Preparative high-performance liquid chromatography of macrotetrolides.
Explore the source record for details and available documents.
Anti-Bacterial Agents↗
Biomedical subjects
M Beran
Publications and source records attributed to M Beran.
The effects of acetaldophosphamide, a novel stable aldophosphamide analogue, on normal human and leukemic progenitor cells in vitro: implications for use in bone marrow purging.
Acetaldophosphamide (A-ALD), a novel in vitro active and stable derivative of aldophosphamide, kills human bone marrow-derived granulocyte-macrophage colony-forming cells (GM-CFC) independent of the cell cycle. The surviving fraction of GM-CFC is an exponential function of the drug concentration and time of exposure. Variation of marrow light-density cell concentration between 2 x 10(6) and 10 x 10(6)/ml does not significantly influence its GM-CFC toxicity. Marrow depleted of GM-CFC by A-ALD subsequently generates GM-CFC when grown in suspension cultures. During the early period after treatment with A-ALD the number of surviving GM-CFC (size of surviving GM-CFC compartment) does influence the speed of the GM-CFC repopulation in suspension cultures. The importance of the number of surviving GM-CFCs for the growth and maintenance of GM-CFC population in such suspension cultures diminishes with time. No significant differences are observed after 2 wk, indicating that the ancestor stem cell population and its regenerative potential responsible for in vitro hematopoiesis have not been significantly affected by the drug treatment. A-ALD-treated progenitor cells retain their ability to integrate with the previously established marrow stromal cell layer and generate GM-CFC within this layer to an extent comparable to that of untreated marrow cells. The effect of A-ALD on human hematopoiesis is comparable to that of 4-hydroperoxycyclophosphamide. Its advantage over 4-hydroperoxycyclophosphamide is a greater stability in vitro. It has sparing effect on GM-CFC ancestor cells. Its toxicity to myeloid leukemia cell line (KBM-3)-derived clonogeneic cells is higher than to the GM-CFC. It is similar in doxorubicin-sensitive (KBM-3) and -resistant (KBM-3/DOX) leukemic cells. Thus, A-ALD appears to be a promising drug for in vitro purging of bone marrow cells.
Bone Marrow↗
Suppression of c-myc and c-myb expression in myeloid cell lines treated with recombinant tumor necrosis factor-alpha.
Proto-oncogenes are thought to be involved in cellular differentiation and proliferation. Tumor necrosis factors (TNFs) are specific cytokines that have cytostatic and cytotoxic effects in vitro against a wide range of human tumor cells. We have previously demonstrated that recombinant TNFs (rTNFs) have an antiproliferative effect on certain human leukemic cell lines (HL-60, KBM3, KBM5) and no effect on others (K562). To study the possible role of the c-myc and c-myb oncogenes in this antiproliferative effect of TNF, we examined their expression in cell lines HL-60, KBM3, KBM5, and K562 before and after incubation with rTNF-alpha. Expression of c-myc and c-myb was elevated in all cell lines prior to incubation with rTNF-alpha. In the sensitive cell lines HL-60, KBM5, and KBM3 expression of c-myc and c-myb decreased rapidly 8-, 16-, and 4-fold, respectively, by 24 hr. K562 cells, insensitive to rTNF-alpha, exhibited no change in c-myc or c-myb expression over 24 hr. These studies demonstrated that down-regulation of c-myc and c-myb expression were associated with antiproliferative effects of rTNF-alpha on these cell lines.
Cell Line↗
Antileukemic effect of recombinant tumor necrosis factor alpha in vitro and its modulation by alpha and gamma interferons.
