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

We studied two cases of chronic myelogenous leukemia (CML) with unusual variant Philadelphia (Ph) translocation (22;22)(q11;q13). Southern blot analysis showed a chromosomal break in the BCR gene within the 5.8-kilobase (kb) breakpoint cluster region (bcr), between bcr exons 2 and 3 and between bcr exons 3 and 4, respectively. Chimeric bcr-abl mRNA was detected using polymerase chain reaction (PCR) which amplified, according to the respective bcr breakpoints, bcr exon 2-abl exon II and bcr exon 3-abl exon II junction products. These results further support the involvement, even when not cytogenetically detectable, of the 9q34 chromosomal region in all variant Ph translocations and that BCR-ABL gene fusion products are causally involved in the development of Ph positive CML.
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PMID:Chronic myeloid leukemia with unusual variant Ph translocation (22;22)(q11;q13). Two cases with chimeric BCR-ABL transcripts. 220 77

Previous reports have indicated that mutations of the RAS oncogenes are not associated with the chronic phase of Philadelphia chromosome-positive chronic myelogenous leukemia (Ph1+ CML). However, further studies were needed to determine their association with Ph1- CML and chronic myelomonocytic leukemia (CMML). Therefore, 6 patients with Ph1- CML who were also negative for BCR rearrangements (Ph1-/BCR- CML) and 30 patients with CMML were analyzed for the presence of RAS oncogene point mutations to determine the similarities of these diseases at the molecular level. The assay used the polymerase chain reaction for amplification of the target RAS sequences and panels of specific synthetic oligonucleotide probes for hybridization to wild type and/or mutated sequences. None of the six Ph1-/BCR- CML patients had mutations in the RAS oncogenes, while 17 of 30 (57%) of the CMML patients had RAS oncogene mutations. Eighty percent of the mutations involved substitution of aspartic acid for glycine (G----A) in the 12th or 13th codons of N-ras or K-ras. Furthermore, although not statistically significant, survival studies raise the possibility of shortened survival in patients with RAS oncogene point mutations, with the average survival being 33 months for Ph1-/BCR- CML, 35 months for CMML without point mutations, and 11 months for CMML with RAS mutations. Thus, RAS mutations appear to be associated with CMML and not Ph1-/BCR- chronic phase CML, there is a high propensity for the K-ras or N-ras mutations to involve an G----A substitution in the 12th or 13th codons, and RAS mutations in CMML may relate to prognosis and require further studies.
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PMID:RAS mutations are rare events in Philadelphia chromosome-negative/bcr gene rearrangement-negative chronic myelogenous leukemia, but are prevalent in chronic myelomonocytic leukemia. 220 9

The presence of Philadelphia chromosome t(9:22) is a hallmark of 95% of clinical cases of chronic myelogenous leukemia (CML) as well as 20% of adult acute lymphoblastic leukemia (ALL) and 5% of acute myeloid leukemia (AML). The product of t(9;22) is a fusion protein BCR-ABL. The fusion proteins of CML, ALL and AML have increased tyrosine kinase activity and show a transforming potential in vitro and in animal models. The shorter p190 protein is associated almost only with ALL and AML, while the protein p210 is present in both chronic phase and blast crisis of CML and also in 50% of Philadelphia-positive (Ph1+) ALL. In CML the transition from chronic phase to blast crisis is usually accompanied by additional genetic events, e.g. additional chromosomal abnormalities, and oncogene activation(s). The detailed understanding of molecular basis of CML, and Ph1+ ALL and AML provides highly sensitive molecular and serological methods to complement classical cytogenetics. The advantages and limitations of these techniques are described and discussed below.
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PMID:Molecular pathology of chronic myelogenous leukemia. 224 53

Double fluorescence in situ hybridization was used to detect Philadelphia (Ph) chromosomes in interphase nuclei and metaphases of patients with chronic myeloid leukemia. Application of cosmid probes for 3' ABL and 5' BCR sequences gave better results than libraries for chromosomes 9 and 22. The present approach may provide an alternative method for monitoring minimal residual disease in Ph+ CML patients.
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PMID:Detection of the Philadelphia chromosome in interphase nuclei. 226 53

Chronic myelogenous leukemia (CML) is characterized by the presence of a novel fusion gene comprised of portions of the BCR gene from chromosome (ch) 22 and the ABL gene from ch 9. The present study was designed to identify regulatory DNA regions as determined by DNAase I hypersensitivity to address the question of whether altered chromatin contributes to changes in ABL expression. We identify five hypersensitive (HS) sites within the abnormal BCR/ABL allele in K562 cells in a pattern different from the normal BCR. The pattern of hypersensitivity is modified when the cells undergo hemin induced differentiation. These results indicate that the normal BCR has a chromatin configuration consistent with active transcription and that the BCR/ABL fusion gene chromatin is different. This may be important in the pathogenesis of CML.
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PMID:Chromatin alterations surrounding the BCR/ABL fusion gene in K562 cells. 226 34

A patient with Philadelphia (Ph1)-negative, breakpoint cluster region (bcr)-positive chronic myeloid leukemia (CML) is reported. Pulsed-field gel electrophoretic analysis demonstrated the comigration of both ABL and BCR sequences on the same BssHII and SacII fragment. Moreover, in situ hybridization studies demonstrated that ABL sequences had been moved from band 9q34 to 22q11 and that the additional t(12;12)(q13;p12) was not involved in the ABUBCR related translocation. Nevertheless, a possible role of oncogenes or regulatory sequences activated or inhibited by the additional translocation cannot be excluded.
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PMID:Molecular and cytogenetic studies of a patient with Philadelphia-negative, BCR-positive chronic myeloid leukemia and t(12;12)(q13;p12). 227 60

