A clinically applicable integrative molecular classification of meningiomas.

Meningiomas are the most common primary intracranial tumour in adults1. Patients with symptoms are generally treated with surgery as there are no effective medical therapies. The World Health Organization histopathological grade of the tumour and the extent of resection at surgery (Simpson grade) are associated with the recurrence of disease; however, they do not accurately reflect the clinical behaviour of all meningiomas2. Molecular classifications of meningioma that reliably reflect tumour behaviour and inform on therapies are required. Here we introduce four consensus molecular groups of meningioma by combining DNA somatic copy-number aberrations, DNA somatic point mutations, DNA methylation and messenger RNA abundance in a unified analysis. These molecular groups more accurately predicted clinical outcomes compared with existing classification schemes. Each molecular group showed distinctive and prototypical biology (immunogenic, benign NF2 wild-type, hypermetabolic and proliferative) that informed therapeutic options. Proteogenomic characterization reinforced the robustness of the newly defined molecular groups and uncovered highly abundant and group-specific protein targets that we validated using immunohistochemistry. Single-cell RNA sequencing revealed inter-individual variations in meningioma as well as variations in intrinsic expression programs in neoplastic cells that mirrored the biology of the molecular groups identified.

Arginine attenuates chronic mountain sickness in rats via microRNA-144-5p.

Hypobaric hypoxia is an environmental stress leading to high-altitude pulmonary hypertension. While high-altitude pulmonary hypertension has been linked to high hematocrit findings (chronic mountain sickness; CMS). The present study is designed to investigate the effect of arginine (ARG) on hypobaric hypoxia-induced CMS of rats. Hypobaric hypoxia resulted in lower body weight, decreased appetite, increased pulmonary artery pressure, and deteriorated lung tissue damage in rats. Red blood cells (RBC), hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin values and blood viscosity were increased in rats, which were alleviated by ARG. microRNA (miRNA) microarray analysis was used to filter differentially expressed miRNAs after ARG in rats. miR-144-5p was reduced under hypobaric hypoxia and upregulated by ARG. miR-144-5p silencing aggravated the erythrocytosis and hyperviscosity in rats, and also accentuated tissue damage and excessive accumulation of RBC. The role of miR-144-5p in rats with CMS was achieved by blocking erythropoietin (EPO)/erythropoietin receptor (EPOR). In conclusion, ARG alleviated CMS symptoms in rodents exposed to hypobaric hypoxia by decreasing EPO/EPOR via miR-144-5p.

Multimodal Ochratoxin A-Aptasensor Using 3'-FAM-Enhanced Exonuclease I Tool and Magnetic Microbead Carrier.

Thanks to its preparatory ease, close affinity, and low cost, the aptasensor can serve as a promising substitute for antibody-dependent biosensors. However, the available aptasensors are mostly subject to a single-mode readout and the interference of unbound aptamers in solution and non-target-induced transition events. Herein, we proposed a multimodal aptasensor for multimode detection of ochratoxin A (OTA) with cross-validation using the 3'-6-carboxyfluorescein (FAM)-enhanced exonuclease I (Exo I) tool and magnetic microbead carrier. Specifically, the 3'-FAM-labeled aptamer/biotinylated-cDNA hybrids were immobilized onto streptavidin-magnetic microbeads via streptavidin-biotin interaction. With the presence of OTA, an antiparallel G-quadruplex conformation was formed, protecting the 3'-FAM labels from Exo I digestion, and then anti-FAM-horseradish peroxidase (HRP) was bound via specific antigen-antibody affinity; for the aptamers without the protection of OTA, the distal ssDNA was hydrolyzed from 3' → 5', releasing 3'-FAM labels to the solution. Therefore, the OTA was detected by analyzing the "signal-off" fluorescence of the supernatant and two "signal-on" signals in electrochemistry and colorimetry through the detection of the coating magnetic microbeads in HRP's substrate. The results showed that the 3'-FAM labels increased the activity of Exo I, producing a low background due to a more thorough digestion of unbound aptamers. The proposed multimodal aptasensor successfully detected the OTA in actual samples. This work first provides a novel strategy for the development of aptasensors with Exo I and 3'-FAM labels, broadening the application of aptamer in the multimode detection of small molecules.

