Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The number of reported cases of leukemia developing in growth hormone (GH) users worldwide has reached 31. Twelve Japanese cases are briefly reviewed; five each of AML and ALL, and one each of CML and malignant histiocytosis. The underlying diseases of these patients consisted of 8 idiopathic disease, 3 tumors and one Fanconi's anemia. Leukemia occurred during GH treatment in 9 cases and after cessation of GH in 3. The longest interval from the cessation of GH therapy was 10 years. GH administration from a younger age tended to be linked to myeloid type. Risk factors and possible mechanisms of leukemogenesis by growth hormone are discussed, and proposals for the future have been made by the Foundation for Growth Science in Japan.
 ...
PMID:Leukemia and other malignancies among GH users. 837 97

The Philadelphia chromosome consists of a reciprocal translocation between the ABL oncogene at chromosome 9q34 and the BCR gene at chromosome 22q11, resulting in the expression of chimeric BCR-ABL mRNAs specific to chronic myelogenous leukemia (CML). Presence of the fusion gene can be detected with high specificity and sensitivity by means of reverse transcription and polymerase chain reaction. Using this assay, it was possible to detect BCR-ABL fusion genes induced among HL60 cells after 100 Gy of X-irradiation in vitro. In total, five fusion gene transcripts were obtained among 10(8) cells examined. These fusion genes contained not only CML-specific BCR-ABL rearrangements, but also other forms of BCR-ABL fusions. These latter genes had junctions of BCR exon 4/ABL exon 2 intervened by a segment of DNA of unknown origin, BCR exon 5/ABL exon 2, and BCR exon 4/ABL exon 2. The results appear to be direct evidence for the induction of the BCR-ABL fusion gene by X-irradiation. In terms of leukemogenesis, it appears that only those cells bearing certain CML-related BCR-ABL fusion genes are positively selected by virtue of a growth advantage in vivo.
 ...
PMID:Induction of BCR-ABL fusion genes by in vitro X-irradiation. 846 27

Recent advances in molecular cytogenetics of leukemia is reported with special reference to the pathogenesis, diagnosis, prognosis, and potential gene therapy. Regarding leukemogenesis, we found that neocarzinostatin induced a variety of deletions and reciprocal translocations. Among these random chromosome abnormalities, two reciprocal translocations which were specific for certain leukemias could be observed; t(11;14)(q13;q32) and t(7;11)(p15p13). This fact suggests that a translocation carrying oncogene rearrangement may be of potential relevance to the leukemogenesis. The success in making a subgroup (FAB classification) identified a number of subtype-specific translocations in leukemias. It has been suggested that an initiation or progression-associated event is mediated through a gross chromosomal change. The molecular characterization of chromosomal rearrangement leads to the identification of genes involved in leukemia. Our recent works in molecular cytogenetics of chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL), FAB-M3 and -M4 were shown in this article. Since rearrangement of relevant genes were cloned, PCR made it feasible to detect minimal residual disease at 10(-6) level after intensive treatment or bone marrow transplantation for CML, Ph-positive ALL, M3 and approximately half of childhood leukemia. Recently developed fluorescent in situ hybridization (FISH) using specific probes can visualize certain chromosomes or chromosomal segments. Ph translocation, for instance, is now demonstrated as three spot-signals in interphase nuclei using YAC (yeast artificial chromosome)-BCR clone. Lastly, the use of antisense oligonucleotides for the BCR-ABL junctions should result in the inhibition of growth of CML clone. The strategy using antisense molecules may be very powerful tool in the gene-targeting therapy for human neoplasms.
 ...
PMID:[Recent advances in molecular cytogenetics of leukemia]. 847 75

DCC (Deleted in Colorectal Cancer) is a putative tumor suppressor gene located on chromosome band 18q21. Allelic deletions of one DCC locus have been found in more than 70% of colorectal carcinomas. Loss of DCC expression has been detected in 80% of all colorectal cancers and in many other types of tumor. DCC is expressed in normal bone marrow and peripheral lymphocytes, nevertheless DCC expression was absent or greatly reduced in 30% of acute leukemias and in 25% of Chronic Myelogenous Leukemias (CML). DCC encodes a transmembrane glycoprotein closely related to the adhesion molecules of the Neural Cell Adhesion Molecule (N-CAM) family. Glycoproteins of this family function like cell surface receptors and are involved in the regulation of many functions including cell recognition and cell differentiation. Highly specialized adhesion molecules participate in the regulation of hemopoiesis by mediating the interactions of hemopoietic cells with the components of the bone marrow microenvironment. Therefore, loss of DCC, as well as loss or alteration of other adhesion receptors, could contribute to leukemogenesis by impairing the interactions of the hemopoietic cells with the bone marrow microenvironment.
 ...
PMID:DCC (deleted in colorectal cancer) inactivation in hematological malignancies. 858 Aug 31

