Molecular heterogeneity in diffuse large B-cell lymphoma and its implications in clinical diagnosis and treatment.

Over half of patients with diffuse large B-cell lymphoma (DLBCL) can be cured by standard R-CHOP treatment (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). However, the remaining patients are refractory and ultimately succumb to progressive or relapsed disease. During the past decade, there has been significant progress in the understanding of molecular mechanisms in DLBCL, largely owing to collaborative efforts in large-scale gene expression profiling and deep sequencing, which have identified genetic alterations critical in lymphomagenesis through activation of key signaling transduction pathways in DLBCL. These discoveries have not only led to the development of targeted therapies, including several currently in clinical trials, but also laid a solid foundation for the future identification of more effective therapies for patients not curable by R-CHOP. This review summarizes the recent advances in our understanding of the molecular characterization and pathogenesis of DLBCL and new treatment directions.

SNX27 and SORLA Interact to Reduce Amyloidogenic Subcellular Distribution and Processing of Amyloid Precursor Protein.

UNLABELLED: Proteolytic generation of amyloidogenic amyloid ß (Aß) fragments from the amyloid precursor protein (APP) significantly contributes to Alzheimer's disease (AD). Although amyloidogenic APP proteolysis can be affected by trafficking through genetically associated AD components such as SORLA, how SORLA functionally interacts with other trafficking components is yet unclear. Here, we report that SNX27, an endosomal trafficking/recycling factor and a negative regulator of the γ-secretase complex, binds to the SORLA cytosolic tail to form a ternary complex with APP. SNX27 enhances cell surface SORLA and APP levels in human cell lines and mouse primary neurons, and depletion of SNX27 or SORLA reduces APP endosome-to-cell surface recycling kinetics. SNX27 overexpression enhances the generation of cell surface APP cleavage products such as soluble alpha-APP C-terminal fragment (CTFα) in a SORLA-dependent manner. SORLA-mediated Aß reduction is attenuated by downregulation of SNX27. This indicates that an SNX27/SORLA complex functionally interacts to limit APP distribution to amyloidogenic compartments, forming a non-amyloidogenic shunt to promote APP recycling to the cell surface. SIGNIFICANCE STATEMENT: Many genes have been identified as risk factors for Alzheimer's disease (AD), and a large proportion of these genes function to limit production or toxicity of the AD-associated amyloid ß (Aß) peptide. Whether and how these genes precisely operate to limit AD onset remains an important question. We identify binding and trafficking interactions between two of these factors, SORLA and SNX27, and demonstrate that SNX27 can direct trafficking of SORLA and the Aß precursor APP to the cell surface to limit the production of Aß. Diversion APP to the cell surface through modulation of this molecular complex may represent a complimentary strategy for future development in AD treatment.

Aß induces astrocytic glutamate release, extrasynaptic NMDA receptor activation, and synaptic loss.

Synaptic loss is the cardinal feature linking neuropathology to cognitive decline in Alzheimer's disease (AD). However, the mechanism of synaptic damage remains incompletely understood. Here, using FRET-based glutamate sensor imaging, we show that amyloid-ß peptide (Aß) engages α7 nicotinic acetylcholine receptors to induce release of astrocytic glutamate, which in turn activates extrasynaptic NMDA receptors (eNMDARs) on neurons. In hippocampal autapses, this eNMDAR activity is followed by reduction in evoked and miniature excitatory postsynaptic currents (mEPSCs). Decreased mEPSC frequency may reflect early synaptic injury because of concurrent eNMDAR-mediated NO production, tau phosphorylation, and caspase-3 activation, each of which is implicated in spine loss. In hippocampal slices, oligomeric Aß induces eNMDAR-mediated synaptic depression. In AD-transgenic mice compared with wild type, whole-cell recordings revealed excessive tonic eNMDAR activity accompanied by eNMDAR-sensitive loss of mEPSCs. Importantly, the improved NMDAR antagonist NitroMemantine, which selectively inhibits extrasynaptic over physiological synaptic NMDAR activity, protects synapses from Aß-induced damage both in vitro and in vivo.