Perk heterozygosity ameliorates chronic hypoxia-induced pulmonary hypertension and right ventricular hypertrophy in male rats.

BACKGROUND: Pulmonary hypertension (PH) is a rare and deadly disease characterized by remodeling of the pulmonary vasculature and increased pulmonary artery pressure. hypobaric pulmonary hypertension (HPH) is clinically classified as group 4 of pulmonary hypertension and has a poor prognosis . Previous reports showed that HPH was associated with increased endoplasmic reticulum (ER) stress. The protein kinase R-like endoplasmic reticulum kinase (PERK) is an ER-associated stress protein. However, to date, its physiological effects on HPH and RVF development remains unknown. This study aimed to assess PERK's role in HPH and RV function using in vivo experimental model. METHODS: Perk-knockout male Sprague-Dawley rats were generated and were housed in either a hypobaric chamber or in a normoxic environment. After stimulation for 4 weeks, the hemodynamic parameters of the rats were measured. The heart and lungs were harvested for pathological observation. Blood was collected for the detection of inflammatory indexes. The right ventricle tissue was collected to assess phosphorylated-AKT, ROCK1, ET1, and MMP2 protein expression. RESULTS: WE FIRSTLY GENERATED PERK+/− RATS,: Under normal conditions, Perk+/- rats showed no changes in mPAP(mean pulmonary artery pressure), RVHI(Right ventricular hypertrophy index), cardiomyocyte size and interstitial fibrosis, and pulmonary vascular remodeling. However, in response to chronic hypoxia, Perk+/- rats exhibited decreased in mPAP, RVHI, ventricular fibrosis, and lung remodeling compared to wild-type rats. Perk+/- rats also showed lower expression of phosphor-AKT, ROCK1, ET1, and MMP2 protein in response to chronic hypoxia. CONCLUSIONS: These findings suggest that Perk heterozygosity protects against HPH and Perk may be a suitable target for treating HPH.

Ultrasensitive Detection of RNA with Single-Base Resolution by Coupling Electrochemical Sensing Strategy with Chimeric DNA Probe-Aided Ligase Chain Reaction.

Accurate and sensitive detection of single-base mutations in RNAs is of great value in basic studies of life science and medical diagnostics. However, the current available RNA detection methods are challenged by heterogeneous clinical samples in which trace RNA mutants usually existed in a large pool of normal wild sequences. Thus, there is still great need for developing the highly sensitive and highly specific methods in detecting single-base mutations of RNAs in heterogeneous clinical samples. In the present study, a new chimeric DNA probe-aided ligase chain reaction-based electrochemical method (cmDNA-eLCR) was developed for RNA mutation detection through the BSA-based carrier platform and the horseradish peroxidase-hydrogen peroxide-tetramethylbenzidine (HRP-H2O2-TMB) system. The denaturing polyacrylamide gel electrophoresis and a fluorophore-labeled probe was ingeniously designed to demonstrate the advantage of cmDNA in ligation to normal DNA templated by RNA with the catalysis of T4 RNA ligase 2 as well as its higher selectivity than DNA ligase system. Finally, the proposed cmDNA-eLCR, compared with the traditional eLCR, showed excellent performance in discriminating single base-mismatched sequences, where the signal response for mismatched targets at a high concentration could overlap completely with that for the blank control. Besides, this cmDNA-eLCR assay had a wide linear range crossing six orders of magnitude from 1.0 × 10-15 to1.0 × 10-10 M with a limit of detection as low as 0.6 fM. Furthermore, this assay was applied to detect RNA in real sample with a satisfactory result, thereby demonstrating its great potential in diagnosis of RNA-related diseases.

Ursolic Acid Improves Monocrotaline-Induced Right Ventricular Remodeling by Regulating Metabolism.

