Hiroyoshi Hattori

Neutrophil-derived TNF-related apoptosis-inducing ligand (TRAIL): a novel mechanism of antitumor effect by neutrophils.

To detect the novel genes expressed uniquely in neutrophils and elucidate their function, the gene expression pattern was compared by using cDNA microarray containing 240 cytokine genes between the neutrophils and peripheral blood mononuclear cells (PBMCs) obtained from healthy human donors. Twenty-six genes, including tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were expressed in neutrophils at a level >10 times higher than that seen in phytohemagglutinin-stimulated PBMCs. The amounts of mRNA and protein of TRAIL were quantified by real-time reverse transcription-PCR and ELISA, respectively. TRAIL was expressed in resting neutrophils at the mRNA and protein levels, and its expression was enhanced after stimulation with IFN-γ. Neutrophils expressed TRAIL on the cell surface and released it into the culture media. The cytotoxicity of neutrophil-derived TRAIL against Jurkat cells was determined by flow cytometry using FITC-conjugated annexin V. When Jurkat cells were cultured with neutrophils in the presence of IFN-γ, the number of Jurkat cells undergoing apoptosis increased, and such increase depended on the effector:target ratio. This cytotoxicity was suppressed partially by adding anti-TRAIL antibody to the media. Neutrophils may exert their own antitumor effect by TRAIL. A microarray analysis was found to be a useful tool for detecting novel genes that are suggested to play unknown roles in the neutrophil function.

Two modes of microsatellite instability in human cancer: differential connection of defective DNA mismatch repair to dinucleotide repeat instability

Microsatellite instability (MSI) is associated with defective DNA mismatch repair in various human malignancies. Using a unique fluorescent technique, we have observed two distinct modes of dinucleotide microsatellite alterations in human colorectal cancer. Type A alterations are defined as length changes of ≤6 bp. Type B changes are more drastic and involve modifications of ≥8 bp. We show here that defective mismatch repair is necessary and sufficient for Type A changes. These changes were observed in cell lines and in tumours from mismatch repair gene-knockout mice. No Type B instability was seen in these cells or tumours. In a panel of human colorectal tumours, both Type A MSI and Type B instability were observed. Both types of MSI were associated with hMSH2 or hMLH1 mismatch repair gene alterations. Intriguingly, p53 mutations, which are generally regarded as uncommon in human tumours of the MSI+ phenotype, were frequently associated with Type A instability, whereas none was found in tumours with Type B instability, reflecting the prevailing viewpoint. Inspection of published data reveals that the microsatellite instability that has been observed in various malignancies, including those associated with Hereditary Non-Polyposis Colorectal Cancer (HNPCC), is predominantly Type B. Our findings indicate that Type B instability is not a simple reflection of a repair defect. We suggest that there are at least two qualitatively distinct modes of dinucleotide MSI in human colorectal cancer, and that different molecular mechanisms may underlie these modes of MSI. The relationship between MSI and defective mismatch repair may be more complex than hitherto suspected.

Differential mRNA expression of glucocorticoid receptor α and β is associated with glucocorticoid sensitivity of acute lymphoblastic leukemia in children

Sensitivity of leukemic blasts to glucocorticoid is one of the important prognostic factors for pediatric acute lymphoblastic leukemia (ALL). Alternative splicing of the glucocorticoid receptor (GR) gene results in several isoforms. We examined an association of the expression pattern of GR isoforms in leukemic blasts with their sensitivity to glucocorticoid in childhood ALL.

High expression of platelet-derived growth factor and transforming growth factor-β1 in blast cells from patients with Down Syndrome suffering from transient myeloproliferative disorder and organ fibrosis

To determine whether platelet‐derived growth factor (PDGF) and transforming growth factor‐β1 (TGF‐β1) are involved in organ fibrosis in patients with transient myeloproliferative disorder (TMD) in Down syndrome, the expression of PDGF and TGF‐β1 mRNA in blast cells of TMD was investigated using real‐time quantitative reverse transcription polymerase chain reaction. Blasts and liver tissue from TMD patients with hepatic fibrosis showed a significantly elevated expression of PDGF gene. The expression of TGF‐β1 gene was higher in TMD and acute megakaryoblastic leukaemia than in the control group. These results suggest that PDGF in combination with TGF‐β1 plays a role in organ fibrosis of TMD.

Immunotherapy with autologous dendritic cells and tumor antigens for children with refractory malignant solid tumors.

Abstract:  Immature DCs were generated from the peripheral blood monocytes from five children with refractory solid tumors (Ewing sarcoma, synovial sarcoma, neuroblastoma) using GM‐CSF and IL‐4. These DCs were then pulsed with tumor‐specific synthetic peptides or tumor lysates in the presence of the immunogenic protein KLH for 12 h. Pulsed DCs were administered subcutaneously every one or two weeks in an outpatient setting without any toxicity. In one patient with Ewing sarcoma, the residual tumor disappeared following autologous PBSCT and DC therapy, and a complete remission has been maintained for 77 months. In two patients with synovial sarcoma or with neuroblastoma, growth of the tumors was temporally suppressed for one and 10 months, respectively, followed by their exacerbation. A DTH response was detected against KLH in all five patients and against the tumor lysate in one patient. In the patients with a possible DC‐mediated anti‐tumor effect, the number of CD8+ HLA‐DR+ lymphocytes and INF‐γ+CD8+ lymphocytes increased and an elevation of the NK cell cytotoxic activity was observed during and/or after DC therapy. DC‐based immunotherapy may therefore be a feasible, well‐tolerated and promising approach in the treatment of children with refractory malignant tumors.

