No abstract

Neoplasms of natural killer (NK)-lineage are rare. Their prognosis is generally poor except for cases of solitary nasal NK-cell lymphoma. The NK-cell Tumor Study Group performed a survey in Japan on patients diagnosed between 1994 and 1998. Of 228 patients selected for analysis, 40 underwent HSCT (15 allografts and 25 autografts). The underlying diseases were myeloid/NK cell precursor acute leukemia (n = 4), blastic NK-cell lymphoma (n = 11), aggressive NK-cell leukemia (n = 3), and nasal-type extranodal NK-cell lymphoma (n = 22). At the time of HSCT, 22 patients were in complete remission (CR), 11 were in relapse, and seven were primary refractory. All patients received myeloablative conditioning regimens including total-body irradiation. Sixteen died of disease progression, and six of treatment-related causes. Overall, 4-year survival was 39% with a median follow-up of 50 months; this was significantly better than that of patients who did not undergo HSCT (21%, P = 0.0003). For patients transplanted in CR, the 4-year overall survival was 68%, which was significantly better than that of patients who went into CR but did not undergo HSCT (P = 0.03). These findings suggest that the HSCT is a promising treatment strategy for NK-cell lineage.

No abstract

SummaryWe assayed serum thrombopoietin (TPO) levels in amegakaryocytic thrombocytopenia (AMT) and immune thrombocytopenic purpura (ITP) patients by using a newly established enzyme-linked immunosorbent assay (ELISA). TPO levels in AMT patients were quite high (mean ± SD = 13.7 ± 11.2 fmoles/ml, n = 4), whereas those in ITP patients were only slightly higher (1.25 ± 0.39, n = 12) than those of the healthy donors (0.55 ± 0.2, n = 20). Furthermore, in ITP patients no correlation was observed between platelet counts and serum TPO levels (correlation coefficient = 0.14). We further assayed serum TPO levels sequentially during steroid treatment in patients with AMT and ITP. In one AMT patient serum TPO levels started to decrease in accordance with the increase of megakaryocyte counts, which preceded the increase in platelet counts. However, in ITP patients serum TPO levels did not change significantly throughout the course of the treatment despite the recovery of platelet counts. Based on these findings, we conclude that serum TPO levels may be regulated at least in part by megakaryocyte counts.

The nuclear proto-oncogene c-myb plays crucial roles in the growth, survival, and differentiation of hematopoietic cells. We established three lines of erythropoietin receptor-transgenic mice and found that one of them exhibited anemia, thrombocythemia, and splenomegaly. These abnormalities were independent of the function of the transgenic erythropoietin receptor and were observed exclusively in mice harboring the transgene homozygously, suggesting transgenic disruption of a certain gene.

The contribution of an eosinophil granule protein, major basic protein (MBP), to the pathogenesis of thrombosis seen in patients with eosinophilia was investigated. The sera from eosinophilic patients containing elevated levels of MBP inhibited thrombomodulin (TM) function as a cofactor for the thrombin-catalysed activation of protein C more significantly than those from normal individuals (means 48.5% v 17.4%, respectively). It was suggested that the binding of mature MBP in the sera to TM was electrostatic, because mature MBP (pI 10.9) bound to TM, whereas pro-MBP (pI 6.2) did not. The inhibition of TM cofactor activity by eosinophil granule proteins was mainly attributed to the mature MBP, because MBP-depleted eosinophil granule proteins did not inhibit TM cofactor activity significantly. This inhibition seemed to be due to the specific thrombin-binding to TM being blocked. We concluded that eosinophil granule proteins, particularly MBP, potentially contribute to the hypercoagulation seen in some conditions of eosinophilia, at least because of the inhibition of TM function as a cofactor of the anticoagulation system.