Pulmonary arterial hypertension (PAH) is a progressive and malignant disease characterized by pulmonary small arteries and right ventricle (RV) remodeling that can lead to severe RV dysfunction and death. The current therapeutic targets for RV dysfunction, which is strongly linked to mortality, are far from adequate. Therefore, we investigated the effect of ursolic acid (UA), a pentacyclic triterpenoid carboxylic acid, on PAH-induced RV remodeling and its underlying mechanism. We established a PAH model by injecting Sprague Dawley rats with monocrotaline (MCT, 60 mg/kg, ip), as verified by echocardiography and hemodynamic examination. Proteomic analysis was performed on RV samples using a Q Exactive high-field mass spectrometer, followed by KEGG enrichment analysis. The effect of 4 weeks of UA (50 mg/kg) treatment on RV remodeling was explored based on ultrasound, hemodynamic parameters, and histological changes, with the mechanism verified in vivo and in vitro by qRT-PCR and western blotting. RV hypertrophy, fibrosis, increased apoptosis, and abnormal metabolism were induced by MCT and suppressed by UA via a mechanism that changed the expression of key markers. UA also attenuated the Phenylephrine-induced hypertrophy of neonatal rat ventricular myocytes and upregulated peroxisome proliferator-activated receptor-alpha (PPARα), a key fatty acid metabolism regulator, and its downstream factor carnitine palmitoyl transferase 1b. In conclusion, UA exerts beneficial effects on PAH-induced RV dysfunction and remodeling by regulating PPARα-dependent fatty acid metabolism.

A novel piperidine identified by stem cell-based screening attenuates pulmonary arterial hypertension by regulating BMP2 and PTGS2 levels.

Genetic defects in bone morphogenetic protein type II receptor (BMPRII) signalling and inflammation contribute to the pathogenesis of pulmonary arterial hypertension (PAH). The receptor is activated by bone morphogenetic protein (BMP) ligands, which also enhance BMPR2 transcription. A small-molecule BMP upregulator with selectivity on vascular endothelium would be a desirable therapeutic intervention for PAH.We assayed compounds identified in the screening of BMP2 upregulators for their ability to increase the expression of inhibitor of DNA binding 1 (Id1), using a dual reporter driven specifically in human embryonic stem cell-derived endothelial cells. These assays identified a novel piperidine, BMP upregulator 1 (BUR1), that increased endothelial Id1 expression with a half-maximal effective concentration of 0.098 µmol·L-1 Microarray analyses and immunoblotting showed that BUR1 induced BMP2 and prostaglandin-endoperoxide synthase 2 (PTGS2) expression. BUR1 effectively rescued deficient angiogenesis in autologous BMPR2+/R899X endothelial cells generated by CRISPR/Cas9 and patient cells.BUR1 prevented and reversed PAH in monocrotaline rats, and restored BMPRII downstream signalling and modulated the arachidonic acid pathway in the pulmonary arterial endothelium in the Sugen 5416/hypoxia PAH mouse model.In conclusion, using stem cell technology we have provided a novel small-molecule compound which regulates BMP2 and PTGS2 levels that might be useful for the treatment of PAH.

Identification of serum proteins AHSG, FGA and APOA-I as diagnostic biomarkers for gastric cancer.

