Acute kidney injury after myeloablative cord blood transplantation in adults: the efficacy of strict monitoring of vancomycin serum trough concentrations.

BACKGROUND: Acute kidney injury (AKI) is a common medical complication after myeloablative allogeneic stem cell transplantation (SCT). We have previously performed a retrospective analysis of AKI after cord blood transplantation (CBT) in adults, and found that the maximum of vancomycin (VCM) trough levels were significantly higher in patients with AKI. Following these results, we have monitored VCM serum trough concentrations more strictly, to not exceed 10.0 mg/L, since 2008. METHODS: In this report, we performed an analysis of AKI in a new group of 38 adult patients with hematological malignancies treated with unrelated CBT after myeloablative conditioning between January 2008 and July 2011. RESULTS: Cumulative incidence of AKI at day 100 after CBT was 34% (95% confidence interval 19-50). The median of the maximum value of VCM trough was 8.8 (4.5-12.2) mg/L. In multivariate analysis, no factor was associated with the incidence of AKI. No transplant-related mortality was observed. The probability of disease-free survival at 2 years was 83%. CONCLUSION: These findings suggest that strict monitoring of VCM serum trough concentrations has a beneficial effect on outcomes of CBT.

Gene set enrichment analysis provides insight into novel signalling pathways in breast cancer stem cells.

BACKGROUND: Tumour-initiating cells (TICs) or cancer stem cells can exist as a small population in malignant tissues. The signalling pathways activated in TICs that contribute to tumourigenesis are not fully understood. METHODS: Several breast cancer cell lines were sorted with CD24 and CD44, known markers for enrichment of breast cancer TICs. Tumourigenesis was analysed using sorted cells and total RNA was subjected to gene expression profiling and gene set enrichment analysis (GSEA). RESULTS: We showed that several breast cancer cell lines have a small population of CD24(-/low)/CD44(+) cells in which TICs may be enriched, and confirmed the properties of TICs in a xenograft model. GSEA revealed that CD24(-/low)/CD44(+) cell populations are enriched for genes involved in transforming growth factor-beta, tumour necrosis factor, and interferon response pathways. Moreover, we found the presence of nuclear factor-kappaB (NF-kappaB) activity in CD24(-/low)/CD44(+) cells, which was previously unrecognised. In addition, NF-kappaB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) prevented tumourigenesis of CD24(-/low)/CD44(+) cells in vivo. CONCLUSION: Our findings suggest that signalling pathways identified using GSEA help to identify molecular targets and biomarkers for TIC-like cells.

Cardiovascular toxicity of cryopreserved cord blood cell infusion.

Although infusion of cryopreserved bone marrow or peripheral blood stem cell is associated with a variety of symptoms, there have been no reports detailing the data of infusion-related toxicities of cryopreserved cord blood (CB) units. We prospectively evaluated the incidence and significance of infusion-related toxicities in 34 adult patients undergoing unrelated CB transplantation. Cryopreserved CB units were thawed and immediately infused, unfiltered, through a central intravenous catheter without further manipulation. Heart rate, blood pressure, oxygen saturation and clinical symptoms were recorded during and after infusion. Twenty-four percent of patients experienced non-cardiovascular toxicities related to infusion. The incidence of systolic and diastolic hypertension and bradycardia was 58, 64 and 32%, respectively. Although three patients (9%) with severe systolic hypertension after the infusion required treatment with antihypertensive agents, no patients experienced life-threatening side effects or needed discontinuation of CB unit infusion. Patient or transplant characteristics had no effect on the hypertension and bradycardia related to the infusion of CB. These data suggest that infusion of cryopreserved CB without further manipulation after thawing is safe and well tolerated. However, cardiovascular toxicities including hypertension and bradycardia were frequently observed.

Preemptive therapy with ganciclovir 5 mg/kg once daily for cytomegalovirus infection after unrelated cord blood transplantation.

