Promoter methylation levels of microRNA-124 in non-neoplastic rectal mucosa as a potential biomarker for ulcerative colitis-associated colorectal cancer in pediatric-onset patients.

PURPOSE: To determine the methylation level of the miR-124 promoter in non-neoplastic rectal mucosa of patients with pediatric-onset ulcerative colitis (UC) to predict UC-associated colorectal cancer (UC-CRC). METHODS: Between 2005 and 2017, non-neoplastic rectal tissue specimens were collected from 86 patients with UC, including 13 patients with UC-CRC; cancer tissues were obtained from the latter group. The methylation status of the miR-124 promoter was quantified using bisulfite pyrosequencing and compared between pediatric- and adult-onset UC patients. RESULTS: Patients with pediatric-onset UC experienced a significantly shorter disease duration than those with adult-onset UC. The levels of miR-124 promoter methylation in non-neoplastic rectal mucosa were positively correlated with the age at the diagnosis and duration of UC. The rate of increase in miR-124 methylation was accelerated in patients with pediatric-onset UC compared to those with adult-onset UC. Furthermore, the miR-124 methylation levels in non-neoplastic rectal mucosa were significantly higher in patients with UC-CRC than in those with UC alone (P = 0.02). A receiver operating characteristic analysis revealed that miR-124 methylation in non-neoplastic tissue discriminated between patients with pediatric-onset UC with or without CRC. CONCLUSION: miR-124 methylation in non-neoplastic rectal mucosa may be a useful biomarker for identifying patients with pediatric-onset UC who face the highest risk of developing UC-CRC.

Comparison of transplant outcomes between haploidentical transplantation and single cord blood transplantation in non-remission acute myeloid leukaemia: A nationwide retrospective study.

Allogeneic haematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for some patients with acute myeloid leukaemia (AML) who are refractory to chemotherapy. Cord blood transplantation (CBT) is a reasonable option in such cases because of its rapid availability. Recently, a growing number of human leucocyte antigen (HLA)-haploidentical related donor HSCTs (haplo-HSCTs) have been performed, although its effectiveness remains undetermined. Using the Japanese nationwide transplantation registry data, we identified 2438 patients aged ≥16 years who received CBT or haplo-HSCT as their first transplant for non-remission AML between January 2008 and December 2018. After 2:1 propensity score matching, 918 patients in the CBT group and 459 patients in the haplo-HSCT group were selected. In this matched cohort, no significant difference in overall survival (OS) was observed between the CBT and haplo-HSCT groups (hazard ratio [HR] of haplo-HSCT to CBT 1.02, 95% confidence interval [CI] 0.89-1.16). Similarly, no significant difference in the cumulative incidence of relapse (HR 1.09, 95% CI 0.93-1.28) or non-relapse mortality (HR 0.94, 95% CI 0.76-1.18). Subgroup analysis showed that CBT was significantly associated with preferable OS in patients receiving myeloablative conditioning. Our data showed comparable outcomes between haplo-HSCT and CBT recipients with non-remission AML.

Intrarenal renin-angiotensin system activation and macrophage infiltrations in pediatric chronic glomerulonephritis.

BACKGROUND: The current study tested the hypothesis that urinary angiotensinogen (UAGT) and urinary monocyte chemoattractant protein-1 (UMCP-1) levels provide a specific index of intrarenal renin-angiotensin system (RAS) status and the degree of infiltration of macrophages associated with RAS blockade and immunosuppressant treatment in pediatric patients with chronic glomerulonephritis. METHODS: We measured baseline UAGT and UMCP-1 levels to examine the correlation between glomerular injury in 48 pediatric chronic glomerulonephritis patients before treatment. Furthermore, we performed immunohistochemical analysis of angiotensinogen (AGT) and CD68 in 27 pediatric chronic glomerulonephritis patients treated with RAS blockades and immunosuppressants for 2 years. Finally, we examined the effects of angiotensin II (Ang II) on monocyte chemoattractant protein-1 (MCP-1) expression in cultured human mesangial cells (MCs). RESULTS: Baseline UAGT and UMCP-1 levels positively correlated with urinary protein levels, scores for mesangial hypercellularity, rate of crescentic formation, and expression levels of AGT and CD68 in renal tissues (p < 0.05). UAGT and UMCP-1 levels were significantly decreased after RAS blockade and immunosuppressant treatment (p < 0.01), which was accompanied by AGT and CD68 (p < 0.01), as well as the magnitude of glomerular injury. Cultured human MCs showed increased MCP-1 messenger ribonucleic acid and protein levels after Ang II treatment (p < 0.01). CONCLUSIONS: The data indicates that UAGT and UMCP-1 are useful biomarkers of the degree of glomerular injury during RAS blockade and immunosuppressant treatment in pediatric patients with chronic glomerulonephritis.

