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Biomedical subjects

K Goi

Publications and source records attributed to K Goi.

At least 19 recordsLinked to original sources

Hypercalcemia in childhood acute lymphoblastic leukemia: frequent implication of parathyroid hormone-related peptide and E2A-HLF from translocation 17;19.

Hypercalcemia is relatively rare but clinically important complication in childhood leukemic patients. To clarify the clinical characteristics, mechanisms of hypercalcemia, response to management for hypercalcemia, incidence of t(17;19) and final outcome of childhood acute lymphoblastic leukemia (ALL) accompanied by hypercalcemia, clinical data of 22 cases of childhood ALL accompanied by hypercalcemia (>12 mg/dl) reported in Japan from 1990 to 2005 were retrospectively analyzed. Eleven patients were 10 years and older. Twenty patients had low white blood cell count (<20 x 10(9)/l), 15 showed hemoglobin> or =8 g/dl and 14 showed platelet count > or =100 x 10(9)/l. Parathyroid hormone-related peptide (PTHrP)-mediated hypercalcemia was confirmed in 11 of the 16 patients in whom elevated-serum level or positive immunohistochemistry of PTHrP was observed. Hypercalcemia and accompanying renal insufficiency resolved quickly, particularly in patients treated with bisphosphonate. t(17;19) or add(19)(p13) was detected in five patients among 17 patients in whom karyotypic data were available, and the presence of E2A-HLF was confirmed in these five patients. All five patients with t(17;19)-ALL relapsed very early. Excluding the t(17;19)-ALL patients, the final outcome of ALL accompanied by hypercalcemia was similar to that of all childhood ALL patients, indicating that the development of hypercalcemia itself is not a poor prognostic factor.

Adolescent↗

Resistance of infant leukemia with MLL rearrangement to tumor necrosis factor-related apoptosis-inducing ligand: a possible mechanism for poor sensitivity to antitumor immunity.

Malignant cells generally acquire some immune escape mechanisms for clonal expansion. Immune escape mechanisms also contribute to the failure of graft-versus-leukemia (GVL) effect after allogeneic hematopoietic stem cell transplantation (allo-SCT). Infant leukemias with mixed-lineage leukemia (MLL) rearrangement have a remarkably short latency, and GVL effect after allo-SCT has not been clearly evidenced in these leukemias. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)- and FasL-mediated cytotoxic pathways play important roles in cytotoxic T-lymphocyte- and natural killer cell-mediated antitumor immunity and optimal GVL activity. We investigated the in vitro sensitivity of MLL-rearranged acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML) cells to TRAIL- and FasL-mediated cytotoxicity. Most of cell lines and primary leukemia cells were highly resistant to TRAIL primarily owing to low cell-surface expression of death receptors in ALL and simultaneous expression of decoy receptors in AML. Nearly half of cell lines and majority of primary leukemia cells showed low sensitivity to FasL. These results suggest that resistance to death-inducing ligands, particularly to TRAIL, could be one of the mechanisms for a rapid clonal expansion and a poor sensitivity to the GVL effect in infant leukemias with MLL rearrangement.

Drug Resistance, Neoplasm↗

Ligand activation of peroxisome proliferator-activated receptor gamma induces apoptosis of leukemia cells by down-regulating the c-myc gene expression via blockade of the Tcf-4 activity.

The peroxisome proliferator-activated receptor gamma (PPAR gamma), a member of the nuclear receptor superfamily, is expressed at highest levels in adipose tissue and functions as a central regulator in the process of adipocyte differentiation. In the present study, we showed that human leukemic cell lines, not only myeloid but also lymphoid, express PPAR gamma and its activation by natural ligand (15-deoxy-Delta(12,14) - prostaglandin J(2)) and synthetic ligand (troglitazone) profoundly inhibited their proliferation by induction of apoptosis preferentially in the serum-free culture. We pursued its mechanism using the representative cell lines, and found that induction of apoptosis was accompanied by caspase-3 activation and specifically blocked by its inhibitor. While status of several apoptosis-related molecules remained unchanged, the c-Myc expression was markedly down-regulated within 24 h after troglitazone treatment. The c-myc mRNA levels were dramatically reduced at 1 h and became undetectable at 12 h after troglitazone treatment, which proved to be accompanied by complete blockade of the Tcf-4 activity in the electrophoretic mobility shift assay. We succeeded in establishing HL-60 cell lines growing well in the presence of troglitazone in the long-term serum-free culture. They showed neither induction of apoptosis nor down-regulation of the c-Myc expression via blockade of the Tcf-4 activity after troglitazone treatment. This is the first identification of the linkage between PPAR gamma-mediated apoptosis and down-regulation of the c-myc gene expression.

