Akihiko Matsumoto

Gain‐of‐function mutations and copy number increases of Notch2 in diffuse large B‐cell lymphoma

Signaling through the Notch1 receptor has a pivotal role in early thymocyte development. Gain of Notch1 function results in the development of T‐cell acute lymphoblastic leukemia in a number of mouse experimental models, and activating Notch1 mutations deregulate Notch1 signaling in the majority of human T‐cell acute lymphoblastic leukemias. Notch2, another member of the Notch gene family, is preferentially expressed in mature B cells and is essential for marginal zone B‐cell generation. Here, we report that 5 of 63 (~8%) diffuse large B‐cell lymphomas, a subtype of mature B‐cell lymphomas, have Notch2 mutations. These mutations lead to partial or complete deletion of the proline‐, glutamic acid‐, serine‐ and threonine‐rich (PEST) domain, or a single amino acid substitution at the C‐terminus of Notch2 protein. Furthermore, high‐density oligonucleotide microarray analysis revealed that some diffuse large B‐cell lymphoma cases also have increased copies of the mutated Notch2 allele. In the Notch activation‐sensitive luciferase reporter assay in vitro, mutant Notch2 receptors show increased activity compared with wild‐type Notch2. These findings implicate Notch2 gain‐of‐function mutations in the pathogenesis of a subset of B‐cell lymphomas, and suggest broader roles for Notch gene mutations in human cancers. (Cancer Sci 2009; 100: 920–926)

Host-Residual Invariant NK T Cells Attenuate Graft-versus-Host Immunity

Invariant NK T (iNKT) cells have an invariant TCR-α chain and are activated in a CD1d-restricted manner. They are thought to regulate immune responses and play important roles in autoimmunity, allergy, infection, and tumor immunity. They also appear to influence immunity after hemopoietic stem cell transplantation. In this study, we examined the role of iNKT cells in graft-vs-host disease (GVHD) and graft rejection in a mouse model of MHC-mismatched bone marrow transplantation, using materials including α-galactosylceramide, NKT cells expanded in vitro, and Jα18 knockout mice that lack iNKT cells. We found that host-residual iNKT cells constitute effector cells which play a crucial role in reducing the severity of GVHD, and that this reduction is associated with a delayed increase in serum Th2 cytokine levels. Interestingly, we also found that host-residual iNKT cause a delay in engraftment and, under certain conditions, graft rejection. These results indicate that host-residual iNKT cells attenuate graft-vs-host immunity rather than host-vs-graft immunity.

Notch Activation Induces the Generation of Functional NK Cells from Human Cord Blood CD34-Positive Cells Devoid of IL-15

The development of NK cells from hematopoietic stem cells is thought to be dependent on IL-15. In this study, we demonstrate that stimulation of human cord blood CD34+ cells by a Notch ligand, Delta4, along with IL-7, stem cell factor, and Fms-like tyrosine kinase 3 ligand, but no IL-15, in a stroma-free culture induced the generation of cells with characteristics of functional NK cells, including CD56 and CD161 Ag expression, IFN-γ secretion, and cytotoxic activity against K562 and Jurkat cells. Addition of γ-secretase inhibitor and anti-human Notch1 Ab to the culture medium almost completely blocked NK cell emergence. Addition of anti-human IL-15-neutralizing Ab did not affect NK cell development in these culture conditions. The presence of IL-15, however, augmented cytotoxicity and was required for a more mature NK cell phenotype. CD56+ cells generated by culture with IL-15, but without Notch stimulation, were negative for CD7 and cytoplasmic CD3, whereas CD56+ cells generated by culture with both Delta4 and IL-15 were CD7+ and cytoplasmic CD3+ from the beginning and therefore more similar to in vivo human NK cell progenitors. Together, these results suggest that Notch signaling is important for the physiologic development of NK cells at differentiation stages beyond those previously postulated.

Immunotherapy against metastatic renal cell carcinoma with mature dendritic cells

Objective:  We performed a clinical trial of immunotherapy using autologous mature dendritic cells (DC) pulsed with autologous tumor lysate, for patients with metastatic renal cell carcinoma (RCC).

CD1d expression level in tumor cells is an important determinant for anti-tumor immunity by natural killer T cells

Invariant natural killer T (iNKT) cells are thought to regulate anti-tumor immunity. Human iNKT (i.e. Vα24+ NKT) cells have been reported to recognize CD1d on target cells and show cytotoxicity directly on the target cells in vitro. However, the anti-tumor effect of mouse iNKT (i.e. Vα14+ NKT) cells has been repeatedly reported to be dependent on the activity of natural killer (NK) cells via interferon-γ, with no evidence of direct cytotoxicity. In the present study, we report that in vitro cytolysis of EL-4 mouse lymphoblastic lymphoma cells by Vα24+ NKT cells and in vivo eradication of these cells are both dependent on the level of CD1d expression on the tumor cell surface. These observations possibly suggest that direct cytotoxicity of tumor cells by iNKT cells is common to both humans and mice, and that the high expression level of CD1d may be a predictor whether the tumor is a good target of iNKT cells.

Pretreatment neutrophil‐to‐lymphocyte ratio as an independent predictor of survival in patients with metastatic urothelial carcinoma: A multi‐institutional study

To evaluate the prognostic significance of the pretreatment neutrophil‐to‐lymphocyte ratio in patients with metastatic urothelial carcinoma who underwent salvage chemotherapy.