BACKGROUND: The development of clinically accessible biomarkers is critical for the early diagnosis of gastric cancer (GC) in patients. High-throughput proteomics techniques could not only effectively generate a serum peptide profile but also provide a new approach to identify potentially diagnostic and prognostic biomarkers for cancer patients. METHODS: In this study, we aim to identify potentially discriminating serum biomarkers for GC. In the discovery cohort, we screened potential biomarkers using magnetic-bead-based purification and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in 64 samples from 32 GC patients that were taken both pre- and post-operatively and 30 healthy volunteers that served as controls. In the validation cohort, the expression patterns and diagnostic values of serum FGA, AHSG and APOA-I were further confirmed by ELISA in 42 paired GC patients (pre- and post-operative samples from 16 patients with pathologic stage I/II and 26 with stage III/IV), 30 colorectal cancer patients, 30 hepatocellular carcinoma patients, and 28 healthy volunteers. RESULTS: ClinProTools software was used and annotated 107 peptides, 12 of which were differentially expressed among three groups (P < 0.0001, fold > 1.5). These 12 peptide peaks were further identified as FGA, AHSG, APOA-I, HBB, TXNRD1, GSPT2 and CAKP5. ELISA data suggested that the serum levels of FGA, AHSG and APOA-I in GC patients were significantly different compared with healthy controls and had favorable diagnostic values for GC patients. Moreover, we found that the serum levels of these three proteins were associated with TNM stages and could reflect tumor burden. CONCLUSION: Our findings suggested that FGA, AHSG and APOA-I might be potential serum biomarkers for GC diagnosis.

Mutant IDH is sufficient to initiate enchondromatosis in mice.

Enchondromas are benign cartilage tumors and precursors to malignant chondrosarcomas. Somatic mutations in the isocitrate dehydrogenase genes (IDH1 and IDH2) are present in the majority of these tumor types. How these mutations cause enchondromas is unclear. Here, we identified the spectrum of IDH mutations in human enchondromas and chondrosarcomas and studied their effects in mice. A broad range of mutations was identified, including the previously unreported IDH1-R132Q mutation. These mutations harbored enzymatic activity to catalyze α-ketoglutarate to d-2-hydroxyglutarate (d-2HG). Mice expressing Idh1-R132Q in one allele in cells expressing type 2 collagen showed a disordered growth plate, with persistence of type X-expressing chondrocytes. Chondrocyte cell cultures from these animals or controls showed that there was an increase in proliferation and expression of genes characteristic of hypertrophic chondrocytes with expression of Idh1-R132Q or 2HG treatment. Col2a1-Cre;Idh1-R132Q mutant knock-in mice (mutant allele expressed in chondrocytes) did not survive after the neonatal stage. Col2a1-Cre/ERT2;Idh1-R132 mutant conditional knock-in mice, in which Cre was induced by tamoxifen after weaning, developed multiple enchondroma-like lesions. Taken together, these data show that mutant IDH or d-2HG causes persistence of chondrocytes, giving rise to rests of growth-plate cells that persist in the bone as enchondromas.

MicroRNAs in gastric cancer metastasis.

Gastric cancer (GC) is common worldwide and has a high rate of metastasis. The underlying molecular mechanism of metastasis are not entirely clear. MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression post-transcriptionally and are reported to be involved in multiple steps of tumor metastasis. Clarifying their roles in GC metastasis will improve understanding of this disease. Here, we review the involvement of miRNAs in multiple steps of GC metastasis, including epithelial-mesenchymal transitions, anoikis, angiogenesis, invasion, and migration. The clinical application of miRNAs as prognostic biomarkers in GC is also discussed.

MicroRNAs in bladder cancer: expression profiles, biological functions, regulation, and clinical implications.

Bladder cancer (UBC) is a common cancer worldwide and has a high rate of recurrence and progression despite systemic therapy. The molecular mechanisms of UBC are not completely understood. MicroRNAs are noncoding RNA molecules of approximately 23 nucleotides that play important roles in multiple steps during the progression of UBC. Here, we review the expression profiles of miRNAs and their biological functions, regulation, and clinical implications in UBC. Either down-regulation or up-regulation of miRNAs occurs in UBC through epigenetic changes or defects of the biogenesis apparatus. Deregulation of miRNAs is involved in cell-cycle arrest, apoptosis, proliferation, metastasis, drug resistance, and other functions in UBC. A number of miRNAs, including urine miRNAs, have been associated with tumor type, stage, or patient survival, and miRNAs might be developed as diagnostic or prognostic markers. Better understanding of the roles of miRNAs in UBC will shed light on the molecular mechanisms of UBC.

Differences in methylation profiles between long-term survivors and short-term survivors of IDH-wild-type glioblastoma.