Improved Antitumor Effect of NK Cells Activated by Neutrophils in a Bone Marrow Transplant Model.

The licensing process mediated by inhibitory receptors of the Ly49 C-type lectin superfamily that recognizes self-major histocompatibility complex (MHC) class I in mice is essential for the proper antitumor function of natural killer (NK) cells. Several models for NK cell licensing can be exploited for adoptive immunotherapy for cancer. However, the appropriate adoptive transfer setting to induce efficient graft versus tumor/leukemia effects remains elusive, especially after hematopoietic stem cell transplantation (HSCT). In our previous experiment, we showed that intraperitoneal neutrophil administration with their corresponding NK receptor ligand-activated NK cells using congenic mice without HSCT. In this experiment, we demonstrate enhanced antitumor effects of licensed NK cells induced by weekly intraperitoneal injections of irradiated neutrophil-enriched peripheral blood mononuclear cells (PBMNCs) in recipient mice bearing lymphoma. Bone marrow transplantation was performed using BALB/c mice (H-2d) as the recipient and B10 mice (H-2b) as the donor. The tumor was A20, a BALB/c-derived lymphoma cell line, which was injected subcutaneously into the recipient at the same time as the HSCT. Acute graft versus host disease was not exacerbated in this murine MHC class I mismatched HSCT setting. The intraperitoneal injection of PBMNCs activated a transient licensing of NK subsets expressed Ly49G2, its corresponding NK receptor ligand to H-2d, and reduced A20 tumor growth in the recipient after HSCT. Pathological examination revealed that increased donor-oriented NK1.1+NK cells migrated into the recipient tumors, depending on neutrophil counts in the administered PBMNCs. Collectively, our data reveal a pivotal role of neutrophils in promoting NK cell effector functions and adoptive immunotherapy for cancer.

Intake of allergenic foods at 1.5 years and 3 years of age in a general child population in Japan: a cross-sectional study.

BACKGROUND: Recent studies indicate that the timing of introduction of potentially allergenic food is crucial for the development of food allergy in children. This cross-sectional study aimed to clarify the reality of allergen food intake in a general population of young children in Japan. METHODS: A questionnaire survey of caregivers was conducted at health checkups for 1.5-year (18-month)-old and 3-year-old children in the fall of 2020. The caregivers were asked about (1) the presence/absence of allergic disease symptoms based on the ISAAC questionnaire, and (2) foods that caregivers avoided giving their children. Ordinal logistic regression analyses were periformed to determine factors associated with food avoidance. RESULTS: Questionnaires were distributed to 1720 caregivers, and 1603 (93%) responded. The responders consisted of 771 and 832 caregivers who participated in 1.5-year-old and 3-year-old checkups, respectively. The prevalence of allergic diseases was comparable to recent epidemiological studies in Japan, indicating that the population may be representative. At 1.5 years old, more than 50% of the children were not exposed to peanuts, tree nuts, fish eggs, shellfish, and buckwheat. At 3 years old, the avoidance rates of the foods had decreased but were still between 18.8% and 32.0%. On the other hand, the avoidance rates of chicken egg and cow's milk, the top 2 common allergenic foods in Japan, were much lower at 2.8% and 1.5% at 1.5 years, and they decreased to 1.4% and 0.7% at 3 years old, respectively. Ordinal logistic analysis showed that avoidance of chicken egg, cow's milk, and wheat was associated with food allergy diagnosis and chicken egg avoidance with eczema, but avoidance of other foods showed no associations with any risk factors for food allergy. CONCLUSION: Caregivers avoided giving various foods, independent of allergy risk factors, to their young children. Since delayed introduction of an allergenic food has been reported to increase the risk of developing an allergy to the food, the results warrant future investigation of the development of food allergies in relation to current eating habits and recommendations.

