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PubMed1981

Glucocorticoid receptors and sensitivity in leukemias.

In an attempt to investigate the utility of glucocorticoid receptor determination to predict clinical responsiveness in human leukemias we have studied glucocorticoid receptors in the leukemic cells from 46 patients and in the lymphocytes from 18 normal donors. In the normal lymphocytes there were 3,875 (Median) specific binding sites per cell. The blasts from 17 patients with ANLL had on average higher levels of binding sites per cell (Median = 7,250, range: 0 to 15,295) than the other leukemias. Of the 15 patients with CLL, six had received glucocorticoid treatment for 3 to 5 years. Their lymphocytes had lower number of receptors (Median = 2,000) than the other cases which were newly diagnosed (Median = 4,500). Four patients had ALL/AUL, three patients had blast crisis as terminal phase of CML, and seven had leukemic Non-Hodgkin lymphomas (Median = 3,500 sites/cell). In 24 patients we have also studied the in vitro sensitivity of the leukemic cells to dexamethasone. There was no marked correlation between glucocorticoid receptor levels and in vitro sensitivity. An attempt to correlate receptor levels with clinical responsiveness demonstrated that glucocorticoid receptor determination might be of value in patients with lymphoid malignancies but probably not in patients with other leukemias.

Adult↗
PubMed1985

Rapid generation of human T cell hybridomas.

Using the concept of a selectable surface marker we have generated screenable human T cell hybridomas within 4-7 days of fusion. OKT4+ T cell blasts were fused with MOLT4, an OKT4- T cell line, and OKT4+ fusion products were obtained by indirect rosetting technique. Supernatants of this heterogeneous population of hybrids were screened and those with activities of interest were subjected to cloning on soft agar and re-screening to dissect out various activities. Fusion efficiency, by staining, ranges from 6 to 80% depending on the state of activation of the T blasts and the growth phase of the MOLT4 line. This method allows for immortalization of T cell subpopulations, clones and malignant cells to study factor production and potentially messenger RNA for these factors. Additionally selectable surface markers may be used in human B cell and rodent:human fusions, avoiding the innate toxicity of various selection media.

Antigens, Surface↗
PubMed2004

Early prediction of molecular remission by monitoring BCR-ABL transcript levels in patients achieving a complete cytogenetic response after imatinib therapy for posttransplantation chronic myelogenous leukemia relapse.

Imatinib induces a high complete cytogenetic response (CCR) rate in relapsed chronic myelogenous leukemia. By analyzing minimal residual disease (MRD) under the levels of CCR, we tried to assess the molecular response after imatinib therapy. By using real-time quantitative reverse transcriptase-polymerase chain reaction (Q-RT-PCR), MRD was evaluated in 23 patients (3 in cytogenetic relapse, 6 in chronic phase, 9 in accelerated phase, and 5 in blast crisis) who were treated with standard-dose imatinib for relapsed chronic myelogenous leukemia after allogeneic stem cell transplantation. With a median therapy time of 399 days (range, 35-817 days), 19 (83%) patients achieved a CCR. Meanwhile, 11 (58%) of them achieved a molecular remission (MR), which was associated with improved survival. The Q-RT-PCR data were compared according to the best response (MR, n = 11; CCR, n = 8) in the patients achieving a CCR. The BCR-ABL/ABL ratios were similar in 2 groups at 3 months but were significantly different at 6 months (median, 0.0000012 for MR and 0.00022 for CCR; P =.003). The probability of a subsequent MR was significantly higher in patients with a lower BCR-ABL/ABL ratio at 6 months (100% for <0.0001 versus 33% for >/=0.0001; P =.006) or a greater reduction in the level between 3 and 6 months (log-reduction >/=1.0;, 100%; <1.0, 17%; P =.003). Q-RT-PCR is a reliable method for monitoring MRD: the early trends in the BCR-ABL/ABL ratio may be clinically useful in discriminating patients who will achieve an MR from those who will remain in CCR.