The effect of recombinant human tumor necrosis factor alpha (rTNF-alpha) on human myelogenous leukemia clonogenic cells growing either in semisolid media or in suspension cultures was studied and compared with the effect on normal granulocyte-macrophage progenitors (GM-CFC). Exposure of cells to a range of rTNF-alpha doses including pharmacologically achievable plasma concentrations revealed a large heterogeneity in the response of leukemic clonogenic growth to rTNF-alpha. Only one of 13 specimens was highly resistant to rTNF-alpha. Eight of ten leukemic samples were significantly more sensitive than were normal GM-CFC, particularly within the in vivo achievable dose range (1 x 10(0) to 1 x 10(2) ng/mL). No significantly increased inhibition of either normal or leukemic clonogenic growth could be achieved by increasing the rTNF-alpha concentration above 250 ng/mL. Proliferation of leukemic clonogenic cells (L-CFC) was studied in suspension cultures. In five cases the clonogenic cells were significantly inhibited by rTNF-alpha while in one case no inhibition was observed. The inhibition of L-CFC growth by rTNF-alpha was dose dependent between 1 x 10(0) and 1 x 10(2) ng/mL. In suspension cultures, the TNF effect on L-CFC was a function of time of exposure, particularly with low concentrations of TNF. A remarkably higher inhibition of L-CFC as compared with the total leukemic population was observed in suspension cultures. Stimulation of L-CFC growth by rTNF-alpha was not observed. Normal GM-CFC were inhibited by alpha and gamma interferons (INF-alpha, -gamma) in a dose-related manner, with higher sensitivity of colonies than clusters. The response of GM-CFC to combination of recombinant IFNs and TNF was influenced by the size of clones scored and the source of colony-stimulating activity. The response of L-CFC to recombinant IFN-alpha and/or -gamma was highly variable, and sensitivity to one of the lymphokines did not predict for sensitivity to another. The response of L-CFC to combinations of rTNF-alpha and either IFN-alpha or IFN-gamma was complex, varying from synergistic to additive and indifferent. In three of six specimens, IFN-gamma acted antagonistically with rTNF-alpha, a phenomenon not observed with IFN-alpha. These observations suggest that the action of rTNF-alpha in acute myelogenous leukemia could be exploited therapeutically and the dose-time-response relationship should be considered in designing treatment schedules.(ABSTRACT TRUNCATED AT 400 WORDS)
Cell Division↗
Tumor necrosis factor and human hematopoiesis: II. Inhibition and mode of action on normal and chronic myelogenous leukemia-derived granulocyte-macrophage progenitor cells.
Recombinant technology-produced tumor necrosis factor alpha (rTNF-alpha) inhibits clonogenic growth of normal granulocyte-macrophage colony-forming cells (GM-CFC) when it is continuously present in the culture medium. In our studies, day 7 and day 14 GM-CFC were inhibited and showed similar response. A decrease in the number of large colonies accounted for most of the inhibition, whereas growth of small clusters was inhibited to a lesser extent. Comparable inhibition was observed when bone marrow cells were cloned at low (2.5 x 10(4)/ml) or high (10 x 10(4)/ml) cell densities. A similar degree of inhibition by rTNF-alpha was found when conditioned medium from the human placenta or a bladder carcinoma cell line was used as the source of the colony-stimulating factors (CSF). The dose-response curve of GM-CFC to rTNF-alpha was sigmoidal, the maximum inhibition (90%) occurring at approximately 100 ng/ml of rTNF-alpha. Short-term treatment of bone marrow in suspension culture for 2 hr did not affect the subsequent colony formation, suggesting that TNF had an antiproliferative rather than a direct toxic effect on normal GM-CFC. GM-CFC derived from previously untreated patients with Philadelphia chromosome-positive chronic myelogenous leukemia (CML) showed an in vitro dose response to rTNF-alpha similar to that of normal GM-CFC. Inhibition of colony formation by CML-derived GM-CFC was more pronounced than GM-CFC from normal marrows, especially at low concentrations of rTNF-alpha. An increase in the concentration of rTNF-alpha above 250 ng/ml had no further effect on colony formation.(ABSTRACT TRUNCATED AT 250 WORDS)
Bone Marrow Cells↗
Detection of leukemic clone maturation in vivo by premature chromosome condensation.
