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)

Diagnosis- and/or prognosis-related alterations of (proto) oncogenes may be detected in neuroblastoma (N-myc), carcinoma of breast and ovary (HER2/neu), NHL (c-myc, bcl-2), CML (c-abl/bcr), and some other neoplasias. A wide variety of methods for the detection of gene alterations can be applied. The methods of detection have to be chosen according to the expected mechanisms of oncogene activation, the availability of adequately prepared tissue, and the technical standard of the laboratory. The sensitivity, specificity, and quantitation of morphological techniques (immunohistochemistry and in situ hybridization) is restricted and their results have to be interpreted most carefully. Whenever possible, at least two different techniques should be used, preferably on two different levels, i.e. RNA/DNA and protein. Furthermore, the combination of morphological and non morphological methods should be aspired.
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PMID:[Oncogenes and oncogene products--possibilities and significance of their detection]. 170 8

The chronic myeloproliferative disorders (CMD) are characterized by sustained or progressive proliferations of bone marrow cells, affecting one or more lineages in varying combinations. They are classified in 4 subgroups but transitional forms and transformations among the different entities are common. Analysing RFLPs and methylation patterns of X-chromosomal genes we could show, that in each entity granulocytes as well as bone marrow cells are of monoclonal origin. These findings support the view that all forms of CMD have in common that they arise from a multipotent hematopoietic stem cell. CML can be differentiated from all other forms of CMD by the Philadelphia-chromosome which on the molecular level has been revealed as bcr-abl gene junction. We investigated 258 cases of CMD for rearrangement of the bcr gene and found that it selectively occurred in CML. The methods applied can be of diagnostic value in differentiating reactive from neoplastic proliferations by analysis of clonality, and in differentiation of CML from other types of CMD by detection of the bcr-rearrangement.
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PMID:[Clonality and stem cell defects in the molecular pathology of chronic myeloproliferative disorders]. 170 35

We have utilized the polymerase chain reaction (PCR) to sensitively detect persistence of the chronic myelogenous leukemia (CML) malignant clone and to study bcr/abl mRNA splicing patterns following bone marrow transplantation. Thirteen of sixteen patients displayed persistent malignant cells during post-BMT clinical remission. In two patients bcr/abl mRNA was detected 4 and 9 months prior to clinical relapse. In eleven of fourteen patients in continued clinical remission malignant cells were detected post-BMT. Ten of these eleven patients were also cytogenetically normal. Seven patients have lost all evidence of bcr/abl transcript, but only at 1-2 years posttransplant, while four have shown persistence of the bcr/abl transcript from 28 days to 3 years post-BMT and one has converted from an initially negative result at 1 year post-BMT to detectable levels of chimeric mRNA at 2 years. Thus, 8/9 patients tested at or before 6 months, 7/12 at 1 year, and 3/10 at 2 years showed persistent detectable CML cells. Intriguingly, mRNA splicing patterns changed in 5 patients following BMT, with complete loss of mRNA containing bcr exon 3 (n = 2) or new appearance of mRNA not containing bcr exon 3 (n = 2). A single patient transiently lost evidence of bcr exon 3 expression while persistently expressing the bcr exon 2/abl exon 2 splice. Our data suggest that the majority of patients harbor small numbers of malignant cells following transplantation, and that such persistence may not inevitably predict clinical relapse. Complete elimination of the malignant CML clone post-BMT may rely on immunological mechanisms (e.g., graft-vs-leukemia).
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PMID:bcr/abl mRNA detection following bone marrow transplantation for chronic myelogenous leukemia. 175 65

Seventy five radiation-related leukemias (acute non-lymphocyte) in Hiroshima including 16 patients exposed to more than one Gray were cytogenetically examined. Statistical analysis of the data on the frequencies of chromosomal aberrations in survivors according to the bone marrow doses of DS86 estimation revealed that heavily exposed patients tended to have significantly higher aberration rates as compared with non-exposed patients. Furthermore, the chromosomal aberrations in the survivors were observed to be of a more complex nature and had characteristic findings of secondary leukemia. These observations therefore suggest that patients with a history of heavy exposure to atomic bomb radiation exhibit leukemic cells that originated from a stem cell which had been damaged by irradiation at the time of bombing and had been involved in the complex chromosome abnormalities. Molecular biological studies on transforming genes in acute and chronic leukemia and the bcr gene in chronic myelocytic leukemia have been performed in exposed and non-exposed groups. So far, no distinctive differences have been observed in the frequency and the sites of point mutations in N- and K-ras genes or in the rearrangement of the bcr gene, for a final conclusion of the specificity of radiation induced leukemia. Further retrospective studies require patient DNAs that developed in the early period of the atomic bomb exposure.
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PMID:Cytogenetic and molecular changes in leukemia found among atomic bomb survivors. 176 3

