Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the role of the BCL-2 gene in Japanese patients with B-cell non-Hodgkin's lymphoma, karyotypic analysis, DNA analysis and clinical characterization were studied. Ten of 73 patients showed t(14;18) and two patients had variant translocations [t(2;18) and t(18;22), respectively]. Of 42 patients examined at the molecular level, eight patients showed the BCL-2 gene rearrangement detected by mbr probe and two patients by 5'BCL-2 probe. Of the eight patients with the BCL-2 gene rearrangement by the mbr probe, t(14;18) was detected in six patients. A discrepancy in the relationship between the occurrence of t(14;18) and BCL-2 gene rearrangement was recognized. Two patients with obvious t(14;18) showed no rearrangement of the BCL-2 gene by mbr, mcr, nor 5' probe. Cytogenetic analysis is an indispensable tool for investigating lymphomogenesis. The two patients with the variant translocations, t(2;18) and t(18;22), showed breakpoints at the 5' site of the BCL-2 gene and both were histologically of the small lymphocytic type. No examples with the co-existence of both the BCL-2 and c-MYC gene rearrangements were found. The median survival time of the patients with the BCL-2 rearrangement and/or t(14;18) was longer than the patients without the BCL-2 gene rearrangement and translocation and also patients with the c-MYC gene rearrangement and/or translocation. Racial and geographical heterogeneities, variant translocations of t(14;18) and the clinical characteristics of B-cell non-Hodgkin's lymphoma with t(14;18) are discussed.
Leukemia 1991 Dec
PMID:Cytogenetic, molecular biological and clinical study of B-cell lymphomas with 14;18 translocation in Japanese patients. 177 56

Geldanamycin is an antibiotic that preferentially inhibits G1/S transition and causes G2/M arrest in human leukemia HL-60 cells. With it, we selectively inhibited recombinant Src tyrosine kinase without significantly inhibiting protein kinase A. The perturbation of cell cycling by geldanamycin was accompanied by marked suppression of c-MYC expression. In contrast to this, pRB expression was remarkably enhanced by geldanamycin. In the untreated HL-60 cells, c-MYC was apparently enriched in nuclear matrix preparation, and significant amounts of hyperphosphorylated pRB, p70 and p40 proteins were observed to associated with the nuclear matrix. The amounts of these proteins associated with the nuclear matrix, however, were markedly decreased by treatment with geldanamycin. This finding suggests that the association of c-MYC, hyperphosphorylated pRB, p70 and p40 proteins with the nuclear matrix is essential in cell cycling, especially in G1/S and G2/M progressions, and that this association is a part of signal transduction pathway in Src kinase activation.
 ...
PMID:Inhibition of the association with nuclear matrix of pRB, p70 and p40 proteins along with the specific suppression of c-MYC expression by geldanamycin, an inhibitor of Src tyrosine kinase. 759 47

The clinical heterogeneity of acute lymphoblastic leukemia (ALL) of B cell lineage reflects the presence of distinct molecular pathways leading to well-defined ALL molecular subtypes. These molecular pathways include the formation of the fusion transcripts BCR/ABL and E2A/PBX1, due to t(9;22) and t(1;19), respectively, as well as rearrangements of the MLL gene at 11q23 and of c-MYC at 8q24. Hyperdiploid ALL in the absence of chromosomal structural abnormalities is an additional ALL molecular subtype. Mutations of the RAS family genes and of the p53 tumor suppressor gene represent additional genetic lesions detected in a fraction (10-20%) of ALL cases. RAS activation in ALL may be detected in all molecular subtypes of ALL and denotes poor prognosis. Conversely, little is known regarding the clinical and biological features of ALL cases carrying p53 mutations. In order to help clarify the role of p53 inactivation in ALL development, we have determined the frequency of p53 mutations throughout the molecular spectrum of B cell lineage ALL. We report that p53 inactivation in ALL of B cell lineage is restricted to cases carrying a rearrangement of MLL or c-MYC, whereas it is consistently negative in other molecular subgroups. These data underline the molecular heterogeneity of ALL of B cell lineage and indicate that at least some of the molecular pathways involved in ALL pathogenesis require more than one genetic lesion.
Leukemia 1995 Jun
PMID:p53 gene inactivation in acute lymphoblastic leukemia of B cell lineage associates with chromosomal breakpoints at 11q23 and 8q24. 759 84

The 21 kDa proteins encoded by RAS genes are thought to be involved in intracellular signal transduction. Expression of RAS genes activated by point mutations after transfection into mammalian cells can modulate the response of these cells to exogenously added growth factors and their expression patterns of growth factors. We analyzed leukemic cells from 50 patients with acute myeloid leukemia (AML) for the presence of activating point mutations of the N-RAS gene using polymerase chain reaction (PCR) and differential oligonucleotide hybridization. This assay allows semiquantitative determination of the relative abundance of cells carrying N-RAS mutations. Clonal activation of N-RAS, noted in the large majority of leukemic cells of the six of these patients, was correlated significantly (p = 0.0003) with the ability of these cells to express interleukin 6 (IL-6), previously shown to be expressed at high levels in approximately 30% of primary AML cells. In 16 patients, the presence of N-RAS mutations was observed only in subpopulations of leukemic cells. The 'subclonal' involvement of some but not all leukemic cells was further demonstrated by PCR analysis of individual clones grown in soft agar culture. We investigated whether additional, complementary changes in oncogene structure occurred in cells exhibiting clonal activation of N-RAS. For instance, concomitant activation of N-RAS and amplification or rearrangement of c-MYC have been observed in various tumor tissues. Southern blot analysis did not, however, reveal gross alternations of MYC gene structure or copy number in these cells.
Leukemia 1993 Dec
PMID:N-RAS gene activation in acute myeloid leukemia: association with expression of interleukin-6. 825 93

