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Biomedical subjects

M Kizaki

Publications and source records attributed to M Kizaki.

At least 55 records · Page 3Linked to original sources
PubMed1996

Mechanisms of retinoid resistance in leukemic cells: possible role of cytochrome P450 and P-glycoprotein.

Retinoic acid (RA) regulates the differentiation and proliferation of a wide variety of different cell types and all-trans RA induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL). However, clinical resistance to retinoids may develop and poses a serious problem for differentiation-inducing therapy. We studied the effects of RA in combination with a cytochrome P450 inhibitor (clotrimazole) and a P-glycoprotein antagonist (verapamil) on cell growth and differentiation of RA-resistant HL-60 cells and fresh RA-resistant leukemic cells from two APL patients. RA-resistant HL-60 cells and APL cells differentiated to mature granulocytes when cultured with all-trans RA and either clotrimazole and verapamil but not with either of the agents alone. These findings were confirmed in these cells by their increased expression of CD11b antigen and migration-inhibitory factor-related protein-8/14 mRNAs and decreased levels of c-myc mRNA. These combinations also markedly decreased the number of viable cells and inhibited cellular proliferation. After isolation of microsomes, measurements showed that levels of cytochrome P450 activities in both wild-type and RA-resistant HL-60 cells were almost comparable. Moreover, expression of the CYP1A1-type cytochrome P450 gene could not be detected in either cell type. However, RA-resistant HL-60 cells and APL cells, but not RA-sensitive HL-60 cells and APL cells, expressed multidrug-resistance-1 gene transcripts. Taken together, acquired resistance to RA may be explained in part by drug metabolism in leukemic cells. Possible mechanisms for accelerated clearance of RA include the induction of non-CYP1A1 cytochrome P450 enzymes and P-glycoprotein.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Differentiation effect of acyclic retinoid on acute promyelocytic leukemia cells.

Acyclic retinoid (all-trans-3, 7, 11, 15-tetramethyl-2, 4, 6, 10, 14-hexadecapentaenoic acid) binds cellular retinoic acid-binding protein with an affinity similar to that of all-trans retinoic acid and induces differentiation of human hepatoma cell lines and a human acute myelogenous leukemia cell line (HL-60). We investigated the in vitro efficacy of acyclic retinoid to induce the differentiation of acute promyelocytic leukemia (APL) cells using primary cultured cells obtained from 11 APL patients. Five days' incubation with acyclic retinoid effected a dose-dependent induction of differentiation. Cells from eight patients showed maximum differentiation at 10(-6) M acyclic retinoid. Cells from one patient required 10(-5) M for maximum differentiation, while those from two patients exhibited moderate differentiation at 10(-5) M. Five days' incubation with acyclic retinoid (10(-7) approximately 10(-5) M) did not affect the viability or number of cells from any patient except one, whose cells showed a slight decrease in viability at 10(-5) M. Thus, we conclude that acyclic retinoid induced the differentiation of primary cultured APL cells at concentrations of 10(-6) approximately 10(-5) M, a range at which it is not toxic.

Antineoplastic Agents↗
PubMed1996

All-trans and 9-cis retinoic acid enhance 1,25-dihydroxyvitamin D3-induced monocytic differentiation of U937 cells.

Retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (D3) are well known for inducing differentiation in many leukemic cell lines. The nuclear signalling pathways of RA and D3 are mediated through their cognate receptors, the retinoic acid receptor (RAR) and vitamin D3 receptor (VDR), respectively. Retinoid X receptor (RXR) is an auxiliary factor that forms a heterodimer with RAR and VDR, enabling their efficient transcriptional activation. 9-cis RA, a high-affinity ligand for RXR, greatly enhanced D3-induced CD14 expression in U937 cells, while RA alone did not induce CD14 expression. 9-cis RA also resulted in morphological changes of U937 cells to macrophage-like cells when combined with D3, while RA alone resulted in granulocyte-like cells. RA and D3 together enhanced c-fms expression, phagocytic activity, and acted synergistically to promote nitroblue tetrazolium reduction activity and inhibit proliferation. Northern analysis showed that U937 cells constitutively expressed RAR-alpha, VDR and RXR-alpha mRNAs. RA or D3 alone or in combination did not affect RAR-alpha and VDR expression, while 9-cis RA and 9-cis RA plus all-trans RA significantly reduced RXR-alpha expression. Interestingly, D3 could restore the down-regulation of RXR-alpha mRNA by 9-cis RA. These findings suggest that there is crossover of the nuclear signalling pathways of RA and D3. This may have clinical implications in that RA and D3 may be used in combination for differentiation-inducing therapy in acute myelogenous leukemia and myelodysplastic syndrome.