It has been reported that patients with chronic myeloid leukemia (CML) with 5' breakpoints within the major breakpoint cluster region (M-BCR) of the BCR gene have somewhat better prognoses than those with 3' breakpoints. We studied the position of the breakpoint in 67 patients with CML in chronic phase using conventional Southern blotting. Using restriction enzymes BglII, BamHI and HindIII and two genomic probes, a 0.6 kb (3' M-BCR) probe hybridizing to a part of the intron between exons b3 and b4 and a 2.0 kb (5' M-BCR) probe hybridizing to sequences including exon b1, we localized the breakpoint in M-BCR as occurring 5' (n = 38) or 3' (n = 28) of the HindIII restriction site located just downstream of exon b3. We failed to localize the breakpoint in one patient. The median durations of chronic phase (37 versus 44 months respectively) and of survival (50 versus 51 months respectively) for patients with 5' and 3' breakpoints were not significantly different. When we analysed only patients whose DNA was collected within 4 weeks of diagnosis (5' breakpoints, n = 30; 3' breakpoints, n = 19), there was again no significant difference in duration of chronic phase or survival. The median survivals of patients divided into good, intermediate and poor prognosis categories in accordance with the prognostic index developed by Sokal and colleagues were 54, 50 and 26 months respectively. This study confirms the value of the Sokal prognostic index but provides no support for the notion that the precise genomic position of the breakpoint in M-BCR correlates with prognosis.
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PMID:The position of the M-BCR breakpoint does not predict the duration of chronic phase or survival in chronic myeloid leukemia. 231 Jun 95

We report on eight patients who were 35 to 77 years old with an isochromosome 17q as the sole structural chromosomal anomaly. Additional numerical chromosomal changes were a trisomy 8 or 17 in two cases each and a trisomy 19 in one case. Five patients had myelodysplastic syndrome (MDS) diagnosed according to the FAB nomenclature as chronic myelomonocytic leukemia (CMML) in two cases, refractory anemia with excess of blasts in transformation (RAEBt) in two cases, and refractory anemia with excess of blasts (RAEB) in one case. One patient suffered from a myeloproliferative disorder (MPS). All cases progressed to acute nonlymphocytic leukemia (ANLL) type M1, M2, or M4 in a period of 2 to 30 months after initial diagnosis, except one patient with RAEBt who died within 2 months. Two patients presented with ANLL-M2 at time of diagnosis. Treatment during the chronic phase of disease consisted of mild cytoreduction and/or substitution of platelets or red blood cells. One patient with CMML received an allogeneic bone marrow graft and relapsed after 33 months with ANLL-M1. Treatment results for overt leukemia were poor, and survival was short, lasting from 1 to 4 months. Overall survival was 1 to 37 months (median duration, 6.5 months). Molecular studies in two cases revealed neither a BCR rearrangement nor a translocation of the ABL protooncogene, as observed in Ph1-positive chronic myeloid leukemia (CML). Thus, an i(17q) anomaly seems to identify a distinct subgroup of mostly myelodysplastic and, less frequently, myeloproliferative disorders that progress rapidly to ANLL, respond poorly to chemotherapy, and are associated with short survival after transformation.
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PMID:Isochromosome 17q in Ph1-negative leukemia: a clinical, cytogenetic, and molecular study. 222 38

Eighteen chronic myeloid leukemia patients with hematological (four patients) or only cytogenetic (14 patients) relapse occurring after T cell-depleted allogeneic bone marrow transplantation (BMT) have been treated with alpha 2b interferon (IFN) at a starting dose of 5 x 10(6) i.u./m2 subcutaneously three times a week. All four patients with hematological relapse achieved long-lasting hematological remission without reduction of bone marrow Ph1 positive cells. When IFN was started the median percentage of bone marrow Ph1-positive metaphases was 50% (range 9-100) for the 14 patients with cytogenetic relapse. Twelve (85.7%) of these patients are alive with a median follow-up of 25 months (range 20-37 months) from cytogenetic relapse and 33 months (range 27-49 months) from BMT. Six (43%) of the 14 patients progressed to hematological relapse and eight patients (57%) are still in hematological remission with two patients achieving complete cytogenetic remission confirmed at molecular level by disappearance of the M-BCR rearranged band. IFN therapy may be a good alternative to conventional chemotherapy for transplanted CML patients with hematological relapse and the treatment of choice for patients with a persistent cytogenetic relapse occurring after T cell-depleted BMT.
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PMID:Interferon therapy for Ph1 positive CML patients relapsing after T cell-depleted allogeneic bone marrow transplantation. 209 16

A patient who was diagnosed with chronic myeloid leukemia remained in chronic phase for 14 years before progressing into a lymphoid blast crisis in 1983. The acute phase was successfully treated, and the patient has remained in an indolent chronic phase to date. Cytogenetic and molecular analysis during this second chronic phase confirm the presence of the Philadelphia chromosome and its transcribed BCR-ABL mRNA. The breakpoint within M-bcr occurred in the 3' portion of the region and expressed a hybrid joining the b3 exon of BCR to the a2 exon of ABL.
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PMID:Molecular analysis of a CML patient with a long duration of chronic phase before and after lymphoid blast crisis. 235 47


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