Cbl negatively regulates erythropoietin-induced growth and survival signaling through the proteasomal degradation of Src kinase.

We examined the biological functions of the gene Cbl in erythropoietin (EPO) signaling using Cbl-deficient F-36P human erythroleukemia cells by the introduction of the Cbl siRNA expression vector. Knockdown of Cbl promoted EPO-dependent proliferation and survival of F-36P cells, especially at a low concentration of EPO (0.01U/mL), similar to serum concentrations of EPO in healthy volunteers (0.005-0.04U/mL). We found that Src was degraded mainly by the proteasomal pathway because the proteasome inhibitor MG-132 but not the lysosome inhibitor NH4Cl suppressed the EPO-induced degradation of Src in F-36P cells and that knockdown of Cbl inhibited EPO-induced ubiquitination and degradation of Src in F-36P cells. The experiments using the Src inhibitor PP1 and co-expression experiments further confirmed that Cbl and the kinase activity of Src are required for the EPO-induced ubiquitination of Src. In addition, the co-expression experiments and in vitro kinase assay demonstrated that the EPO-induced tyrosine phosphorylation and ubiquitination of Cbl were dependent on the kinase activity of Src but not Jak2. Thus, Cbl negatively regulates EPO signaling mainly through the proteasome-dependent degradation of Src, and the E3 ligase activity of Cbl and its tyrosine phosphorylation are regulated by Src but not Jak2.

Diagnosis and evaluation of intestinal graft-versus-host disease after allogeneic hematopoietic stem cell transplantation following reduced-intensity and myeloablative conditioning regimens.

Colonoscopic evaluation of mucosal tissues after allogeneic hematopoietic stem cell transplantation (HSCT) is very useful in evaluating pathogenesis and diagnosis of intestinal graft-versus-host disease (GVHD). However, information on the timing and sites of biopsies and the immunohistological evaluation of mucosal tissues for diagnosing intestinal GVHD, especially following reduced-intensity (RIC) regimens, remains very limited. A total of 33 patients with histologically proven GVHD after allogeneic HSCT with RIC (n = 23) and myeloablative conditioning (MAC, n = 10) regimens were enrolled in the present study. Colonoscopy was performed due to gastrointestinal symptoms, especially diarrhea and anorexia. Sites of biopsies with the worst histopathological grading were the terminal ileum in 67 % of patients. In the RIC group, the onset of diarrhea prior to colonoscopy examination was later (median: RIC, 57 vs. MAC, 27 days) and the number of patients who developed abdominal pain tended to be higher (RIC, 70 % vs. MAC, 30 %). A lower number of CD4+ cells and a higher ratio of Foxp3+ cells to CD4+ cells were detected in the involved lesions of intestinal GVHD following RIC. These differences in the RIC and MAC groups suggest that regimen-specific therapeutic strategies are required for diagnosing intestinal GVHD.

Comparison of autologous hematopoietic cell transplantation and chemotherapy as postremission treatment in non-M3 acute myeloid leukemia in first complete remission.

UNLABELLED: Randomized trials of acute myeloid leukemia (AML) in first complete remission (CR1) showed that autologous hematopoietic cell transplantation (auto-HCT) improves relapse-free survival (RFS) but not overall survival (OS), compared with chemotherapy. Using a database of 2518 adult patients with AML in CR1, we conducted a 5-month landmark analysis and found that auto-HCT improves 3-year RFS but not OS compared with chemotherapy. INTRODUCTION: A number of randomized trials in patients with AML in CR1 have been conducted and they showed that auto-HCT improves RFS but not OS, compared with chemotherapy. However, because these trials have had compliance problems, the value of auto-HCT still has not been clearly established. PATIENTS AND METHODS: Using a database of 2518 adult patients with AML in CR1, we retrospectively analyzed the outcome of auto-HCT and compared it with intensive nonmyeloablative chemotherapy using landmark analyses. RESULTS: In 103 auto-HCT recipients, OS and RFS at 3 years from treatment were 65% and 57%, respectively. Multivariate analysis showed that unfavorable risk cytogenetics and entry into CR1 after 2 courses of induction treatment predicted a poor outcome. Because the median time interval between CR1 and auto-HCT was 153 days, landmark analyses at 5 months after CR1 were performed to compare 1290 patients who received chemotherapy alone (median age, 52 years; range, 16-70) with 103 who received auto-HCT (median age, 48 years; range, 16-67). Auto-HCT improves 3-year RFS (58% vs. 37%; P < .001) but not OS compared with chemotherapy alone. Among patients with unfavorable risk cytogenetics or those who required 2 courses to reach CR1, there was no significant difference in RFS between the 2 groups. CONCLUSION: Auto-HCT can be considered as a postremission therapy for AML patients with favorable or intermediate risk cytogenetics who achieve CR1 after a single course of induction treatment.

