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)

We present two cases in which translocations involving 21q22 were found at presentation in acute nonlymphocytic leukemia (ANLL). The first of these translocations, t(3;21)(q26-q27;q22), is previously unknown in ANLL, but appears indistinguishable from that reportedly associated with Philadelphia-positive chronic myelogenous leukemia. The second case involves t(15;21)(q21-q22;q22), a translocation previously undescribed in ANLL. Both of these exchanges involve 21q22 plus another chromosome region associated with leukemogenesis. We attempted to interrelate these cytogenetic data with the oncogenic significance of 21q22.
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PMID:Novel translocations in acute nonlymphocytic leukemia. Two cases involving chromosome 21, band q22. 229 84

Cellular or proto-oncogenes are normal cellular genes important in normal cell growth and development. In some instances abnormal expression of these genes is associated with altered cell growth or with malignant transformation. Abnormalities of cellular oncogenes are common in human leukemias. These arise by multiple mechanisms such as mutation, translocation, amplification, and others. Sometimes more than one abnormality is present within a single oncogene. In other instances, a leukemia cell may contain abnormalities of several different oncogenes. Some oncogene abnormalities are relatively specific for certain leukemias and occur in almost all cases; examples include ABL in chronic myelogenous leukemia or MYC in Burkitt leukemia/lymphoma. Other abnormalities are also relatively specific but occur in only some cases such as NRAS in acute myelogenous leukemia or BCL2 in B-cell acute lymphoblastic leukemia. In other leukemias, such as most cases of acute lymphoblastic leukemia and chronic lymphocytic leukemia, oncogene abnormalities are uncommon. The precise role of oncogenes in the pathogenesis of human leukemia is unknown. Retrovirus transduced versions of some of the oncogenes modified in human leukemias cause leukemia in animals. Other oncogenes, modified or unmodified, transform animal and human hematopoietic cells in vitro. Some oncogene products are hematopoietic growth factors or growth factor receptors while others regulate cell proliferation or differentiation by diverse mechanisms. Disruption of the balance between these processes seems the most likely mechanism of oncogene related leukemogenesis. If the role of oncogenes in human leukemias can be defined, innovative diagnostic and therapeutic strategies may be forthcoming.
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PMID:Oncogenes and leukemia. 240 17

A case of acute myelocytic leukemia (AML-M2) with a late appearance of Philadelphia chromosome (Ph1) is presented. Chromosome analysis revealed a normal karyotype at the time of diagnosis and for 23 months, when hematological relapse occurred, accompanied by abnormal clones, 46, XX, t(9;22) (q34;q11) (78%) and 45,XX, -16, t(9;22) (q34;q11), del (5) (q13q31) (22%). The patient died of GVHD after bone marrow transplantation. Molecular analysis confirmed bcr gene rearrangement in the cells with Ph1 chromosome. Acquisition of Ph1 chromosome during the course of hematological malignancies other than CML is extremely rare. This case is undoubtedly important for the understanding of leukemogenesis and the evolution of leukemia clones. The authors discussed possible mechanisms of Ph1 acquisition in the late stages of AML.
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PMID:[Late appearance of Philadelphia chromosome with bcr gene rearrangement in an acute myelocytic leukemia patient]. 269 64

The major consequence of the Philadelphia (Ph) translocation in chronic myeloid leukemia (CML) is the formation of a bcr-abl hybrid oncogene encoding a tumor cell-specific protein P210bcr-abl. In contrast to this, in Ph chromosome-positive acute lymphoblastic leukemia (Ph + ALL), a P190bcr-abl can be observed. This P190bcr-abl has been implicated in acute rather than chronic leukemogenesis. Therefore, it can be hypothesized that the transition from chronic to blast phase in CML is accompanied by an alternative splice in the bcr-abl mRNA, which results in a switch of the production of P210bcr-abl into P190bcr-abl. Initial S1 nuclease protection mapping supported this theory. However, this result appears to be based on an artifact in the S1 analysis. By using the polymerase chain reaction we provide evidence for the absence of alternative splicing in bcr-abl mRNA in two CML blast crisis cell lines.
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PMID:Absence of alternative splicing in bcr-abl mRNA in chronic myeloid leukemia cell lines. 284 1

The Philadelphia chromosome (Ph) is an abbreviated chromosome number 22 resulting, in the majority of cases, from a balanced translocation between the 9 and 22 long arms. It is considered a marker of chronic myeloid leukemia and its diagnostic and prognostic value in this disease has been demonstrated. It is also present in a number of patients with acute leukemias of poor prognosis. The Ph arises in a bone marrow progenitor cell and seems to allow the clonal expansion of the malignant cells. The typical 9;22 translocation results in the transposition of the cellular oncogene Abelson in close proximity of chromosome 22 linked critical sequences. This structural change leads to the transcription of an hybrid mRNA coding for an abnormal protein with a tyrosine kinase activity which could play a major role in the leukemogenesis process.
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PMID:[The Philadelphia chromosome: clinical and biological significance]. 294 11

