Relationship of DNA topoisomerase II alpha and beta expression to cytotoxicity of antineoplastic agents in human acute lymphoblastic leukemia cell lines

The levels of expression of topoisomerase II alpha and topoisomerase II beta were investigated in six established cell lines of human childhood acute lymphoblastic leukemia (ALL) as a function of doubling time, cell cycle distribution, and of sensitivity to the antineoplastic agents Adriamycin and etoposide. The slowest growing cell line, ALL-G, was most sensitive to both drugs, whereas the fastest growing cell line, ALL-C, was 15.3- and 6.4-fold more resistant than ALL-G to Adriamycin and etoposide, respectively. Furthermore, ALL-W, the second most rapidly dividing cell line, was most resistant to both Adriamycin (22.8-fold) and etoposide (14.1-fold). Expression of topoisomerase II alpha varied inversely with doubling time, whereas no correlation was found between topoisomerase II beta levels and doubling time. Expression of topoisomerase II beta varied inversely with that of topoisomerase II alpha. The level of topoisomerase II alpha correlated directly with the percentage of cells in S and G2-M phases, whereas topoisomerase II beta expression varied directly with the number of cells in G1. An inverse correlation was found between the level of expression of topoisomerase II beta and resistance to Adriamycin, whereas a direct correlation was observed between the level of expression of topoisomerase II alpha and resistance to Adriamycin. Studies with etoposide, although not statistically significant, were consistent with the pattern observed with Adriamycin. These findings suggest that in ALL cells, cytocidal activity of Adriamycin and etoposide may be mediated, at least in part, by topoisomerase II beta.

Tumor formation by a human pre-B leukemia cell line in scid mice is enhanced by matrigel and is associated with induction of CD10 expression

We have previously demonstrated the engraftment of human pre-B acute lymphoblastic leukemia (ALL) cells injected intravenously into irradiated scid mice. We now report on the ability of the reconstituted extracellular matrix, Matrigel, to promote the formation of subcutaneous tumors in non-irradiated scid mice by a CD10- pre-B ALL cell line termed G2. Lymphatic tumors infiltrating the dermis were seen in all eight mice sacrificed 10-13 weeks after the co-injection of G2 cells and Matrigel but in only 2/8 mice injected with leukemic cells alone. Infiltration of bone marrow, spleen, thymus, lung and liver was observed earlier and was more extensive in the Matrigel-treated group. The tumor cells derived from Matrigel-treated mice could be passaged in vitro and their colony-forming ability was higher than that of the original G2 line. When re-injected intravenously into non-irradiated scid mice, the tumor cells invaded the thymus earlier than did the G2 cells. The expression of CD10/neutral endopeptidase was induced at high levels in all tumors, in Matrigel or non Matrigel-treated animals. This up-regulation was transient as the tumor variants grown in vitro or in vivo lost expression of CD10. However, 6-8 weeks later, induction of CD10 was observed on both tumor variants and parental G2 cells growing in the thymus and at a lower level on cells in bone marrow and spleen. Culturing G2 cells in vitro at high density or in the presence of documented growth-promoting cytokines such as IL-3, IL-6, IL-7, and GM-CSF did not stimulate the expression of CD10 mRNA. The induction of this surface endopeptidase was thus associated with growth of leukemic cells in the specific microenvironments provided by the lymphoid tumors and the thymus in scid mice. The function of CD10 might be related to the hydrolysis of peptides which are critical in regulating interactions between adjacent pre-B cells, the stromal microenvironment and the transduction of growth and/or differentiation signals.

Early discharge of pediatric febrile neutropenic cancer patients by substitution of oral for intravenous antibiotics

In an open, prospective pilot study of pediatric cancer patients, 23 episodes of fever and neutropenia were treated with intravenous and then oral antibiotics. After 72 hours, patients were changed from intravenous to oral antibiotics if the following criteria were met: negative blood cultures, temperature 38.0 degrees C or lower for 24 hours, absolute neutrophil count less than 0.5 x 10(9)/L, and absence of clinical sepsis. Three patients (13%) had recurrent fever. Intravenous antibiotics were reinstituted in two of these three patients, and oral antibiotics were continued in the third. Fever was believed to be related to relapsed leukemia in one of the three patients. No focus of infection was defined in the other two, and both had good clinical outcomes. The study suggests that this approach to therapy is feasible and can be safely used for selected patients who are anticipated to have a short duration of neutropenia.