Fetal Biometric Assessment and Infant Developmental Prognosis of the Tadalafil Treatment for Fetal Growth Restriction.

Background and Objectives: Tadalafil is expected to treat fetal growth restriction (FGR), a risk factor for stillbirth and neonatal morbidity. This study aimed to evaluate the fetal biometric growth pattern of fetuses with FGR treated with tadalafil by ultrasonographic assessment. Materials and Methods: This was a retrospective study. Fifty fetuses diagnosed with FGR and treated by maternal administration of tadalafil and ten controls who received conventional treatment at Mie University Hospital from 2015 to 2019 were assessed. Fetal biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), and estimated fetal weight (EFW) at the start of treatment and at two weeks and four weeks of treatment were mainly assessed by ultrasound examination. The Wilcoxon signed-rank test was used to assess the measures. The Kyoto Scale of Psychological Development (KSPD) was used to assess the developmental prognosis on tadalafil-treated children at 1.5 years of corrected age (CA) and 3 years old. Results: The median gestational age at the start of treatment was 30 and 31 weeks in the tadalafil and control groups, respectively, and the median gestational age at delivery was 37 weeks in both groups. The Z-score of HC was significantly increased at 4 weeks of treatment (p = 0.005), and the umbilical artery resistance index was significantly decreased (p = 0.049), while no significant difference was observed in the control group. The number of cases with an abnormal score of less than 70 on the KSPD test was 19% for P-M, 8% for C-A, 19% for L-S, and 11% for total area at 1.5 years CA. At 3 years old, the respective scores were 16%, 21%, 16%, and 16%. Conclusions: Tadalafil treatment for FGR may maintain fetal HC growth and infants' neuro-developmental prognosis.

Perinatal hypoxia aggravates occlusive pulmonary vasculopathy in SU5416/hypoxia-treated rats later in life.

Pulmonary arterial hypertension (PAH) is a fatal disease, which is characterized by occlusive pulmonary vascular disease (PVD) in small pulmonary arteries. It remains unknown whether perinatal insults aggravate occlusive PVD later in life. We tested the hypothesis that perinatal hypoxia aggravates PVD and survival in rats. PVD was induced in rats with/without perinatal hypoxia (embryonic day 14 to postnatal day 3) by injecting SU5416 at 7 wk of age and subsequent exposure to hypoxia for 3 wk (SU5416/hypoxia). Hemodynamic and morphological analyses were performed in rats with/without perinatal hypoxia at 7 wk of age (baseline rats, n = 12) and at 15 wk of age in 4 groups of rats: SU5416/hypoxia or control rats with/without perinatal hypoxia (n = 40). Pulmonary artery smooth muscle cells (PASMCs) from the baseline rats with/without perinatal hypoxia were used to assess cell proliferation, inflammation, and genomic DNA methylation profile. Although perinatal hypoxia alone did not affect survival, physiological, or pathological parameters at baseline or at the end of the experimental period in controls, perinatal hypoxia decreased weight gain and survival rate and increased right ventricular systolic pressure, right ventricular hypertrophy, and indices of PVD in SU5416/hypoxia rats. Perinatal hypoxia alone accelerated the proliferation and inflammation of cultured PASMCs from baseline rats, which was associated with DNA methylation. In conclusion, we established the first fatal animal model of PAH with worsening hemodynamics and occlusive PVD elicited by perinatal hypoxia, which was associated with hyperproliferative, proinflammatory, and epigenetic changes in cultured PASMCs. These findings provide insights into the treatment and prevention of occlusive PVD.

A risk-stratified therapy for infants with acute lymphoblastic leukemia: a report from the JPLSG MLL-10 trial.