Potentiated activation of VLA-4 and VLA-5 accelerates proplatelet-like formation.

Fibronectin (FN) plays important roles in the proliferation, differentiation, and maintenance of megakaryocytic-lineage cells through FN receptors. However, substantial role of FN receptors and their functional assignment in proplatelet-like formation (PPF) of megakaryocytes are not yet fully understood. Herein, we investigated the effects of FN receptors on PPF using the CHRF-288 human megakaryoblastic cell line, which expresses VLA-4 and VLA-5 as FN receptors. FN and phorbol 12-myristate 13-acetate (PMA) were essential for inducing PPF in CHRF-288 cells. Blocking experiments using anti-ß1-integrin monoclonal antibodies indicated that the adhesive interaction with FN via VLA-4 and VLA-5 were required for PPF. PPF induced by FN plus PMA was accelerated when CHRF-288 cells were enforced adhering to FN by TNIIIA2, a peptide derived from tenascin-C, which we recently found to induce ß1-integrin activation. Adhesion to FN enhanced PMA-stimulated activation of extracellular signal-regulated protein kinase 1 (ERK1)/2 and enforced adhesion to FN via VLA-4 and VLA-5 by TNIIIA2-accelerated activation of ERK1/2 with FN plus PMA. However, c-Jun amino-terminal kinase 1 (JNK1), p38, and phosphoinositide-3 kinase (PI3K)/Akt were not stimulated by FN plus PMA, even with TNIIIA2. Thus, the enhanced activation of ERK1/2 by FN, PMA plus TNIIIA2 was responsible for acceleration of PPF with FN plus PMA.

Prognosis of acute myeloid leukemia harboring monosomal karyotype in patients treated with or without allogeneic hematopoietic cell transplantation after achieving complete remission.

To evaluate the prognostic impact of monosomal karyotype on post-remission outcome in acute myeloid leukemia, we retrospectively analyzed 2,099 patients who had achieved complete remission. Monosomal karyotype was noted in 73 patients (4%). Of these, the probability of overall survival from first complete remission was 14% at four years, which was significantly lower than that reported in patients without monosomal karyotype, primarily due to a high relapse rate (86%). Monosomal karyotype remained significantly associated with worse overall survival among patients with unfavorable cytogenetics or complex karyotype, and even in patients who underwent allogeneic hematopoietic cell transplantation during first complete remission. These findings confirm that monosomal karyotype has a significantly adverse effect on post-remission outcome in patients with acute myeloid leukemia treated with and without allogeneic hematopoietic cell transplantation in first complete remission, emphasizing the need for the development of alternative therapies for this patient population.

S-1 induced secondary acute erythroid leukemia with a chromosome inv(12)(p13;q13).

Adjuvant chemotherapy by S-1 following gastrectomy is considered standard treatment in Japan. Analysis of follow-up data have proved the efficacy of S-1 administration, and that hematological adverse events were relatively rare. Pyrimidine anti-metabolites, including S-1, have shown relatively lower risks for secondary hematological malignancies in comparison to alkylating agents and topoisomerase-II inhibitors. We here report a case of therapy-related leukemia after S-1 administration. A patient who had received S-1as the sole adjuvant chemotherapy was diagnosed with acute erythroid leukemia. To the best of our knowledge, our patient represents the first report of S-1 induced acute leukemia.

Feasibility of reduced-intensity cord blood transplantation as salvage therapy for graft failure: results of a nationwide survey of adult patients.