Differential effects of synaptic and extrasynaptic NMDA receptors on Aß-induced nitric oxide production in cerebrocortical neurons.

Oligomerized amyloid-ß (Aß) peptide is thought to contribute to synaptic damage, resulting in dysfunctional neuronal networks in patients with Alzheimer's disease. It has been previously suggested that Aß may be detrimental to neuronal health, at least in part, by triggering oxidative/nitrosative stress. However, the mechanisms underlying this process remain to be elucidated. Here, using rat primary cerebrocortical cultures, we demonstrate that Aß1-42 oligomers trigger a dramatic increase in intracellular nitric oxide (NO) concentration via a process mediated by activation of NMDA-type glutamate receptors (NMDARs). Considering that synaptic NMDARs and extrasynaptic NMDARs (eNMDARs) can have opposite effects on neuronal viability, we explored their respective roles in Aß-induced increases in NO levels. Surprisingly, after pharmacological isolation of eNMDARs, we discovered that eNMDARs are primarily responsible for the increase in neuronal NO triggered by Aß oligomers. Moreover, we found that the eNMDAR-mediated increase in NO can produce S-nitrosylation of Drp1 (dynamin-related protein 1) and Cdk5 (cyclin-dependent kinase 5), targets known to contribute to Aß-induced synaptic damage. These results suggest that pharmacological intervention specifically aimed at eNMDARs may decrease Aß-induced nitrosative stress and thus ameliorate neurotoxic damage to synapses.

Synaptic protein α1-takusan mitigates amyloid-ß-induced synaptic loss via interaction with tau and postsynaptic density-95 at postsynaptic sites.

The synaptic toxicity of soluble amyloid-ß (Aß) oligomers plays a critical role in the pathophysiology of Alzheimer's disease (AD). Here we report that overexpressed α1-takusan, which we previously identified as a protein that enhances synaptic activity via interaction with PSD-95, mitigates oligomeric Aß-induced synaptic loss. In contrast, takusan knockdown results in enhanced synaptic damage. α1-Takusan interacts with tau either directly or indirectly, and prevents Aß-induced tau hyperphosphorylation and mitochondrial fragmentation. Deletion analysis identified the second domain (D2) within the takusan protein that is required for PSD-95 clustering and synaptic protection from Aß. A 51 aa sequence linking D2 to the PDZ-binding C terminus was found to be as effective as full-length takusan in protecting synapses from Aß-induced damage. Moreover, a sequence containing the D2 from the human protein discs large homolog 5, when linked to a C-terminal PDZ-binding motif, can also increase the clustering of PSD-95 in cortical dendrites. In summary, α1-takusan protects synapses from Aß-induced insult via interaction with PSD-95 and tau. Thus, takusan-based protein sequences from either mouse or human may be of potential therapeutic benefit in AD.

Multi­omics approach to improve patient­tailored therapy using immune checkpoint blockade and cytokine­induced killer cell infusion in an elderly patient with lung cancer: A case report and literature review.

The 5-year survival rate of patients with advanced non-small cell lung cancer (NSCLC) remains low, despite recent advances in targeted therapy and immunotherapy. Therefore, there is a need to identify alternative strategies to improve treatment outcomes. Modern diagnostics can significantly facilitate the selection of treatment plans to improve patient outcomes. In the present study, multi-form diagnostic methodologies were adopted, including next-generation sequencing-based actionable gene sequencing, programmed death ligand 1 (PD-L1) immunohistochemistry, a circulating tumor cell (CTC) assay, flow cytometric analysis of lymphocyte subsets and computed tomography, to improve disease management in an 86-year-old female patient with relapsed metastatic NSCLC. High expression of PD-L1, elevated CTC tmutations, were observed. Based on these results, the patient was initially treated with the programmed death protein 1 blocking antibody sintilimab for two cycles, resulting in the stabilization of their condition, although the patient still exhibited severe pain and other symptoms, including fatigue, malaise, a loss of appetite and poor mental state. Informed by dynamic monitoring of the patient's response to treatment, the treatment plan was subsequently adjusted to a combination therapy with sintilimab and autologous cytokine-induced killer cell infusion, which eventually led to improved outcomes in both the management of the cancer and quality of life. In conclusion, multi-omics analysis may be used to establish patient-tailored therapies to improve clinical outcomes in hard-to-treat elderly patients with metastatic NSCLC.