The prognosis for infants with acute lymphoblastic leukemia (ALL), particularly those with KMT2A gene rearrangement (KMT2A-r), is dismal. Continuous efforts have been made in Japan to investigate the role of hematopoietic stem cell transplantation (HSCT) for infants with KMT2A-r ALL, but improvement in outcome was modest. In the Japanese Pediatric Leukemia/Lymphoma Study Group MLL-10 trial, infants with ALL were stratified into 3 risk groups (low risk [LR], intermediate risk [IR], and high risk [HR]) according to KMT2A status, age, and presence of central nervous system leukemia. Children's Oncology Group AALL0631 modified chemotherapy with the addition of high-dose cytarabine in early intensification was introduced to KMT2A-r patients, and the option of HSCT was restricted to HR patients only. The role of minimal residual disease (MRD) was also evaluated. Ninety eligible infants were stratified into LR (n = 15), IR (n = 19), or HR (n = 56) risk groups. The 3-year event-free survival (EFS) rate for patients with KMT2A-r ALL (IR + HR) was 66.2% (standard error [SE], 5.6%), and for those with germline KMT2A (KMT2A-g) ALL (LR), the 3-year EFS rate was 93.3% (SE, 6.4%). The 3-year EFS rate was 94.4% (SE, 5.4%) for IR patients and 56.6% (SE, 6.8%) for HR patients. In multivariable analysis, female sex and MRD ≥0.01% at the end of early consolidation were significant factors for poor prognosis. Risk stratification and introduction of intensive chemotherapy in this study were effective and were able to eliminate HSCT for a subset of infants with KMT2A-r ALL. Early clearance of MRD seems to have translated into favorable outcomes and should be incorporated into risk stratifications in future trials. This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) as #UMIN000004801.

CRISPR-mediated Bmpr2 point mutation exacerbates late pulmonary vasculopathy and reduces survival in rats with experimental pulmonary hypertension.

BACKGROUND: Patients with pulmonary arterial hypertension (PAH) carrying bone morphogenetic protein receptor type 2 (Bmpr2) mutations present earlier with severe hemodynamic compromise and have poorer survival outcomes than those without mutation. The mechanism underlying the worsening clinical phenotype of PAH with Bmpr2 mutations has been largely unaddressed in rat models of pulmonary hypertension (PH) because of the difficulty in reproducing progressive PH in mice and genetic modification in rats. We tested whether a clinically-relevant Bmpr2 mutation affects the progressive features of monocrotaline (MCT) induced-PH in rats. METHODS: A monoallelic single nucleotide insertion in exon 1 of Bmpr2 (+/44insG) was generated in rats using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9, then PH, pulmonary vascular disease (PVD) and survival after MCT injection with or without a phosphodiesterase type 5 inhibitor, tadalafil, administration were assessed. RESULTS: The +/44insG rats had reduced BMPR2 signalling in the lungs compared with wild-type. PH and PVD assessed at 3-weeks after MCT injection were similar in wild-type and +/44insG rats. However, survival at 4-weeks after MCT injection was significantly reduced in +/44insG rats. Among the rats surviving at 4-weeks after MCT administration, +/44insG rats had increased weight ratio of right ventricle to left ventricle plus septum (RV/[LV + S]) and % medial wall thickness (MWT) in pulmonary arteries (PAs). Immunohistochemical analysis showed increased vessels with Ki67-positive cells in the lungs, decreased mature and increased immature smooth muscle cell phenotype markers in the PAs in +/44insG rats compared with wild-type at 3-weeks after MCT injection. Contraction of PA in response to prostaglandin-F2α and endothelin-1 were significantly reduced in the +/44insG rats. The +/44insG rats that had received tadalafil had a worse survival with a significant increase in RV/(LV + S), %MWT in distal PAs and RV myocardial fibrosis compared with wild-type. CONCLUSIONS: The present study demonstrates that the Bmpr2 mutation promotes dedifferentiation of PA smooth muscle cells, late PVD and RV myocardial fibrosis and adversely impacts both the natural and post-treatment courses of MCT-PH in rats with significant effects only in the late stages and warrants preclinical studies using this new genetic model to optimize treatment outcomes of heritable PAH.

Autonomic Nervous System in Preterm Very Low Birth Weight Neonates with Intraventricular Hemorrhage.