We have previously reported expression of WT1 in acute leukemia. To elucidate its biological significance, we examined the effect of the suppression of the WT1 expression by WT1 antisense oligomers on the growth of the leukemic cells expressing WT1. When 20 different WT1 antisense (AS) oligomers covering from the 5' cap sites of the WT1 gene to the 3' end were examined for the inhibitory effect on the growth of K562 cells expressing WT1, four WT1 AS oligomers inhibited the cell growth, whereas WT1 sense and random sequence oligomers had no effect on the cell growth of K562. Moreover, WT1 AS oligomers significantly inhibited the growth of the clonogenic cells of fresh leukemic cells in six of 14 patients with acute myeloid leukemia, in one of two patients with chronic myelogenous leukemia (CML) chronic phase, and in one of one patient with CML blastic crisis. However, these oligomers did not inhibit normal colony-forming unit-granulocyte-macrophage. Western blot analysis clearly demonstrated the significant reduction in the WT1 protein levels in the K562 and fresh leukemic cells that were treated with the WT1 AS oligomers, confirming that the inhibitory effect of the WT1 AS oligomers on the cell growth operates via the reduction in the WT1 protein levels. These results show that WT1 plays an important role in leukemogenesis.
 ...
PMID:Growth inhibition of human leukemic cells by WT1 (Wilms tumor gene) antisense oligodeoxynucleotides: implications for the involvement of WT1 in leukemogenesis. 863 7

Evi-1 is a transforming gene originally identified in a common integration site of murine leukemia retrovirus and mapped in human chromosome 3q26. It is not normally expressed in either human or murine hematopoietic cells, but is overexpressed in retrovirus-induced murine myeloid leukemias as well as human myeloid leukemias with 3q26 abnormalities, and thus thought to be responsible for both human and murine leukemogenesis. In this study, possible involvement of the Evi-1 gene in human leukemias was evaluated by Northern blot analysis in a total of 73 patients with various types of leukemias. We found that increased expression of the Evi-1 gene was most frequently observed in patients with CML in blastic crisis. It was found in 10 of 14 (71.0%) samples from CML in blastic crisis, three of 15 (20.0%) from acute myelocytic leukemia, three of 11 (27.3%) from MDS-derived leukemia, and one of 11 (9.1%) from acute lymphoblastic leukemia. Among 18 patients showing increased Evi-1 expression, none of 17 informative patients showed cytogenetic abnormalities involving 3q26. In addition, Southern blot analysis revealed neither amplification nor rearrangements of the Evi-1 gene in 11 Evi-1-positive patients whose DNA samples were available. Our results suggest that increased expression of the Evi-1 gene may play an important role in development of human leukemias, especially in progression from chronic phase to blastic crisis of CML even without 3q26 abnormalities.
 ...
PMID:Increased Evi-1 expression is frequently observed in blastic crisis of chronic myelocytic leukemia. 865 73

Microsatellites are important highly polymorphic genetic markers dispersed in the human genome. Using a panel of 22 (CA)n repeat microsatellite markers mapped to recurrent breakpoint cluster regions specifically involved in leukemia, we investigated 114 adult leukemias (25 acute lymphocytic leukemia [ALL], 32 acute myeloid leukemia [AML], 36 chronic lymphocytic leukemia [CLL], and 21 chronic myeloid leukemia [CML] in chronic phase) for somatic mutations at these loci. In each patient, DNA from fresh leukemia samples was analyzed alongside normal constitutive DNA from buccal epithelium. We detected loss of heterozygosity (LOH) in 81 of 114 patients (ALL 16/25, AML 25/32, CLL 30/36, CML 10/21). Deletions were most often seen in ALL at 11q23 and 19p13; in AML at 8q22 and 11q23; in CLL at 13q14.3, 11q13, and 11q23; and in CML at 3q26. Only six deletions were reported in 74 karyotypes analyzed, whereas in these same cases, 91 LOH events were detected by microsatellites. Of 26 leukemias with a normal karyotype, 16 nevertheless showed at least one LOH by microsatellite analysis. Replication errors were found in 10 of 114 patients (8.8%). Thus, microsatellite instability is rare in leukemia in contrast to many solid tumors. Our findings suggest that in adult leukemia, LOH may be an important genetic event in addition to typical chromosomal translocations. LOH may point to the existence of tumor suppressor genes involved in leukemogenesis to a degree that has hitherto been underestimated.
 ...
PMID:Frequent clonal loss of heterozygosity but scarcity of microsatellite instability at chromosomal breakpoint cluster regions in adult leukemias. 870 11