The purpose of this study was to determine the feasibility of using the technique of premature chromosome condensation to detect the in vivo maturation of abnormal elements in patients with chronic myelogenous leukemia (CML), myelodysplastic syndrome, and acute leukemia. Patients were chosen for study if there were a clinical suggestion of in vivo maturation and a leukemic clone exhibiting a distinguishable karyotypic abnormality. Mature peripheral blood granulocytes were enriched by two-step Ficoll-Hypaque gradient sedimentation and fused with mitotic Chinese hamster ovary cells to induce the formation of prematurely condensed chromosomes (PCC). These PCC were then analyzed for chromosome number per cell (in the case of patients with a numerical abnormality) or by G-banding (in the case of specific translocations). Of 13 patients chosen for study, 12 showed karyotypic evidence for maturation of the abnormal elements in vivo. Maturation was observed in a number of clinical situations including before treatment in benign CML and myelodysplasia, after low-dose and high-dose chemotherapy in myelodysplasia and acute myelogenous leukemia (AML), and in remission. These results suggest that the technique of premature chromosome condensation can be a powerful tool in better understanding the biology of disease and mode of response to therapy in vivo in patients with leukemia and preleukemic syndromes, especially during treatment with agents thought to induce maturation of the leukemic elements.
Aneuploidy↗
Lack of breakpoint cluster region rearrangement in marrow fibroblasts of patients with Philadelphia chromosome-positive chronic myelogenous leukemia.
Involvement of marrow fibroblasts in myeloproliferative disorders such as chronic myelogenous leukemia (CML) is controversial. We examined the blood leukocytes and bone marrow fibroblasts of four patients with Philadelphia chromosome- (Ph1) positive CML for evidence of rearrangement in the breakpoint cluster region (BCR). Fibroblasts were obtained by growing bone marrow in long-term culture, disposing of nonadherent cells, and passaging three times before final trypsinization and analysis. DNA from fibroblasts and peripheral leukocytes was digested with Bg1II, Bc1I, EcoRI, and HindIII restriction endonucleases and hybridized to both 3' and 5' BCR probes. Southern blot analysis of the DNA from the peripheral leukocytes in all four patients demonstrated rearrangement in the BCR. However, analysis of DNA from marrow fibroblasts showed only the normal BCR restriction fragments in all patients. This study demonstrates the absence of the Ph1 -associated molecular events in the fibroblasts of patients with CML. It is consistent with previous studies using G6PD isoenzymes to show polyclonality in CML fibroblasts and with most cytogenetic studies that did not show the Ph1 in these cells. In summary, we present further evidence that involvement of CML fibroblasts is a secondary event in the leukemogenic process.
Bone Marrow Cells↗
Tumor necrosis factor and human hematopoiesis: I. Kinetics and diversity of human bone marrow cell response to recombinant tumor necrosis factor alpha in short-term suspension cultures in vitro.
The response of normal human bone marrow-derived granulocyte macrophage progenitor cells (GM-CFC) to human recombinant tumor necrosis factor alpha (TNF-alpha) was studied in short-term suspension cultures, in the presence or absence of human placenta-derived colony-stimulating factors (CSF). The effect of rTNF-alpha on GM-CFC was correlated with its influence on more mature progeny, as defined by standard morphological criteria, and was related to both dose of rTNF-alpha and length of exposure. After very short-term exposure (2 h), "inactivation" of a substantial number of GM-CFC was observed only in the presence of very high rTNF-alpha doses (1 x 10(4) ng/ml). When the exposure was prolonged to 16 h, a significant killing of both day 8 (GM-CFC8d) and day 14 (GM-CFC14d) progenitor cells was detected in the presence of 10 ng of rTNF-alpha/ml. Exposure for 5 days resulted in a further increase in the GM-CFC killing. Presence of yet unknown factor(s) in human placenta-conditioned medium sensitized GM-CFC to the action of rTNF-alpha. By morphological analysis of marrow cells, it was found that rTNF-alpha inhibited growth and/or recruitment of granulocytic precursor cells and caused inhibition of their differentiation. This effect was not dose dependent above 1 x 10(1) ng/ml. The presence of rTNF-alpha slightly promoted dose-dependent differentiation along the macrophage pathway. rTNF-alpha appeared to promote eosinophilic differentiation, also in a dose-dependent manner.
Colony-Stimulating Factors↗
Phenotypic and molecular heterogeneity in Philadelphia chromosome-positive acute leukemia.