Adult↗
PubMed2005

Re-analysis of the cell line NALM-1 karyotype by GTG-banding, spectral karyotyping, and whole chromosome painting.

Chronic myelogenous leukemia (CML) is a clonal bone marrow disease with progression from a chronic phase to an aggressive blast crisis. The cell line NALM-1 was originally established by Minowada and coworkers from the peripheral blood of a patient in CML blastic crisis. A karyotype analysis of the NALM-1 cell line was performed in the 1970s. To the best of our knowledge, this karyotype was not re-analyzed by molecular cytogenetic techniques, although this cell line is the source of many molecular investigations including expression studies. To establish this cell line as a CML control in our own laboratory, NALM-1 was analyzed by GTG banding, fluorescence in situ hybridization, and spectral karyotyping. Our results differ from the original publication of Sonta and coworkers. We describe for the first time the karyotype of the NALM-1 cell line: 44,X,-X,der(7)t(7;9;15)(q10;?;q15),der(9)t(9;9)(p24;q33 approximately q34)t(9;22)(q34;q11),der(15)t(7;9;15) (?;?;q15),der(22)t(9;22)(q34;q11).

Cell Line, Tumor↗
PubMed2004

Biology of chronic myelogenous leukemia--signaling pathways of initiation and transformation.

Chronic myeloid leukemia (CML) is caused by the Bcr-Abl oncoprotein,the product of the t(9;22) chromosomal translocation that generates the Philadelphia chromosome. Different disease phenotypes are associated with each of the three Bcr-Abl isoforms: p190Bcr-Abl, p210Bcr-Abl, and p230Bcr-Abl all of which have a constitutively activated tyrosine kinase. Mechanisms associated with malignant transformation include altered cellular adhesion, activation of mitogenic signaling pathways, inhibition of apoptosis, and proteasomal degradation of physiologically important cellular proteins.CML is subject to an inexorable progression from an "indolent" chronic phase to a terminal blast crisis. Disease progression is presumed to be associated with the phenomenon of genomic instability.

Cell Transformation, Neoplastic↗
PubMed2004

Comparison of M-FISH and conventional cytogenetic analysis in accelerated and acute phases of CML.

FISH and multicolor FISH (M-FISH) techniques have greatly enhanced the resolution of conventional cytogenetic analysis, thus enabling the identification of novel regions of rearrangement in hematological malignancies. We report on the analysis of cells from 24 chronic myelogenous leukemia (CML) patients, in either accelerated phase (14 cases) or blast crisis (10 cases) aimed at searching for previously unidentified additional abnormalities related to disease evolution. Indeed, in 6 of 24 cases (25%) M-FISH allowed a more precise description of chromosomal aberrations, the finding of cryptic rearrangements, characterization of markers, identification of additional material and a better interpretation of complex aberrations. However, new recurrent aberration did not emerge from M-FISH analysis.

Adult↗
PubMed1998

Treatment of relapse after allogeneic bone marrow transplantation with unmanipulated G-CSF-mobilized peripheral blood stem cell preparation.