Antineoplastic Agents↗
PubMed1996

Circulating endogenous thrombopoietin, interleukin-3, interleukin-6 and interleukin-11 levels in patients undergoing allogeneic bone marrow transplantation.

To elucidate the physiologic role of thrombopoietin (TPO) for hematologic reconstitution following allogeneic bone marrow transplantation (BMT), serum TPO levels as well as interleukin-3 (IL-3), IL-6 and IL-11 were serially measured in 55 samples from 3 patients who underwent allogeneic BMT using an enzyme-linked immunosorbent assay (ELISA). The TPO level was higher in the serum taken during marrow aplasia than in the pretransplant serum. The serum TPO levels and platelet counts showed a strong inverse relationship in all patients examined. We also sequentially measured endogenous serum TPO levels before and within 36 h after platelet transfusions. Endogenous serum TPO levels were inversely correlated with platelet mass following platelet transfusions. Serum levels of IL-3 had no apparent correlation with platelet counts and serum levels of IL-11 remained below the detection levels (31.3 pg/ml) in all samples. Serum levels of IL-6 were high during myeloaplasia and more upregulated in the febrile period. These findings support the view that TPO is the central regulator for megakaryopoiesis in vivo and the rationale for its clinical use after allogeneic BMT.

Adult↗
PubMed1996

Serial quantification of minimal residual disease of t(8;21) acute myelogenous leukaemia with RT-competitive PCR assay.

The chromosomal translocation (8;21)(q22;q22) in the AML M2 subtype according to the FAB classification, results in the production of a novel fusion gene AML1/ETO. The chimaeric AML1/ETO transcript is useful for the detection of minimal residual disease (MRD). Recently, several studies on the detection of AML1/ETO transcripts in t(8;21) AML have been reported. However, the clinical significance of a small number of AML1/ETO transcripts by a reverse transcription-polymerase chain reaction (RT-PCR) remains to be elucidated. We have developed a novel quantitative RT-competitive PCR assay and evaluated the clinical usefulness of this method by the monitoring of MRD in eight patients with t(8;21) AML. In four patients in first continuous complete remission (CR) the value of MRD was always < 0.1 fg of the competitor dose throughout their courses, whereas in four relapsed patients there was an increase in the value of MRD to > 0.1 fg of the competitor dose before cytogenetic relapse. We conclude that the detection of the presence of cells with AML1/ETO fusion transcripts by our RT-competitive PCR assay may be useful to monitor disease progression and to predict subsequent relapse.

Aged↗
PubMed1996

CD7 positive acute lymphoblastic leukemia successfully treated with high dose cytosine arabinoside and mitoxantrone: a case report.

A 45-year-old woman with acute lymphoblastic leukemia (ALL) who failed to achieve complete remission (CR) after one course of induction chemotherapy with vincristine, daunorubicin, prednisolone and l-asparaginase was successfully treated with a high dose of cytosine arabinoside (Ara-C) and mitoxantrone. The leukemic blasts were CD7, 19, 33, and 38 antigens positive, and had a rearrangement in the T-cell receptor delta chain gene. The karyotype was normal. Primary induction failure and positivity for myeloid antigens are both reported to be poor prognostic factors for ALL. Nevertheless, this patient was successfully treated with the high dose Ara-C and mitoxantrone, and she remains in CR for over 20 months. Combination chemotherapy with high dose Ara-C and mitoxantrone may be of benefit for refractory ALL with both CD7 and myeloid antigens.

Antigens, CD7↗
PubMed1996

[Proposals for the objective indices for evaluating the differentiation of leukemic cells by all-trans retinoic acid in the patients with acute promyelocytic leukemia].