Diagnosis of leukemia and lymphoma has been made by morphological, cytochemical, and immunophenotypical methods. Recently molecular biological approaches have been introduced to clarify the cellular lineage of the tumor cells and to demonstrate the monoclonality. Southern blot analysis using immunoglobulin (Ig) and T cell receptor (TcR) genes revealed the presence of monoclonal components in some cases of angioimmunoblastic lymphadenopathy (AILD), in which demonstration of monoclonality was difficult by conventional methods. In preB-ALL, many cases had rearranged IgH and TcR genes simultaneously. These "dual genotype" cases were found to be of accidental involvement of TcR gene in the process of making effective IgH gene rearrangements by the precise analysis of rearranged IgH gene structures. The rearranged TcR gene which was detected in initial lymphoblastic lymphoma cells, was observed in relapsed blasts after lineage conversion to myeloid leukemia, which indicates the same clonal origin. Diagnosis and detection of minimal residual disease by the polymerase chain reaction (PCR) are now recognized as sensitive methods. PCR using oligonucleotides common to each VH and JH gene detects the rearranged IgH gene sensitively. PCR using primers located on the translocation boundary, such as bcr and abl in CML, is very useful in the diagnosis and pursuit of the disease course. PCR study also can be applied to the detection of alteration of some particular genes such as tumor suppressor genes.
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PMID:[Molecular diagnosis of leukemia and lymphoma]. 176 82

We have studied the haematologic, cytogenetic and molecular features in a patient with Ph positive ALL. The cytogenetic study showed the presence of a Ph chromosome since diagnosis. Molecular analysis showed rearrangement within the first intron of bcr gen instead of M-bcr as in CML. This an evidence of genic fusion between c-abl oncogene and bcr gene and also show the possibility of rearrangement outside M-bcr in these patients.
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PMID:[Philadelphia-positive ALL with rearrangement of the 1st intron of the BCR gene]. 181 84

Cancer is caused by specific DNA damage. Several common mechanisms that cause DNA damage result in specific malignant disorders: First, proto-oncogenes can be activated by translocations. For example, translocation of the c-myc proto-oncogene from chromosome 8 to one of the immunoglobulin loci on chromosomes 2, 14, or 22 results in Burkitt's lymphomas. Translocation of the c-abl proto-oncogene from chromosome 9 to the BCR gene located on chromosome 22 produces a hybrid BCR/ABL protein resulting in chronic myelogenous leukemia. Second, proto-oncogenes can be activated by point mutations. For example, point mutations of genes coding for guanosine triphosphate-binding proteins, such as H-, K-, or N-ras or G proteins, can be oncogenic as noted in a large variety of malignant neoplasms. Proteins from these mutated genes are constitutively active rather than being faithful second messengers of periodic extracellular signals. Third, mutations that inactivate a gene can result in tumors if the product of the gene normally constrains cellular proliferation. Functional loss of these "tumor suppressor genes" is found in many tumors such as colon and lung cancers. The diagnosis, classification, and treatment of cancers will be greatly enhanced by understanding their abnormalities at the molecular level.
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PMID:Molecular mechanisms of cancer. 181 12