Non-invasive detection of lymphoma with circulating tumor DNA features and protein tumor markers.

Background: According to GLOBOCAN 2020, lymphoma ranked as the 9th most common cancer and the 12th leading cause of cancer-related deaths worldwide. Traditional diagnostic methods rely on the invasive excisional lymph node biopsy, which is an invasive approach with some limitations. Most lymphoma patients are diagnosed at an advanced stage since they are asymptomatic at the beginning, which has significantly impacted treatment efficacy and prognosis of the disease. Method: This study assessed the performance and utility of a newly developed blood-based assay (SeekInCare) for lymphoma early detection. SeekInCare utilized protein tumor markers and a comprehensive set of cancer-associated genomic features, including copy number aberration (CNA), fragment size (FS), end motif, and lymphoma-related virus, which were profiled by shallow WGS of cfDNA. Results: Protein marker CA125 could be used for lymphoma detection independent of gender, and the sensitivity was 27.8% at specificity of 98.0%. After integrating these multi-dimensional features, 77.8% sensitivity was achieved at specificity of 98.0%, while its NPV and PPV were both more than 92% for lymphoma detection. The sensitivity of early-stage (I-II) lymphoma was up to 51.3% (47.4% and 55.0% for stage I and II respectively). After 2 cycles of treatment, the molecular response of SeekInCare was correlated with the clinical outcome. Conclusion: In summary, a blood-based assay can be an alternative to detect lymphoma with adequate performance. This approach becomes particularly valuable in cases where obtaining tissue biopsy is difficult to obtain or inconclusive.

Takusan: a large gene family that regulates synaptic activity.

We have characterized a rodent-specific gene family designated alpha-takusan (meaning "many" in Japanese). We initially identified a member of the family whose expression is upregulated in mice lacking the NMDAR subunit NR3A. We then isolated cDNAs encoding 46 alpha-takusan variants from mouse brains. Most variants share an approximately 130 aa long sequence, which contains the previously identified domain of unknown function 622 (DUF622) and is predicted to form coiled-coil structures. Single-cell PCR analyses indicate that one neuron can express multiple alpha-takusan variants and particular variants may predominate in certain cell types. Forced expression in cultured hippocampal neurons of two variants, alpha1 or alpha2, which bind either directly or indirectly to PSD-95, leads to an increase in PSD-95 clustering, dendritic spine density, GluR1 surface expression, and AMPAR activity. Conversely, treating cultured neurons with RNAi targeting alpha-takusan variants resulted in the opposite phenotype. Hence, alpha-takusan represents a large gene family that regulates synaptic activity.

Excitatory glycine responses of CNS myelin mediated by NR1/NR3 "NMDA" receptor subunits.

NMDA receptors are typically excited by a combination of glutamate and glycine. Here we describe excitatory responses in CNS myelin that are gated by a glycine agonist alone and mediated by NR1/NR3 "NMDA" receptor subunits. Response properties include activation by d-serine, inhibition by the glycine-site antagonist CNQX, and insensitivity to the glutamate-site antagonist d-APV. d-Serine responses were abrogated in NR3A-deficient mice. Our results suggest the presence of functional NR1/NR3 receptors in CNS myelin.

Neuroprotection by the NR3A subunit of the NMDA receptor.