Lymphoid blast crisis of B-lineage phenotype with monosomy 7 in a patient with juvenile chronic myelogenous leukemia (JCML)

We studied a patient with juvenile chronic myelogenous leukemia (JCML) whose terminal course was characterized by transformation to acute lymphoblastic leukemia. Karyotypic studies identified monosomy 7 in leukemic myelomonocytic marrow cells during the chronic phase and in the lymphoblasts during the transformation phase. Our ability to sustain the transformed lymphoblasts in culture allowed us to characterize them further. CD19, HLA-DR, and CD10 were present, consistent with a pre-B acute lymphoblastic leukemia phenotype. CD14 (My-4) and CD13 (My-7) were negative. Rearrangement of immunoglobulin heavy- and light-chain genes identified monoclonal populations of cells of the B lineage. This case provides further evidence that JCML is a clonal disease of pluripotent stem-cell origin.

Failure of recombinant human interleukin-3 therapy to induce erythropoiesis in patients with refractory Diamond-Blackfan anemia

In two previous studies, we observed that recombinant human interleukin-3 (IL-3) induced an increase in marrow burst-forming unit-erythroid-derived colonies in vitro in some patients with Diamond-Blackfan anemia (DBA). To determine whether a similar erythropoietic response could be induced in vivo, we treated 13 patients with DBA (aged 4 to 19 years) with two preparations of IL-3. All patients had absent absolute reticulocyte counts and markedly reduced to absent recognizable bone marrow erythroid elements; patients with circulating reticulocytes in the previous 12 months were excluded from study. All patients except 1 had failed steroid therapy and had been transfusion-dependent since infancy; 1 patient was maintained on high-dose prednisone at the time of enrollment. On the first arm of the study, IL-3 (Immunex Corp, Seattle, WA) was administered subcutaneously using a dose escalation regimen of 125 to 500 micrograms/m2/day in divided dosage at 12-hour intervals, coadministered with 1.5 mg/kg/d of oral ferrous sulphate. Of the 13 patients that entered the trial, 4 stopped prematurely because of adverse side effects. In the other 9 evaluable cases, reticulocytes increased transiently in 1 patient from 0 to 65 x 10(9)/L after 35 days of IL-3 therapy at 250 micrograms/m2, but transfusion dependency persisted. One transient peak in absolute reticulocyte count was noted in 6 other patients, but no erythroid response was observed after completion of a full course of IL-3. Oral prednisone at 0.5 mg/kg/d was then coadministered with IL-3 at 500 micrograms/m2 to 5 of the patients without effect, and treatment was stopped. In 2 patients, a second preparation of IL-3 (Sandoz Canada Inc, Dorval, Quebec, Canada) was initiated in a dose escalation regimen of 2.5 to 10 micrograms/kg and was coadministered with ferrous sulphate. No erythroid response was observed in either patient, and in one of the two, alternate-day subcutaneous recombinant erythropoietin at 300 U/kg was administered for 3 weeks in combination with daily IL-3 at 10 micrograms/kg, but no increased erythropoiesis was seen. Significant increases in white blood cell and eosinophil counts during administration of both preparations of IL-3 were observed in all patients. These data show that the response of DBA patients to IL-3 in vivo is heterogeneous and cannot be predicted from in vitro studies. The absence of a corrective effect of IL-3 in these patients with DBA indicates that a deficiency of the cytokine is not central in the pathogenesis of the disorder.

Hb FM-Fort Ripley: confirmation of autosomal dominant inheritance and diagnosis by PCR and direct nucleotide sequencing

We describe a normal neonate who presented at four days of age with asymptomatic cyanosis. There was no evidence of cardiac or pulmonary abnormality and an extended family history included 13 other affected family members with asymptomatic cyanosis lasting one to three months. Polymerase chain reaction (PCR) amplification and direct nucleotide sequencing of the proband's G gamma chain gene revealed the mutation at codon 92 (CAC-->TAC) previously shown in haemoglobin FM-Fort Ripley (alpha 2 gamma G gamma 92 (F8) His-->Tyr). This is the first family with Hb FM-Fort Ripley reported so far. It demonstrates autosomal dominant inheritance of this condition and incomplete penetrance.

