Acute myeloid leukemia with high ecotropic viral integration site-1 expression (EVI1(high) AML) is classified as a refractory type of leukemia with a poor prognosis. To provide new insights into the ...prevention and treatment of this disease, we identified the high expression of EVI1-regulated G protein-coupled receptor 56 (GPR56), and the association of high cell adhesion and antiapoptotic activities in EVI1(high) AML cells. Knockdown of GPR56 expression decreased the cellular adhesion ability through inactivation of RhoA signaling, resulting in a reduction of cellular growth rates and enhanced apoptosis. Moreover, in Gpr56(-/-) mice, the number of hematopoietic stem cells (HSCs) was significantly decreased in the bone marrow (BM) and, conversely, was increased in the spleen, liver and peripheral blood. The number of Gpr56(-/-) HSC progenitors in the G0/G1-phase was significantly reduced and was associated with impaired cellular adhesion. Finally, the loss of GPR56 function resulted in a reduction of the in vivo repopulating ability of the HSCs. In conclusion, GPR56 may represent an important GPCR for the maintenance of HSCs by acting as a co-ordinator of interactions with the BM osteosteal niche; furthermore, this receptor has the potential to become a novel molecular target in EVI1(high) leukemia.
HLH encompasses several entities, including the primary or familial form and the secondary forms associated with infections or malignancies. 1, 2 In all forms, HLH is believed to be a reactive ...process resulting from hyperactivation, proliferation, and migration of macrophages and type 1 T cells. 3 Cytotoxic chemotherapy and/or immune suppressive therapy are usually effective in achieving symptomatic remission of HLH. 4, 5 The proven curative potential of haematopoietic stem cell transplantation underscores the premise that all forms of HLH result from genetic defects intrinsic to the immune system. 5- 7 Abnormalities in the function (but rarely the quantity) of cytotoxic immune cells, principally natural killer (NK) cells, but also cytotoxic T cells, have been observed in patients with HLH for nearly 20 years. 8- 11 Several genetic changes are thought to contribute to the development of HLH. All of the patients with PRF1 mutations demonstrated absent or decreased perforin expression in NK cells by flow cytometry, in the proportion of perforin expressing cells and/or intensity of staining (table 1), and all but one (P35) demonstrated absent or markedly decreased NK cell function, suggesting that a single amino acid substitution can drastically affect the expression and/or function of the protein.
The responsible gene for autoimmune polyglandular syndrome type 1, known as autoimmune regulator (AIRE), was identified by positional cloning. The AIRE gene was reported to be expressed in the thymus ...medulla and lymph nodes. However, an expression of the AIRE gene in peripheral blood cells has not yet been reported. In the present study, we found that the AIRE gene was restrictively expressed in peripheral CD14-positive monocytes but not in CD4-positive T cells nor polymorphonuclear cells, as assessed by RT-PCR. Moreover, immunocytochemical study revealed the expression of the AIRE protein not only in CD14-positive monocytes but also in differentiated dendritic cells, cultured in RPMI1640 medium containing 800 U/ml GM-CSF, 1000 U/ml IL-4 and 100 U/ml TNF-α. Thus, it was concluded that the AIRE gene is restrictively expressed in the peripheral monocyte/dendritic cell lineage.
We retrospectively analyzed our results of 30 patients with three distinctive primary immunodeficiency diseases (PIDs)--severe combined immunodeficiency (SCID, n = 11), Wiskott-Aldrich syndrome (WAS, ...n = 11) and X-linked hyper-immunoglobulin M (IgM) syndrome (XHIM, n = 8)--who underwent hematopoietic SCT (HSCT) during the past 20 years. Until 1995, all donors were HLA-haploidentical relatives with T-cell depletion (TCD) (n = 8). Since 1996, the donors have been HLA-matched related donors (MRD) (n = 8), unrelated BM (UR-BM) (n = 7) and unrelated cord blood (UR-CB) (n = 7). Twenty-seven of 30 patients had various pre-existing infections with or without organ damages before HSCT. Conditioning regimen and GVHD prophylaxis were determined according to disease, donor and pretransplant status. Although one of eight patients transplanted with TCD is alive with full engraftment, the other seven died. On the other hand, 18 of 22 patients transplanted without TCD are alive and well, including six of eight transplanted from MRD, seven of seven from UR-BM and five of seven from UR-CB. All 19 survivors did not require Ig supplementation after HSCT. These results indicate that UR-CBT as well as UR-BMT provides good results for PID comparable to MRD-SCT, and that early diagnosis, HSCT at early stage, careful supportive therapy and monitoring for various pathogens are important for the successful HSCT.
Chromosomal integration of the human herpesvirus‐6 (HHV‐6) genome (CIHHV‐6) is an important consideration if HHV‐6 DNA is detected during the course of transplantation. A 4‐year‐old girl with ...refractory anemia with excess blasts type‐2 was diagnosed with CIHHV‐6 before a cord blood transplantation. HHV‐6 DNA was serially quantitated by polymerase chain reaction assay in the transplant period. The possibility of HHV‐6 reactivation in a transplant recipient with CIHHV‐6 was suspected in our case.