OBJECTIVE: Heart rate variability (HRV) indicates cardiac autonomic nerve activity and is influenced by brain damage during the neonatal period. We aimed to determine whether a correlation exists between the HRV of extremely preterm neonates and neurodevelopmental test scores. STUDY DESIGN: Electrocardiogram data of neonates were assessed and HRV patterns in extremely preterm neonates with severe intraventricular hemorrhage (IVH; n = 6) and those with no/mild IVH (n = 28) were compared. We analyzed the relationship between HRV and neurodevelopmental outcomes at 18 months (n = 21) and 3 years (n = 23) in extremely preterm neonates. RESULTS: HRV was significantly associated with IVH severity in extremely preterm neonates (p < 0.05). Neonates with severe IVH exhibited increased HR and decreased mean R-to-R interval (NN) compared with neonates with no/mild IVH. HRV parameters significantly decreased in the severe IVH group, but not in the no/mild IVH group, suggesting that both sympathetic and parasympathetic activities decreased in neonates with severe IVH. Additionally, decreased HR and increased NN were significantly related to impaired neurodevelopmental outcomes in the no/mild IVH group at corrected ages of 18 months and 3 years, respectively (all p < 0.05). CONCLUSION: HRV was significantly associated with IVH severity and neurodevelopmental outcome in extremely preterm neonates. HRV can distinguish extremely preterm neonates who subsequently had severe IVH from those who had no/low-grade IVH. HRV may identify extremely preterm neonates needing adjuvant neuroprotective interventions. These findings warrant further investigation in a larger population of extremely preterm neonates. KEY POINTS: · HRV was associated with IVH severity.. · HRV can predict subsequent severe IVH in extremely preterm neonates.. · HRV are predictive of neurodevelopmental outcomes in extremely premature neonates with low-grade IVH..

Report of 2 Pediatric Cases With Li-Fraumeni Syndrome Related Malignancy in a Family.

Li-Fraumeni syndrome (LFS) is a rare inherited disease characterized by a high and early-onset cancer risk. A cancer surveillance program is important to reduce cancer-related morbidity and mortality in individuals with LFS. We report 2 pediatric cases with LFS-related malignancy in a family. Eight-year-old elder brother was diagnosed with adrenocortical carcinoma and was found to have a heterozygous missense germline mutation c.736A>G: p.Met246Val in the TP53 gene. Cancer screening led to the diagnosis of rhabdomyosarcoma at a curable stage in his 2-year-old younger brother. Comprehensive surveillance resulted in early tumor detection and improved survival.

Anti-tumor effect of Huaier extract against neuroblastoma cells in vitro.

Huaier extract, the main active constituent proteoglycan, has anti-tumor activity in various experimental and clinical settings. However, the potential anti-neuroblastoma and associated mechanisms have not been investigated. Therefore, in this study, we aimed to elucidate the potential role of Huaier extract in 3 human neuroblastoma cell lines. Our study demonstrated that incubation with Huaier extract resulted in a marked decrease in cell viability in a dose-dependent manner. Huaier extract induced cell cycle arrest at G0/G1 phase in neuroblastoma and decreased the cell cycle related protein expression of cyclin D3. Western blotting analysis also showed that Huaier extract induced neuroblastoma cell apoptosis and autophagy. Signaling analysis indicated that Huaier extract suppressed the MEK/ERK and mTOR signaling pathways simultaneously. In conclusion, we verify that Huaier extract causes cell proliferation inhibition, apoptosis, autophagy, and cell cycle arrest in G0/G1 phase via MEK/ERK and mTOR signaling. Huaier extract may act as a complementary agent for treating neuroblastoma.

Revalidation of inferior petrosal sinus sampling: the latest results from a single-center experience.

