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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic myeloid leukemia (CML) was diagnosed in a 19-year-old man in 1961, and the disease remained in chronic phase, with occasional exacerbations, for 27 years. In 1976, when the first cytogenetic analysis was performed, t(9;22)(q34;q11) was found as the sole abnormality in all mitoses. During accelerated phase in 1988, a second cytogenetic investigation showed the karyotype 45,XY,t(9;22)(q34;q11),-15,-17,+der(15) t(15;17)(p13;q11). Molecular analysis revealed a rearrangement in the 5' end of the major breakpoint cluster region (M-bcr). With the case presented here, sublocalization of the bcr breakpoint has now been undertaken in altogether five CML patients with extremely long survival. It is noteworthy that in all these cases the chromosome 22 breakpoint was located in the 5' region of the M-bcr.
Leukemia 1990 Jun
PMID:Remarkably long survival of a patient with Ph1-positive chronic myeloid leukemia and 5' bcr rearrangement. 235 44

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.
Leukemia 1990 Jun
PMID:Molecular analysis of a CML patient with a long duration of chronic phase before and after lymphoid blast crisis. 235 47

A case of Philadelphia (Ph1) chromosome positive acute myelogeneous leukemia (AML) following a refractory anemia with excess of blasts (RAEB) with 8 trisomy is reported. The 80-year-old man developed pancytopenia during the course of follow-up after the surgical operation of the carcinoma of the sigmoid colon and the rectum for which no irradiation therapy nor chemotherapy had been applied. The diagnosis of RAEB was made according to the diagnostic criteria proposed by FAB co-operative group. Chromosomal analysis revealed 8 trisomy in 54% of the metaphases of bone marrow cells. The remainders showed normal karyotype without Ph1 chromosome. He was on androgenic steroid and activated Vitamin D3 without significant changes in the clinical and the hematological features until 3 months later when many atypical blasts appeared in the peripheral blood. The diagnosis of AML (M2) was made. Chromosomal analysis revealed Ph1 chromosome with the typical 9;22 translocation in 100% of the examined cells. 8 trisomy was not detected any more. Southern blot analysis using bcr probe showed bcr rearrangement. He was treated with a small doses of Ara-C. There was some reduction in the number of blasts in the peripheral blood. However, he died of septicemia 2 months later. The present case indicates that Ph1 positive acute leukemia with bcr rearrangement is not necessarily considered as a blastic transformation of chronic myelogeneous leukemia and such a cytogenic abnormality can appear in a leukemic transformation of myelodysplastic syndrome.
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PMID:[Acquisition of Philadelphia chromosome with bcr rearrangement concomitant with transformation of refractory anemia with excess of blasts with 8 trisomy into acute myelogenous leukemia]. 236 38

We studied the pattern of BCR involvement in 52 patients with chronic myeloid leukemia by Southern blotting. Of 33 Philadelphia (Ph)-positive patients, 30 had evidence of M-BCR rearrangement, two cases were difficult to interpret, and one clearly lacked evidence of M-BCR rearrangement. Of 19 Ph-negative patients, nine showed M-BCR rearrangement, nine showed no rearrangement, and one result was uncertain. We selected for more detailed study eight patients (three Ph-positive and five Ph-negative). Two of the Ph-positive patients, whose Southern blots were difficult to interpret, had rearranged bands when the BCR gene was studied by pulsed field gel electrophoresis (PFGE). Results of PFGE studies and in situ hybridization to metaphase chromosomes in the third Ph-positive patient, whose DNA clearly lacked M-BCR rearrangement on Southern analysis, were consistent with a breakpoint on chromosome 22 located 3' of all known exons of the BCR gene. However, mRNA studied with the polymerase chain reaction showed evidence of a classical b2-a2 linkage. The findings in this patient may be explained by an unusual genomic breakpoint downstream of the BCR gene associated with long range splicing that excluded all of the 3' BCR exons. Of the five patients with Ph-negative M-BCR non-rearranged CML studied by PFGE for BCR gene rearrangement, none had evidence of rearranged bands. We conclude that PFGE is a valuable adjunct to standard molecular techniques for the study of atypical cases of CML. Occasional patients with Ph-positive CML have breakpoints outside M-BCR. The BCR gene is probably not involved in patients with Ph-negative, M-BCR non-rearranged CML.
Leukemia 1990 Sep
PMID:Use of pulsed field gel electrophoresis to characterize BCR gene involvement in CML patients lacking M-BCR rearrangement. 239 84