Donor lymphocyte infusions (DLI) are an effective treatment of leukemia relapse after allogeneic bone marrow transplantation. Undesired side-effects are the development of graft-versus-host disease (GVHD) and the occurrence of pancytopenia in some patients. In a pilot study, we investigated if unmanipulated G-CSF-mobilized peripheral blood stem cells which naturally contain large numbers of T lymphocytes (D-PBSC/LI) would be equally effective or even superior than DLI in generating a graft-versus-leukemia reaction (GVL) but could mitigate or prevent the development of pancytopenia. We treated 12 patients with CML chronic phase (n = 5), CML blast crisis (n = 2), AML (n = 2), ALL (n = 1), CLL (n = 1) and multiple myeloma (n = 1). In five patients with acute leukemia or CML blast crisis D-PBSC/LI followed intensive chemotherapy (group A), in seven patients D-PBSC/LI were given without any prior chemotherapy (group B). In group A two patients were evaluable for hematologic toxicity. Leukopenia <1000/microl lasted for 10 and 19 days, and thrombocytopenia <20,000/microl for 11 and 13 days, respectively. In group B leukopenia <1000/microl and thrombocytopenia <20,000/microl was observed in only one patient. Moderate cytopenia developed in four of five evaluable patients. A complete remission could be achieved in all seven patients with CML who all developed acute and/or chronic GVHD. None of the remaining five patients achieved a complete remission despite acute and/or chronic GVHD in two of them. Four patients died from disease progression, one patient from a secondary lymphoma, and one patient as a result of uncontrolled GVHD. In conclusion, D-PBSC/LI is effective in inducing GVL reaction but it does not prevent pancytopenia in each case. It remains unclear if it mitigates the incidence and severity of pancytopenia.

Adult↗
PubMed2005

Centrosome aberrations in chronic myeloid leukemia correlate with stage of disease and chromosomal instability.

Centrosome abnormalities are hallmarks of various cancers and have been implicated in chromosome missegregation, chromosomal instability, and aneuploidy. Since genetic instability is a common feature in chronic myeloid leukemia (CML), we sought to investigate whether centrosome aberrations occur and correlate with disease stage and cytogenetic findings in CML. We examined 34 CML samples including CD 34+Ph+cells of 18 newly diagnosed patients (chronic phase (CP)) and 16 blast crisis (BC) specimens by using a centrosome-specific antibody to pericentrin. All CP and BC samples displayed centrosome alterations as compared with corresponding CD 34+control cells. Centrosome abnormalities were detected in 29.1+/-5.9% of CP blasts and in 54.3+/-4.8% of BC blasts, but in only 2.4+/-1.1% of controls (P<0.0001). Additional karyotypic alterations to the t(9;22) translocation were found in only 1/18 CML-CP patients. In contrast, 11/16 (73%) CML-BC patients displayed additional karyotype alterations in 48.7% of analyzed cells, correlating with an abnormal centrosome status (P=0.0005). Our results indicate that centrosome defects are a common and early detectable feature in CML that may contribute to acquisition of chromosomal aberrations and aneuploidy. They may be considered as the driving force of disease progression and could serve as future prognostic markers.

Adolescent↗
PubMed2002

Phosphatidylinositol-3 kinase inhibitors enhance the anti-leukemia effect of STI571.

BCR/ABL fusion tyrosine kinase is responsible for the initiation and maintenance of the Philadelphia chromosome (Ph(1))-positive chronic myelogenous leukemia (CML) and a cohort of acute lymphocytic leukemias (ALL). STI571 (Gleevec), a novel anti-leukemia drug targeting BCR/ABL kinase can induce remissions of the Ph(1)-positive leukemias. STI571 was recently combined with the standard cytostatic drugs to achieve better therapeutic results and to overcome emerging drug resistance mechanisms. We decided to search for a more specific partner compound for STI571. Our previous studies showed that a signaling protein phosphatidylinositol-3 kinase (PI-3k) is essential for the growth of CML cells, but not of normal hematopoietic cells (Blood, 86:726,1995). Therefore the anti- Ph(1)-leukemia effect of the combination of BCR/ABL kinase inhibitor STI571 and PI-3k inhibitor wortmannin (WT) or LY294002 (LY) was tested. We showed that STI571+WT exerted a synergistic effect against the Ph(1)-positive cell lines, but did not affect the growth of Ph(1)-negative cell line. Moreover, the combinations of STI571+WT or STI571+LY were effective in the inhibition of clonogenic growth of CML-chronic phase and CML-blast crisis patient cells, while sparing normal bone marrow cells. Single colony RT-PCR assay showed that colonies arising from the mixture of CML cells and normal bone marrow cells after treatment with STI571+WT were selectively depleted of BCR/ABL-positive cells. Biochemical analysis of the CML cells after the treatment revealed that combination of STI571+WT caused a more pronounced activation of caspase-3 and induced massive apoptosis, in comparison to STI571 and WT alone. In conclusion, combination of STI571+WT or STI571+LY may represent a novel approach against the Ph(1)-positive leukemias.