We investigated the cause of myelofibrosis and proliferation of megakaryocytes in myelodysplastic syndrome with myelofibrosis (MDS-MF (+)). Plasma-transforming growth factor-beta1 (PTGF-beta1) ...concentrations closely correlated with myelofibrosis grade in MDS-MF (+) and were higher than those in idiopathic myelofibrosis (IMF), essential thrombocythemia (ET), idiopathic thrombocytopenic purpura (ITP), MDS-without MF (MDS-MF (-)) or healthy volunteers (HV). Peripheral blood mononuclear cells from MDS-MF (+) patients expressed more TGF-beta1 mRNA than those from IMF, MDS-MF (-) or HV. When we immunostained bone marrow specimens of MDS-MF (+) for TGF-beta, the intensity of blasts was apparently higher than that of megakaryocytes, while in MDS-MF (-), megakaryocytes were immunostained with a similar intensity as that in MDS-MF (+), but blasts were negative for staining. In IMF, megakaryocytes, monocytes and small mononuclear cells representing CD34+ cells were all similarly stained with a much lower intensity than that of blasts in MDS-MF (+). The number of bone marrow megakaryocytes were increased the most in MDS-MF (+), followed by ET, ITP, MDS-MF (-) and NHL and correlated with plasma thrombopoietin (TPO) levels or with plasma TGF-beta1 levels, respectively, in each disease. Thus, in MDS-MF (+), both myelofibrosis and the increased megakaryocytes were ascribed to overproduction of TGF-beta1 from blasts.
To assess the relationship between the insertion (I)/deletion (D) polymorphism of the ACE gene and arterial distensibility in patients with type 2 diabetes and healthy control subjects.
Aortic and ...carotid arterial distensibility were evaluated by measuring aortic pulse-wave velocity (a-PWV) and carotid stiffness beta using an echo-tracking system in 137 patients with type 2 diabetes and 260 age-matched control subjects.
a-PWV and carotid stiffness beta were significantly higher in patients with type 2 diabetes than in age-matched control subjects (P < 0.05). Both stiffness beta and a-PWV were significantly higher in the patients with the II genotype than in those with the DD genotype (P < 0.001). In the control subjects, multiple regression analysis showed that age and decreased HDL cholesterol were independently associated with increased a-PWV (R2 = 0.244, P < 0.0001) and that age, systolic and diastolic blood pressure, and BMI were independently associated with increased carotid stiffness beta (R2 = 0.454, P < 0.0001). In the patients with type 2 diabetes, age, gene dose of the I allele, and systolic and diastolic blood pressure were independently associated with increased a-PWV (R2 = 0.545, P < 0.0001), and age, gene dose of the I allele, and systolic blood pressure were associated with increases in carotid stiffness beta (R2 = 0.314, P < 0.0001).
These results suggested that ACE polymorphism is associated with the impairment of aortic and carotid distensibility in patients with type 2 diabetes.
We have previously reported that superoxide stimulates the motility of tumor cells and the administration of Cu-Zn superoxide dismutase (SOD) significantly suppresses metastasis. However, ideally, ...anti-metastatic therapy should be long-lasting, systemically effective and have low toxicity. The half-life of Cu-Zn SOD in plasma is so short that it cannot provide long-lasting effects. Therefore, in this study we have developed a gene therapy in a mouse model utilizing extracellular SOD (EC-SOD), which is the most prevalent SOD isoenzyme in extracellular fluids. We retrovirally transfected fibroblasts (syngeneic) with the EC-SOD gene and established EC-SOD-secreting fibroblasts. Inoculation of EC-SOD-secreting fibroblasts suppressed both artificial and spontaneous metastatic lung nodules in mouse metastasis models. These data indicate the feasibility of anti-metastatic gene therapy utilizing the EC-SOD gene.
Aberrant crypt foci of the colon are possible precursors of adenoma and cancer, but these lesions have been studied mainly in surgical specimens from patients who already had colon cancer.
Using ...magnifying endoscopy, we studied the prevalence, number, size, and dysplastic features of aberrant crypt foci and their distribution according to age in 171 normal subjects, 131 patients with adenoma, and 48 patients with colorectal cancer. We also prospectively examined the prevalence of aberrant crypt foci in 11 subjects (4 normal subjects, 6 with adenoma, and 1 with cancer) before and after the administration of 100 mg of sulindac three times a day for 8 to 12 months and compared the results with those in 9 untreated subjects (4 normal subjects and 5 with adenoma). All 20 subjects had aberrant crypt foci at base line.
We identified 3155 aberrant crypt foci, 161 of which were dysplastic; the prevalence and number increased with age. There were significant (P<0.001) correlations between the number of aberrant crypt foci, the presence of dysplastic foci, the size of the foci, and the number of adenomas. After sulindac therapy, the number of foci decreased, disappearing in 7 of 11 subjects. In the untreated control group, the number of foci was unchanged in eight subjects and slightly increased in one (P<0.001 for the difference between the groups).
Aberrant crypt foci, particularly those that are large and have dysplastic features, may be precursors of adenoma and cancer.
Mutations in the perforin gene have been described in some patients with hemophagocytic lymphohistiocytosis (HLH), but the role of perforin defects in the pathogenesis of HLH remains unclear. ...Four-color flow cytometric analysis was used to establish normal patterns of perforin expression for control subjects of all ages, and patterns of perforin staining in cytotoxic lymphocytes (natural killer NK cells, CD8+ T cells, CD56+ T cells) from patients with HLH and their family members were studied. Eleven unrelated HLH patients and 19 family members were analyzed prospectively. Four of the 7 patients with primary HLH showed lack of intracellular perforin in all cytotoxic cell types. All 4 patients showed mutations in the perforin gene. Their parents, obligate carriers of perforin mutations, had abnormal perforin-staining patterns. Analysis of cytotoxic cells from the other 3 patients with primary HLH and remaining family members had normal percentages of perforin-positive cytotoxic cells. On the other hand, the 4 patients with Epstein-Barr virus–associated HLH typically had depressed numbers of NK cells but markedly increased proportions of CD8+ T cells with perforin expression. Four-color flow cytometry provides diagnostic information that, in conjunction with evidence of reduced NK function, may speed the identification of life-threatening HLH in some families and direct further genetic studies of the syndrome.
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