The induction of CD10 on a pre-B leukemia cell line occurs with progression of the disease in scid mice

We have previously demonstrated the engraftment and dissemination of human pre-B acute lymphoblastic leukemia (ALL) cells into scid mice. In the current study, the temporal pattern of infiltration of a CD10- pre-B leukemia line (G2) in various murine tissues and the progression of the disease in the whole animal were monitored by quantifying human CD44 mRNA expression by the polymerase chain reaction (PCR). Irradiated scid mice were injected intravenously with 10(6) G2 cells and killed 3 days to 10 weeks later. After 2 weeks, leukemic cells were found mostly in bone marrow, but also in lung. At 6 to 7 weeks, spleen and lung contained 30% human RNA, while peripheral blood, liver, and kidney contained 2-3%. Infiltration to brain and thymus was observed at 8-9 weeks. In terms of the whole animal, spleen and liver were the major sites of tumor burden. The induction of CD10 expression was previously observed in transplanted CD10- G2 leukemic cells recovered from scid thymus at 10-12 weeks, which corresponds to the terminal stage of disease. In this study, the CD10 expression on the leukemic cells was monitored at earlier time points by flow cytometry and quantitative PCR. Induction of CD10 was first observed in bone marrow, spleen, peripheral blood, and liver at 6-7 weeks (10-fold), at the time of the onset of dissemination of the leukemia. Despite the presence of 30% human RNA in lung at 6-7 weeks, CD10 induction was not significant in that site before 10 weeks. Increased levels of CD10 were seen in all tissues between 8 and 10 weeks; the highest levels were observed in leukemic cells proliferating in thymus (113-fold) and in those found in circulation. These findings suggest that initial induction of CD10 occurs in hematopoietic tissues at the time of rapid proliferation of the leukemic cells and their infiltration of several tissues. At later time points, the increase in CD10 expression is seen on the leukemic cells found in all peripheral organs suggesting an association with disease progression.

Erythropoiesis in Diamond-Blackfan anemia and the role of interleukin 3 and steel factor

Diamond-Blackfan anemia (DBA) is pleiotropic clinically and in vitro, and there is a strong suspicion that DBA is really a family of diseases that shares a common hematological phenotype. Although standard clonogenic assays of erythroid progenitors have been very informative about pathogenesis, they are not diagnostic of DBA, have no relationship to the clinical presentation and do not relate to the hemoglobin level or to the percentage of marrow erythroids at the time of study. Studies on progenitor-enriched marrow cells have furthered our understanding of DBA and have clearly shown marked differences among patients with respect to erythropoietin and "burst-promoting activity" responsiveness. In vitro addition of corticosteroids, interleukin 3 (IL-3) and/or Steel factor has produced a corrective effect on erythropoiesis in some DBA patients and has prompted clinical trials with IL-3 with variable results. It is clear that there is a disparity between the vitro data and clinical outcome, and therefore, the erythroid progenitor responsiveness to steroids and cytokines has limited predictive value clinically. Based on more than two decades of study, a model of DBA has evolved based on putative blocks at various stages along the erythropoietic differentiation pathway. These blocks likely represent a disorder of receptor-ligand interaction involving one or more growth-promoting cytokines.

Autocrine and paracrine growth control by granulocyte-monocyte colony-stimulating factor of acute lymphoblastic leukemia cells

Blast colony assays were performed on freshly obtained bone marrow samples from 19 newly diagnosed or relapsed children with acute lymphoblastic leukemia (ALL) of B lineage to determine the effect of added granulocyte-monocyte colony-stimulating factor (GM-CSF). Of the 19 marrow samples tested, 7 responded to GM-CSF with a mean increase in ALL blast colonies of 346%. Blast cells from one of the responders chosen for flow cytometric study showed expression of GM-CSF receptors on 38% of cells. These findings prompted us to establish five ALL cell lines of diverse phenotypes to examine the expression of GM-CSF and GM-CSF receptor genes in human leukemia, and to determine the role of GM-CSF in autocrine and paracrine growth control of ALL cells. One line, termed G2, manifested a GM-CSF-mediated autocrine pattern of cell growth with the following features: G2 blast colony growth in a serum-free system without added growth factor was density dependent; exogenous GM-CSF augmented G2 colony formation when the cells were seeded at low density; G2 cells constitutively expressed mRNA for GM-CSF and GM-CSF receptor; G2 cells also produced and secreted measurable amounts of GM-CSF into cell culture supernatant; and, monoclonal anti-GM-CSF antibodies abolished G2 colony growth when added to cultures with cells seeded at low density without growth factors. Of the other four ALL cell lines, three expressed mRNA for GM-CSF receptor and responded in vitro to added GM-CSF with increased blast colony growth; however, none of these four cell lines expressed mRNA for constitutive production of GM-CSF. A fifth ALL cell line lacked receptors for GM-CSF and did not respond in clonogenic assays to added GM-CSF. Thus, a bioregulator of normal hematopoiesis plays a central role in autocrine growth control of G2 ALL cells, and an important paracrine growth-promoting role in three of four other ALL cell lines.