Hyperactivation of NMDA-type glutamate receptors (NMDARs) results in excitotoxicity, contributing to damage in stroke and neurodegenerative disorders. NMDARs are generally comprised of NR1/NR2 subunits but may contain modulatory NR3 subunits. Inclusion of NR3 subunits reduces the amplitude and dramatically decreases the Ca2+ permeability of NMDAR-associated channels in heterologous expression systems and in transgenic mice. Since excessive Ca2+ influx into neurons is a crucial step for excitotoxicity, we asked whether NR3A subunits are neuroprotective. To address this question, we subjected neurons genetically lacking NR3A to various forms of excitotoxic insult. We found that cultured neurons prepared from NR3A knock-out (KO) mice displayed greater sensitivity to damage by NMDA application than wild-type (WT) neurons. In vivo, neonatal, but not adult, WT mice contain NR3A in the cortex, and neonatal NR3A KO mice manifested more damage than WT after hypoxia-ischemia. In adult retina, one location where high levels of NR3A normally persist into adulthood, injection of NMDA into the eye killed more retinal ganglion cells in adult NR3A KO than WT mice. These data suggest that endogenous NR3A is neuroprotective. We next asked whether we could decrease excitotoxicity by overexpressing NR3A. We found that cultured neurons expressing transgenic (TG) NR3A displayed greater resistance to NMDA-mediated neurotoxicity than WT neurons. Similarly in vivo, adult NR3A TG mice subjected to focal cerebral ischemia manifested less damage than WT mice. These data suggest that endogenous NR3A protects neurons, and exogenously added NR3A increases neuroprotection and could be potentially exploited as a therapeutic.

Molecular and clinical progress in follicular lymphoma lacking the t(14;18) translocation (Review).

Although the majority of patients with follicular lymphoma (FL) harbor the t(14;18)(q32;q21) IGH/BCL2 gene rearrangement that leads to the overexpression of BCL2 protein, approximately 20% of FL cases lack t(14;18)(q32;q21). It is considered that BCL2 overexpression underscores the development of the majority of cases of FL and their transformation to more aggressive lymphoma [known as transformed FL (tFL)]. However, FL cases lacking the t(14;18)(q32;q21) translocation exhibit symptoms analogous to their t(14;18)­positive counterparts. An important goal of recent research on FL has been to clarify the distinctions between the two different forms of FL. Numerous studies have shed light onto the genetic and molecular features of t(14;18)­negative FL and the related clinical manifestations. In this review, we summarize the current knowledge of t(14;18)­negative FL occurring in the lymph nodes with an emphasis on the underlying molecular and clinical features. In addition, novel treatment directions are discussed.

Circulating and tumor-infiltrating arginase 1-expressing cells in gastric adenocarcinoma patients were mainly immature and monocytic Myeloid-derived suppressor cells.

Myeloid-derived suppressor cells (MDSCs) are a group of heterogeneous cells derived from immature myeloid cells (IMCs). MDSCs are known to play important roles in tumor immune evasion. While we know that there are a large number of circulating and tumor-infiltrating MDSCs existing in gastric cancer (GC) patients, the phenotypic characteristics and arginase 1 (ARG1) expression levels of these MDSCs remain very unclear. In our study, flow cytometric analysis of circulating MDSCs from 20 gastric adenocarcinoma (GAC) patients found that ≥80% ARG1-expressing MDSCs were mainly early-stage MDSCs (HLA-DR-CD33+CD14-CD15-MDSCs). In addition, our investigation showed that tumor-infiltrating MDSCs from 6 GAC patients consisted of >35% ARG1-expressing naïve MDSCs (HLA-DR-CD33-CD11b-CD14-CD15-MDSCs), >15% early-stage MDSCs and >40% monocytic MDSCs (HLA-DR-CD14+MDSCs). This preliminary study describes the phenotypic characteristics and ARG1 expression levels of MDSCs from GAC patients and shows that circulating and tumor-infiltrating ARG1-expressing cells were mainly immature and monocytic MDSCs, which provides information to better understand the mechanisms that allow gastric cancer cells to evade the immune system.

Identification of a novel PDGFRA point mutation at p.P6L as a potential molecular target of imatinib in an eosinophilia patient showing genetic heterogeneity.