This phase I ⁄ II study was conducted to evaluate the safety and efficacy of bortezomib-melphalan-prednisolone in Japanese patients with previously untreated multiple myeloma who are ineligible for hematopoietic stem cell transplantation. One hundred and one patients were enrolled, and 99 patients received up to nine 6-week cycles of bortezomib (0.7 ⁄ 1.0 ⁄ 1.3 mg ⁄ m 2 ) on days 1,4,8,11, 22, 25, 29, and 32 in cycles 1-4 and on days 1, 8, 22, and 29 in cycles 5-9, with melphalan (9 mg ⁄ m 2 ) and prednisolone (60 mg ⁄ m 2 ) on days 1-4 of each cycle. The recommended dose was determined in the phase I portion, and the overall response rate and safety of bortezomib-melphalan-prednisolone at the recommended dose were assessed in the phase II portion. The recommended dose of bortezomib was determined to be 1.3 mg ⁄ m 2 . Grade 3 or higher non-hematological adverse events included diarrhea (12%) and peripheral neuropathy (10%); grade 4 hematological adverse events included lymphopenia (41%), neutropenia (30%), and thrombocytopenia (22%). Eleven patients had lung injury associated with bortezomib; two had grade 3 disease, and the other nine had grade 1 or 2 disease. Of the 86 patients treated with 1.3-mg ⁄ m 2 bortezomib in phases I and II, the median number of treatment cycles was 4.5, and the overall response rate was 70% (95% confidence interval: 59-79%). Bortezomib-melphalan-prednisolone with 1.3-mg ⁄ m 2 bortezomib was considered to be tolerable and effective in Japanese patients with previously untreated multiple myeloma. However, further investigation is needed to refine the administration schedule. (Cancer Sci 2013; 104: 912-919)

The human ␤-globin locus is comprised of embryonic, fetal, and adult globin genes, each of which is expressed at distinct stages of pre-and postnatal development. Functional defects in globin proteins or expression results in mild to severe anemia, such as in sickle-cell disease or ␤-thalassemia, but the clinical symptoms of both disorders are ameliorated by persistent expression of the fetal globin genes. Recent genome-wide association studies (GWAS) identified the intergenic region between the HBS1L and MYB loci as a candidate modifier of fetal hemoglobin expression in adults. However, it remains to be clarified whether the enhancer activity within the HBS1L-MYB regulatory domain contributes to the production of fetal hemoglobin in adults. Here we report a new mouse model of hereditary persistence of fetal hemoglobin (HPFH) in which a transgene was randomly inserted into the orthologous murine Hbs1l-Myb locus. This mutant mouse exhibited typically elevated expression of embryonic globins and hematopoietic parameters similar to those observed in human HPFH. These results support the contention that mutation of the HBS1L-MYB genomic domain is responsible for elevated expression of the fetal globin genes, and this model serves as an important means for the analysis of networks that regulate fetal globin gene expression. The human ␤-type globin locus consists of embryonic, fetal, and adult globin genes. The embryonic and fetal globin genes are typically expressed in the yolk sac and fetal liver, respectively (1). In the adult spleen and bone marrow, the adult globin gene is activated, while the embryonic and fetal globin genes are silenced (1). Two mechanisms have been proposed to regulate silencing of the embryonic and fetal globin genes in the adult: autonomous active silencing of the embryonic and fetal globin genes by gene autonomous recruitment of repressors and passive silencing due to competitive sequestration of locus control region (LCR) enhancer activity by the adult ␤-globin gene (1). Reactivation of the embryonic and/or fetal globin genes could be a critically useful ploy for establishing therapies for hereditary anemias and the associated pathophysiology caused by adult globin gene mutations, such as sickle-cell disease and ␤-thalassemia (2-5).A couple of genome-wide association study (GWAS) experiments independently identified two candidate regions that might influence the expression of fetal hemoglobin in adults (6, 7). One is the BCL11A locus. BCL11A encodes a well-characterized hematopoietic transcription factor (8), and persistent expression of ␥-globin was observed in BCL11A-deficient human and murine erythroid cells, demonstrating a contribution of BCL11A to hereditary persistence of fetal hemoglobin (HPFH) (9, 10). The other is the intergenic region between the human HBS1L and MYB genes. A 24-kbp linkage disequilibrium (LD) block located 33 kbp 5= to HBS1L and 65 kbp 5= to MYB was found to exhibit strong association with elevated levels of fetal hemoglobin (7), and the LD block was designated ...