The efficacy and safety of preemptive therapy using ganciclovir (GCV) 5 mg/kg once daily for CMV infection after unrelated cord blood transplantation (CBT) were studied. The initial preemptive therapy with GCV 5 mg/kg once daily led to resolution of CMV antigenemia in 25 of 34 patients (74%). In the remaining 9 patients (26%), antigenemia resolved after dose-escalation of GCV or change to foscarnet therapy. Recurrence of antigenemia was seen in 18 patients (53%). A total of 12 patients received the second preemptive therapy with GCV 5 mg/kg once daily, which led to resolution of antigenemia in 11 of 12 patients (92%). The remaining 1 patient (8%) required change to foscarnet therapy. None of 34 patients developed CMV disease. Neutropenia with an absolute neutrophil number of less than 1 and 0.5 x 10(9) per liter after GCV therapy occurred in 12 (35%) and 1 (3%) patients, respectively, after the initial therapy, and in 2 (17%) and 0 (0%) patients, respectively, after the second therapy. No patients developed neutropenic fever or secondary graft failure after GCV therapy. There were no deaths directly attributable to GCV therapy. The present study suggests that antigenemia-based preemptive strategy using GCV 5 mg/kg once daily is feasible and effective for CBT recipients.

Unrelated cord blood transplantation in CML: Japan Cord Blood Bank Network analysis.

We analysed 86 patients with CML who received unrelated cord blood transplantation (UCBT), identified through a registry of the Japan Cord Blood Bank Network. At transplantation, the median patient age was 39 years (range, 1-67 years); 38 patients were in chronic phase (CP), 13 in the accelerated phase (AP) and 35 in blast crisis (BC). Median duration from diagnosis to UCBT was 1.5 years (range, 0.2-14.6 years). A nucleated cell (NC) dose of more than 3.0 x 10(7) per kg was sufficient to achieve neutrophil (91%) and platelet recovery (86%), whereas the lower dose of NC achieved only 60 and 61%, respectively. The duration and type of pre-transplant treatment did not affect neutrophil or platelet recovery. Results of multivariate analysis indicated that older patients (>50 years) had a higher incidence of transplant-related mortality. Advanced-disease stage and lower doses of NCs were significantly associated with lower leukaemia-free and event-free survival. At 2-year survival for patients in CP, AP and BC was 71, 59 and 32%, respectively (P=0.0004). A pre-transplant European Group for Blood and Marrow Transplantation scoring system was effective in predicting the outcome of UCBT. We conclude that UCBT is a reasonable alternative therapy for patients with CML.

No occurrence of Pneumocystis jiroveci (carinii) pneumonia in 120 adults undergoing myeloablative unrelated cord blood transplantation.

The incidence of pneumonia caused by Pneumocystis carinii (PCP) (organism now renamed Pneumocystis jiroveci) during the early period after cord blood transplantation (CBT) was studied in 120 adults. Initially 89 patients (74%) received oral administration of 2 single-strength trimethoprim-sulfamethoxazole (TMP-SMZ) tablets twice daily from day -21. In 45 of 89 patients (51%), TMP-SMZ administration for a scheduled duration was completed. In the remaining 44 patients (49%), however, TMP-SMZ administration was discontinued prior to day -3 because of toxicity. Among these patients, 42 subsequently received aerosolized pentamidine (AP) on a median of day -13 (range, -20 to -6). Thirty-one patients (26%) received AP without TMP-SMZ administration on a median of day -14 (range, -21 to -9). None of the 120 patients were diagnosed with PCP within 100 days or 2 years after CBT; however, one patient who received AP before CBT but no prophylaxis after CBT developed cerebral toxoplasmosis on day +91. Pre-transplant prophylaxis against PCP did not significantly affect transplantation-related mortality or disease-free survival at 2 years after CBT. The results suggest that PCP during the early period after CBT can be effectively prevented by any pre-transplant prophylactic method.

Impact of ABO incompatibility on engraftment and transfusion requirement after unrelated cord blood transplantation: a single institute experience in Japan.

