Clinical features and prognostic impact of PRDM16 expression in adult acute myeloid leukemia.

High PRDM16 (also known as MEL1) expression is a representative marker of acute myeloid leukemia (AML) with NUP98-NSD1 and is a significant predictive marker for poor prognosis in pediatric AML. However, the clinical features of adult AML with PRDM16 expression remain unclear. PRDM16 is highly homologous to MDS1/EVI1, which is an alternatively spliced transcript of MECOM (also known as EVI1). We investigated PRDM16 expression in 151 AML patients, with 47 (31%) exhibiting high PRDM16 expression (PRDM16/ABL1 ratio ≥ 0.010). High PRDM16 expression significantly correlated with DNMT3A (43% vs. 15%, P < 0.001) and NPM1 (43% vs. 21%, P = 0.010) mutations and partial tandem duplication of KMT2A (22% vs. 1%, P < 0.001). Remarkably, high-PRDM16-expression patients were frequent in the noncomplete remission group (48% vs. 21%, P = 0.002). Overall survival (OS) was significantly worse in high-PRDM16-expression patients than in low-PRDM16-expression patients (5-year OS, 18% vs. 34%; P = 0.002). This trend was observed more clearly among patients aged <65 years (5-year OS, 21% vs. 50%; P = 0.001), particularly in FLT3-ITD-negative patients in the intermediate cytogenetic risk group (5-year OS, 25% vs. 59%; P = 0.009). These results suggest that high PRDM16 expression is a significant predictive marker for poor prognosis in adult AML patients, similar to pediatric AML patients.

ASXL2 mutations are frequently found in pediatric AML patients with t(8;21)/ RUNX1-RUNX1T1 and associated with a better prognosis.

ASXL2 is an epigenetic regulator involved in polycomb repressive complex regulation or recruitment. Clinical features of pediatric acute myeloid leukemia (AML) patients with ASXL2 mutations remain unclear. Thus, we investigated frequencies of ASXL1 and ASXL2 mutations, clinical features of patients with these mutations, correlations of these mutations with other genetic alterations including BCOR/BCORL1 and cohesin complex component genes, and prognostic impact of these mutations in 369 pediatric patients with de novo AML (0-17 years). We identified 9 (2.4%) ASXL1 and 17 (4.6%) ASXL2 mutations in 25 patients. These mutations were more common in patients with t(8;21)(q22;q22)/RUNX1-RUNX1T1 (ASXL1, 6/9, 67%, P = 0.02; ASXL2, 10/17, 59%, P = 0.01). Among these 25 patients, 4 (27%) of 15 patients with t(8;21) and 6 (60%) of 10 patients without t(8;21) relapsed. However, most patients with relapse were rescued using stem cell transplantation irrespective of t(8;21). The overall survival (OS) and event-free survival (EFS) rates showed no differences among pediatric AML patients with t(8;21) and ASXL1 or ASXL2 mutations and ASXL wild-type (5-year OS, 75% vs. 100% vs. 91% and 5-year EFS, 67% vs. 80% vs. 67%). In 106 patients with t(8;21) AML, the coexistence of mutations in tyrosine kinase pathways and chromatin modifiers and/or cohesin complex component genes had no effect on prognosis. These results suggest that ASXL1 and ASXL2 mutations play key roles as cooperating mutations that induce leukemogenesis, particularly in pediatric AML patients with t(8;21), and these mutations might be associated with a better prognosis than that reported previously.

Retrospective observational study of occult cervical lymph-node metastasis in T1N0 tongue cancer.

Objective: Delayed neck metastasis is the most significant prognostic factor for early tongue cancer. The main strategies for controlling cervical lymph nodes in Japan are elective neck dissection or watchful waiting. Elective neck dissection offers significantly better survival, but adversely impacts patient quality of life; consequently, here we investigated how to identify high-risk patients warranting elective neck dissection. Methods: We retrospectively evaluated 67 patients with T1N0 oral tongue squamous cell carcinoma who underwent primary treatment in our department from April 2001 to March 2015. All the patients underwent watchful waiting alone for neck management. We investigated the rates of occult neck metastasis, prognosis and circumstances of recurrence, and associations with pathological tumor thickness, depth and muscle invasion by the primary tumor. Correlation between the thickness in pathological specimens and that at magnetic resonance imaging was additionally investigated. Results: Neck recurrence was evident in 20 patients, of which 19 developed within 1 year. Therefore, the rate of occult neck metastasis was 29.9%. Patients with muscle invasion, tumor thickness ≥2 mm or tumor depth ≥2 mm on surgical specimens were significantly more likely to develop delayed neck metastasis. Prognosis was significantly worse for patients with muscle invasion or tumor thickness ≥2 mm. Thickness using magnetic resonance imaging was well correlated with pathological thickness. Conclusions: Patients with tumors ≥2 mm in thickness or muscle invasion developed neck metastasis, suggesting that elective neck dissection may be warranted for patients with these findings. For preoperative assessment of the need for elective neck dissection, magnetic resonance imaging would be a potential modality for T1N0 tongue cancer.