Torsion of the hernia sac within a hydrocele of the scrotum in a child

Abstract Torsion of the hernia sac is a rare disease that presents as acute scrotum in children. Including the present case, only six cases have been reported in the English literature.

Nomogram for predicting survival of postcystectomy recurrent urothelial carcinoma of the bladder

PURPOSE We aimed to identify prognostic clinicopathological factors and to create a nomogram able to predict overall survival (OS) in recurrent urothelial carcinoma of the bladder (UCB) after radical cystectomy (RC). MATERIALS AND METHODS Among 1,087 patients with UCB who had undergone RC at our 11 institutions between 1990 and 2010, 306 patients who subsequently developed distant metastasis or local recurrence or both were identified. Clinical data were collected with medical record review. Univariate and multivariate Cox regression models addressed OS after recurrence. A nomogram predicting postrecurrence OS was constructed based on Cox proportional hazards model, without using postrecurrence factors (systemic chemotherapy and resection of metastasis). The performance of the nomogram was internally validated by assessing concordance index and calibration plots. RESULTS Of the 306 patients, 268 died during follow-up with a median survival of 7 months (95% CI: 5.8-8.5). Postrecurrence chemotherapy was administered in 119 patients (38.9%). Multivariable analysis identified 9 independent predictors for OS; period of time from RC to recurrence (time-to-recurrence), symptomatic recurrence, liver metastasis, hemoglobin level, serum alkaline phosphatase level, serum lactate dehydrogenase level, serum C-reactive protein level, postrecurrence chemotherapy, and resection of metastasis. A nomogram was formed with the following 5 variables to predict OS: time-to-recurrence, symptomatic recurrence, liver metastasis, albumin level, and alkaline phosphatase level. Concordance index rate was 0.75 (95% CI: 0.72-0.78) by internal validation using Bootstraps with 1,000 resamples. Calibration plots showed that the nomogram fitted well. CONCLUSIONS We identified 9 clinicopathological factors as independent OS predictors in postcystectomy recurrence of UCB. We also created a validated nomogram with 5 variables that efficiently stratified those patients regardless of eligibility for chemotherapy. The nomogram would be useful for acquiring relevant prognostic information and for stratifying patients for clinical trials.

Neutralization of interleukin-2 retards the growth of mouse renal cancer

To examine the significance of the thymus and the neutralization of interleukin‐2 (IL‐2) in treating renal cancer, as the involvement of immunoregulatory cells in tumour development in vivo is well known, naturally occurring CD25+CD4+ T cells possess potent immunoregulatory functions, and they are of thymic origin dependent on IL‐2.

Deep vein puncture under ultrasonographic guidance-an alternative approach for vascular access of apheresis therapies.

To the Editor: Granulocyte monocyte apheresis (GMA) is one of the modalities in apheresis that is reported to be clinically effective for inflammatory bowel diseases (IBD) [1]. Those who suffer from IBD often experience dehydration and for whom the vascular access is difficult to be placed due to collapse of superficial veins. When we consider the blood flow of upper limbs, blood flow from the brachial artery must enter into either superficial or deep veins. Even if superficial veins do not accept sufficient blood flow, it can be considered that blood is drained through deep veins. Ultrasonography (US) guided central vein puncture has been reportedly related to improving success rate and to reduce complications [2,3]. The procedure was also used for deep veins in emergency department for intravenous access [4]. We have developed and reported the procedure of US-guided vascular access puncture on hemodialysis patients [5]. We also have applied this method to GMA patients who have difficult vascular accesses. In order to elucidate usefulness of US-guided deep vein puncture, we retrospectively evaluated the medical charts of the patients who required such access puncture methods. From June 2013 to January 2015, we investigated the patients: (1) who received GMA therapy, (2) for whom we could not draw sufficient blood flow from superficial veins, and (3) whose deep veins were punctured under US guidance. The effectiveness and adverse events were assessed from the medical chart of such patients. Actual procedures were reported previously [5]. We describe them here in brief. We used a portable US device, Nanomaxx (Covidien Japan, Tokyo, Japan) with linear probe (6–13 MHz) for the current procedure. We investigate the direction of the deep vein under longitudinal view. Next, we place the probe perpendicular to the vein. At this time, the positions of vital structures such as brachial arteries and median veins nerves are identified in relation to the target deep vein, so that we should not damage them during the procedure (Fig. 1). Thereafter, we puncture the vein under US guidance. Once the tip of the needle is observed on the screen, we gradually thrust the needle little by little. After we place the needle in proper place, we remove the inner needle and complete the puncture. In total, we applied this method to four patients with ulcerative colitis. Their ages range from 26 to 63 years old. The reasons why we selected the deep veins as vascular access are as follows: (1) damaged superficial veins due to repeated cannulation in one patient, (2) small sized superficial veins probably by nature in two, and (3) dehydration due to discontinuation of fluid therapy after amelioration of IBD in one. In total 33 sessions of GMA were performed on them with Adacolumn (JIMRO, Takasaki, Japan). Blood flow rate was kept as 30 mL/min and session length was set as 60 min. Needle size was uniformly set as 17 Gauge. All of the sessions were completed without interruption, although most of the sessions (23 sessions) required tourniquet. No adverse events such as injury of the arteries or nerves, or bleeding complications were experienced. We demonstrated that deep vein puncture under US guidance can be a useful strategy for GMA procedure on those whose superficial veins accept only inadequate blood flow for the therapy. Deep veins as the