Two patients with acute myelocytic leukemia (AML) showing double minute (dmin) chromosomes were analysed to identify oncogene activation. Cytogenetic analysis showed 1-53 dmin chromosomes with the normal karyotype in the first patient and 1-84 dmin chromosomes with complex chromosome aberrations. Analysis of DNA from two patients revealed five- to tenfold amplification of c-MYC oncogene in the leukemic cells. The other sixteen oncogenes studied showed no increase in the gene content. Furthermore, a transforming gene, N-RAS was detected in the first patient by nude mouse tumorigenicity assay (in vivo selection assay). These results suggest that the amplification of c-MYC gene is common in dmin-positive AML patients and co-ordination of c-MYC and N-RAS oncogene might also play a significant role in the pathogenesis of some AML patients.
Leukemia 1993 Mar
PMID:Amplification of c-MYC oncogene and point mutation of N-RAS oncogene point mutation in acute myelocytic leukemias with double minute chromosomes. 844 53

The genes for acetylcholinesterase (ACHE) and butyrylcholinesterase (BCHE) are located within regions subject to non-random chromosomal abnormalities in the myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). Acetylcholinesterase is mapped to 7q22, within the critical deleted region presumed to contain a myeloid specific tumour suppressor gene. Butyrylcholinesterase is mapped to 3q26: abnormalities at this region are associated with sub-types of MDS and AML with thrombocytopenia, or with increased platelet counts. Both ACHE and BCHE have been implicated as playing a role in megakaryopoiesis and thrombopoiesis, and these genes have been observed to be co-amplified in acute myeloid leukaemia. Recent findings suggest a more significant role for the ACHE gene in haemopoiesis by regulating multipotent stem cell proliferation, and apoptosis in cells undergoing erythroid and myeloid differentiation. This led us to investigate gene copy-number alterations at these genes in MDS and AML. Samples were screened by slot-blot hybridization, and if changes were observed, by Southern blotting. A total of 42 samples from 31 de novo AML patients, 10 samples from eight cases of post-MDS AML and 85 samples from 67 MDS patients were analysed with probes for ACHE, BCHE, c-MYC, MDR-1 and globin control. Changes in ACHE and/or BCHE were observed in 9/31 de novo AML patients, and in 7/67 MDS patients: 1/37 cases of refractory anaemia (RA), 1/10 cases of refractory anaemia with excess blasts (RAEB) and 5/20 chronic myelomonocytic leukaemia (CMML) patients. The amplification events observed generated copy numbers no greater than 10, showed normal restriction patterns and had no clear correlation with megakaryopoiesis or thrombopoiesis. Loss of signal at the ACHE locus was observed: haploid signal intensity was seen in seven samples: one RA with thrombocytopenia, three CMML, one AML-M5a (no karyotypic abnormalities of chromosome 7), one AML-M4 (monosomy 7), and one case of AML-M7 (karyotype unknown). Homozygous deletion was observed at relapse of an additional patient with AML-M4. These data reinforce the possibility that ACHE may play a role as a myeloid tumour suppressor gene.
 ...
PMID:Deletion of the acetylcholinesterase locus at 7q22 associated with myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). 863 18

AIDS-related non-Hodgkin lymphomas (AIDS-NHL) are most frequently derived from B cells and include small non-cleaved cell lymphoma (SNCCL) and diffuse large cell lymphoma (DLCL) and less frequently anaplastic large cell lymphoma (ALCL) or body cavity-based lymphoma (BCBL). AIDS-NHL cell lines have proved useful to study AIDS-NHL pathogenesis. In this report, we describe the establishment and molecular characterization of two novel AIDS-NHL cell lines (HBL-4 and HBL-6) derived from lymphomatous effusions. HBL-4 was derived from a patient with SNCCL, whereas HBL-6 was derived from a patient with BCBL. The identity of the cell lines with the original tumor clone was established by immunoglobulin gene rearrangement analysis. Both HBL-4 and HBL-6 carry a monoclonal EBV infection and do not contain HIV. In addition, HBL-6 harbors DNA sequences of the recently identified Kaposi's sarcoma-associated herpesvirus (KSHV), now formally called human herpesvirus 8 (HHV8). Finally, HBL-4, but not HBL-6, harbors a rearranged c-MYC allele, while the BCL-6 gene displayed a germline configurations in both cell lines. These AIDS-NHL cell lines may prove useful in understanding the biologic events contributing to AIDS-NHL development.
Leukemia 1996 Jul
PMID:Establishment of AIDS-related lymphoma cell lines from lymphomatous effusions. 868 8