Androstadienes↗
PubMed1996

p190bcr/abl rearrangement in myelodysplastic syndromes: two reports and review of the literature.

We describe two patients with myelodysplastic syndrome (MDS) and the Philadelphia chromosome (Ph). The patients were 64- and 69-year-old men who were diagnosed as having refractory anaemia with excess of blasts. During the terminal phase, the MDS evolved to myeloblastic leukaemia. Chromosome analysis showed normal karyotypes mixed with metaphases containing a classic Ph chromosome t(9;22)(q34;q11). Surprisingly, molecular studies showed breakpoint cluster region rearrangement between exons e1 and a2, compatible with a p190bcr/abl breakpoint, as observed in acute lymphoblastic leukaemia. We discuss the correlation between MDS and acquisition of the Ph chromosome, and the occurrence of p190bcr/abl in MDS.

Adult↗
PubMed2001

Blastic mantle cell lymphoma associated with Burkitt-type translocation and hypodiploidy.

Two elderly men with stage IV mantle cell lymphoma (MCL) rapidly developed a leukaemic phase with unusually high blast counts that proved fatal. One lymph node biopsy showed diffuse MCL, the other blastic morphology. In addition to t(11;14), there were t(8;14) and t(1;19) in case 1 and dup(8)(q24q13) in case 2. Fluorescence in situ hybridization revealed genomic fusion of IgH/MYC genes in case 1 and an extra copy of C-MYC gene in case 2. The genomic alteration of C-MYC oncogene is probably implicated in the blastic transformation and aggressive behaviour of the disease.

Aged↗
PubMed2001

Dose-reduced conditioning for allografting in 44 patients with chronic myeloid leukaemia: a retrospective analysis.

This retrospective study describes the outcome of patients with chronic myeloid leukaemia after allografting using dose-reduced conditioning with fludarabine and busulphan. Forty-four Philadelphia chromosome (Ph)-positive patients were transplanted in nine German centres; 26 patients were in chronic phase, 11 in accelerated phase and seven in blast crisis. Thirty-four patients achieved complete remission, with 18 alive and disease-free at a median follow-up of 562 d (range 244-922 d). Grade II-IV acute graft-versus-host disease (GVHD) incidence was 43%. Twenty patients died, 15 of causes unrelated to relapse. Risk factors predisposing to graft failure by univariate analysis were an unrelated donor (8/23 compared with a related donor 2/21, P = 0.07) and interferon therapy within 90 d of transplant (4/6 versus 3/17, P = 0.025). At the last follow-up, of 31 patients for whom molecular or cytogenetic data were available, 16 (52%) were polymerase chain reaction-negative, and seven (23%) were Ph-negative by fluorescent in situ hybridization. These findings demonstrate that dose-reduced conditioning with fludarabine and busulphan provides durable engraftment and a low rate of relapse. However, in this population, many of whom were not eligible for high-dose conditioning due to age, reduced performance status, previous complications or extensive pre-treatment, these data highlight the need for effective anti-infectious and GVHD prophylaxis. In addition, this study supports the discontinuation of interferon therapy at least 90 d before transplant

Adult↗
PubMed1980

[Prognostic factors in acute lymphoblastic leukaemia--with special consideration of pre-diagnostic duration of signs (author's transl)].