Antineoplastic Agents↗

The JAK2 inhibitor AG490 predominantly abrogates the growth of human B-precursor leukemic cells with 11q23 translocation or Philadelphia chromosome.

The Janus kinase (JAK) family is one of intracellular protein tyrosine kinases (PTKs) present in hematopoietic and lymphoid cells and has been shown to play a crucial role in a variety of biological responses. It was reported that a human B-precursor leukemic cell line was potently inhibited in its proliferation by one of synthetic PTK inhibitors (tyrphostins), AG490, via anti-JAK2 activity. However, no extensive studies about it have been performed. In the present study, we tested 16 human lymphoid leukemic cell lines (B-precursor, 12; T cell, four) for their sensitivity to AG490 using 3H-thymidine incorporation and colony formation assays, and found that B-precursor cell lines with 11q23 translocation or Philadelphia chromosome (Ph1) whose JAK2 proved to be constitutively phosphorylated were predominantly sensitive to AG490 at a concentration that has few inhibitory effect on normal hematopoiesis. We first revealed the association of JAK2 with BCR-ABL in Ph1-positive cell lines and with Bruton's tyrosine kinase (BTK) in cell lines with 11q23 translocation by coimmunoprecipitation experiments. Of interest, AG490 markedly down-regulated phosphorylation of JAK2, but rather transiently up-regulated phosphorylation of BCR-ABL and BTK, suggesting direct implication of AG490 in the process of the JAK2 dephosphorylation. These results indicate that AG490 exerts a potent inhibitory activity to B-precursor leukemia with specific chromosomal abnormalities, and a therapeutic approach using AG490 is expected.

Antineoplastic Agents↗

The E2A-HLF oncoprotein activates Groucho-related genes and suppresses Runx1.

The E2A-HLF fusion gene, formed by the t(17;19)(q22;p13) chromosomal translocation in leukemic pro-B cells, encodes a chimeric transcription factor consisting of the transactivation domain of E2A linked to the bZIP DNA-binding and protein dimerization domain of hepatic leukemia factor (HLF). This oncoprotein blocks apoptosis induced by growth factor deprivation or irradiation, but the mechanism for this effect remains unclear. We therefore performed representational difference analysis (RDA) to identify downstream genetic targets of E2A-HLF, using a murine FL5.12 pro-B cell line that had been stably transfected with E2A-HLF cDNA under the control of a zinc-regulated metallothionein promoter. Two RDA clones, designated RDA1 and RDA3, were differentially upregulated in E2A-HLF-positive cells after zinc induction. The corresponding cDNAs encoded two WD40 repeat-containing proteins, Grg2 and Grg6. Both are related to the Drosophila protein Groucho, a transcriptional corepressor that lacks DNA-binding activity on its own but can act in concert with other proteins to regulate embryologic development of the fly. Expression of both Grg2 and Grg6 was upregulated 10- to 50-fold by E2A-HLF. Immunoblot analysis detected increased amounts of two additional Groucho-related proteins, Grg1 and Grg4, in cells expressing E2A-HLF. A mutant E2A-HLF protein with a disabled DNA-binding region also mediated pro-B cell survival and activated Groucho-related genes. Among the transcription factors known to interact with Groucho-related protein, only RUNX1 was appreciably downregulated by E2A-HLF. Our results identify a highly conserved family of transcriptional corepressors that are activated by E2A-HLF, and they suggest that downregulation of RUNX1 may contribute to E2A-HLF-mediated leukemogenesis.

Amino Acid Sequence↗

[Cord blood transplantation with two mismatched HLA loci in a child with acute lymphoblastic leukemia in second remission: follow-up of minimal residual disease using a clone-specific probe].