The impact of ABO incompatibility between donor and recipient on engraftment and transfusion requirement was studied in 95 adults who underwent unrelated cord blood transplantation (CBT). The patients included 27 ABO-identical, 29 minor, 21 major and 18 bidirectional ABO-incompatible recipients. Neutrophil engraftment did not differ between ABO-identical/minor ABO-incompatible and major/bidirectional ABO-incompatible recipients (hazard ratio (HR) 1.17, P=0.48). Cumulative incidence of platelet engraftment in ABO-identical/minor ABO-incompatible recipients was higher than in major/bidirectional ABO-incompatible recipients (HR 1.88, P=0.013). In addition, fewer platelet transfusions were required during the first 60 days after CBT in ABO-identical/minor ABO-incompatible recipients (HR 0.80, P=0.040). RBC engraftment did not differ between the two groups (HR 1.25, P=0.33). However, fewer RBC transfusions were required in ABO-identical/minor ABO-incompatible recipients than in major/bidirectional ABO-incompatible recipients (HR 0.74, P<0.005). No patients developed pure red-cell aplasia after CBT. These results indicate that ABO incompatibility affected platelet engraftment and transfusion requirement of RBC and platelet in CBT recipients. Further studies including larger patient numbers are required to elucidate the impact of ABO incompatibility on the clinical outcome of CBT.

Unregulated expression of the erythropoietin receptor gene caused by insertion of spleen focus-forming virus long terminal repeat in a murine erythroleukemia cell line.

A murine erythroleukemia (MEL) cell line, F5-5, expressed 10,000 binding sites for erythropoietin (EPO) per cell, 10-fold more than was expressed by other murine erythroleukemia cell lines and normal erythroid progenitors. Northern (RNA) and Southern blot analyses revealed overexpression of mRNA for the EPO receptor (EPOR) and rearrangement of one of the EPOR gene alleles in F5-5 cells, respectively. Molecular cloning of F5-5-derived cDNA encoding EPOR revealed that the 5' noncoding region of the EPOR cDNA corresponds to the 3' long terminal repeat sequence of the polycythemic strain of Friend spleen focus-forming virus (F-SFFVP). The aberrant EPOR transcripts containing the 3' long terminal repeat sequence were mainly expressed in F5-5 cells. The same integration upstream of the EPOR gene was also observed in other subclones and the parent cell line. It is possible that overexpression of EPOR by viral promoter insertion will confer growth advantage to an F-SFFVP-infected erythroid progenitor cell, leading to positive clonal selection through further leukemogenic steps.

Addiction to the IGF2-ID1-IGF2 circuit for maintenance of the breast cancer stem-like cells.

The transcription factor nuclear factor-κB (NF-κB) has important roles for tumorigenesis, but how it regulates cancer stem cells (CSCs) remains largely unclear. We identified insulin-like growth factor 2 (IGF2) is a key target of NF-κB activated by HER2/HER3 signaling to form tumor spheres in breast cancer cells. The IGF2 receptor, IGF1 R, was expressed at high levels in CSC-enriched populations in primary breast cancer cells. Moreover, IGF2-PI3K (IGF2-phosphatidyl inositol 3 kinase) signaling induced expression of a stemness transcription factor, inhibitor of DNA-binding 1 (ID1), and IGF2 itself. ID1 knockdown greatly reduced IGF2 expression, and tumor sphere formation. Finally, treatment with anti-IGF1/2 antibodies blocked tumorigenesis derived from the IGF1Rhigh CSC-enriched population in a patient-derived xenograft model. Thus, NF-κB may trigger IGF2-ID1-IGF2-positive feedback circuits that allow cancer stem-like cells to appear. Then, they may become addicted to the circuits. As the circuits are the Achilles' heels of CSCs, it will be critical to break them for eradication of CSCs.

Induction of the receptor for erythropoietin in murine erythroleukemia cells after dimethyl sulfoxide treatment.