Philadelphia chromosome-positive (Ph1) acute leukemia is a heterogeneous subset of acute leukemia with a poor prognosis. We studied five patients to determine the potential for phenotypic and molecular heterogeneity. Cellular characterization studies included light myeloperoxidase (L-MPO), terminal deoxynucleotidyl transferase (TdT), ultrastructural MPO (U-MPO), and immunophenotyping by flow cytometry using T11, T3, T4, T8, Leu 1, B1, Leu 12, HLA-DR (la), CALLA (J5), OKM1, My4, My7, My8, My9, and My10. DNA was analyzed for rearrangements of the breakpoint cluster region (bcr), immunoglobulin heavy chain, joining region (JH), immunoglobulin kappa light chain constant region (C kappa), and T cell receptor (TcR beta). RNA dot blots were hybridized by using molecular probes for MPO and TdT. We found that four of five cases were acute mixed-lineage leukemia (AMLL). One patient had acute unclassifiable leukemia. Of the four patients classified as having AMLL, three showed myeloid and lymphoid features, with one patient showing myeloid, T cell, and B cell features. The last case showed T cell and B cell features only. In one patient MPO/RNA was positive in spite of insufficient L-MPO or U-MPO to diagnose acute myelogenous leukemia (AML), thereby suggesting significant MPO gene expression before the production of sufficient MPO protein to meet the French-American-British criteria for AML. Three of the five patients showed rearrangement of bcr (cases 1, 2, and 5). Studies of these five patients support the concepts of molecular and phenotypic heterogeneity in Ph1 acute leukemia, demonstrate a high incidence of AMLL in this subset of acute leukemia, and support the use of lineage-associated molecular probes to define lineage at an earlier stage than previously possible.
Acute Disease↗
Effect of 1-beta-D-arabinofuranosylcytosine (ara-C) on nuclear topoisomerase II activity and on the DNA cleavage and cytotoxicity produced by 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) and etoposide in m-AMSA-sensitive and -resistant human leukemia cells.
The ability of a noncytotoxic dose of ara-C to modulate the amount of 4'-(9-acridinylamino)-methanesulfon-m-anisidide (m-AMSA)- or etoposide-induced topoisomerase II-mediated DNA cleavage and cytotoxicity was examined in m-AMSA-sensitive and -resistant HL-60 human leukemia cells. Ara-C pretreatment (0.1 microM x 48 hr) sensitized m-AMSA-sensitive cells to the cytotoxicity and DNA cleavage produced by both m-AMSA and etoposide. The actions of m-AMSA in the m-AMSA-resistant cells were affected minimally by ara-C. By contrast, ara-C enhanced etoposide-induced DNA cleavage and, to an even greater extent, etoposide-induced cytotoxicity in m-AMSA-resistant cells. These cells were only minimally cross-resistant to etoposide. Ara-C did not affect the cellular uptake of m-AMSA or etoposide, the amount of 0.35 M NaCl-extractable nuclear topoisomerase II activity from either cell line, or the ability of this enzyme activity to covalently bind to DNA in the presence of the drugs, m-AMSA- and etoposide-induced DNA cleavage is thought to result from drug-induced stabilization of a topoisomerase II-DNA complex. The ability of ara-C to modulate this effect and associated cytotoxicity appears to be mediated by the effects of ara-C on cellular targets other than topoisomerase II but which are important to topoisomerase II-mediated events, such as protein-associated DNA cleavage. A good candidate for such a target may be cellular chromatin.
Amsacrine↗
The interaction between nuclear topoisomerase II activity from human leukemia cells, exogenous DNA, and 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) or 4-(4,6-O-ethylidene-beta-D-glucopyranoside) (VP-16) indicates the sensitivity of the cells to the drugs.
The presumptive intracellular target of the anti-leukemia agents 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) and 4-(4,6-O-ethylidene-beta-D-glucopyranoside) (VP-16) is the enzyme topoisomerase II. We found that 350 mM NaCl extracts of nuclei from HL-60 and HL-60/AMSA, an m-AMSA resistant HL-60 subline, contained equivalent topoisomerase II activity. However, the ability of m-AMSA to stimulate cleavage of exogenous DNA and to stimulate crosslinking of exogenous DNA with protein, processes which are topoisomerase II-mediated, was greatly reduced in the HL-60/AMSA extracts compared to the HL-60 extracts. HL-60 and HL-60/AMSA were almost equally sensitive to the cytotoxic effects of VP-16 and differences in VP-16-stimulated, topoisomerase II-mediated exogenous DNA cleavage and protein crosslinking between HL-60 and HL-60/AMSA extracts were much less than the differences in m-AMSA-stimulated exogenous DNA cleavage and protein crosslinking. Thus, the interaction between topoisomerase II activity, exogenous DNA, and m-AMSA or VP-16 indicated the susceptibility HL-60 and HL-60/ AMSA to the cytotoxic effects of the drugs. A similar correlation may exist in explanted leukemia cells from patients with acute myelogenous leukemia.