The alterations of transcription factor genes by chromosomal translocations play an important role in leukemogenesis and lymphomagenesis. The alterations are classified into two groups. One is the chimeric gene formation, and the other is the aberrant expression without structural changes. The former type is associated with the chromosomal translocations found in acute myeloid leukemia, such as the AML1/MTG8 in t(8;21) and PML/RAR alpha in t(15;17). The latter is the main mechanism in the gene activations observed in acute lymphoblastic leukemia and lymphoma. Many transcription factor genes are activated by the recombination with the immunoglobulin genes in B cell malignancies or T cell receptor genes in T cell malignancies. We isolated the AML1/EVI-1 fusion gene generated by the t(3;21) translocation, which is usually found in blastic crisis of chronic myelocytic leukemia. The chimeric transcription factor encoded by the fusion gene has dual functions, namely differentiation block and stimulation of proliferation. These findings provide new insight into the molecular mechanism in leukemogenesis by the chimeric transcription factors.
 ...
PMID:Chromosomal abnormalities and oncogenes. 886 20

Cell proliferation control is ensured by a group of proteins named cyclin-dependent kinases (CDKs), the activation of which is dependent on phosphorylation and cyclin association. In parallel, these CDKs are negatively controlled by two distinct groups of inhibitory proteins, the cyclin-dependent kinase inhibitors (CKIs). The first group, including p16Ink4a, p15Ink4b, p18Ink4c and p19Ink4d, is specific for the G1 CDKs, CDK4 and CDK6, inhibiting the kinase activity of cyclin D/CDK4-CDK6 complexes on pRb. p16Ink4a, down-regulated by pRb, inhibits G1 CDKs by competition with cyclin D; p15Ink4b, the synthesis of which is induced by TGF beta, seems to be a mediator of TGF beta-mediated cell cycle arrest. Furthermore, p18Ink4c inhibits CDK6 phosphorylation and activation by CAK. The second CKIs family is constituted by p21Waf1, p27Kip1 and p57Kip2. Their inhibitory action concerns a large range of cyclin/CDK complexes involved in G1 and S phase. p21Waf1, induced in part by p53, is up-regulated by senescence, DNA damage and cellular differentiation. p21Waf1 forms quaternary complexes with CDKs, cyclins and PCNA. Its inhibitory action, preventing CDK from phosphorylation, depends on the stoichiometry of the components. As p15Ink4b, p27Kip1 causes late G1 cell cycle arrest after TGF beta treatment and contact inhibition. The implications of CKIs in hematological malignancies are function of deletions or mutations of their genes. p16Ink4a and p15Ink4b genes, localized on 9p21, present frequent homozygous deletions in ALL T, ATL and lymphoblastic acutisation of CML. The other CKIs present very rare homozygous deletions or mutations, particularly p21Waf1 and p27Kip2. However, reduction of inhibitory activity due to hemizygous deletions might favour leukemogenesis.
 ...
PMID:Cyclin-dependent kinase inhibitors (CKIs) and hematological malignancies. 889 23

Primary myelodysplasia (MDP) and acute and chronic myelogenous leukemias (AML, CML) are considered disorders of clonal stem cell division. Several constitutive gene defects that contribute to the development of abnormal cell behavior have been identified in the hematopoietic cells. The role of bone marrow stroma cells in leukemogenesis, however, has not been established. We studied the organization of the bone marrow (BM) microenvironment to see if it was impaired during the initiation and progression of these malignancies. The buffy coat, hematon, and plasma fractions were separated from BM aspirates taken from healthy donors and diseased subjects at distinct clinical stages. The structural integrity of the BM microenvironment was evaluated analyzing the morphogenetic unit, the hematon. The hematon is a multicellular complex that includes fibroblasts, adipocytes, endothelial cells, resident macrophages, hematopoietic cobblestone area-forming cells (CAFC), high-proliferative potential colony-forming cells (HPP-CFC), granulocyte-macrophage colony-forming unit (GM-CFU), burst-forming unit erythroid (BFU-E), and terminally differentiated cells in normal BM. Hematon complexes were present in most BM aspirates from healthy donors (46H+/55). But they were absent from most of the patients with MDP (21H+/62) and AML (5H+/24) in the first perceptible phase, and from those with CML throughout the disease (5H+/55). Hematon complexes were present in the BM aspirate in 22/36 AML patients at clinical remission after chemotherapy or differentiation therapy. The hematon fraction isolated from normal BM, contained 25 times more 25-hydroxyvitamin D3 and about 500-fold more 1alpha,25-dihydroxyvitamin D3 than the BM plasma. The concentration of 1alpha,25-dihydroxyvitamin D3 was low or undetectable in the BM plasma of some, but not all, patients with MDP (18/35) or AML (9/24). Thus, in the BM microenvironment, the metabolism of low-density lipids and lipophylic hormones are severely impaired prior to initiation or during the accelerated expansion of leukemia cells. The lack of organized stromal network and the decreased level of some lipophylic hormones, acting probably as morphogens, may contribute to the onset and progression of human myeloid leukemias.
 ...
PMID:Bone marrow stromal cell defects and 1 alpha,25-dihydroxyvitamin D3 deficiency underlying human myeloid leukemias. 890 1


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