All-trans retinoic acid (ATRA) is widely used as a differentiation-inducing agent for acute promyelocytic leukemia (APL). However, one of the problems with this therapy is the difficulty in evaluating the extent of differentiation of leukemic cells. To determine objective indices for differentiation which can be used for judging complete remission, we treated 18 patients with acute promyelocytic leukemia, and performed sequential analysis of bone marrow, karyotype, RAR alpha gene rearrangement and PML-RAR alpha fusion gene transcript. The karyotype, RAR alpha rearrangement and PML-RAR alpha transcript returned to a normal pattern on days 31, 2, 34.8 and 47.6, respectively. We defined and analyzed maturation index (MI) by bone marrow findings as follows; (metamylocyte + band neutrophil + segmented neutrophil) (%)/(myeloblast + promyelocyte + myelocyte) (%). MI increased along with the differentiation of leukemic cells, and the days for MI exceeding 2 well correlated with the normalization of karyotype. These results suggested that MI can be used as an index of differentiation during ATRA therapy.

Adolescent↗
PubMed1995

Ribozymes cleave the AML1/MTG8 fusion transcript and inhibit proliferation of leukemic cells with t(8;21).

The AML1/MTG8 fusion gene is thought to have a critical role in the leukemogenesis of AML with t(8;21)(q22;q22). To specifically inhibit the proliferation of leukemic cells having the AML1/MTG8 fusion gene, we constructed two hammerhead ribozymes against AML1/MTG8. Two cleavage sites were targeted as follows: site 1 for ribozyme 1(Rz1), a CUC located 3 bases upstream from the fusion site; site 2 for ribozyme 2(Rz2), an AUC located 3 bases downstream from the fusion site. In a cell-free system, Rz1 and Rz2 specifically cleaved AML1/MTG8 substrate, dependent on the concentration of ribozymes. When these ribozymes were transfected to Kasumi-1 cells, an AML cell line with AML1/MTG8, they were able to inhibit the cell growth. These data suggest that Rz1 and Rz2 may be applied as a new therapeutic agent in the treatment of AML with t(8;21).

Base Sequence↗
PubMed1995

Acute promyelocytic leukemia developed in a patient with congenital antithrombin III deficiency.

A case of acute promyelocytic leukemia (APL) developed in a patient with congenital antithrombin III (AT-III) deficiency is reported. Despite the presence of disseminated intravascular coagulation (DIC), plasma AT-III activity was not decreased at the diagnosis of APL compared to the patient's baseline level (approximately 50% of normal). He was successfully treated with all-trans retinoic acid (ATRA) to achieve complete remission without the use of heparin. Although he developed phlebitis at the site of insertion of the intravenous catheter during remission-induction, no major thrombotic episode was noted. Coagulation parameters including fibrin and fibrinogen degradation products (FDP-E), thrombin-antithrombin complex (TAT), FDP-D dimer (D-D dimer), and plasmin-alpha 2 plasmin inhibitor complex (PIC) improved rapidly after initiation of ATRA. This case is a clear demonstration of the characteristics of DIC developing in APL, i.e. no or minimal decrease in the level of AT-III activity and a predominant increase in the fibrinolytic system, rather than hypercoagulability.

Antithrombin III Deficiency↗
PubMed1995

Spontaneous resolution of transfusion-associated graft-versus-host disease.

BACKGROUND: Transfusion-associated graft-versus-host disease (TA-GVHD) is a serious complication of blood transfusion that is characterized by high fever, a scaly maculopapular erythematous rash, diarrhea, hepatocellular damage with marked elevation of liver function test values, and pancytopenia. It can occur in immunocompetent as well as immunocompromised recipients. The existence of atypical TA-GVHD that resolves spontaneously and does not exhibit all of the manifestations has been suggested, but there has been to date no documented diagnosis of GVHD supported by evidence of engraftment. CASE REPORT: A female patient presented and was diagnosed with acute myelogenous leukemia (AML:M4), and, after unsuccessful combination chemotherapy, she received a transfusion and developed manifestation of TA-GVHD as well as evidence of chimerism. TA-GVHD was proved by demonstrating Y chromosome-specific genes in the skin by polymerase chain reaction. The manifestations of clinical GVHD abated within 4 months. CONCLUSION: Polymerase chain reaction analysis of Y chromosomes in specimens from female patients is useful in the diagnosis of suspected cases of spontaneously resolving TA-GVHD.