It is concluded from the prognostic factors of acute lymphoblastic leukaemia, as far as they have become known up to now, such as initial leukocyte count, extent of organ infiltration, etc, that the pre-diagnostic duration of signs, representing a measure of the proliferation activity of the leukaemia cells, could also represent a relevant prognostic characteristic. A check conducted in 90 children treated between 1966--1975 yields a correlation only between a very short pre-diagnostic duration of signs (less than 2 weeks) and the duration of the first complete remission (as well as the survival time). However, even those prognostic factors which are already generally recognised, possess merely limited reliability, because they do not take the individual response to therapy into account. Hence, improvement of prognosis of the course of the disease can be expected only if the continuous decrease of the remaining population of blasts during the early phase of remission can be determined with greater accuracy than before.

Child↗
PubMed1990

[Allogeneic bone marrow transplantation in chronic myeloid leukemia. The results of HLA-identical transplants in the Federal Republic of Germany].

In a multicenter study (seven University clinics) in the German Federal Republic bone marrow transplants from HLA-identical donors were performed in 177 patients (113 men, 64 women, mean age 32 [1.3-50] years) with Philadelphia chromosome-positive chronic myeloid leukaemia from 1982 to 1988. The survival rate among the 144 patients in whom the transplant had been carried out during the first chronic phase amounted to 58.4 +/- 11.4% after a median observation period of 3 years; survival rate among the 24 patients who underwent transplantation during the acceleration phase was 29.2 +/- 20.4%. All nine patients who received bone marrow transplants in the second chronic phase or during a blast crisis died during the period of observation (after median periods of 4 and 2 months, respectively). The most frequent causes of death among the group as a whole (82/177 patients) were interstitial pneumonia, acute and chronic graft versus host reactions (GVHD), recurrences and the toxic effects of previous treatment. The risk factors which significantly diminished survival rate were moderate to severe acute GVHD, chronic GVHD and age over 30 years.

Bone Transplantation↗
PubMed1990

Expression of mdr1 and mdr3 multidrug-resistance genes in human acute and chronic leukemias and association with stimulation of drug accumulation by cyclosporine.

We determined the expression levels of the mdr1 and mdr3 multidrug-resistance genes (also known as PGY1 and PGY3, respectively) in peripheral blood cells from 69 adult patients with acute and chronic leukemias, using an RNase protection assay. Expression of mdr1 was found in samples from patients with acute nonlymphocytic leukemia (13 of 17), chronic myelocytic leukemia (CML, chronic phase, 10 of 10; blast crisis, three of four), acute lymphocytic leukemia (ALL, eight of 11), B-cell chronic lymphocytic leukemia (B-CLL, 17 of 17), hairy cell leukemia (HCL, one of two), and T-cell prolymphocytic leukemia (one of one), but not in B-cell prolymphocytic leukemia (B-PLL, 0 of seven). Expression of mdr3 was only detected in samples from B-cell lymphocytic leukemias: CML, lymphoid blast crisis (one of one), B-cell ALL (two of two), B-CLL (17 of 17), B-PLL (seven of seven), and HCL (two of two). In vitro drug uptake studies by on-line flow cytometry showed that in leukemia cells expressing either mdr1 or mdr3, the steady-state accumulation of daunorubicin could be significantly increased by addition of cyclosporine and, to a lesser extent, by verapamil. Because cyclosporine and verapamil are known as inhibitors of the mdr1-encoded P-glycoprotein drug-efflux pump, and because the mdr1 and mdr3 genes are highly homologous, our data suggest that the mdr3 gene encodes a functional drug pump in B-cell lymphocytic leukemias. The results of this study may have implications for clinical therapy for acute or chronic leukemias expressing the mdr1 or mdr3 gene, in particular, treatment with combinations of cytotoxic drugs plus agents that reverse multidrug resistance. Since mdr1 and mdr3 are frequently expressed in untreated as well as treated leukemia, such combination therapy should be considered for untreated patients as well as treated patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Woronin body function in Magnaporthe grisea is essential for efficient pathogenesis and for survival during nitrogen starvation stress.

