The level of MLL-AF9 mRNA expression was examined by RT-PCR and the expression of MLL-AF9 and p27 protein was detected by Western blot. Chromatin immunoprecipitation (ChIP) assay was used to confirm whether MLL-AF9 binds to the p27 promoter in THP-1 cell.

RESULTSSiRNA transfection efficiency was (69.1 +/- 1.8)%. The level of p27 expression was up-regulated at both mRNA [(0.84 +/- 0.12) vs (0.35 +/- 0.03) of control group] and protein levels after MLL-AF9 expression was significantly inhibited in siRNA-transfected cells (0.31 +/- 0.07) compared with that in the controls (1.25 +/- 0.13) (P<0.01). MLL-AF9 fusion protein bond to DNA fragment of p27 gene promoter region in THP-1 cell.

CONCLUSIONMLL-AF9 fusion gene silence up-regulates p27 gene expression, and the mechanism maybe the recovery of p27 gene expression due to MLL-AF9 fusion protein binding to p27 promoter.

Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p27 ; genetics ; metabolism ; Gene Fusion ; Humans ; Leukemia, Monocytic, Acute ; genetics ; pathology ; Myeloid-Lymphoid Leukemia Protein ; genetics ; Oncogene Proteins, Fusion ; genetics ; RNA Interference ; Transfection

No abstract available.
Adult ; Antigens, CD4/*metabolism ; Antigens, CD56/*metabolism ; Bone Marrow/metabolism/pathology ; Dendritic Cells/cytology/*metabolism ; Diagnostic Errors ; Exons ; Female ; Flow Cytometry ; Gene Rearrangement ; Hematologic Neoplasms/diagnosis ; Histone-Lysine N-Methyltransferase/genetics ; Humans ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; Leukemia, Myeloid, Acute/*diagnosis ; Male ; Middle Aged ; Myeloid-Lymphoid Leukemia Protein/genetics ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; Transcription Factors/genetics ; Translocation, Genetic

No abstract available.
Base Sequence ; Cell Cycle Proteins/*genetics ; Chromosomes, Human, Pair 11 ; Chromosomes, Human, Pair 22 ; Female ; Gene Rearrangement ; Histone-Lysine N-Methyltransferase/*genetics ; Humans ; Immunophenotyping ; In Situ Hybridization, Fluorescence ; Karyotype ; Leukemia, Myeloid, Acute/*diagnosis/metabolism ; Male ; Myeloid-Lymphoid Leukemia Protein/*genetics ; Oncogene Proteins, Fusion/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Septins/*genetics ; Sequence Analysis, DNA ; Translocation, Genetic ; Young Adult

OBJECTIVETo detect the expression of the fusion genes resulting from chromosome abnormalities in childhood acute lymphoblastic leukemia(ALL) and its conformity to WHO classification.

METHODSSixty-two children with ALL were investigated. The expression of fusion genes was determined by multiplex reverse transcription-polymerase chain reaction (RT-PCR), karyotyping (R band) and immunophenotyping (by flow cytometry) were also performed.

RESULTSOf the 62 patients, 23(37.1%) were found to carry 13 different fusion genes. The patients with immunophenotype of Pre-B-ALL were found to carry: TEL/AML1(3 cases); E2A/PBX1, E2A/HLF, TLS/ERG, MLL/AF4, MLL/AF9, MLL/AF10, MLL/AFX-MLL/AF6-MLL/ELL, MLL/AF6-MLL/ELL, dupMLL (one case for each); and HOX11 (6 cases). The patients with immunophenotype of Pre-T-ALL were found to carry: TAL1D (4 cases, one is also found to have HOX11 expression); and HOX11 (2 cases). The multiplex RT-PCR in combination with chromosome analysis revealed genetic abnormalities in 69.4%(43/62) of childhood ALL.

CONCLUSIONMultiplex RT-PCR combined with chromosome analysis and immunophenotyping can provide reliable and helpful information for the diagnosis, therapy evaluation and prognosis prediction in childhood ALL, which may also serve as a basis on which to implement the criteria of WHO classification.

Adolescent ; Child ; Child, Preschool ; Chromosome Aberrations ; Core Binding Factor Alpha 2 Subunit ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Flow Cytometry ; Homeodomain Proteins ; genetics ; metabolism ; Humans ; Immunophenotyping ; Infant ; Karyotyping ; Myeloid-Lymphoid Leukemia Protein ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; RNA-Binding Protein FUS ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transcription Factors ; genetics ; metabolism

The chromosome band 11q23 is a common target region of chromosomal translocation in different types of leukemia, including infantile leukemia and therapy-related leukemia. The target gene at 11q23, MLL, is disrupted by the translocation and becomes fused to various translocation partners. We report a case of AML with a rare 3-way translocation involving chromosomes 1, 9, and 11: t(1;9;11)(p34.2;p22;q23). A 3-yr-old Korean girl presented with a 5-day history of fever. A diagnosis of AML was made on the basis of the morphological evaluation and immunophenotyping of bone marrow specimens. Flow cytometric immunophenotyping showed blasts positive for myeloid lineage markers and aberrant CD19 expression. Karyotypic analysis showed 46,XX,t(1;9;11)(p34.2;p22;q23) in 19 of the 20 cells analyzed. This abnormality was involved in MLL/MLLT3 rearrangement, which was confirmed by qualitative multiplex reverse transcription-PCR and interphase FISH. She achieved morphological and cytogenetic remission after 1 month of chemotherapy and remained event-free for 6 months. Four cases of t(1;9;11)(v;p22;q23) have been reported previously in a series that included cases with other 11q23 abnormalities, making it difficult to determine the distinctive clinical features associated with this abnormality. To our knowledge, this is the first description of t(1;9;11) with clinical and laboratory data, including the data for the involved genes, MLL/MLLT3.
Antigens, CD19/metabolism ; Bone Marrow Cells/pathology ; Child, Preschool ; Chromosomes, Human, Pair 1 ; Chromosomes, Human, Pair 11 ; Chromosomes, Human, Pair 9 ; Female ; Humans ; Immunophenotyping ; In Situ Hybridization, Fluorescence ; Karyotyping ; Leukemia, Myeloid, Acute/*diagnosis/genetics/immunology ; Myeloid-Lymphoid Leukemia Protein/*genetics ; Nuclear Proteins/*genetics ; *Translocation, Genetic