Immunotherapy with autologous dendritic cells and tumor-specific synthetic peptides for synovial sarcoma.

Synovial sarcoma in an 11-year-old Japanese girl relapsed 5 months after autologous stem cell transplantation. Autologous dendritic cells (DCs) were generated from her peripheral blood mononuclear cells using granulocyte/macrophage colony-stimulating factor and IL-4. Dendritic cells were pulsed with synthetic peptides containing a junctional region of SYT-SSX2 fusion protein generated by t(X;18) and were administered once per week. No side effects were observed. Growth of metastatic nodules in the lung was temporally suppressed. The delayed-type hypersensitivity responses in skin were enhanced to tumor lysate but not to peripheral blood mononuclear cell lysate. The CD3+ cells cultured with pulsed DCs lysed tumor cells in vitro. Immunotherapy using DCs and tumor-specific peptides may be a safe approach in the treatment of childhood cancer.

Unrelated cord blood transplantation for an infant with chemotherapy-resistant progressive Langerhans cell histiocytosis.

The authors describe a patient successfully treated with unrelated cord blood transplantation (CBT) for chemotherapy-resistant progressive Langerhans cell histiocytosis (LCH). An 8-month-old boy had LCH diagnosed based on the histologic examination of skin lesions. Despite intensive chemotherapy and immunotherapy, the disease was progressive, with organ dysfunction. He received unrelated CBT after a conditioning regimen consisting of total body irradiation, etoposide, and melphalan. He was in complete remission 12 months after the transplantation. The authors suggest that CBT could be considered in the treatment of patients with chemotherapy-resistant progressive LCH, especially if there are no available human leukocyte antigen-matched family donors.

Expression of cytokine-associated genes in dendritic cells (DCs): Comparison between adult peripheral blood- and umbilical cord blood-derived DCs by cDNA microarray

OBJECTIVE The expression of cytokine-associated genes in dendritic cells (DCs) derived from umbilical cord blood (UCB) and adult peripheral blood (APB) was comprehensively compared in order to elucidate the difference in DC function between newborns and adults. STUDY DESIGN Immature DCs were obtained from UCB and APB of healthy human donors. Several cytokines were added to generate mature DCs. Gene expression was compared using cDNA microarray containing 553 cytokine-associated genes. Eleven genes with differential expression were selected and determined their expression levels in DCs by quantitative real-time RT-PCR. RESULTS The expression of the Th1 response-related genes (IL-12B and IL-18) and chemokine genes (CXCL9, CXCL13, CCL18 and CCL24) was significantly lower in UCB-DCs than in APB-DC in both maturation states. On the other hand, calgranulins A and B, which are speculated to induce immune tolerance, showed higher expression in UCB-DCs. The expression of cell cycle-related genes (CDC2 and cyclin B1) was significantly higher in UCB-DCs than in APB-DCs, and immature UCB-DCs proliferated more rapidly than immature APB-DCs. CONCLUSION The expression of genes related to immune responses was significantly different between UCB- and APB-DCs, which may cause a decreased DC-mediated immunity and an increased susceptibility to infection in newborns.

An Infant with Precursor Natural Killer (NK) Cell Leukemia Successfully Treated with an Unrelated Cord Blood Transplantation

Here we report a case with precursor natural killer (NK) cell leukemia successfully treated with an unrelated cord blood transplantation. A 7-month-old Japanese boy was diagnosed to have NK cell leukemia based on the existence of abnormal cells in the bone marrow with the phenotype of CD3-/CD4 /CD7-/CD8-/CD167-CD33+/CD34-/CD56+/HLA-DR+NKBI+ CD94+. The leukemic cells showed few azurophilic granules in the cytoplasm and weak cytotoxic activity. Although he presented with a huge mass occupying the bilateral paranasal sinuses and hepatosplenomegaly, he achieved complete remission by the conventional chemotherapeutic regimen for acute myelogenous leukemia, followed by an unrelated cord blood transplantation. He has remained in complete remission for 14 months posttransplant. To our knowledge. this is the youngest reported case with precursor NK cell leukemia; cord blood transplantation may thus be the treatment of choice for this disease.

Frequent microsatellite instability in non-Hodgkin lymphomas irresponsive to chemotherapy.

Microsatellite instability (MSI) in haematopoietic malignancies has been controversial. Particularly in non-Hodgkin lymphoma, the data published to date lack unity. Using a unique fluorescent technique, we found MSI in eight (14%) tumours in a panel of 59 carefully selected non-Hodgkin lymphoma patients. Our fluorescent technique also reveals two qualitatively distinct modes of MSI, i.e. Type A and Type B. Based on our previous studies using DNA mismatch repair (MMR) gene-knock out animals, we have concluded that Type A MSI is a direct consequence of defective MMR. MSI observed in non-Hodgkin lymphomas was uniformly Type A, which implies that MMR deficiency occurs in this malignancy. Intriguingly, in non-Hodgkin lymphoma patients treated by CHOP/VEPA-based therapies, response to chemotherapy was significantly worse in those with microsatellite-unstable tumours (p=0.027). As a consequence, the patient outcomes at 1 year after treatment were significantly less favourable in this population (p=0.046), although the survival difference was not statistically confirmed in a longer term. These findings suggest that in some non-Hodgkin lymphomas MMR deficiency may lead to drug resistance in tumour cells and, consequently, to poor patient outcomes. In non-Hodgkin lymphoma, MSI may be a potential biomarker that predicts the tumour response against chemotherapy.