We have followed one patient with Philadelphia (Ph)-negative chronic myelogenous leukemia and identified an additional four patients from the literature who showed the rearrangement in the breakpoint cluster region (bcr) on chromosome 22 characteristic of Ph-positive chronic myelogenous leukemia. The clinical course of these five patients was similar to that of Ph-positive patients, with easily controlled leukocyte counts, a prolonged benign phase, and prolonged survival. Furthermore, we have shown, for the first time, that bcr rearrangement in Ph-negative chronic myelogenous leukemia can result in expression of the aberrant 210-kilodalton bcr-abl fusion protein, which has been strongly implicated in Ph-positive leukemogenesis. Research data pertaining to possible cytogenetic mechanisms leading to production of p210bcr-abl in the absence of the Ph chromosome are reviewed. Molecular analysis provides an important tool for classifying and predicting prognosis of some patients with Ph-negative chronic myelogenous leukemia.
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PMID:Rearrangement in the breakpoint cluster region and the clinical course in Philadelphia-negative chronic myelogenous leukemia. 309 18

The Philadelphia (Ph) translocation t(9;22)(q34;q11) occurs frequently in chronic myeloid leukemia (CML) but is less common in acute lymphoblastic leukemia (ALL) and rare in acute myeloid leukemia (AML). In most cases of CML and some cases of Ph+ ALL the protooncogene ABL from 9q34 is translocated to the breakpoint cluster region (bcr) of the BCR gene at 22q11 to form a chimeric gene encoding a novel 210-kd protein (P210 BCR-ABL) with enhanced tyrosine kinase activity. In other patients with Ph+ ALL and Ph+ AML, the breakpoint probably occurs in the first intron of the BCR gene; this results in a smaller chimeric gene which encodes a P190 BCR-ABL. We studied a patient with AML (FAB M6) arising de novo who had a "masked" Ph chromosome in association with extensive karyotypic changes. The leukemic cells initially showed rearrangement of the bcr, presence of a hybrid mRNA, and expression of the P210 BCR-ABL. These changes were absent in remission. These results support the concept that the BCR-ABL chimeric gene plays a crucial role in leukemogenesis but suggest that factors other than the position of the breakpoint in the BCR gene determine the lineage of the target cell for malignant transformation.
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PMID:Rearrangement of the breakpoint cluster region and expression of P210 BCR-ABL in a "masked" Philadelphia chromosome-positive acute myeloid leukemia. 317 49

DNA of peripheral blood or bone marrow leukocytes from 8 normal subjects, 7 cases of acute lymphocytic leukemia (ALL), 2 of acute myelogenous leukemia (AML) and 1 of chronic myelogenous leukemia (CML), having been digested by endonuclease Eco RI or Pst I separately, was hybridized with the probes of 3' fragment (Pst I/Hind III) or 5' fragment (Hinc II/Pst I) of Abelson murine leukemia virus (A-MuLV) oncogene v-abl. The proto-oncogene c-abl, which is homologous to v-abl, was found amplified in 4 ALL, 1 CML and 1 AML. In one of these 4 ALL, c-abl was amplified even over 100 times. A new c-abl BamH I fragment with 6.7 kilobase pairs (kb) in length was observed in 2 ALL and 1 CML out of these 6 cases with amplification, but none of this fragment was found in the normal subjects or other leukemia patients. These 3 patients with the presence of 6.7 kb fragment were high risk ones and 2 of them had died, suggesting that 6.7 kb fragment be the index of poor prognosis. The amplification and rearrangement of c-abl imply the activation of proto-oncogene in leukemogenesis.
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PMID:[Amplification and rearrangement of proto-oncogene c-abl in human leukemia cells]. 321 75

The identical cytogenetic marker, t(9;22)(q34;q11) (Philadelphia [Ph] translocation), is found in approximately 90%, 20%, and 2% of adult patients with chronic myelogenous leukemia (CML), acute lymphoblastic leukemia (ALL), and acute myelogenous leukemia (AML), respectively. In CML, the molecular events resulting from the Ph translocation include a break within the bcr locus on chromosome 22, transfer of the c-abl protooncogene from chromosome 9 to 22, and formation of an aberrant 210-kD bcr-abl fusion protein (p210bcr-abl). Recently, the absence of bcr rearrangement and expression of a distinct aberrant 190-kd abl protein (p190c-abl) has been described in Ph-positive ALL, with the suggestion that the two abl variants may be pathogenetically associated with myeloid v lymphoid leukemogenesis. Here we report that the genomic configuration and translation product of Ph-positive AML can be similar to that of Ph-positive ALL: the break at 22q11 may occur outside the 5.8 kb bcr region and result in expression of a 190-kD abl protein lacking these bcr sequences. Phosphokinase enzymatic activity, a fundamental property of p210bcr-abl, was also associated with AML-derived p190c-abl. Our current observations indicate that p190c-abl can be found in cells of lymphoid or myeloid lineage and is therefore unlikely to play a specific role in the development of lymphoid leukemias. Formation of p190c-abl instead of p210bcr-abl appears to be a characteristic of the acute rather than the chronic Ph-positive leukemic state.
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PMID:Expression of c-abl in Philadelphia-positive acute myelogenous leukemia. 331 Dec 7

Because of the uncertainty in dosimetry at the Japanese cities, I have recalculated the probability of x-ray or gamma-ray leukemogenesis using the revised doses given by the Livermore group. The theory is of the two hit type. The first hit damages DNA repair capability of base damage. The second hit causes derepression of a two repressor system. Inactivation of the first repressor permits synthesis of the second which will repress the expression of the leukocyte maturation gene. In comparing the observed data, I convert data expressed as mortality per year to leukemia incidence. I also supply evidence of the lack of the importance of chromosomal aberration and consider CML, AML, and ALL data lumped together. Agreement between theory and observation is good.
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PMID:X-ray or gamma-ray leukemogenesis at Hiroshima and Nagasaki. 340 21


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