Biologically active 125I-labeled human recombinant erythropoietin (EPO) was used to demonstrate specific receptors for this erythroid-specific hemopoietic growth factor on the cell surface of murine erythroleukemia cell clone B8. The binding of radioiodinated EPO to these cells was time and temperature dependent, specific, saturable, and reversible. During erythroid differentiation by dimethyl sulfoxide, B8 cells displayed a rapid and marked increase in the amount of specific 125I-EPO binding before the appearance of hemoglobin-containing cells. Scatchard analysis of the saturation binding data revealed that B8 cells had a single class and low number (350 to 650) of EPO receptors per cell with an apparent Kd of 1.2 to 1.4 nM. In addition, the number of EPO receptors on B8 cells was increased twice by induction with DMSO for 1 day, but the binding affinity of EPO toward its receptors did not change significantly. Affinity cross-linking experiments with disuccinimidyl suberate demonstrated two radiolabeled components with apparent molecular weights of 145,000 and 130,000 under both reducing and nonreducing conditions. Labeling of the two components was inhibited by incubation of cells with unlabeled EPO. These results suggest that some murine erythroleukemia cells potentially express EPO receptors as a differentiation marker of erythroid lineage, which contain two polypeptides with molecular weights of 109,000 and 94,000.

Nucleotide sequence and expression of a novel human receptor-type tyrosine kinase gene (flt) closely related to the fms family.

A new human gene encoding a receptor-type tyrosine kinase was isolated by a weak cross-hybridization with v-ros oncogene. A cDNA of about 7.7 kb carried a 4.2 kb open reading frame, and the predicted amino acid sequence of 1338 residues contained extracellular, transmembrane and tyrosine kinase domains. Although its extracellular domain is approximately 220 amino acids longer than those of the products of the fms family, i.e. c-fms, c-kit and platelet-derived growth factor receptor genes, the overall structure including cysteine motifs in its extracellular domain and a long peptide insertion in its tyrosine kinase domain indicates that this new gene is closely related to the fms family. Consequently, the gene was designated as flt (fms-like tyrosine kinase) gene. The expression of the flt gene was strongly suppressed in most of the tumor cell lines examined so far, whereas this mRNA was expressed in a variety of normal tissues of adult rat.

MLLT3 gene on 9p22 involved in t(9;11) leukemia encodes a serine/proline rich protein homologous to MLLT1 on 19p13.

Recently, the MLL gene at 11q23 was found to be involved in a subset of leukemias with an 11q23 abnormality. In the present study, we isolated chimeric cDNAs between the MLL and a gene designated MLLT3 at 9p22 from a cDNA library of an IMS-M1 cell line with a t(9;11)(p22;q23) translocation, a representative karyotypic abnormality seen in acute monocytic leukemia. We also isolated a normal MLLT3 cDNA and found an open reading frame encoding at least 318 amino acids with high serine/proline content (24.8%). The chimeric mRNAs were demonstrated to be fused to MLL in frame, as found in t(11;19) and t(4;11) leukemias. The predicted MLLT3 protein demonstrated a significant homology to that of the MLLT1 gene at 19p13 involved in t(11;19) leukemia. The highest homology, up to 74.1%, was found in 86 amino acids of the C-terminus, suggesting that this region is of particular importance for leukemogenesis in t(9;11) leukemia. Northern blot analysis with the MLLT3 cDNA probe against normal tissues revealed multiple transcripts in lymphoid organs. A survey of hematopoietic cell lines demonstrated relatively stronger signals in cells belonging to megakaryocytic and erythroid lineages. As previously found in t(11;19) leukemia, heterogeneous MLL-MLLT3 chimeric mRNAs could be detected by the reverse transcriptase-polymerase chain reaction (RT-PCR) in t(9;11) leukemia samples.

Characterization and molecular features of the cell surface receptor for human granulocyte-macrophage colony-stimulating factor.

The receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF) on the surfaces of normal and leukemic myeloid cells were characterized using 125I-labeled bacterially synthesized GM-CSF. The binding was rapid, specific, time dependent, and saturable. Scatchard analysis of the 125I-GM-CSF binding to peripheral blood neutrophils indicated the presence of a single class of binding site (Kd = 99 +/- 21 pM; 2,304 +/- 953 sites/cell). However, for peripheral blood monocytes and two GM-CSF-responsive myeloid cell lines (U-937 and TF-1), the Scatchard plots were biphasic curvilinear, which were best fit by curves derived from two binding site model: one with high affinity (Kd1 = 10-40 pM) and the other with low affinity (Kd2 = 0.9-2.0 nM). For U-937 cells, the number of high-affinity receptors was 1,058 +/- 402 sites/cell and that of low-affinity receptors was estimated to be 10,834 +/- 2,396 sites/cell. Cross-linking studies yielded three major bands with molecular masses of 150 kDa, 115 kDa, and 95 kDa, which were displaced by an excess amount of unlabeled GM-CSF, suggesting 135-kDa, 100-kDa, and 80-kDa species for the individual components of the human GM-CSF receptor. These bands comigrated for different cell types including peripheral blood neutrophils, U-937 cells and TF-1 cells. In experiments using U-937 cells, only the latter two bands appeared to be labeled in a dose-dependent manner in a low-affinity state. These results suggest that the human GM-CSF receptor possibly forms a multichain complex.

Possible correlation between fusion pattern of BCR/ABL mRNA and clinical response to alpha-interferon in chronic myelogenous leukemia.

Twenty six patients with Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) treated with IFN-alpha were classified on the basis of the fusion pattern of BCR/ABL chimeric mRNA determined by a reverse-transcriptase-polymerase chain reaction (RT-PCR) method. The relationship between the fusion pattern of BCR/ABL mRNA and the clinical outcome was also analysed. Twelve patients showed M-bcr exon 3/ABL exon 2 (B3/A2) chimeric mRNA and nine had M-bcr exon 2/ABL exon 2 (B2/A2) mRNA. Eleven of the 12 patients with B3/A2 achieved complete hematological response with IFN-alpha therapy, as did three of the nine patients with B2/A2. The mean duration to blastic crisis was significantly longer in the B3/A2 patients (mean 52.4 months) than in the B2/A2 patients (mean 26.2 months) (p less than 0.01). These results suggest that the fusion pattern of BCR/ABL mRNA may affect the therapeutic response to IFN-alpha and clinical outcome in CML patients.

Significant expression of G-CSF-induced gene-1 (GIG-1) protein in myeloid cells and NK cells.

The granulocyte colony-stimulating factor (G-CSF)-induced gene, GIG-1, was originally cloned from G-CSF-stimulated bone marrow mononuclear cells obtained from a patient with chronic myelogenous leukemia (CML). We have characterized the GIG-1 gene and its protein product. Expression of GIG-1 mRNA was elevated by treatment with G-CSF in normal bone marrow mononuclear cells, as well as in some cases of blast cells obtained from patients with acute myelogenous leukemia (AML) and CML. Western blot analysis with anti-GIG-1 peptide antiserum showed the molecular mass of GIG-1 product was about 17 kDa. Immunostaining of the hematopoietic cells demonstrated that GIG-1 product was mainly localized to the cytoplasm of both myeloid and natural killer (NK) cells. These results suggested that GIG-1 protein is an integral component that is accumulated during the differentiation of myeloid cells toward the stage of mature neutrophils. Expression of GIG-1 gene in mature neutrophils was tightly regulated and reactivation of GIG-1 gene by G-CSF in mature neutrophils may represent a compensation process for the protein lost through the activation of these cells, thus implying an important role for this protein in host defense mechanisms.

Preparation of a liquid nitrogen target for measurement of gamma-rays in the 14N(n, gamma)15N reaction as an intensity standard in energy regions up to 11 MeV.

We have developed a liquid nitrogen (N(2)) target that allows us to clearly measure gamma-rays below 2 MeV and to improve neutron beam availability. The intensity of the prompt 2223 keV gamma-ray from the (1)H(n, gamma) reaction in the present target could be reduced to about 160 in comparison with the one in the commercially available melamine (C(3)H(6)N(6)) target. The statistics of the full-energy-peak counts were improved by factors of 15-30 and about 4 in the energy regions below and above 2 MeV, respectively.