Interleukin 6 induces myeloid differentiation of a human biphenotypic leukemic cell line

The human leukemic cell line B1, is characterized by a specific 4;11 chromosomal translocation, immature myeloid/pre-B biphenotypic features, expression of multiple cytokine receptors and IL-1-dependent autocrine growth regulation [Cohen et al. (1991) Blood 78, 94]. Exposure of B1 cells to low concentrations of IL-6 abolished the leukemic cells ability to form colonies in semi-solid medium and slowed down their proliferation rate in suspension. Associated with these changes in growth characteristics, the B1 cells differentiated along the myeloid lineage as judged by the induction of the myeloid-specific surface antigens CD33, CD13 and CD11b, as well as histochemical and morphological changes characteristic of myeloid cells. The induction of differentiation was specific to IL-6 since none of the other cytokines which inhibited B1 cell growth (IL-7, gamma IFN and TNF alpha) were able to induce myeloid or lymphoid differentiation in these cells. The IL-6-induced differentiation was completed over a two week period and was essentially irreversible. Together with the phenotypic changes, IL-6 induced the expression of the protein tyrosine phosphatase (CD45) which may be associated with altered growth observed in IL-6-treated cells. Induction of terminal differentiation of leukemic cells by recombinant bioregulators has therapeutic implications and merits further study.

Growth failure and bony changes induced by deferoxamine

We reviewed the linear growth and growth plate morphology in all children with homozygous beta thalassemia followed in Toronto, for whom monthly height percentiles were available before, and for a 36-month period after, the initiation of nightly subcutaneous deferoxamine therapy. All patients were less than 7 years of age when begun on deferoxamine, and had received nightly deferoxamine for a minimum of 36 months. Marked abnormalities of the metaphyseal growth plate were readily observed in the distal ulnar, radial, and tibial metaphyses in 11 of 37 patients in whom a significant decline in mean height percentile was also noted. (In 10 of these 11 patients, height was less than the 15th percentile after 36 months.) These 11 patients had received a significantly greater (p less than 0.025) initial and average daily dose of deferoxamine, and had maintained a significantly lower (p less than 0.025) mean serum ferritin concentration over the 36 months, than the remainder of the cohort. To determine whether deferoxamine played a causative role in growth failure, growth in patients who began deferoxamine before the age 2 years was compared to that of patients who began after age 5 years, for the period between 2 and 5 years of age. Only patients begun on deferoxamine prior to age 2 years demonstrated a significant (p less than 0.01) decline in height percentile by the third year, implicating deferoxamine therapy as the cause of growth failure. We conclude that both the decline in height percentile and the bony changes observed in well-chelated patients are directly related to deferoxamine therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Central role of tumour necrosis factor, GM-CSF, and interleukin 1 in the pathogenesis of juvenile chronic myelogenous leukaemia