Base Sequence↗
PubMed1994

Retinoids (all-trans and 9-cis retinoic acid) stimulate production of macrophage colony-stimulating factor and granulocyte-macrophage colony-stimulating factor by human bone marrow stromal cells.

Retinoic acids (RAs) exert pleiotropic effects on cellular growth and differentiation. All-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA), a stereoisomer of ATRA, induce differentiation of leukemic cell lines and cells from patients with acute myelogenous leukemia (AML) in vitro. Despite information on the effects of RAs on hematopoietic cells, little is known about how RAs act on the hematopoietic microenvironment, especially on bone marrow stromal cells. Based on recent observations that various cytokines produced mainly by bone marrow stromal cells regulate hematopoiesis, we analyzed the effects of RAs on cytokine production by these cells. ATRA or 9-cis RA treatment of human bone marrow stromal cell line KM101, which produces macrophage colony-stimulating factor (M-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) constitutively, enhanced mRNA levels of both cytokines in a dose-dependent manner. Both RAs also stimulated M-CSF production from primary cultures of human bone marrow stromal cells. Both retinoic acid receptor (RAR)-alpha and retinoid X receptor (RXR)-alpha were expressed constitutively in KM101 cells. ATRA did not affect the expression of either receptor, whereas 9-cis RA increased RXR-alpha mRNA expression in a dose-dependent manner, but did not affect levels of RAR-alpha mRNA. These findings may have important biologic implications for both the role of RAs in hematopoiesis and the therapeutic effects of ATRA on the hematopoietic microenvironment in patients with acute promyelocytic leukemia (APL).

Bone Marrow Cells↗
PubMed1994

Dose escalation of biweekly cyclophosphamide, doxorubicin, vincristine, and prednisolone using recombinant human granulocyte colony stimulating factor in non-Hodgkin's lymphoma.

BACKGROUND: Several uncontrolled trials have suggested that dose intensity of chemotherapy is a crucial determinant of treatment outcome for patients with non-Hodgkin's lymphoma (NHL). To explore the possibility of increasing dose intensity, a dose-escalation study of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) using recombinant human granulocyte colony stimulating factor (rhG-CSF) was initiated. METHODS: First, the feasibility of standard dose CHOP (750 mg/m2 cyclophosphamide intravenously [i.v.] on Day 1;50 mg/m2 doxorubicin i.v. on Day 1; 1.4 mg/m2 vincristine i.v. on Day 1; and 100 mg/body prednisolone orally on Days 1-5) repeated biweekly at the original dose was assessed. rhG-CSF was given subcutaneously at doses of 2-5 micrograms/kg every day or every other day on Days 3-13. The safety of increasing the dose of cyclophosphamide during biweekly CHOP then was tested. Besides the standard dose (750 mg/m2), two dose levels of cyclophosphamide were set (1200 mg/m2 and 1500 mg/m2 in patients younger than 61 years of age, and 1200 mg/m2 in patients 61-75 years old). RESULTS: Twenty-seven patients with NHL who had received minimal or no previous treatment were enrolled in this study. In the 750 mg/m2 group, 9 patients received 3-6 cycles of treatment (mean, 3.9 cycles), in the 1200 mg/m2 group, 10 patients received 3-6 cycles (mean, 4.8), and in the 1500 mg/m2 group, all 8 patients received 6 cycles. No significant differences among the groups were observed in the extent and the duration of neutropenia in each cycle, and a leukocyte count of more than 3000/microliters on Day 15 was achieved in all 131 cycles. Hemoglobin values and platelet counts, however, decreased in the later cycles in the 1500 mg/m2 group. Two patients were hepatitis-B virus carriers, one of whom died of fulminant hepatitis after completion of six cycles. Another patient developed a transient increase of transaminases after the second cycle. One other patient developed Grade 4 mucositis (World Health Organization scale). The numbers of patients who achieved complete and partial responses, respectively, were 4 (50%) and 2 (25%) in the 750 mg/m2 group, 8 (80%) and 2 (20%) in the 1200 mg/m2 group, and 8 (100%) and 0 (0%) in the 1500 mg/m2 group. CONCLUSIONS: The dose of cyclophosphamide in biweekly CHOP can be increased up to 1500 mg/m2 with no increase in the incidence of treatment-related early mortalities without any organ damage in younger patients. The efficacy of this dose intensification of CHOP currently is being investigated in a multicenter prospective randomized trial using three different dose levels of cyclophosphamide.