Amsacrine↗
Development and characterization of a human myelogenous leukemia cell line resistant to 4'-(9-acridinylamino)-3-methanesulfon-m-anisidide.
The human myelogenous leukemia cell line HL-60 was made resistant to amsacrine (m-AMSA) by repeated exposure in vitro to increasingly large doses of the drug. Resistance to m-AMSA developed in a triphasic process and was accompanied by a slightly slower growth rate and cloning efficiency and a more differentiated morphological phenotype. Extensive chromosomal rearrangement also took place. Among other chromosomal aberrations, one of the No. 6 homologues showed an added segment on the long arm in the form of an homogeneously staining region. One of the homologues of chromosome 14 in every cell showed a deletion of the distal end of the long arm that was replaced by an unidentified homogeneously staining segment. Membrane-associated 170 kd glycoprotein was not overexpressed in the resistant cells, which together with an absence of cross-resistance to Vinca alkaloids and anthracyclines points toward a mechanism of resistance different from multidrug resistance. The ability of resistant cells to respond to differentiation-inducing agents was not significantly changed as compared with that of the parental line. Growth of resistant cells in the absence of m-AMSA for over 200 population doublings within a period of more than 1.5 years did not result in reversion of the resistance, suggesting a stable genomic change. Resistance was not due to a decrease in the bioavailability of the drug. Uptake of [14C]m-AMSA by either whole cells or isolated nuclei of resistant cells exceeded that of the parental cell line, and outward transport of the drug was not more active; thus there were higher levels of intracellularly bound drug. The cell line represents an excellent model for studies of the mechanisms of resistance to m-AMSA and its modulation in human myelogenous leukemia.
Amsacrine↗
In vitro toxicity and DNA cleaving capacity of benzisoquinolinedione (nafidimide; NSC 308847) in human leukemia.
Benzisoquinolinedione (nafidimide; NSC 308847) is an investigational drug currently in phase I clinical testing. We have studied the antileukemic activity in vitro, the cellular drug transport, and the molecular mechanism of action with DNA of this new compound. By agarose gel electrophoresis, we verified that nafidimide is an intercalating agent, through its alteration of the electrophoretic migration of DNA products produced by the relaxing action of DNA topoisomerase I. Concentrations of up to 100 microM of nafidimide did not produce topoisomerase I-mediated DNA cleavage. Nafidimide produced DNA single-strand breaks (SSB), double-strand breaks, and DNA-protein cross-links in human myeloid leukemia cells (measured with filter elution). The ratio of SSB/DNA-protein cross-links was 1.32 +/- 0.36, a value similar to that produced by 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA), suggesting that nafidimide, like m-AMSA, produced protein-associated DNA-strand breaks through a topoisomerase II-mediated reaction. The production of double-strand breaks by nafidimide also suggests the involvement of topoisomerase II in the drug-induced DNA cleavage. The cytotoxic activity of nafidimide was quantified in human myeloid leukemia cell lines differing by a factor of 70 in their cytotoxic sensitivity to m-AMSA. The m-AMSA-resistant line was less than 2-fold resistant to nafidimide. Cellular drug uptake was rapid and reached a steady state level in 30 min at 37 degrees C. At the end of exposure, drug egress was rapid, as was the disappearance of the DNA SSB. Rapid cellular uptake of nafidimide, with low retention at the end of exposure and rapid rejoining of DNA SSB suggest that prolonged cellular exposure may be necessary for optimal antitumor effect. In vitro cloning data suggest that nafidimide may be a therapeutic option for patients with leukemia resistant to m-AMSA.
Adenine↗
Infiltrated blue-gray plaques in a patient with leukemia. Chloroma (granulocytic sarcoma).
Explore the source record for details and available documents.