In previous studies on patients with juvenile chronic myelogenous leukaemia (JCML), we found excessive proliferation of malignant monocyte-macrophage elements in the absence of exogenous growth factor, and impaired growth of normal haematopoietic progenitors. In the current study, six newly-diagnosed JCML patients were investigated to characterize the disease further. In co-cultures, JCML cell culture supernatant as well as patient plasma obtained at diagnosis produced a striking reduction in numbers of control marrow BFU-E, CFU-GM, CFU-Meg and CFU-GEMM colonies. Monoclonal anti-tumour necrosis factor alpha neutralizing antibodies (anti-TNF-alpha Ab) abolished these inhibitory properties. In sharp contrast, JCML supernatants exerted a marked growth-promoting effect on autologous JCML cells cultured in clonogenic assays. Anti-TNF-alpha Ab and anti-granulocyte-macrophage colony-stimulating factor neutralizing antibodies (anti-GM-CSF Ab) both reversed the stimulating effect. Recombinant GM-CSF and recombinant TNF alpha produced a profound increase in JCML colonies when tested individually and anti-GM-CSF Ab reversed the TNF-alpha effect. Expression studies of TNF-alpha and TNF-alpha receptor genes of cultured JCML cells demonstrated mRNAs for both. Further, TNF-alpha activity was assayed in a wide variety of cell culture supernatants and in normal and patients' plasma, and only the JCML specimens showed increased TNF-alpha values. Recombinant interleukin-1 alpha (IL-1 alpha) also stimulated JCML colony growth, but polyclonal anti-IL-1 neutralizing antibodies did not suppress JCML colony numbers nor did it reverse the effects of TNF-alpha or GM-CSF. The evidence indicated that the JCML monokine which inhibits normal haematopoiesis is TNF-alpha and that the endogenously-produced TNF-alpha and GM-CSF from JCML cells play an important role in the pathogenesis of the disease by acting as autocrine growth factors. IL-1 alpha also stimulates JCML cell proliferation as an accessory factor and augments the effect of GM-CSF, TNF-alpha or both.

Differential kinetics of engraftment and induction of CD10 on human pre-B leukemia cell lines in immune deficient scid mice

The sensitivity of the scid mouse model was assessed by comparing the growth of two pre-B acute lymphoblastic leukemia (ALL) cell lines, A1 and G2, established from patients at relapse. When cell numbers varying from 10(4) to 10(7) were injected intravenously into scid mice, advanced growth and dissemination of leukemia was observed at 10-12 weeks with the G2 cells. Bone marrow, spleen and thymus contained high levels of human leukemic cells and infiltration into lung, kidney, liver, and brain was observed. Two of three mice grafted with only 100 cells showed high levels of infiltration at 15 weeks, suggesting that 100 G2 cells was near the limiting cell number that could produce disseminated leukemia. With the A1 line, a minimum of 10(5) cells was needed to obtain dissemination to liver, lung, brain, and kidney; a low level of spleen infiltration occurred and thymus invasion was not observed. In vitro, both lines showed a density dependent growth in clonogenic assays but the cloning efficiency of the A1 line was 10-fold higher than for G2 cells. These results indicate that G2 and A1 lines have a dissimilar aggressiveness in vivo which does not correlate with clonogenic assay in vitro. Neither G2 nor A1 lines, growing in vitro, expressed CD10/CALLA on their surface, despite low levels of antigen on the freshly obtained relapse samples. Although A1 cells remained CD10-negative in the scid mice, G2 cells showed detectable levels of CD10, particularly on those cells found in the thymus. Several subclones of the G2 line were derived from isolated colonies in vitro; they were found to be CD10- in vitro, but to become CD10+ when proliferating into scid mouse thymus, suggesting the induction of CD10 by the murine microenvironment.

Bone marrow from children in relapse with pre-B acute lymphoblastic leukemia proliferates and disseminates rapidly in scid mice

Bone marrow samples from patients with pre-B acute lymphoblastic leukemia (pre-B ALL), either at diagnosis or at relapse, were transplanted into scid mice to determine whether these freshly obtained leukemic cells could proliferate in vivo and whether there were any differences in their in vivo growth characteristics. Cells from three patients who relapsed within 13 months of diagnosis proliferated rapidly in the murine bone marrow, spleen, and thymus, invaded peripheral organs, and resulted in morbidity and mortality of the animals within 4 to 16 weeks. Cells from two patients who relapsed 3.5 years after diagnosis grew much slower than the early relapse samples, taking up to 30 weeks to infiltrate the bone marrow of recipient mice. In contrast, leukemic cells were absent or were detected at low numbers in scid mice transplanted with cells obtained at diagnosis from three patients who have not yet relapsed. These results show an increased ability of leukemic cells from patients with aggressive lymphoblastic leukemia of poor prognosis to proliferate in scid mice.