Eosinophilia is a severe disease with increased eosinophil count. The transcript of FIP1L1-PDGFRA fusion gene is a genetic biomarker of clonal eosinophilia screened routinely by reverse transcript PCR (RT-PCR) during diagnosis. Another significant genetic biomarker is the PDGFRA gene alone as some of its mutations are targets of imatinib. In this study, we identified a patient who had typical symptoms of Eosinophilia but had no response to the first-line treatment of hormonotherapy. This patient also showed bone rupture and eosinophil bone infiltration, which are extremely rare among all known eosinophilia patients. We identified the FIP1L1-PDGFRA fusion gene via RT-PCR and Sanger sequencing. Using next generation sequencing (NGS), we detected point mutations in PDGFRA, MYOM2, and ASXL3. The patient then received imatinib therapy, leading to the complete disappearance of FIP1L1-PDGFRA fusion gene and mutated MYOM2. The level of PDGFRA point mutation was also decreased from pre-treatment: 57.86% down to 42.99% at 6 months and to 38.80% at one-year after treatment. The level of ASXL3 mutations did not change significantly. To the best of our knowledge, this is the first case in which the point mutation of PDGFRA has been identified at p.P6L in exon 2, likely making it sensitive to imatinib and thus should be further studied as a potential new molecular target of imatinib therapy.

Exosomal miRNA-107 induces myeloid-derived suppressor cell expansion in gastric cancer.

  Background: Myeloid-derived suppressor cells (MDSCs) promote immunosuppression in the tumor microenvironment, support tumor growth and survival, and may contribute to immunotherapy resistance. Recent studies showed that tumor-derived exosomes (TDEs) can induce MDSCs accumulation and expansion, the mechanisms of which are largely unknown. Methods: The morphologies and sizes of the exosomes was observed by using a JEM-1400 transmission electron microscope. MicroRNA(miR)-107 and ARG1, DICER1, PTEN, PI3K, AKT, mTOR, and NF-kB mRNAs were quantified by quantitative reverse tanscription PCR. Dual-Luciferase Reports Assay were used to examine the expression of genes which was targeted by miR-107. The expression of proteins were analyzed by using western blot. Results: MiR-107 was not only overexpressed in gastric cancer cells but also enriched in their secreted TDEs. Also, these miR-107 enriched TDEs could be taken up by HLA-DR-CD33+MDSCs, where miR-107 was able to target and suppress expression of DICER1 and PTEN genes. Dampened DICER1 expression supported expansion of MDSCs , while decreased PTEN led to activation of the PI3K pathway, resulting in increased ARG1 expression. Furthemore, gastric cancer-derived miR-107 TDEs, when dosed intravenously into mice, were also capable of inducing expansion of CD11b+Gr1+/high MDSCs in mouse peripheral blood and altering expression of DICER1, PTEN, ARG1, and NOS2 in the MDSCs. Conclusions: Our findings demonstrate for the first time that gastric cancer-secreted exosomes are able to deliver miR-107 to the host MDSCs where they induce their expansion and activition by targeting DICER1 and PTEN genes, thereby may provide novel cancer therapeutics target for gastric cancer.

Elevated Serum Level of CA125 Is a Biomarker That Can Be Used to Alter Prognosis Determined by BRCA Mutation and Family History in Ovarian Cancer.

AIMS: In this study, we determined whether serum tumor markers (STMs), including CA125, are associated with BRCA mutation status and if they can be used prognostically in sporadic ovarian cancer (SOC) and familial ovarian cancer (FOC). METHODS: BRCA gene mutations were screened using next-generation sequencing (NGS) in 31 FOC and 66 SOC patients enrolled between 2013 and 2014. The serum levels of STM CEA, CA125, CA199, and HE4 were also measured in these patients to determine the prognostic potential of these markers and their association with BRCA mutations. RESULTS: Elevated levels of CA125, but not the other three STMs, were associated with FOC and BRCA mutations. Median progression-free survival (PFS) was significantly longer in patients with FOC, higher CA125 expression (>2000 U/mL), and BRCA mutation. Strikingly, the median PFS was not reached in either BRCA+/higher CA125 or FOC/higher CA125 patient groups and these patients had significantly longer PFS than those in other groups. As reported previously, we also detected more BRCA mutations in FOC than in SOC. No significant differences were observed in onset age, menopausal status, tumor stage, and distant metastasis between FOC and SOC patients or between BRCA+ and BRCA- patients. CONCLUSIONS: Elevated levels of serum CA125 are associated with FOC and BRCA mutations, which can be further exploited as a prognostic marker in OC.