A 9-year-old girl with acute lymphoblastic leukemia in second remission underwent cord blood transplantation (CBT) from an HLA-mismatched (2 loci by serotype, 3 loci by genotype) unrelated donor. The infused nucleated cell count was 1.95 x 10(7)/kg. FK506 and mini-MTX were used to prevent graft-versus-host disease (GVHD), but grade II acute GVHD developed on the skin (stage III). The GVHD subsided after administration of corticosteroid, but marked hyperglycemia developed, which required transient insulin therapy for its control. Minimal residual disease (MRD) was assessed using a clone-specific probe for the JH region. MRD was positive before CBT, but became negative one month after CBT. Now, at 14 months after CBT, the patient is in a disease-free state without detectable MRD. These observations suggest that CBT with two mismatched HLA loci can be performed safely, and that sequential analysis of MRD is useful for evaluation of the disease status after CBT.

Blood Donors↗

[Transient myelodysplasia associated with human parvovirus B19 infection in a child without underlying disease].

Human parvovirus B19 (HPV-B19) infection is known to frequently induce aplastic crisis in patients with hemolytic anemia, but rarely causes hematological disorders in healthy subjects. We report a 5-year-old boy who showed transient myelodysplasia associated with HPV-B19 infection. He was admitted with severe nasal bleeding, and laboratory data showed marked thrombocytopenia (1,000/microliter), anemia (Hb: 8.4 g/dl), and mild leukopenia (3,000/microliter). A bone marrow smear revealed myelodysplastic changes in three cell lineages, but no giant proerythroblasts or megakaryocytes. The pancytopenia and myelodysplastic changes were resolved spontaneously within a week without any medication other than transfusion of red blood cells and platelets. Serological examination revealed an elevation of IgG antibody against HPV-B19 on days 15 and 120 and its subsequent decrease thereafter, although HPV-B19-specific DNA was not detected in the serum at onset. The clinical course and laboratory data suggest an etiologic role of HPV-B19 infection in the occurrence of transient myelodysplasia.

Child, Preschool↗

Participation of granulocyte colony-stimulating factor in the growth regulation of leukemia cells from Philadelphia chromosome-positive acute leukemia and blast crisis of chronic myeloid leukemia.

Granulocyte colony-stimulating factor (G-CSF) has been shown to support the growth of multipotential hematopoietic stem cells in addition to the cells of neutrophilic lineage. Philadelphia chromosome (Ph1)-positive leukemia has its origin in the hematopoietic stem cell. In the present study, we demonstrated that the proliferation of leukemic cells from chronic myeloid leukemia in blast crisis (CML-BC) and Ph1-positive acute lymphoblastic leukemia (ALL) cases is frequently stimulated with G-CSF in vitro. We next studied a total of 12 leukemic cell lines established from CML-BC (n= 6) and Ph1-positive acute leukemia (n= 6): four 'myeloid', five 'biphenotypic', and three 'lymphoid' types. All cell lines expressed G-CSF receptor (G-CSFR) in flow cytometric analysis, but their proliferative response to G-CSF in 3H-thymidine incorporation assay varied. The 'biphenotypic' cell lines expressed G-CSFR at higher levels and showed the most pronounced response to G-CSF. The 'lymphoid' cell lines showed intermediate G-CSFR expression with the modest response to G-CSF. Unexpectedly, 'myeloid' cell lines showed lower G-CSFR expression and lower G-CSF response compared with 'biphenotypic' cell lines. In three of four 'myeloid' cell lines, proliferation was partially inhibited by an addition of anti-G-CSF neutralizing monoclonal antibody into culture medium. Further, the % inhibition of 3H-thymidine uptake of cell lines positively correlated with the amount of their intracellular G-CSF measured by enzyme immunoassay, suggesting an autocrine growth mechanism via the G-CSF/G-CSFR interaction. These results suggest that G-CSF play an important role in the growth regulation of leukemia cells from Ph1-positive acute leukemia and CML-BC.

Blast Crisis↗

Expression of thrombopoietin receptor and its functional role in human B-precursor leukemia cells with 11q23 translocation or Philadelphia chromosome.