Recently, Molecular genetics has remarkably advanced and it is introduced in medicine. The use of recombinant DNA methods for the diagnosis of leukemias is reported with special reference to the contribution of cytogenetic findings, such as specific chromosome aberrations previously obtained. Therefore, cytogenetic studies on Ph1 chromosome and other specific aberrations found in leukemias are historically reviewed. Using Southern blotting, PFGE, PCR, and in situ chromosome mapping techniques we have analyzed many cases with CML and cases with ALL. We found M-bcr rearrangements not only in standard Ph1, but also in complex types and in Ph1 (-) ve CML. Chromosomal in situ hybridization was very informative identifying transposition of bcr and abl genes between chromosomes 22 and 9. In this connection, FISH (fluorescence in situ hybridization) technique was developed by us, which is expected to have an exceptional power of analysis. ALL had either M-bcr or m-bcr rearrangements, the latter being identified by PFGE. Next, application of PCR technique that enables to obtain more than 10(5) copies of target sequences could monitor minimal residual diseases in CML. Recently, the relevant gene were cloned respectively in FAB-M2 and APL (FAB-M3), so that detection of minimal residual diseases will be successfully performed in these types of leukemia. Finally, targeting chemotherapy using antisense sequences is prospectively described.
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PMID:[Advances in molecular genetic diagnosis of leukemia]. 181 42

Seventy five radiation-related leukemia patients in Hiroshima including 16 patients exposed to more than one Gray were cytogenetically examined. Statistical analysis of data on the frequencies of chromosomal aberrations in the survivor groups according to bone marrow doses by DS86 estimation revealed that the heavily exposed group tended to have significantly higher aberration rates compared to the non-exposed group. Furthermore, the chromosomal aberrations in the survivors were observed to be of a more complex nature and had the characteristic findings of secondary leukemia. These observations therefore suggest that patients with a history of heavy exposure to atomic bomb radiation had leukemic cells originating from a stem cell which had been damaged by irradiation at the time of the bombing as well as cells involved in complex chromosome abnormalities. Molecular biologic studies on ras genes in acute and chronic leukemias and the bcr gene in chronic myelocytic leukemia were performed in exposed and non-exposed groups. So far, no distinctive differences have been observed in the frequency and sites of point mutations in N- and K-ras genes or in the rearrangement of the bcr gene. Further, retrospective analysis using DNA from leukemia patients who developed this disease in the early period from atomic bomb radiation exposure would be useful for the elucidation of the mechanisms of radiation-induced leukemia.
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PMID:Cytogenetic and molecular changes in leukemia among atomic bomb survivors. 182 62

In chronic myelogenous leukemia (CML), amplification of a segment of bcr-abl messenger RNA (mRNA) by polymerase chain reaction (PCR) can be used to detect minimal residual disease after bone marrow transplantation (BMT). Previous studies have shown that this sensitive technique can often detect small numbers of leukemia cells in patients who are otherwise in complete remission. Nevertheless, the clinical significance of PCR positivity remains unclear because the majority of patients with PCR-detectable bcr-abl mRNA can remain disease-free for prolonged periods after allogeneic BMT. In the present studies, we applied PCR to detect bcr-abl-positive cells in 100 serial blood or BM samples from 24 patients with CML who underwent CD6 T-cell-depleted allogeneic BMT. After BMT, bcr-abl mRNA could be detected in 20 patients (83.3%) during complete cytogenetic or clinical remission. Patients in whom PCR positivity was sustained over time had a higher probability of CML relapse than patients in whom PCR was intermittently negative (P = .0095, log rank test). PCR detection of bcr-abl transcript between 2 and 10 weeks post-BMT also was associated with a high probability of subsequent relapse (P = .023, log rank test). In eight selected patients, we used a titration assay of the PCR-amplified product to estimate the number of residual tumor cells in each clinical sample post-BMT. PCR results in four patients showed a continuing increase in the number of tumor cells from early posttransplant until either cytogenetic or clinical relapse could be detected by conventional methods 1 to 2 years later. In contrast, PCR detected either no leukemia cells or relatively low and stable numbers of residual tumor cells throughout the follow-up period in four patients who remained in clinical remission. These results show that detection of the bcr-abl transcript by PCR after allogeneic BMT in patients with CML has important prognostic value. Estimation of the number of tumor cells in serial analyses can also be used to detect proliferation of the residual leukemic population. Sensitive detection of minimal residual disease can be used to assess the effectiveness of the transplant preparative regimen and to direct and evaluate further therapy post-BMT, before the development of overt relapse.
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PMID:Clinical significance of bcr-abl gene rearrangement detected by polymerase chain reaction after allogeneic bone marrow transplantation in chronic myelogenous leukemia. 182 68


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