Pure erythropoietic colony and burst formations in serum-free culture and their enhancement by insulin-like growth factor I.

Recombinant human insulin-like growth factor I (IGF-I) increased human and murine erythropoietic colony formation in serum-free culture. In order to investigate the effects of purified factors such as IGF-I on hemopoietic progenitor cells, we have established a serum-free culture system which supports the clonal growth of CFU-E- and BFU-E-derived colonies. Exogenously supplied ingredients were bovine serum albumin (BSA), transferrin, lipid suspensions, 2-mercaptoethanol, and recombinant human erythropoietin (epo). Among these, BSA and cholesterol were found to be essential ingredients. The optimum concentration of BSA sufficient to grow BFU-E was 3%. Erythroid colony and burst formation of human and murine marrow cells was enhanced twofold (p less than 0.05) by a physiological concentration of recombinant human IGF-I. Potentiation was observed in a dose-dependent manner between 10(-9) and 10(-7) M. A few murine CFU-E colonies were formed in the absence of epo. These results suggest that IGF-I has a supportive effect on the proliferation and differentiation of erythroid precursor cells stimulated by epo and that its action is synergistic with that of epo.

Binding of iodinated erythropoietin to rat bone marrow cells under normal and anemic conditions.

Specific binding sites for erythropoietin (Epo) were shown in normal and anemic rat bone marrow cells using [125I]labeled human recombinant Epo. When rats were treated once or several times with phenylhydrazine or malotilate, or by phlebotomy, the serum Epo level determined by RIA began to increase rapidly. Thereafter, both the number of erythroid colony-forming unit (CFU-E)-derived colonies and the Epo binding capacity of bone marrow cells increased almost simultaneously in response to induced anemic states, suggesting that the amount of Epo binding in bone marrow cells may reflect in vivo erythropoiesis. Scatchard analysis of the binding data from normal rats revealed the presence of a single class of binding sites (Kd = 0.18 +/- 0.04 nM, 38 +/- 5 sites/cell). In anemic states, the apparent average receptor number per cell increased (52-62 sites/cell) without changing in binding affinity toward Epo. Furthermore, [125I]Epo was cross-linked to the cell surface molecule of approximately 165 kd in nonreducing conditions and 75 kd in reducing conditions. Autoradiographic analysis indicated that Epo receptors were distributed on immature erythroid cells. Proerythroblasts were the most heavily labeled, whereas orthochromatic erythroblasts and cells of myeloid and lymphoid lineages were not labeled. Calculations based on Scatchard and autoradiographic analysis showed that proerythroblasts have 390 receptor sites per cell, twice as many as basophilic or polychromatophilic erythroblasts have. These results are consistent with the stage-specific action of Epo in physiological differentiation of erythroid cells.

Binding properties and proliferative potency of insulin-like growth factor I in fetal mouse liver cells.

Specific high-affinity receptor(s) for insulin-like growth factor I have been identified in fetal mouse liver cells (FMLC) rich in late erythroid progenitors (CFU-E). Competition for [125I]IGF-I binding by IGFs and insulin demonstrated the presence of Type-I IGF receptors. Scatchard analysis of the binding data revealed a single class of receptors (Kd, 1.2 nM; R0, 600 sites per cell). Erythroid colony formation and DNA synthesis by these cells were enhanced by IGF-I alone or in combination with erythropoietin (Epo). Subfractionations of FMLC using Percoll density gradients showed that a significant part of [125I]IGF-I binding was observed in the CFU-E-enriched fraction and that the erythroid colony formation was mostly enhanced by IGF-I in the same fraction. IGF-I stimulated the phosphorylation of the beta-subunit of the Type-I receptors. These results indicate that IGF-I modulates the Epo-stimulated proliferation and differentiation of erythroid progenitors via its specific receptors.