Pathologic subtype-defined prognosis is dependent on both tumor stage and status of oncogenic driver mutations in lung adenocarcinoma.

Previous studies have shown that the prognosis of lung adenocarcinoma is associated with pathological characterization. In this study, we investigated whether pathology-based prognosis was further influenced by both tumor stage and oncogenic driver mutations. To this end, we recruited a cohort of 465 lung adenocarcinoma patients in China. These patients were classified into 6 pathology-defined subtypes i.e., lepidic-predominant adenocarcinoma (LPA), acinar-predominant adenocarcinoma (APA), papillary-predominant adenocarcinoma (PPA), micropapillary-predominant adenocarcinoma (MPA), solid-predominant adenocarcinoma (SPA), and invasive mucinous adenocarcinoma (IMA). Oncogenic mutations in EGFR, KRAS, ALK, RET, and BRAF genes were determined using fluorescent real-time RT-PCR. The associations of pathogenic subtype or oncogenic mutation with clinical characteristics were analyzed using Fisher's exact tests. The interactive effects on overall survival (OS) by pathologic subtype, oncogenic mutations, and tumor stage were also determined. We have found that pathogenic subtype of lung adenocarcinoma correlated with smoking habit and tumor cell differentiation. These pathology-defined subtypes can be regrouped into 3 pathology-based prognostic groups: PPG1 (LPA), PPG2 (IMA+APA+PPA), and PPG3 (MPA+SPA) with a favorable, intermediate, and poor OS, respectively. We further demonstrated that this pathology-determined OS can be affected by both tumor stage and status of oncogenic mutations in EGFR, KRAS, ALK, RET, and BRAF genes. Interestingly, the presence of genetic mutations related to ALK, RET and BRAF had an opposite effect on OS between PPG2 (worsen) and PPG3 (improved) patients, reversing the prognostic favorability for patients within these two groups. In conclusion, prognosis of lung adenocarcinoma was defined interactively by pathologic subtype, tumor stage and oncogenic mutation.

Characterization of common and rare mutations in EGFR and associated clinicopathological features in a large population of Chinese patients with lung cancer.

Lung cancer with EGFR mutation is often associated pathological characteristics and good responses to EGFR tyrosine kinase inhibitors (TKIs). However, certain types of rare EGFR mutations have be linked to cases with poor response to EGFR TKIs. Therefore, extensive molecular screening and pathological characterization are essential for accurate diagnosis and selection of effective treatment plans. Although a large body of studies have established the rate of EGFR mutations as a whole entity, the rates of each individual types of mutations, especially those rare ones, have not been precisely determined in large patient populations with uniform genetic background. To address this issue, we assembled a large cohort of 456 Chinese patients with lung cancers to determine the rate of both common and rare forms of EGFR mutations and associated clinicopathological features in this retrospective study. We have found single or double EGFR mutations in 200 (43.9%) patients, including exon 19 deletions (E19del) (20%), exon 21 L858R (17.1%) and L861Q (1.5%) point mutations, exon 20 T790M (1.3%) and other mutations (1,3%), exon 18 mutations (1.3%), and double mutations (1.3%). EGFR mutation as well as its subtypes E19del, L858R, or double mutations were associated with female patients or never-smokers. In contrast, rare mutations, especially EGFR TKI resistant exon 20 mutations, were not statistically associated with any clinicopathological features, implicating that tumorigenesis driven by different EGFR mutations were mechanistically different. In summary, we have determined occurring rate of EGFR subtype mutations and demonstrated that different mutations showed different clinicopathological manifestations in lung cancer.