To evaluate whether rescue with cord blood transplantation (CBT) could improve the poor survival after graft failure (GF), we surveyed the data of 80 adult patients (median age, 51 years) who received CBT within 3 months of GF (primary 64, secondary 16), with fludarabine-based reduced-intensity regimens with or without melphalan, busulfan, cyclophosphamide, and/or 2-4 Gy total-body irradiation (TBI). A median number of 2.4 × 10(7)/kg total nucleated cells (TNC) were infused, and among the 61 evaluable patients who survived for more than 28 days, 45 (74%) engrafted. The median follow-up of surviving patients was 325 days, and the 1-year overall survival rate was 33% despite poor performance status (2-4, 60%), carryover organ toxicities (grade 3/4, 14%), and infections (82%) prior to CBT. Day 100 transplantation-related mortality was 45%, with 60% related to infectious complications. Multivariate analysis showed that the infusion of TNC ≥2.5 × 10(7)/kg and an alkylating agent-containing regimen were associated with a higher probability of engraftment, and that high risk-status at the preceding transplantation and grade 3/4 organ toxicities before CBT were associated with an increased risk of mortality. In conclusion, in an older population of patients, our data support the feasibility of CBT with a reduced-intensity conditioning regimen for GF.

Acute leukemia of ambiguous lineage, biphenotype, without CD34, TdT or TCR-rearrangement.

Biphenotypic acute leukemia (BAL) is a rare entity that comprises 0.5-3% of all acute leukemias and probably arises from multipotent progenitor cells. The optimal approach for BAL therapy is unknown. Thus, it is important to elucidate the origin of the neoplastic cells for determination of the appropriate therapy. We report the case of a 41-year-old man with BAL having myeloid and T-lymphoid lineage phenotypes. Strangely, neither CD34 nor TdT expression nor rearrangement of TCR-alpha/beta, delta/gamma genes were shown. This pattern is rarely encountered and suggests that the blast cells were possibly considered immature with aspects of differentiation indicating myeloid lineage, rather than T-lymphoid lineage.

Gab1 transduces PI3K-mediated erythropoietin signals to the Erk pathway and regulates erythropoietin-dependent proliferation and survival of erythroid cells.

In this study, we examined the biological functions of Gab1 in erythropoietin receptor (EPOR)-mediated signaling in vivo. Knockdown of Gab1 by the introduction of the Gab1 siRNA expression vector into F-36P human erythroleukemia (F-36P-Gab1-siRNA) cells resulted in a reduction of cell proliferation and survival in response to EPO. EPO-induced activation of Erk1/2 but not of Akt was significantly suppressed in F-36P-Gab1-siRNA cells compared with mock-transfected F-36P cells. The co-immunoprecipitation experiments revealed an EPO-enhanced association of Gab1 with the Grb2-SOS1 complex and SHP-2 in F-36P cells. A selective inhibitor of phosphatidylinositol 3-kinase (PI3K) LY294002 and short interfering RNA (siRNA) duplexes targeting the p85 regulatory subunit of PI3K (p85-siRNA) independently suppressed tyrosine phosphorylation of Gab1; its association with Grb2, SHP-2 and p85; and the activation of Erk in EPO-treated F-36P cells. LY294002 inhibited EPO-induced tyrosine phosphorylation of Gab1 and its association with Grb2 in human primary EPO-sensitive erythroid cells. The co-immunoprecipitation experiments using the Jak inhibitor AG490 or siRNA duplexes targeting Jak2 and in vitro binding experiments demonstrated that Jak2 regulated Gab1-mediated Erk activation through tyrosine phosphorylation of Gab1. Taken together, these results suggest that Gab1 couples PI3K-mediated EPO signals with the Ras/Erk pathway and that Gab1 plays an important role in EPOR-mediated signal transduction involved in the proliferation and survival of erythroid cells.

Prognostic factors and clinical outcomes in patients with leptomeningeal metastasis from solid tumors.

BACKGROUND: Leptomeningeal metastasis (LM) occurs in 4-15% of patients with solid tumors. Although the clinical outcomes in cancer patients have been improving recently, no standard treatment for LM has been established as yet. The purpose of this study was to identify the prognostic factors in patients with solid tumors with cytologically proven LM. METHODS: We retrospectively analyzed a series of 85 consecutive patients with cytologically proven LM who were treated between 1997 and 2005. RESULTS: The primary diseases were as follows; lung cancer (n = 36), breast cancer (n = 33), gastric cancer (n = 8), and others (n = 8). Forty-nine patients had brain metastasis at the time of diagnosis of the LM, and in 51 patients, MRI revealed meningeal dissemination in the brain or spine. The performance status (PS) was 0-1 in 26 patients and 2-4 in 59 patients. Thirty-one patients, including 19 with breast cancer, four with lung cancer, five with gastric cancer and three with other cancers, were treated by intrathecal (IT) chemotherapy. The response rate to the IT was 52% (95% confidence interval (CI): 41.4-62.6%). The median survival was 51 days (range, 3-759 days). A univariate analysis identified breast cancer, good PS (0-1), time to development of the LM (>1 year), and treatment by IT chemotherapy as being associated with a good prognosis, and multivariate analysis identified poor PS (HR: 1.72 (95% CI, 1.04-2.86) P = 0.04) and MRI-proven LM (HR: 1.82 (95% CI, 1.11-2.98) P = 0.02) as being associated with a poor prognosis. CONCLUSION: In patients with poor prognostic factors, such as poor PS or MRI-proven LM, palliative therapy might be the most suitable treatment strategy.