Thrombopoietin (TPO) is a hematopoietic growth factor which plays a central role in normal megakaryocytopoiesis and thrombopoiesis. Although the interaction between TPO and its receptor c-Mpl encoded by the c-mpl gene is now known to be implicated in the proliferation and/or differentiation of abnormal myeloid cells and normal hematopoietic stem cells, little is known about a role of the TPO/c-Mpl system in lymphoid leukemia cells. In the present study, we first examined the expression of c-mpl/c-Mpl in 23 human lymphoid leukemic cell lines (T-lineage 4, B-lineage 19) using three distinct methods. The c-mpl mRNA was detectable in as many as 20 cell lines (T-lineage 3, B-lineage 17) by reverse transcriptase-polymerase chain reaction, but its translated product, c-Mpl, was demonstrable by Western blot only in B-lineage cell lines. Flow cytometric analysis revealed the surface c-Mpl expression in 13 of 17 B-lineage cell lines, but its higher expression (>40%) was restricted in nine B-precursor cell lines, eight of which had 11q23 translocation or Philadelphia chromosome (Ph1). We also demonstrated that two of eight cell lines with 11q23 translocation or Ph1 exhibited a significant proliferative response to TPO in the 3H-thymidine uptake and colony-forming assays. Triggering of these cell lines by TPO transiently up-regulated tyrosine phosphorylation of JAK-2 and Shc, indicating that their receptor is functional. Primary leukemia cells separated from patients with B-precursor acute lymphoblastic leukemia with Ph1 or 11q23 translocation also showed the surface c-Mpl expression and a significant responsiveness to TPO. These results suggest that the TPO/c-Mpl interaction may play a physiological role in the growth regulation of B-precursor leukemia cells particularly with specific chromosomal abnormalities.

Antigens, Surface↗

Analysis of serum lactate dehydrogenase and its isozymes during administration of granulocyte colony-stimulating factor in children.

Serum lactate dehydrogenase (LDH) activity is known to become elevated following granulocyte colony-stimulating factor (G-CSF) therapy in some patients, but no extensive studies on this phenomenon have been performed. In 26 children with malignancies in complete remission who received recombinant human G-CSF intravenously after combined chemotherapy, we measured serum LDH and its isozymes (81 episodes) before chemotherapy (pre-Tx), during administration of G-CSF (mid-Tx), and after stopping G-CSF (post-Tx) and compared the obtained data using paired t test. Twelve episodes were excluded from analysis because of liver dysfunction (alanine aminotransferase > 45 IU/L). Serum LDH at mid-Tx (343.1+/-19.8 IU/L; mean +/- SE) was significantly higher than that at pre-Tx (186.9+/-6.7 IU/L) and post-Tx, but this difference was observed only when change in white blood cell counts (WBCs) (WBC at mid-Tx minus WBC at pre-Tx) was greater than or equal to 4000/microL (58 episodes). Percentages of LDH isozymes 3, 4, and 5 at mid-Tx (23.5+/-1.0, 11.7+/-0.8, and 8.3+/-0.7) were significantly increased compared with those at pre-Tx (19.5+/-0.7, 6.3+/-0.3, and 4.2+/-0.5) and post-Tx, resulting in a significant decrease in percentages of LDH isozymes 1 and 2 at mid-Tx. In episodes of change in WBCs > or =4000/microL, change in LDH significantly correlated to changes in WBCs and granulocytes but not to change in lymphocytes or monocytes. These results suggest that serum LDH is significantly elevated during G-CSF administration in accordance with the increase in peripheral granulocytes, which accompanies change in the pattern of percentages of LDH isozymes.

Adolescent↗

Development of acute lymphoblastic leukemia with translocation (4;11) in a young girl with familial pericentric inversion 12.

We report a case of a 1-year-old girl with familial pericentric inv(12) who developed acute lymphoblastic leukemia (ALL) with t(4;11) 1 month after recovery from idiopathic hemophagocytic lymphohistiocytosis (HLH). The inv(12)(p13q15) was first found in bone marrow (BM) cells when she was diagnosed as having HLH, and then detected in the BM blasts together with t(4;11)(q21;q23) when she developed ALL. The inv(12) was retained in the BM cells after she achieved complete remission. Cytogenetic analysis on the PHA-stimulated peripheral lymphocytes revealed inv(12) in all of the 30 cells examined. Because the data that ALL with t(4;11) predicts an extremely poor prognosis, she received an allogeneic BM transplantation from an HLA-matched sibling at 10 months from the onset of ALL. She is now at 26 months post transplantation and maintains in a state of complete remission. Familial cytogenetic study demonstrated that 4 of 8 maternal members examined had the inv(12), but they showed no family history of a higher risk of development of hematological and other types of malignancies, suggesting that pericentric inv(12) itself might not be directly involved in the development of ALL in this case.