The hallmarks of chronic myelogenous leukemia (CML) include the Philadelphia chromosome (Ph) translocation [t (9;22)(q34;q11)] and consistent molecular genetic aberrations: a break within a restricted 5.8 kb DNA segment, bcr, on chromosome 22q11; transposition of the c-abl protooncogene from chromosome 9q34 to 22q11; and formation of a hybrid bar-abl gene encoding an abnormal 210 Kd bcr-abl protein with augmented tyrosine kinase enzymatic activity. These molecular phenomena may occur even in the absence of cytogenetic evidence of the Ph translocation. They are highly specific and sensitive markers for CML, and are presumed to play a significant role in the pathogenesis of this malignancy. Surprisingly, we have encountered 11 patients who lacked the Ph translocation, bcr rearrangement, and (in the four patients with available mRNA) a bcr-abl message, and yet had a disease phenotype at diagnosis that was a morphologic facsimile of classic chronic phase CML. These patients presented with high white blood cell counts, neutrophilia, occasional basophilia, splenomegaly, and a hypercellular bone marrow with granulocytic hyperplasia and a left shift in myeloid maturation. Despite the striking resemblance between the early stages of bcr-negative and bcr-positive CML, disease progression manifests distinctly in these two disorders. In contrast to the blastic transformation that inevitably complicates bcr-positive CML, the natural history of our 11 Ph-negative, bcr-negative CML patients was characterized by increasing leukemia burden with leukocytosis, pronounced organomegaly, extramedullary infiltrates, and eventual bone marrow failure (anemia and thrombocytopenia) without marked increases in blast cells. Our current observations suggest that a chronic myeloid leukemia process can develop without associated changes in the bcr or c-abl genes. Although the initial phase of this disease is indistinguishable from CML, the presence or absence of molecular markers may aid in the prediction of the clinical course of Ph-negative CML.
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PMID:Philadelphia chromosome-negative chronic myelogenous leukemia without breakpoint cluster region rearrangement: a chronic myeloid leukemia with a distinct clinical course. 240 27

Antibodies against phosphotyrosine are a powerful tool with which to identify proteins phosphorylated on tyrosine residues, such as viral oncogene-encoded transforming proteins and their cellular protein substrates. Probed on human leukemia cell lines, phosphotyrosine antibodies recognized a 210,000-molecular-weight protein (p210) in K562 cells, a cell line derived from a Philadelphia (Ph)'-positive chronic myelogenous leukemia (CML), but recognized no protein in control Ph'-negative non-CML leukemia cells. The p210 protein was also recognized by antisera against v-abl-encoded polypeptides and displayed kinase activity, phosphorylating itself on tyrosine, in an immunocomplex kinase assay. These data are consistent with reported findings of the expression of a recombined bcr-abl gene in Ph'-positive CML cells, leading to the synthesis of an altered p210c-abl protein endowed with tyrosine kinase activity. Phosphotyrosine antibodies also detected the expression of the p210c-abl protein in fresh bone marrow cells harvested from CML patients in blast crisis. Besides the p210c-abl protein kinase, phosphotyrosine antibodies recognized other proteins with molecular weights of 110,000, 68,000, and 36,000 (p110, p68, and p36) in K562 cells. When [gamma-32P]ATP was added to nonionic detergent-extracted cells, these proteins became phosphorylated on tyrosine, as confirmed by phosphoamino acid analysis. A comparison with fibroblasts transformed by the v-abl, v-src, and v-fps oncogenes suggested the identity of the p36 protein with the common 36-kilodalton protein substrate of viral oncogene-encoded tyrosine kinases. Enhanced tyrosine phosphorylation of cellular proteins is thus a feature shared by cells transformed by v-abl and cells expressing a rearranged bcr-abl gene.
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PMID:Phosphotyrosine antibodies identify the p210c-abl tyrosine kinase and proteins phosphorylated on tyrosine in human chronic myelogenous leukemia cells. 243 Dec 86