Endoplasmic Reticulum Stress Response and Mutant Protein Degradation in CHO Cells Accumulating Antithrombin (C95R) in Russell Bodies.

Newly synthesized secretory proteins are folded and assembled in the endoplasmic reticulum (ER), where an efficient protein quality control system performs a critically important function. When unfolded or aggregated proteins accumulate in the ER, certain signaling pathways such as the unfolded protein response (UPR) and ER-overload response (EOR) are functionally active in maintaining cell homeostasis. Recently we prepared Chinese hamster ovary (CHO) cells expressing mutant antithrombin (AT)(C95R) under control of the Tet-On system and showed that AT(C95R) accumulated in Russell bodies (RB), large distinctive structures derived from the ER. To characterize whether ER stress takes place in CHO cells, we examined characteristic UPR and EOR in ER stress responses. We found that the induction of ER chaperones such as Grp97, Grp78 and protein disulfide isomerase (PDI) was limited to a maximum of approximately two-fold. The processing of X-box-binding protein-1 (XBP1) mRNA and the phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) subunit were not induced. Furthermore, the activation of nuclear factor-kappa B (NF-κB) was not observed. In contrast, CHO cells displayed UPR and EOR when the cells were treated with thapsigargin and tumor necrosis factor (TNF)-α, respectively. In addition, a portion of the mutant AT(C95R) was degraded through proteasomes and autophagy. CHO cells do respond to ER stress but the folding state of mutant AT(C95R) does not appear to activate the ER stress signal pathway.

IGF1 receptor signaling regulates adaptive radioprotection in glioma stem cells.

Cancer stem cells (CSCs) play an important role in disease recurrence after radiation treatment as a result of intrinsic properties such as high DNA repair capability and antioxidative capacity. It is unclear, however, how CSCs further adapt to escape the toxicity of the repeated irradiation regimens used in clinical practice. Here, we have exposed a population of murine glioma stem cells (GSCs) to fractionated radiation in order to investigate the associated adaptive changes, with the ultimate goal of identifying a targetable factor that regulates acquired radioresistance. We have shown that fractionated radiation induces an increase in IGF1 secretion and a gradual upregulation of the IGF type 1 receptor (IGF1R) in GSCs. Interestingly, IGF1R upregulation exerts a dual radioprotective effect. In the resting state, continuous IGF1 stimulation ultimately induces downregulation of Akt/extracellular-signal-regulated kinases (ERK) and FoxO3a activation, which results in slower proliferation and enhanced self-renewal. In contrast, after acute radiation, the abundance of IGF1R and increased secretion of IGF1 promote a rapid shift from a latent state toward activation of Akt survival signaling, protecting GSCs from radiation toxicity. Treatment of tumors formed by the radioresistant GSCs with an IGF1R inhibitor resulted in a marked increase in radiosensitivity, suggesting that blockade of IGF1R signaling is an effective strategy to reverse radioresistance. Together, our results show that GSCs evade the damage of repeated radiation not only through innate properties but also through gradual inducement of resistance pathways and identify the dynamic regulation of GSCs by IGF1R signaling as a novel mechanism of adaptive radioprotection.

Metal-Multilayered Nanomechanical Cantilever Sensor for Detection of Molecular Adsorption.

A metal-multilayered nanomechanical cantilever sensor was proposed to reduce the temperature effect for highly sensitive gas molecular detection. The multilayer structure of the sensor reduces the bimetallic effect, allowing for the detection of differences in molecular adsorption properties on various metal surfaces with higher sensitivity. Our results indicate that the sensor exhibits higher sensitivity to molecules with greater polarity under mixed conditions with nitrogen gas. We demonstrate that stress changes caused by differences in molecular adsorption on different metal surfaces can be detected and that this approach could be used to develop a gas sensor with selectivity for specific gas species.

Aberrations of NEGR1 on 1p31 and MYEOV on 11q13 in neuroblastoma.

MYEOV and NEGR1 are novel candidate gene targets in neuroblastoma that were identified by chromosomal gain in 11q13 and loss in 1p31, respectively, through single nucleotide polymorphism array analysis. In the present study, to assess the involvement of MYEOV and NEGR1 in the pathogenesis of neuroblastoma, we analyzed their mutation status and/or expression profiles in a panel of 55 neuroblastoma samples, including 25 cell lines, followed by additional functional studies. No tumor-specific mutations of MYEOV or NEGR1 were identified in our case series. Expression of MYEOV was upregulated in 11 of 25 cell lines (44%) and in seven of 20 fresh tumors (35%). The siRNA-mediated knockdown of MYEOV in NB-19 cells, which exhibit high expression of MYEOV, resulted in a significant decrease in cell proliferation (P = 0.0027). Conversely, expression studies of NEGR1 revealed significantly lower expression of this gene in neuroblastomas at an advanced stage of the disease. Exogenous NEGR1 expression in neuroblastoma cells induced significant inhibition of cell growth (P = 0.019). The results of these studies provide supporting evidence for MYEOV and NEGR1 as gene targets of 11q13 gains and 1p31 deletions in a neuroblastoma subset. In addition, the findings suggest a possible prognostic value for NEGR1 in neuroblastoma.