Cushing's disease (CD), which manifests as excess cortisol secretion, is caused by adrenocorticotrophic hormone (ACTH)-secreting pituitary adenomas. Such adenomas are occasionally difficult to identify on magnetic resonance imaging (MRI), and thorough endocrinological examination may be required to detect them. Inferior petrosal sinus (IPS) sampling (IPSS) has been the gold standard test for distinguishing CD from ectopic ACTH syndrome (EAS). However, IPSS is an invasive procedure, and proper catheterization is occasionally challenging due to anatomical variations. Thus, there have been ongoing debates regarding the necessity of this procedure. Here, we present our recent IPSS data derived from the analysis of 65 patients who were referred to us for possible CD between April 2018 and December 2020 after undergoing meticulous endocrinological testing. Even with detailed MRI, no obvious lesions were identified in 19 patients. IPSS performed on these 19 individuals identified an IPS-to-peripheral ACTH gradient in 15 of them. The four patients who lacked this gradient were subjected to a classical algorithm using concurrently measured prolactin levels, the results of which were consistent with their ultimately confirmed diagnoses: two true-positive and two true-negative diagnoses. These findings support the validity of the algorithm and demonstrate that the prolactin-adjusted IPS-to-peripheral ACTH ratio can improve the differentiation between CD and EAS. We had no false-negative results, but three patients were false-positive. Consequently, those three patients in which no apparent tumor was clarified during surgery could not have any endocrinological improvement postoperatively.

Impact of a multi-professional expert team on EOL care of children with cancer.

BACKGROUND: The quality of end-of-life (Q-EOL) care is influenced by various factors such as resources for palliative care (PC). We introduced a multi-professional expert team (MET) in 2014, which provides home-based care for children and adolescents with incurable cancer. This study investigated the impacts of the outreach activities by the MET on Q-EOL care of pediatric oncology patients. METHODS: This observational study retrospectively examined 112 patients receiving end-of-life care between 1989 and 2018 at a pediatric cancer center in Japan. Some of the indicators of Q-EOL care before and after the introduction of the outreach activities by the MET were compared. The subjects were 92 in pre-MET and 20 in post-MET periods. RESULTS: The median number of days for which the patients stayed at home during the final seven or 30 days were significantly prolonged in the post-MET period (0.0 vs 1.5 days, P = 0.020, 3.0 vs 12.0 days, P = 0.042). The change was more significant in hematologic malignancies than solid and central nervous system tumors. Patients receiving longer PC before their deaths could stay at home longer during the last 7 days. The ratio of patients receiving PC for more than 2 months was significantly increased in post-MET period (60.9 vs 90.0%, P = 0.014). More patients also greeted their deaths at home in the post-MET period (3.3 vs 25.0%, P < 0.001). CONCLUSIONS: The activities of the MET transformed the end-of-life care of children and adolescents with incurable cancer. Earlier transitions to PC from curative treatment were associated with longer home-based care and more deaths at home.

Respiratory illness and acute flaccid myelitis in the Tokai district in 2018.

BACKGROUND: An outbreak of acute flaccid myelitis was chronologically correlated with an outbreak of severe respiratory illness in Japan in 2015. We hypothesized that increases in children hospitalized with severe respiratory illnesses might also be associated with increase in acute flaccid myelitis in autumn 2018. METHODS: We explored the temporal correlations between respiratory illness outbreaks and acute flaccid myelitis during autumn season between 2016 and 2018 using questionnaire surveys. One questionnaire explored the monthly numbers of children with acute flaccid myelitis, Guillain-Barré syndrome, and other acute flaccid paralyses. The other questionnaire explored the monthly numbers of children hospitalized with respiratory illnesses associated with wheezing. A correlation between the monthly numbers of children with acute flaccid myelitis and those with respiratory illness was analyzed using the Pearson correlation test. RESULTS: Although the number of patients hospitalized with respiratory illness did not correlate with the number of those admitted with myelitis, increases in children aged 7-12 and 13-19 years requiring intensive care unit admission correlated temporally with an outbreak of acute flaccid myelitis. CONCLUSIONS: An increase in intensive care unit admissions to treat respiratory disease occurred in association with a cluster of acute flaccid myelitis. An increase in the number of intensive care unit admissions due to respiratory illness may be a clue to expect the occurrence of acute flaccid myelitis.

Anti-tumor effect of AZD8055 against neuroblastoma cells in vitro and in vivo.