Molecular profiling identifies prognostic markers of stage IA lung adenocarcinoma.

We previously showed that different pathologic subtypes were associated with different prognostic values in patients with stage IA lung adenocarcinoma (AC). We hypothesize that differential gene expression profiles of different subtypes may be valuable factors for prognosis in stage IA lung adenocarcinoma. We performed microarray gene expression profiling on tumor tissues micro-dissected from patients with acinar and solid predominant subtypes of stage IA lung adenocarcinoma. These patients had undergone a lobectomy and mediastinal lymph node dissection at the Shanghai Chest Hospital, Shanghai, China in 2012. No patient had preoperative treatment. We performed the Gene Set Enrichment Analysis (GSEA) analysis to look for gene expression signatures associated with tumor subtypes. The histologic subtypes of all patients were classified according to the 2015 WHO lung Adenocarcinoma classification. We found that patients with the solid predominant subtype are enriched for genes involved in RNA polymerase activity as well as inactivation of the p53 pathway. Further, we identified a list of genes that may serve as prognostic markers for stage IA lung adenocarcinoma. Validation in the TCGA database shows that these genes are correlated with survival, suggesting that they are novel prognostic factors for stage IA lung adenocarcinoma. In conclusion, we have uncovered novel prognostic factors for stage IA lung adenocarcinoma using gene expression profiling in combination with histopathology subtyping.

NitroSynapsin therapy for a mouse MEF2C haploinsufficiency model of human autism.

Transcription factor MEF2C regulates multiple genes linked to autism spectrum disorder (ASD), and human MEF2C haploinsufficiency results in ASD, intellectual disability, and epilepsy. However, molecular mechanisms underlying MEF2C haploinsufficiency syndrome remain poorly understood. Here we report that Mef2c +/-(Mef2c-het) mice exhibit behavioral deficits resembling those of human patients. Gene expression analyses on brains from these mice show changes in genes associated with neurogenesis, synapse formation, and neuronal cell death. Accordingly, Mef2c-het mice exhibit decreased neurogenesis, enhanced neuronal apoptosis, and an increased ratio of excitatory to inhibitory (E/I) neurotransmission. Importantly, neurobehavioral deficits, E/I imbalance, and histological damage are all ameliorated by treatment with NitroSynapsin, a new dual-action compound related to the FDA-approved drug memantine, representing an uncompetitive/fast off-rate antagonist of NMDA-type glutamate receptors. These results suggest that MEF2C haploinsufficiency leads to abnormal brain development, E/I imbalance, and neurobehavioral dysfunction, which may be mitigated by pharmacological intervention.

Diagnostic application of next-generation sequencing in ZMYM2-FGFR1 8p11 myeloproliferative syndrome: A case report.

The 8p11 myeloproliferative syndrome (EMS), also known as 8p11 myeloproliferative neoplasm (8p11 MPN), is a collection of rare hematologic malignancies that are associated with fusion genes involving the tyrosine kinase receptor gene FGFR1 in chromosome 8p11. The entity is an aggressive disease with a high rate of transformation to acute myeloid leukemia (AML) and pathologically characterized by its associated eosinophilia. In this study, we reported a distinctive EMS case featuring an in-frame ZMYM2-FGFR1 fusion gene identified by next-generation sequencing technology (NGS). This patient exhibited not only typical EMS signs including elevated white blood cells in peripheral blood and hypercellular bone marrow with marked leukocytosis, but also exceptional characteristics including erythrocytosis in blood and bone marrow basophilia. Moreover, we detected 2 novel genomic mutations in 2 known leukemogenic genes, IKZF1 and ASXL1. Whether these 2 mutations play a part in EMS pathogenesis or contribute to its specific presentations clinically remain to be determined. In summary, we present a unique EMS case involving a ZMYM2-FGFR1 fusion with distinctive hematologic characteristics.