Transcriptome analysis offers a comprehensive illustration of the genetic background of pediatric acute myeloid leukemia.

Recent advances in the genetic understanding of acute myeloid leukemia (AML) have improved clinical outcomes in pediatric patients. However, ∼40% of patients with pediatric AML relapse, resulting in a relatively low overall survival rate of ∼70%. The objective of this study was to reveal the comprehensive genetic background of pediatric AML. We performed transcriptome analysis (RNA sequencing [RNA-seq]) in 139 of the 369 patients with de novo pediatric AML who were enrolled in the Japanese Pediatric Leukemia/Lymphoma Study Group AML-05 trial and investigated correlations between genetic aberrations and clinical information. Using RNA-seq, we identified 54 in-frame gene fusions and 1 RUNX1 out-of-frame fusion in 53 of 139 patients. Moreover, we found at least 258 gene fusions in 369 patients (70%) through reverse transcription polymerase chain reaction and RNA-seq. Five gene rearrangements were newly identified, namely, NPM1-CCDC28A, TRIP12-NPM1, MLLT10-DNAJC1, TBL1XR1-RARB, and RUNX1-FNBP1. In addition, we found rare gene rearrangements, namely, MYB-GATA1, NPM1-MLF1, ETV6-NCOA2, ETV6-MECOM, ETV6-CTNNB1, RUNX1-PRDM16, RUNX1-CBFA2T2, and RUNX1-CBFA2T3. Among the remaining 111 patients, KMT2A-PTD, biallelic CEBPA, and NPM1 gene mutations were found in 11, 23, and 17 patients, respectively. These mutations were completely mutually exclusive with any gene fusions. RNA-seq unmasked the complexity of gene rearrangements and mutations in pediatric AML. We identified potentially disease-causing alterations in nearly all patients with AML, including novel gene fusions. Our results indicated that a subset of patients with pediatric AML represent a distinct entity that may be discriminated from their adult counterparts. Based on these results, risk stratification should be reconsidered.

[Usefulness of growth chart in children and adolescents with chronic fatigue syndrome].

We presented three sheets of growth chart in children with chronic fatigue syndrome. The growth chart in 14-year-old boy (patient 1) showed decreased weight gain because of too much exercise. After that he complained nausea, abdominal pain, sleep disturbance and debilitating fatigue. The growth chart in 12-year-old girl (patient 2) revealed increased weight gain because of overeating due to the divorce of her parents. She developed syncope, sleep disturbance, and fatigue during overeating. The growth chart in 13-year-old girl (patient 3) showed decreased weight gain after she developed lymph node enlargement. We diagnosed her as autoimmune fatigue syndrome because of persistent positive antinuclear antibody. Although growth chart will not be able to detect childhood chronic fatigue syndrome prospectively, the chart may be useful for detecting some life events in these children.

Integrated analysis identifies different metabolic signatures for tumor-initiating cells in a murine glioblastoma model.

BACKGROUND: The metabolic preference of malignant glioma for glycolysis as an energy source is a potential therapeutic target. As a result of the cellular heterogeneity of these tumors, however, the relation between glycolytic preference, tumor formation, and tumor cell clonogenicity has remained unknown. To address this issue, we analyzed the metabolic profiles of isogenic glioma-initiating cells (GICs) in a mouse model. METHODS: GICs were established by overexpression of H-Ras(V12) in Ink4a/Arf-null neural stem cells. Subpopulations of these cells were obtained by single-cell cloning, and clones differing in extracellular acidification potential were assessed for metabolic characteristics. Tumors formed after intracranial implantation of these clones in mice were examined for pathological features of glioma and expression of glycolytic enzymes. RESULTS: Malignant transformation of neural stem cells resulted in a shift in metabolism characterized by an increase in lactic acid production. However, isogenic clonal populations of GICs manifested pronounced differences in glucose and oxygen consumption, lactate production, and nucleoside levels. These differences were paralleled by differential expression of glycolytic enzymes such as hexokinase 2 and pyruvate kinase M2, with this differential expression also being evident in tumors formed by these clones in vivo. CONCLUSIONS: The metabolic characteristics of glioma cells appear early during malignant transformation and persist until the late stages of tumor formation. Even isogenic clones may be heterogeneous in terms of metabolic features, however, suggesting that a more detailed understanding of the metabolic profile of glioma is imperative for effective therapeutic targeting.

Diffusion-weighted imaging of an atypical teratoid/rhabdoid tumor of the cervical spine.

Spinal atypical teratoid/rhabdoid tumor (AT/RT) is a rare, aggressive malignant neoplasm of the central nervous system usually seen in young children and infants. We present diffusion-weighted imaging (DWI) findings for an intradural extramedullary AT/RT in the cervical spine of a 6-year-old boy. High signal on DWI and low apparent diffusion coefficients may represent high cellularity of the tumor. These findings indicated a highly malignant tumor.