The Woronin body is a peroxisome-derived dense-core vesicle that is specific to several genera of filamentous ascomycetes, where it has been shown to seal septal pores in response to cellular damage. The Hexagonal peroxisome (Hex1) protein was recently identified as a major constituent of the Woronin body and shown to be responsible for self-assembly of the dense core of this organelle. Using a mutation in the Magnaporthe grisea HEX1 ortholog, we define a dual and essential function for Woronin bodies during the pathogenic phase of the rice blast fungus. We show that the Woronin body is initially required for proper development and function of appressoria (infection structures) and subsequently necessary for survival of infectious fungal hyphae during invasive growth and host colonization. Fungal mycelia lacking HEX1 function were unable to survive nitrogen starvation in vitro, suggesting that in planta growth defects are a consequence of the mutant's inability to cope with nutritional stress. Thus, Woronin body function provides the blast fungus with an important defense against the antagonistic and nutrient-limiting environment encountered within the host plant.

Base Sequence↗
PubMed1981

Haemoglobin and prognosis in childhood acute lymphoblastic leukaemia.

Two hundred and nine children presenting consecutively with acute lymphoblastic leukaemia to a regional paediatric oncology unit were investigated to determine the prognostic significance of various factors at diagnosis. There was a strong positive correlation between the pretreatment haemoglobin level and the percentage of bone marrow blast cells in S phase of the cell cycle as assessed by flow cytometry. Patients with T- and B-cell leukaemia had significantly higher haemoglobin levels than non-B non-T patients. In patients with total white cell counts less than 20 X 10(9)/l, aged less than 13 years, and no mediastinal mass, there was no association of haemoglobin with length of first remission. However, among those with white blood counts greater than 20 +/- 10(9)/l there was a strong positive trend towards shorter remission with higher haemoglobin levels. Children with high white blood counts at diagnosis and low haemoglobin levels may have a better prognosis than predicted by the white blood count alone.

Child↗
PubMed2002

Cytogenetic and molecular genetic aspects of chronic myeloid leukaemia.

Chronic myeloid leukaemia (CML) is caused by the product of the BCR-ABL oncogene, located on the Philadelphia (Ph) chromosome. BCR-ABL is generated as a result of a reciprocal t(9;22) chromosomal translocation. The mechanisms responsible for this illegitimate recombination event remain elusive but are presumed to require a close spatial association of the translocation partners (chromosomes 9 and 22). BCR-ABL fusion transcripts can be detected by a sensitive reverse transcription-polymerase chain reaction (RT-PCR) in the leucocytes of some healthy individuals suggesting that chromosomal translocations may occur frequently in the general population. The presence of BCR-ABL fusion transcripts does not imply that the individual will inevitably develop CML since other conditions must be favourable for expansion of the abnormal clone. Breakpoints in the ABL gene occur within a 5' segment. BCR-ABL fusion transcripts lack ABL exon a1 and consist of BCR exons fused directly to ABL exon a2. The breakpoints in the BCR gene on chromosome 22 are found within three defined regions. Depending on the position of the BCR breakpoint, fusion genes are generated that encode 190-, 210- or 230-kD forms of the Bcr-Abl tyrosine kinase. Since the ABL component of the fusion gene is largely invariant, it follows that variability in disease phenotype may be due to protein sequences encoded by the translocation partner, BCR. Different disease phenotypes are associated with each of the three Bcr-Abl oncoproteins, p190(Bcr-Abl), p210(Bcr-Abl )and p230(Bcr-Abl). Mechanisms associated with malignant transformation include altered cellular adhesion, activation of mitogenic signalling pathways, inhibition of apoptosis and proteasomal degradation of physiologically important cellular proteins. CML is subject to an inexorable progression from an 'indolent' chronic phase to a terminal blast crisis. Disease progression is presumed to be associated with the phenomenon of genomic instability.

Apoptosis↗