Neuroblastoma (NB) is one of the most common solid tumors in children. High-risk NB remains lethal in about 50% of patients despite comprehensive and intensive treatments. Activation of PI3K/Akt/mTOR signaling pathway correlates with oncogenesis, poor prognosis and chemotherapy resistance in NB. Due to its central role in growth and metabolism, mTOR seems to be an important factor in NB, making it a possible target for NB. In this study, we investigated the effect of AZD8055, a potent dual mTORC1-mTORC2 inhibitor, in NB cell lines. Our data showed that mTOR signaling was extensively activated in NB cells. The activity of mTOR and downstream molecules were down-regulated in AZD8055-treated NB cells. Significantly, AZD8055 effectively inhibited cell growth and induced cell cycle arrest, autophagy and apoptosis in NB cells. Moreover, AZD8055 significantly reduced tumor growth in mice xenograft model without apparent toxicity. Taken together, our results highlight the potential of mTOR as a promising target for NB treatment. Therefore, AZD8055 may be further investigated for treatment in clinical trials for high risk NB.

Induction of MEK/ERK activity by AZD8055 confers acquired resistance in neuroblastoma.

Mammalian target of rapamycin (mTOR) complex (mTORC) is frequently activated in diverse cancers. Although dual mTORC1/2 inhibitors are currently under development to treat various malignancies, the emergence of drug resistance has proven to be a major complication. AZD8055 is a novel, potent ATP-competitive and specific inhibitor of mTOR kinase activity, which blocks both mTORC1 and mTORC2 activation. In this study, we acquired AZD8055-resistant neuroblastoma (NB) cell sublines by using prolonged stepwise escalation of AZD8055 exposure (4-12 weeks). Here we demonstrate that the AZD8055-resistant sublines (TGW-R and SMS-KAN-R) exhibited marked resistance to AZD8055 compared to the parent cells (TGW and SMS-KAN). The cell cycle G1/S transition was advanced in resistant cells. In addition, the resistance against AZD8055 correlated with over-activation of MEK/ERK signaling pathway. Furthermore, combination of AZD8055 and MEK inhibitor U0126 enhanced the growth inhibition of resistant cells significantly in vitro and in vivo. In conclusion, these data show that targeting mTOR kinase and MEK/ERK signaling simultaneously might help to overcome AZD8055 resistance in NB.

Weekly Rituximab Followed by Monthly Rituximab Treatment for Autoimmune Disease Associated With RAS-associated Autoimmune Leukoproliferative Disease.

Recently, a new disease of lymphocyte homeostasis caused by somatic mosaicism for the RAS mutation has been discovered (known as RALD, RAS-associated leukoproliferative disorder). Since few cases have been reported in literature, the prognosis and standard treatment for autoimmune diseases associated with RALD remain poorly understood. Standard rituximab therapy (375 mg/m for 4 wk) is effective in patients with autoimmune diseases, but early recurrences are common. We highlight the potential for monthly administration of rituximab in a patient with autoimmune thrombocytopenia and hemolytic anemia associated with RALD. RALD was diagnosed in an 11-year-old girl following a 9-year history of severe hepatosplenomegaly and autoimmune cytopenias. Genetic analyses confirmed somatic mosaicism for the G13C KRAS mutation without an autoimmune lymphoproliferative syndrome-related gene mutation. Rituximab therapy was used because of the refractory character of the autoimmune cytopenias which failed to respond to steroids and other immunosuppressive agents. Her treatment consisted of weekly infusions of rituximab for 4 weeks followed by monthly rituximab for 11 months. She maintained her response in hematologic parameters for 2 years after monthly rituximab was ceased and her scores representing quality of life were improved. Rituximab could improve clinical responses and quality of life of the patients with RALD.

A Heterozygous CFHR3-CFHR1 Gene Deletion in a Pediatric Patient With Transplant-associated Thrombotic Microangiopathy Who was Treated With Eculizumab.

Complement system dysregulation, such as complement Factor H (CFH) autoantibodies and deletions in CFH-related (CFHR) genes 3 and 1, might cause transplant-associated thrombotic microangiopathy (TA-TMA). The use of eculizumab, a terminal complement inhibitor, could be a targeted therapy for TA-TMA. We report a 1-year-old girl who developed TA-TMA, just after autologous peripheral blood stem cell transplantation in neuroblastoma therapy. Eculizumab improved TA-TMA. Investigation for the complement alternative pathway showed a heterozygous CFHR3-CFHR1 gene deletion, which is involved in complement activation. The patient might develop TA-TMA as a result of complement regulatory gene mutation.