Constitutive expression and role in growth regulation of interleukin-1 and multiple cytokine receptors in a biphenotypic leukemic cell line

A cell line (B1) was established from the bone marrow of a patient with a relapse of acute leukemia characterized by a 4;11 chromosomal translocation and biphenotypic features of early B and myeloid lineages. Analysis of the growth requirements of this cell line showed density-dependent growth and secretion of an autostimulatory growth factor, suggesting an autocrine mechanism. Several lines of evidence implicate the participation of interleukin-1 (IL-1) in the autocrine growth regulation of B1 cells. These cells constitutively express the messenger RNA (mRNA) for IL-1 and IL-1 receptor and secrete IL-1; recombinant IL-1 stimulated the growth of colonies when cells were seeded at low density, and anti-IL-1 antibodies inhibited the growth of colonies with cells seeded at higher density. B1 cells do not express detectable levels of mRNA for any of the other cytokines tested, and other cytokines failed to support the growth of B1 cells at low density. In addition, B1 cells express multiple cytokine receptor genes, including the receptors for IL-6, IL-7, tumor necrosis factor and gamma-interferon. Addition of the respective cytokines to the B1 cells resulted in inhibition of the growth of leukemic cells in vitro. The multiplicity of growth-inhibitory cytokine receptors on this leukemic cell line might be due to its biphenotypic lineage and may suggest new therapeutic possibilities in controlling leukemic cell proliferation.

A new frameshift beta zero-thalassemia mutation (codons 27-28 +C) found in a Chinese family

A new beta zero-thalassemia mutation, a frameshift mutation with an insertion of a single cytosine nucleotide in codon 27-28, is described. The propositus, who is compound heterozygous for this mutation and the IVSII-654 C----T beta zero-thalassemia mutation, has the phenotype of severe beta-thalassemia major.

Fibrolamellar carcinoma of the liver in a patient with Fanconi anemia

A 9-year-old boy with Fanconi anemia treated with oxymethalone, a synthetic androgen, died of intracerebral hemorrhage. At autopsy, the liver contained several adenomas and a large fibrolamellar hepatocellular carcinoma, as well as phlebectatic peliosis hepatis. The 11 previously reported cases of hepatocellular carcinoma in Fanconi anemia were not, apparently, of the fibrolamellar type, which has a better prognosis, occurs in children of both sexes, and generally is not associated with cirrhosis. The malignant potential of primary liver tumors associated with Fanconi anemia as well as the nature of their relationship to Fanconi anemia and to anabolic steroid therapy is discussed.

Fanconi's anaemia and pregnancy

We have identified six new cases of Fanconi's anaemia (FA) who had pregnancies, and reviewed 11 others from the literature. At least 110 FA females have reached 16 years of age or more, of whom 15% became pregnant. There were a total of 26 pregnancies, resulting in 19 births and 18 surviving children. Anaemia and/or thrombocytopenia worsened during pregnancy in 10 patients, but five subsequently improved: seven had no haematological problems. Seven of the FA patients who had pregnancies died subsequently from cancer, and two from thrombocytopenic bleeding 3 and 20 years later. There were no peripartum deaths. Pregnancy in FA is clearly possible, with increased risks that are manageable from both the haematological and the obstetric aspects.

Acute lymphoblastic leukemia blast cells do not inhibit bone marrow hematopoietic progenitor colony formation

In newly diagnosed patients with acute lymphoblastic leukemia (ALL), bone marrow (BM) morphology always shows "replacement" by blasts with decreased or absent normal hematopoietic elements. To answer the question of whether ALL blasts inhibit replication and maturation of normal marrow progenitors, we studied the interaction of normal marrow with BM specimens from 16 new cases of ALL. Irradiated ALL blasts, supernatant derived from ALL blasts in suspension cultures, and conditioned medium prepared from ALL blasts augmented the colony-forming ability of normal marrow erythroid burst-forming unit (BFU-E), granulocyte-macrophage colony-forming unit (CFU-GM), megakaryocyte colony-forming unit (CFU-MK), and multilineage colony-forming unit (CFU-GEMM) progenitors. In sharp contrast to published data on the suppressive effects of acute myeloblastic leukemia cells on normal hematopoiesis in vitro, our results indicate that the growth advantage of ALL cells over normal marrow elements is not mediated through an inhibitory mechanism derived from leukemia cells.