Stromal cells in bone marrow play important roles in pro-inflammatory cytokine secretion causing fever following bortezomib administration in patients with multiple myeloma.

Bortezomib blocks the activation of nuclear factor-kappaB-mediated pro-inflammatory cytokines, however, systemic inflammatory symptoms following bortezomib administration have been reported, although their mechanisms remain elusive. Serum samples were obtained from five patients, who participated in a phase I/II study of Japanese patients with relapsed or refractory multiple myeloma (MM), and developed cyclic fever following bortezomib administration, to measure cytokine levels. Significant correlations between interleukin (IL)-6 or interferon (IFN)-gamma and the body temperature were observed in two patients each. Furthermore, we found that IL-6 elevation was not observed after the addition of bortezomib to any examined MM cells alone, but was noted in a case of bone marrow stromal cells (BMSCs) of macrophage origin alone or co-cultured with MM cells. Similarly, a marked increase in IFN-gamma levels was induced by adding bortezomib to BMSCs of fibroblast origin. Although this investigation was a preliminary study with a small number of patients, our results suggested that pro-inflammatory cytokines causing bortezomib-associated fever were secreted from BMSCs rather than MM cells.

[Tolerability of imatinib for patients with chronic myelogeneous leukemia (CML)].

The adequate dose of imatinib has not been defined for the Japanese population. Indeed, about half of patients experience mild to moderate adverse events due to this drug, some of which result in intolerance. We reviewed a patients' cohort treated with imatinib in our hospital in 2007 for chronic myelogeneous leukemia (CML). The cohort included 14 patients (5 men and 9 women) whose median age was 53 (range 16-81). The disease status at onset was chronic phase in 13 patients and accelerated phase in 1. During the 2-year observation period, 2 patients (14%) failed to respond and 6 (42%) became intolerant to imatinib. After the appearance of the intolerance, 5 of the 6 patients were treated with a reduced dose of imatinib (300 mg/day in 4, 200 mg/day in 1). In 4 of these 6 intolerant cases, CR was maintained 2 years after the start of imatinib therapy. Nevertheless, 42% of patients were intolerant to imatinib therapy through 2 years, and progression-free survival was 86%. In conclusion, an adjusted dose exerting minimal toxicity and showing a favorable outcome should be researched in Japanese patients including the elderly.

[Limited but potential efficacy by graft-versus-leukemia (GVL) for Pro T-ALL].

We present a 22-year-old male diagnosed with pro T-acute lymphoblastic leukemia (ALL). His laboratory test showed 181,900/microL of WBC complicated with lymphoadenopathy, pleural effusion, pericardial effusion and hepatosplenomegaly at the onset. Flow cytometry analysis of the leukemic cells showed cCD3+, CD7+, CD2+, CD1a-, CD3-, CD5-, CD4-, CD8-, CD34+, and HLA-DR+ as a pro T-cell phenotype. The patient was treated with induction therapy followed by 3 courses of consolidation therapy and achieved his first complete remission. He underwent up-front stem cell transplantation (SCT) from an HLA-full matched sibling, with early relapse just before transplantation. The conditioning regimen consisted of fludarabine (100 mg/m2) and melphalan (180 mg/m2). He relapsed with an extramedullary mass (gingival, testis, and femoral muscles) 1 year after transplantation. Since bone marrow involvement was not apparent, he received involved field radiation therapy (25.2 Gy/14 frequencies) in each mass. Six months after extramedullary relapse, bone marrow relapse occurred, and the patient died of sepsis due to Pseudomonas aeruginosa during re-induction therapies. Based on the immature T cell phenotype frequently with myeloid markers, a graft-versus- leukemic effect might be expected after allogeneic SCT for Pro T-ALL and a positive indication of SCT for this disease should be considered.