Junctional sequences created by chromosomal translocations in mature B-cell neoplasms, which involve immunoglobulin gene loci (IG) and putative proto-oncogenes on reciprocal partner chromosomes, are unique to neoplastic cells characterized by particular histological and immunological phenotypes. To establish a rapid and sensitive method to detect neoplastic cells carrying a specific chromosomal translocation, we have developed a novel strategy based on long-distance polymerase chain reaction (LD-PCR) amplification. Genomic DNA was extracted from tumor cells carrying t(14;19)(q32;q13), t(8;14)(q24;q32), t(3;22)(q27;q11), t(2;3)(p12;q27), or t(3;14)(q27;q32). Thirty-two to 35-mer oligonucleotide primer pairs were designed to be complementary to exons or flanking sequences of the BCL3, c-MYC and BCL6 oncogenes, and to IG constant region genes. LD-PCR with a newly available Taq polymerase for longer product synthesis successfully amplified fragments representing BCL3/C alpha junctional sequences for t(14;19); c-MYC/C mu, c-MYC/C gamma, and c-MYC/C alpha for t(8;14); BCL6/C lambda for t(3;22); BCL6/C kappa for t(2;3); 5'-BCL6/C mu, and 5'-BCL6/C gamma for t(3;14). In Burkitt's lymphoma/leukemia, all materials in which c-MYC rearrangements were detectable by conventional Southern blot hybridization showed positive LD-PCR amplification. The sizes of the amplified fragments varied from 1.8 kb to 12 kb, and these were specific to each material. Serial dilution of tumor cells or DNA in negative materials demonstrated a single band on agarose gel electrophoresis stained with ethidium bromide at a level of sensitivity of 10(-3), and hybridization with radioactive probe improved the level by one order of magnitude (1 cell in 10(4)), indicating that this LD-PCR approach is a sensitive technique capable of detecting minimal residual disease. Thus, the present study provided a useful tool for diagnosis and subsequent management of B-cell neoplasms characterized by specific chromosomal translocations.
 ...
PMID:Application of long-distance polymerase chain reaction to detection of junctional sequences created by chromosomal translocation in mature B-cell neoplasms. 870 58

T cell lines (Coculture-14, Coculture-5) derived from human T-cell leukemia virus type I (HTLV-I)-seronegative persons acquired interleukin-2 (IL-2)-dependent continuous growth capacity (immortalized) following in vitro HTLV-I infection. They showed structural abnormalities of chromosomes carrying proviral DNA as seen by in situ hybridization. Following ultraviolet (UV) irradiation, Coculture-5 cells achieved IL-2-independent autonomous growth (transformed) resulting in the establishment of UV-1 and UV-5 lines. They showed additional abnormalities of the same chromosomes. Cocultivation of Coculture-5 cells with IUdR-treated UV-1 cells also resulted in autonomous growth of Coculture-5 cells, giving rise to three cell lines. By ABC immunostaining with specific antibodies, expression of proteins coded for growth regulatory genes, including Ki-67, Topo II, Pol alpha, c-MYC, p53, Rb, bcl-3, bcl-2, and BM-1, was found to be variably altered in transformed cells compared with immortalized cells. These results demonstrated chromosomal instability, altered gene product expression of HTLV-I-infected human lymphocytes, and their susceptibility to transformation without exposure to an initiating carcinogen.
 ...
PMID:Genetic instability as a basis for transformation of human lymphocytes infected with human retrovirus. 870 44

To establish a rapid and sensitive method to detect neoplastic cells carrying a specific chromosomal translocation in B-cell lymphoma/leukemia, we have developed a novel strategy based on long distance polymerase chain reaction (LD-PCR) amplification. Genomic DNA were extracted from tumor cells carrying a t(14;19)(q32;q13), a t(8;14)(q24;q32), a t(3;22)(q27;q11), a t(2;3)(p12;q27), and a t(3;14)(q27;q32). Oligonucleotide primer pairs were designed to be complementary to exons or flanking sequences of the BCL3, c-MYC and BCL6 oncogenes, and to constant region genes of the IG genes. LD-PCR with a newly available Taq polymerase for longer product synthesis successfully amplified fragments representing BCL3/C alpha junctional sequences for t(14;19); c-MYC/C mu, c-MYC/C gamma and c-MYC/C alpha for t(8;14); BCL6/C lambda for t(3;22); BCL6/C kappa for t(2;3); 5'-BCL6/C mu and 5'-BCL6/C gamma for t(3;14), respectively. The sizes of the amplified fragments were varied from 1.8 kb to 12 kb, which were specific to each material. Present study provides a useful tool for diagnosis and subsequent management of B-cell lymphoma/leukemia characterized with specific chromosomal translocation.
Leukemia 1997 Apr
PMID:Long distance polymerase chain reaction for detection of chromosome translocations in B-cell lymphoma/leukemia. 920 76


1 2 3 4 5 6 7 8 9 10 Next >>