In chronic granulocytic leukemia (CGL) the Philadelphia translocation results in the production of a novel 210 kDa bcr-abl fusion protein which shows increased tyrosine protein kinase activity in comparison with its normal 145 kDa c-abl counterpart. Using an immunoblotting method and antiphosphotyrosine antibody, we have identified the tyrosine protein kinase substrates present in intact cells from two Philadelphia-positive CGL derived cell lines (K562 and BV173) and compared these with the substrates present in a Philadelphia-negative myeloid cell line (HL60). We have demonstrated an increased number of substrates, particularly of low (less than 110 kDa) molecular weight in the K562 or BV173 cells compared with the HL60 cells. There is virtual identity of the substrates present in the two CGL-derived lines. This work supports the hypothesis that the functional changes present in the bcr-abl 210 kDa protein of CGL results in altered tyrosine phosphorylation of intracellular proteins and that this is of importance in the pathogenesis of CGL.
Leukemia 1987 Jun
PMID:Tyrosine protein kinase substrates in Philadelphia-positive human chronic granulocytic leukemia derived cell lines (K562 and BV173): detection by using an immunoblotting technique. 244 34

Chronic myelocytic leukaemia is a myeloproliferative syndrome with two highly specific characteristics: it has a cytogenetic clonal marker known as Philadelphia chromosome and a molecular marker in the form of bcr-abl rearrangement, and it progresses in two phases: a chronic phase followed by an acute terminal phase of blastic transformation. The fatal outcome of this blood disease can only be checked if we possess one or several treatments providing a complete and stable clinical, haematological and cytogenetic remission. Such a course is seldom observed. The conventional treatment of the chronic phase consists of single drug chemotherapeutic regimens which have succeeded in increasing the patients' median survival but do not prevent blastic transformation which is beyond therapeutic resources. In some cases multiple drug chemotherapy, and notably bone marrow transplantation, may result in disappearance of the Philadelphia chromosome and arrest of the natural course of the disease. Interferon is a new treatment which eradicates the Philadelphia chromosome and offers hopes of complete and prolonged, if not permanent, remissions. The present experience, although limited, suggests that alpha-interferons are effective. Judging from the available data, it is very likely that the future treatment of myelocytic leukaemia will consist of chemotherapy combined with interferon(s) with or without bone marrow transplantation.
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PMID:[Does the Philadelphia chromosome disappear after treatment with interferon?]. 245 50

The gene for human leukemia inhibitory factor (LIF) has been mapped by Southern analysis of a series of mouse/human somatic cell hybrids and by in situ hybridization to the chromosomes of two normal males and some individuals with chromosomal rearrangements. The gene maps to 22q11-q12.2, between the Philadelphia translocation BCR gene and the breakpoint of the translocation in cell line GM2324 at 22q12.2. From the grain distribution over high resolution chromosome preparations, the most likely location is 22q12.1----q12.2. Southern analysis of DNA from one Ewing sarcoma with t[11;22][q24;q12] showed that the breakpoint on chromosome 22 is more than 15 kb 5' or 8 kb 3' from the LIF gene. The location of the LIF gene indicates that translocations of this gene are unlikely to play a role in myeloid leukemia and myeloproliferative disorders.
Leukemia 1989 Jan
PMID:The gene for human leukemia inhibitory factor (LIF) maps to 22q12. 249 97

A 31/2-year-old female presented with thrombocytopenia and anemia. The bone marrow showed marked hemophagocytosis with an increase in macrophages. Over the next 2 months, there was a progressive de-differentiation of this monocytic population with the accumulation of blasts in the blood and bone marrow. The blasts had a normal 46XX karyotype and showed no fusion of the bcr and abl genes associated with Philadelphia chromosome positive leukemia. Intensive chemotherapy produced a transient hypoplastic state during which a bone marrow transplant was performed. The bone marrow after transplant again demonstrated a large population of macrophages. These cells continued to de-differentiate over the ensuing year up until the time of the patient's death. The mononuclear blast cell population was inducible toward monocytic maturation in tissue culture by low doses of ARA-c or daunorubicin. These mononuclear blasts expressed c-myc and c-fos mRNA at high levels, a further marker of their proliferative state and monocytic origin.
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PMID:Juvenile chronic myeloid leukemia: oncogene characterization. 251 62


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