Adult↗
PubMed1994

Myeloid differentiation mediated through retinoic acid receptor/retinoic X receptor (RXR) not RXR/RXR pathway.

Retinoids, such as all-trans-retinoic acid and 9-cis-retinoic acid, are naturally occurring ligands of the nuclear retinoic acid receptors (RARs). In concert with binding of ligand, these receptors from heterodimers with the retinoic X receptor (RXR) and transactivate RAR/RXR-responsive genes. Retinoids can differentiate leukemic cell lines in vitro and induce clinically complete remissions in patients with acute promyelocytic leukemia. Synthetic ligands to the RAR and RXR receptors have been developed that selectively bind and activate RAR/RXR (TTAB) and RXR/RXR dimers (SR11217). We investigated the affect of these ligands, either alone or in combination, on in vitro growth and differentiation of cells from the HL-60, KG-1, THP-1, and WEHI-3 myeloid cell lines as well as on clonal growth of fresh myeloid leukemic blasts from patients. Clonal inhibition of proliferation of these cells was studied in soft agar cultures. Cells were plated in the presence of either one or a combination of retinoids at concentrations of 10(-5) to 10(-10) mol/L. TTAB inhibited 50% clonal growth at an effective dose (ED50) that was about 1,000-fold lower than the concentration of SR11217 required to achieve an ED50 for the same leukemic cells. Combination of both ligands at a variety of concentrations showed no synergistic effects. Superoxide production (nitroblue tetrazolium reduction) and CD11b expression as parameters of differentiation of HL-60 cells were also examined. Results paralleled those of clonal growth, with SR11217 being markedly less potent than TTAB. These results show that the ligand selective for RXR-homodimers has little effect on either inducing differentiation or inhibiting clonal growth of leukemic cells. The differentiating and antiproliferative effects of retinoids are mainly induced through RAR/RXR heterodimers, and development of therapeutic analogs should focus on this category of retinoids.

Animals↗
PubMed1994

Novel retinoic acid, 9-cis retinoic acid, in combination with all-trans retinoic acid is an effective inducer of differentiation of retinoic acid-resistant HL-60 cells.

Recent studies have shown that a high proportion of patients with acute promyelocytic leukemia (APL) achieve complete remission after treatment with all-trans retinoic acid (RA). Nevertheless, despite an initial good response, most patients that received continuous treatment with all-trans RA relapse and develop RA-resistant disease. The 9-cis RA is a high-affinity ligand for retinoid X receptors (RXRs) and also binds efficiently to retinoic acid receptors (RARs); all-trans RA is a ligand for RARs. Both alone are able to induce differentiation of wild-type HL-60 cells. We found that neither all-trans RA nor 9-cis RA (< 2 x 10(-6) mol/L) induced differentiation of RA-resistant HL-60 cells into either mature granulocytes or monocytes. However, morphologic differentiation of the RA-resistant HL-60 cells was induced by 10(-6) mol/L all-trans RA combined with various concentrations (10(-12) to 10(-6) mol/L) of 9-cis RA. Electron microscopic examination also confirmed that the combination of both retinoids induced RA-resistant HL-60 cells to differentiate to mature granulocytes. Functional analysis of differentiation (NBT reduction activity) confirmed the necessity of both analogs to induce differentiation. Also, expression of myeloid-specific differentiation antigens (CD11b and CD14) as well as migration inhibitory factor-related protein (MRP)-8/14 mRNAs were upregulated only in the presence of both retinoids in a dose-dependent manner. In these conditions 3H-thymidine incorporation was inhibited and numbers of viable cells were decreased, suggesting that all-trans RA with 9-cis RA may inhibit cell growth and induce differentiation of RA-resistant HL-60 cells into mature granulocytes. These studies suggest that 9-cis RA in combination with all-trans RA is an effective inducer of RA-resistant HL-60 cells and may have implications for both the biology of retinoids and clinical treatment of RA-resistant acute myelogenous leukemia, including APL patients.

Antigens, Differentiation↗