Background: Patients with glioblastoma (GBM) have a median overall survival (OS) of approximately 16 months. However, approximately 5% of patients survive >5 years. This study examines the differences in methylation profiles between long-term survivors (>5 years, LTS) and short-term survivors (<1 year, STS) with isocitrate dehydrogenase (IDH)-wild-type GBMs. Methods: In a multicenter retrospective analysis, we identified 25 LTS with a histologically confirmed GBM. They were age- and sex-matched to an STS. The methylation profiles of all 50 samples were analyzed with EPIC 850k, classified according to the DKFZ methylation classifier, and the methylation profiles of LTS versus STS were compared. Results: After methylation profiling, 16/25 LTS and 23/25 STS were confirmed to be IDH-wild-type GBMs, all with +7/-10 signature. LTS had significantly increased O6-methylguanine methyltransferase (MGMT) promoter methylation and higher prevalence of FGFR3-TACC3 fusion (P = .03). STS were more likely to exhibit CDKN2A/B loss (P = .01) and higher frequency of NF1 (P = .02) mutation. There were no significant CpGs identified between LTS versus STS at an adjusted P-value of .05. Unadjusted analyses identified key pathways involved in both LTS and STS. The most common pathways were the Hippo signaling pathway and the Wnt pathway in LTS, and GPCR ligand binding and cell-cell signaling in STS. Conclusions: A small group of patients with IDH-wild-type GBM survive more than 5 years. While there are few differences in the global methylation profiles of LTS compared to STS, our study highlights potential pathways involved in GBMs with a good or poor prognosis.

Insulin induces C2C12 cell proliferation and apoptosis through regulation of cyclin D1 and BAD expression.

Insulin is a secreted peptide hormone identified in human pancreas to promote glucose utilization. Insulin has been observed to induce cell proliferation and myogenesis in C2C12 cells. The precise mechanisms underlying the proliferation of C2C12 cells induced by insulin remain unclear. In this study, we observed for the first time that 10 nM insulin treatment promotes C2C12 cell proliferation. Additionally, 50 and 100 nM insulin treatment induces C2C12 cell apoptosis. By utilizing real-time PCR and Western blotting analysis, we found that the mRNA levels of cyclinD1 and BAD are induced upon 10 and 50 nM/100 nM insulin treatment, respectively. The similar results were observed in C2C12 cells expressing GATA-6 or PPARα. Our results identify for the first time the downstream targets of insulin, cyclin D1, and BAD, elucidate a new molecular mechanism of insulin in promoting cell proliferation and apoptosis.

Insulin induces proliferation and cardiac differentiation of P19CL6 cells in a dose-dependent manner.

Insulin is a peptide hormone produced by beta cells of the pancreas. The roles of insulin in energy metabolism have been well studied, with most of the attention focused on glucose utilization, but the roles of insulin in cell proliferation and differentiation remain unclear. In this study, we observed for the first time that 10 nmol/L insulin treatment induces cell proliferation and cardiac differentiation of P19CL6 cells, whereas 50 and 100 nmol/L insulin treatment induces P19CL6 cell apoptosis and blocks cardiac differentiation of P19CL6 cells. By using real-time polymerase chain reaction (PCR) and Western blotting analysis, we found that the mRNA levels of cyclin D1 and α myosin heavy chain (α-MHC) are induced upon 10 nmol/L insulin stimulation and inhibited upon 50/100 nmol/L insulin treatment, whereas the mRNA levels of BCL-2-antagonist of cell death (BAD) exists a reverse trend. The similar results were observed in P19CL6 cells expressing GATA-6 or peroxisome proliferator-activated receptor α (PPARα). Our results identified the downstream targets of insulin, cyclin D1, BAD, α-MHC, and GATA-4, elucidate a novel molecular mechanism of insulin in promoting cell proliferation and differentiation.

miR-200b targets GATA-4 during cell growth and differentiation.