[Aggravated post-herpetic neuralgia due to bortezomib].

Bortezomib, a proteasome inhibitor, has been used for patients with refractory multiple myeloma. We present a 58-year old man who had IgG-gamma-type multiple myeloma, refractory for MP (melphalan-predonisolone) and VAD (vincrisitine-doxorubicin-dexamethasone) therapy. He was complicated with reactivation of varicella-zoster virus (VZV) 4 weeks before bortezomib administration. Two weeks of consolidation treatment with standard dose valaciclovir caused VZV infection to settle down and, after a further 2 weeks, VZV remission was confirmed. Bortezomib was started at a dose of 1.3 mg/m2 with prophylactic use of valaciclovir for VZV reactivation, post-herpetic neuralgia exacerbated the following day and grade 3 neuralgia developed the following week without recurrence of skin eruption. Neuralgia improved after the cessation of bortezomib with various supportive treatments and interventions. Although the reactivation of VZV was suspicious, no apparent skin lesions were observed. Although the mechanisms of post-herpetic neuralgia and chemotherapy-induced neuropathy are different, bortezomib might enhance post-herpetic neuralgia independent of the manner of viral reactivation.

Preengraftment serum C-reactive protein (CRP) value may predict acute graft-versus-host disease and nonrelapse mortality after allogeneic hematopoietic stem cell transplantation.

In a mouse model, inflammatory cytokines play a primary role in the development of acute graft-versus-host disease (aGVHD). Here, we retrospectively evaluated whether the preengraftment C-reactive protein (CRP) value, which is used as a surrogate marker of inflammation, could predict posttransplant complications including GVHD. Two hundred twenty-four adult patients (median age, 47 years; range: 18-68 years) underwent conventional stem cell transplantation (CST, n = 105) or reduced-intensity stem cell transplantation (RIST, n = 119). Patients were categorized according to the maximum CRP value during neutropenia: the "low-CRP" group (CRP < 15 mg/dL, n = 157) and the "high-CRP" group (CRP >or= 15 mg/dL, n = 67). The incidence of documented infections during neutropenia was higher in the high-CRP group (34% versus 17%, P = .004). When patients with proven infections were excluded, the CRP value was significantly lower after RIST than after CST (P = .017) or after related than after unrelated transplantation (P < .001). A multivariate analysis showed that male sex, unrelated donor, and HLA-mismatched donor were associated with high CRP values. The high-CRP group developed significantly more grade II-IV aGVHD (P = .01) and nonrelapse mortality (NRM) (P < .001), but less relapse (P = .02). The present findings suggest that the CRP value may reflect the net degree of tissue damage because of the conditioning regimen, infection, and allogeneic immune reactions, all of which lead to subsequent aGVHD and NRM.

Hyperglycemia during the neutropenic period is associated with a poor outcome in patients undergoing myeloablative allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) frequently require support with parenteral nutrition and immunosuppressive drugs, which introduce the risk of hyperglycemia. Van den Berghe et al. showed that the strict glucose control improved the outcome of patients treated in the intensive care unit, and this point was evaluated in this study in a HSCT setting. METHODS: A cohort of 112 consecutive adult patients treated by myeloablative allogeneic HSCT between January 2002 and June 2006 was reviewed retrospectively. Twenty-one patients were excluded due to graft failure, preexisting infectious diseases, preexisting neutropenia or previous allogeneic HSCT. The remaining 91 patients were categorized according to mean fasting blood glucose (BG) level in the neutropenic period after conditioning: normoglycemia (BG <110 mg/dL, n=28), mild hyperglycemia (110 to 150 mg/dL, n=49), and moderate/severe (>150 mg/dL, n=14). The primary endpoint was the occurrence of febrile neutropenia (FN) and documented infection during neutropenia, and the secondary endpoints included organ dysfunction according to the definition used by van den Berghe, acute graft-versus-host disease (GVHD), overall survival, and nonrelapse mortality (NRM). RESULTS: Although the incidence of FN or documented infections was similar between the three groups, hyperglycemia was significantly associated with an increased risk of organ dysfunction, grade II-IV acute GVHD, and NRM. CONCLUSIONS: While the results suggested an association between the degree of hyperglycemia during neutropenia and an increased risk of posttransplant complications and NRM, the possibility that intensive glucose control improves the outcome after HSCT can only be confirmed in a prospective randomized trial.