Bone Marrow↗

Two candidate downstream target genes for E2A-HLF.

The E2A-HLF fusion gene, formed by the t(17;19)(q22;p13) chromosomal translocation, is thought to drive the leukemic transformation of early B-cell precursors by repressing an evolutionarily conserved apoptotic pathway. To test this hypothesis, we sought to identify downstream targets of E2A-HLF in t(17;19)+ pro-B leukemia cells (UOC-B1) that had been transfected with a zinc-inducible vector encoding a dominant-negative suppressor (E2A-HLF[dn]) of the oncoprotein. Representational difference analysis of mRNAs from E2A-HLF(dn)+ UOC-B1 cells grown with (E2A-HLF inactive) or without (E2A-HLF active) the addition of zinc yielded several differentially expressed cDNA fragments that were individually subcloned. Two of the clones, designated F-5 and G-4, hybridized with mRNAs that were upregulated by E2A-HLF. Levels of both transcripts declined sharply within 8 to 12 hours after suppression of E2A-HLF DNA-binding activity, becoming undetectable after 96 hours. The F-5 cDNA was identified as a portion of ANNEXIN VIII, whose product was expressed in promyelocytic leukemia cells and UOC-B1 cells, but not in other leukemic cell lines. A novel full-length cDNA cloned with the G-4 fragment encoded a protein that we have named SRPUL (sushi-repeat protein upregulated in leukemia). It is normally expressed in heart, ovary, and placenta, but could not be detected in leukemic cell lines other than UOC-B1. Neither protein prevented apoptosis in interleukin-3-dependent murine pro-B cells, suggesting that they have paraneoplastic roles in leukemias that express E2A-HLF, perhaps in the disseminated intravascular coagulopathy and hypercalcemia that characterize these cases.

Amino Acid Sequence↗

SLUG, a ces-1-related zinc finger transcription factor gene with antiapoptotic activity, is a downstream target of the E2A-HLF oncoprotein.

The E2A-HLF fusion gene transforms human pro-B lymphocytes by interfering with an early step in apoptotic signaling. In a search for E2A-HLF-responsive genes, we identified a zinc finger transcription factor, SLUG, whose product belongs to the Snail family of developmental regulatory proteins. Importantly, SLUG bears close homology to the CES-1 protein of C. elegans, which acts downstream of CES-2 in a neuron-specific cell death pathway. Consistent with the postulated role of CES-1 as an antiapoptotic transcription factor, SLUG was nearly as active as Bcl-2 or Bcl-xL in promoting the survival of IL-3-dependent murine pro-B cells deprived of the cytokine. We conclude that SLUG is an evolutionarily conserved transcriptional repressor whose activation by E2A-HLF promotes the aberrant survival and eventual malignant transformation of mammalian pro-B cells otherwise slated for apoptotic death.

Animals↗

The KOR-SA3544 antigen predominantly expressed on the surface of Philadelphia chromosome-positive acute lymphoblastic leukemia cells is nonspecific cross-reacting antigen-50/90 (CD66c) and invariably expressed in cytoplasm of human leukemia cells.

We previously reported a novel monoclonal antibody KOR-SA3544 which predominantly reacted with a surface antigen (sSA3544) expressed on Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia (ALL). In the present study, we demonstrate that the antibody specifically recognized nonspecific cross-reacting antigen (NCA)-50/90 (CD66c), one of the carcinoembryonic antigen (CEA)-related glycoproteins encoded by a member of the CEA gene family. In addition, we show that the SA3544 antigen (NCA-50/90) was invariably expressed in cytoplasm of all of the human leukemic cell lines examined (sSA3544-positive B-lymphoid two, sSA3544-negative T or B-lymphoid and non-lymphoid 24) regardless of the presence or absence of surface expression of this antigen. Immunoelectromicroscopic examination revealed that the cytoplasmic antigen was mainly present in granules in sSA3544-positive leukemia cells, whereas it was diffusely present in cytosol in sSA3544-negative leukemia cells. Thus, among members of the CEA family, NCA-50/90 was first demonstrated to be expressed not only on the surface of some leukemia cells, but also in cytoplasm of various types of leukemia cells.

Antibodies, Monoclonal↗