GATA-4 is an important transcription factor involved in several developmental processes of the heart, such as cardiac myocyte proliferation, differentiation and survival. The precise mechanisms underlying the regulation of GATA-4 remain unclear, this is especially true for the mechanisms that mediate the post-transcriptional regulation of GATA-4. Here, we demonstrate that miR-200b, a member of the miR-200 family, is a critical regulator of GATA-4. Overexpression of miR-200b leads to the downregulation of GATA-4 mRNA and a decrease in GATA-4 protein levels. Moreover, miR-200b not only inhibits cell growth and differentiation but also reverses the growth response mediated by GATA-4, whereas depletion of miR-200b leads to a slight reversal of the anti-growth response achieved by knocking down endogenous GATA-4. More importantly, the cell cycle-associated gene cyclin D1, which is a downstream target of GATA-4, is also regulated by miR-200b. Thus, miR-200b targets GATA-4 to downregulate the expression of cyclin D1 and myosin heavy chain (MHC), thereby regulating cell growth and differentiation.

DNA methylation profiling of a lipomatous meningioma: illustrative case.

BACKGROUND: Lipomatous meningiomas are an extremely rare, benign meningioma subtype subcategorized under metaplastic meningioma in the most recent 2021 update to the World Health Organization classification. They make up less than 0.3% of all meningiomas and, to date, less than 70 cases have been reported in the literature, none of which have undergone molecular profiling. This study aims to promote the utility of molecular profiling to better diagnose these rare tumors. OBSERVATIONS: The authors present the first case of a lipomatous meningioma with DNA methylation profiling that both confirmed its benign biology and uncovered unique cytogenetic changes. Molecular characterization of a lipomatous meningioma confirmed its diagnosis as a distinct, benign meningioma subtype and revealed several copy number variations on chromosome 8 and in NF2 and SMARCB1. Here we discuss some of the radiological and histopathological features of lipomatous meningiomas, how they can be used to distinguish from other meningiomas and other similarly presenting tumors, and a brief literature review discussing the pathophysiology and presentation of this rare tumor. LESSONS: This study provides evidence supporting the use of molecular profiling to diagnose lipomatous meningiomas and guide their clinical management more accurately.

CD142 Identifies Neoplastic Desmoid Tumor Cells, Uncovering Interactions Between Neoplastic and Stromal Cells That Drive Proliferation.

The interaction between neoplastic and stromal cells within a tumor mass plays an important role in cancer biology. However, it is challenging to distinguish between tumor and stromal cells in mesenchymal tumors because lineage-specific cell surface markers typically used in other cancers do not distinguish between the different cell subpopulations. Desmoid tumors consist of mesenchymal fibroblast-like cells driven by mutations stabilizing beta-catenin. Here we aimed to identify surface markers that can distinguish mutant cells from stromal cells to study tumor-stroma interactions. We analyzed colonies derived from single cells from human desmoid tumors using a high-throughput surface antigen screen, to characterize the mutant and nonmutant cells. We found that CD142 is highly expressed by the mutant cell populations and correlates with beta-catenin activity. CD142-based cell sorting isolated the mutant population from heterogeneous samples, including one where no mutation was previously detected by traditional Sanger sequencing. We then studied the secretome of mutant and nonmutant fibroblastic cells. PTX3 is one stroma-derived secreted factor that increases mutant cell proliferation via STAT6 activation. These data demonstrate a sensitive method to quantify and distinguish neoplastic from stromal cells in mesenchymal tumors. It identifies proteins secreted by nonmutant cells that regulate mutant cell proliferation that could be therapeutically. Significance: Distinguishing between neoplastic (tumor) and non-neoplastic (stromal) cells within mesenchymal tumors is particularly challenging, because lineage-specific cell surface markers typically used in other cancers do not differentiate between the different cell subpopulations. Here, we developed a strategy combining clonal expansion with surface proteome profiling to identify markers for quantifying and isolating mutant and nonmutant cell subpopulations in desmoid tumors, and to study their interactions via soluble factors.