Female↗
Sensitivity and resistance to chemotherapy in acute leukemia: correlation with in vitro drug uptake and lack of potentiation by verapamil.
The calcium channel blocker verapamil has been reported to circumvent acquired resistance to different antitumor agents in tumor cell lines in vitro. We studied its effect on in vitro uptake of m-AMSA and adriamycin in fresh leukemic cells from 11 leukemia patients. Six previously untreated patients were sensitive to m-AMSA (obtained remission). Four were clinically resistant to m-AMSA, and two of these also to adriamycin. Leukemic cells were incubated in pharmacological doses of 14C-adriamycin and 14C-m-AMSA for up to 2 h. Samples were supplemented with verapamil (750 ng ml-1) 30 min prior to the addition of m-AMSA or adriamycin. Drug uptake was measured at 15 min intervals up to 2 h and drug retention was measured during 30 min after the end of incubation, following washing and resuspension in fresh medium without cytotoxic drugs. Adriamycin uptake was the same irrespective of verapamil in all four cell samples, two of which were derived from patients resistant to adriamycin. The cellular m-AMSA uptake was higher in cells from clinically sensitive than from resistant patients (510 +/- 155 fg cell-1 vs 275 +/- 125 fg cell-1; P less than 0.01). Retention of m-AMSA 30 min after incubation was higher in cells from sensitive compared to resistant patients (187 +/- 78 vs 25 +/- 7; P less than 0.05). Our data suggest: (1) in vitro uptake greater than or equal to 350 fg cell-1 and subsequent retention greater than 75 fg cell-1 correlate to clinical sensitivity to the drug; and (2) neither m-AMSA nor adriamycin uptake could be significantly increased by verapamil.
Acute Disease↗
Molecular characteristics of chronic myelogenous leukemia in blast crisis.
We have studied the expression of c-abl and c-myc in leukemic cells of patients in all clinical phases of chronic myelogenous leukemia. We demonstrate that an aberrant 8-Kb c-abl related transcript is present in the RNA of the leukemic cell from all patients with Ph+ CML and that the loss of both normal chromosome #9 is associated with the loss of the normal c-abl related transcripts. This represents direct evidence that the normal c-abl related transcripts derive from the normal c-abl gene locus on the normal chromosome #9, while the aberrant c-abl related transcript in Ph+ CML derives from the hybrid bcr-abl gene formed as a result of the t(9;22). We further demonstrate that trisomy 8 in some instances is associated with enhanced expression of the c-myc oncogene.
Blast Crisis↗
Ph-positive chronic myeloid leukemia with near-haploid conversion in vivo and establishment of a continuously growing cell line with similar cytogenetic pattern.
Blast cells from a 39-year-old man in the blastic phase of chronic myeloid leukemia, with a benign phase of 15 years duration, as well as a cell line arising from this cell population, were studied. Cellular morphology, cytochemical staining pattern, and absence of terminal deoxynucleotidyl transferase showed the blast cells to be of myeloid character. Cytogenetic studies revealed the presence of two near-haploid cell populations with +8 and +8, +15, respectively, both of them containing the translocation t(9;22) in the original tumor cell sample. The cell line derived from this patient's leukemic cell sample contained both near-haploid and hyperdiploid clones, the hyperdiploid clones being multiples of the near-haploid clone(s). All of the clones carried the t(9;22) in the form of a Philadelphia chromosome.
Adult↗
Haemostatic disorders in habitual nose-bleeders.
Ninety-one habitual nose-bleeders were screened for haemostatic disorders. 46 screening results in 38 nose-bleeders were outside the normal range. After extended investigation, it was found that 25 (27 per cent) habitual nose-bleeders had haemostatic disorders, all except one in the primary haemostasis. The disorders found could be classified as mild bleeding disorders (MBD) and compared to the estimated frequency of MBD in the population there was an increased incidence of haemostatic disorders in the habitual nose-bleeders. Abnormal vessels in the nasal mucosa were present in 85 per cent of the investigated nose-bleeders, equally distributed between nose-bleeders with and without haemostatic disorders. This indicates that abnormal vessels and haemostatic disorders in habitual nose-bleeders, it is possible to detect previously unknown but clinically important disorders.
Adolescent↗