Genomic and RNA-Seq profiling of patients with HFrEF unraveled OAS1 mutation and aggressive expression.

BACKGROUND: Heart failure (HF) is a complex pathophysiological state characterized by inadequate delivery of blood and nutrients to the cardiac tissues. It is rarely curable and is commonly associated with a poor prognosis. In this study, we aimed to analyse exomic and RNA-Seq data from patients with HF to identify the key altered pathways in HF. METHODS: Whole blood samples were collected from patients with HF and subjected to whole exome sequencing (WES) and RNA-Seq analysis. The gene expression and RNA-Seq data obtained were verified using gene chip analysis and RT-PCR. RESULTS: Both exomic and RNA-Seq data confirmed the dysregulation of phosphorylation and immune signalling in patients with HF. Specifically, exomic analysis showed that TITIN, OBSCURIN, NOD2, CDH2, MAP3K5, and SLC17A4 mutations were associated with HF, and RNA-Seq revealed that S100A12, S100A8, S100A9, PFDN5, and TMCC2, were upregulated in patients with HF. Additionally, comparison between RNA-seq and WES data showed that OAS1 mutations are associated with HF. CONLCUSION: Our findings indicated that patients with HF show an overall disruption of key phosphorylation and immune signalling pathways. Based on RNA-seq and WES, OAS1 mutations may be primarily responsible for these changes.

Multiplatform molecular profiling uncovers two subgroups of malignant peripheral nerve sheath tumors with distinct therapeutic vulnerabilities.

Malignant peripheral nerve sheath tumor (MPNST) is a highly aggressive sarcoma, and a lethal neurofibromatosis type 1-related malignancy, with little progress made on treatment strategies. Here, we apply a multiplatform integrated molecular analysis on 108 tumors spanning the spectrum of peripheral nerve sheath tumors to identify candidate drivers of MPNST that can serve as therapeutic targets. Unsupervised analyses of methylome and transcriptome profiles identify two distinct subgroups of MPNSTs with unique targetable oncogenic programs. We establish two subgroups of MPNSTs: SHH pathway activation in MPNST-G1 and WNT/ß-catenin/CCND1 pathway activation in MPNST-G2. Single nuclei RNA sequencing characterizes the complex cellular architecture and demonstrate that malignant cells from MPNST-G1 and MPNST-G2 have neural crest-like and Schwann cell precursor-like cell characteristics, respectively. Further, in pre-clinical models of MPNST we confirm that inhibiting SHH pathway in MPNST-G1 prevent growth and malignant progression, providing the rational for investigating these treatments in clinical trials.

A primary DICER1-sarcoma with KRAS and TP53 mutations in a child with suspected ECCL.

A child had been followed since infancy by our multi-disciplinary neuro-oncology clinic with annual magnetic resonance imaging (MRI) under the presumed diagnosis of encephalocraniocutaneous lipomatosis (ECCL), with clinical features including nevus psiloliparus, scalp lipoma, nodular skin tag on and coloboma of the eyelid, cortical atrophy and meningeal angiomatosis. At the age of 4, she was found to have a large temporoparietal lesion causing elevated intracranial pressure requiring surgical resection. Histopathological exam of the tumor was suggestive of an intracranial sarcoma. Sequencing analysis of the tumor revealed mutations in DICER1, KRAS and TP53. Subsequent germline testing confirmed DICER1 syndrome and revealed an insignificant FGFR1 variant at a low frequency. Methylation profile of the tumor showed the tumor clustered most closely with sarcoma (rhabdomyosarcoma-like), confirming this tumor to be a primary DICER1-sarcoma. Compared to the previously reported cases, our unique case of primary DICER1-sarcoma also demonstrated neurofilament and chromogranin positivity, and genomic instability with loss of chromosome 4p, 4q, 8p, 11p, and 19p, as well as gains in chromosome 7p, 9p, 9q, 13q, and 15q on copy variant analysis. The detailed sequencing and methylation information discovered in this unique case of DICER1-sarcoma will hopefully help further our understanding of this rare and emerging entity.