The pivotal role of irradiation-induced apoptosis in the pathogenesis and therapy of medulloblastoma.

BACKGROUND: Medulloblastoma (MB) is a rare primitive neuroectodermal tumors originating from the cerebellum. MB is the most common malignant primary brain tumor of childhood. MB originates from neural precursor cells in distinctive regions of the rhombic lip, and their maturation occurs in the cerebellum or the brain stem during embryonal development. Also, apoptosis is a programmed cell death associated with numerous physiological as well as pathological regulations. RECENT FINDINGS: Irradiation (IR)-induce apoptosis triggers cell death, with or without intervening mitosis within a few hours of IR and these share different morphologic alteration such as, loss of normal nuclear structure as well as degradation of DNA. Moreover, MB is strikingly sensitive to DNA-damaging therapies and the role of apoptosis a key treatment modality. Furthermore, in MB, the apoptotic pathways are made up of several triggers, modulators, as well as effectors. Notably, IR-induced apoptotic mechanisms in MB therapy are very complex and they either induce radiosensitivity or inhibit radioresistance leading to potential effective treatment strategies for MB. CONCLUSION: This review explicitly explores the pivotal roles of IR-induced apoptosis in the pathogenesis and therapy of MB.

Identification and validation of a metabolism-related gene signature for predicting the prognosis of paediatric medulloblastoma.

Medulloblastoma (MB) is a malignant brain tumour that is highly common in children and has a tendency to spread to the brain and spinal cord. MB is thought to be a metabolically driven brain tumour. Understanding tumour cell metabolic patterns and characteristics can provide a promising foundation for understanding MB pathogenesis and developing treatments. Here, by analysing RNA-seq data of MB samples from the Gene Expression Omnibus (GEO) database, 12 differentially expressed metabolic-related genes (DE-MRGs) were chosen for the construction of a predictive risk score model for MB. This model demonstrated outstanding accuracy in predicting the outcomes of MB patients and served as a standalone predictor. An evaluation of functional enrichment revealed that the risk score showed enrichment in pathways related to cancer promotion and the immune response. In addition, a high risk score was an independent poor prognostic factor for MB in patients with different ages, sexes, metastasis stages and subgroups (SHH and Group 4). Consistently, the metabolic enzyme ornithine decarboxylase (ODC1) was upregulated in MB patients with poor survival time. Inhibition of ODC1 in primary and metastatic MB cell lines decreased cell proliferation, migration and invasion but increased immune infiltration. This study could aid in identifying metabolic targets for MB as well as optimizing risk stratification systems and individual treatment plans for MB patients via the use of a metabolism-related gene prognostic risk score signature.

Cerebellar phenotypes in germline PTEN mutation carriers.

PTEN hamartoma tumour syndrome (PHTS) comprises different hereditary conditions caused by germline PTEN mutations, predisposing to the development of multiple hamartomas in many body tissues and also increasing the risk of some types of cancer. Cerebellar involvement in PHTS patients has been long known due to the development of a pathognomonic cerebellar hamartoma (known as dysplastic gangliocytoma of the cerebellum or Lhermitte-Duclos disease). Recently, a crucial role of the cerebellum has been highlighted in the pathogenesis of autism spectrum disorders, now recognised as a phenotype expressed in a variable percentage of PHTS children. In addition, rare PTEN variants are indeed identified in medulloblastoma as well, even if they are less frequent than other germline gene mutations. The importance of PTEN and its downstream signalling enzymatic pathways, PI3K/AKT/mTOR, has been studied at different levels in both human clinical settings and animal models, not only leading to a better understanding of the pathogenesis of different disorders but, most importantly, to identify potential targets for specific therapies. In particular, PTEN integrity makes an important contribution to the normal development of tissue architecture in the nervous system, including the cerebellum. Thus, in patients with PTEN germline mutations, the cerebellum is an affected organ that is increasingly recognised in different disorders, whereas, in animal models, cerebellar Pten loss causes a variety of functional and histological alterations. In this review, we summarise the range of cerebellar involvement observed in PHTS and its relationships with germline PTEN mutations, along with the phenotypes expressed by murine models with PTEN deficiency in cerebellar tissue.

Heterogeneity and tumoral origin of medulloblastoma in the single-cell era.

Medulloblastoma is one of the most common malignant pediatric brain tumors derived from posterior fossa. The current treatment includes maximal safe surgical resection, radiotherapy, whole cranio-spinal radiation and adjuvant with chemotherapy. However, it can only limitedly prolong the survival time with severe side effects and relapse. Defining the intratumoral heterogeneity, cellular origin and identifying the interaction network within tumor microenvironment are helpful for understanding the mechanisms of medulloblastoma tumorigenesis and relapse. Due to technological limitations, the mechanisms of cellular heterogeneity and tumor origin have not been fully understood. Recently, the emergence of single-cell technology has provided a powerful tool for achieving the goal of understanding the mechanisms of tumorigenesis. Several studies have demonstrated the intratumoral heterogeneity and tumor origin for each subtype of medulloblastoma utilizing the single-cell RNA-seq, which has not been uncovered before using conventional technologies. In this review, we present an overview of the current progress in understanding of cellular heterogeneity and tumor origin of medulloblastoma and discuss novel findings in the age of single-cell technologies.

Development of a high-throughput screening platform to identify new therapeutic agents for Medulloblastoma Group 3.

Pediatric brain tumors (PBTs) represent about 25 % of all pediatric cancers and are the most common solid tumors in children and adolescents. Medulloblastoma (MB) is the most frequently occurring malignant PBT, accounting for almost 10 % of all pediatric cancer deaths. MB Group 3 (MB G3) accounts for 25-30 % of all MB cases and has the worst outcome, particularly when associated with MYC amplification. However, no targeted treatments for this group have been developed so far. Here we describe a unique high throughput screening (HTS) platform specifically designed to identify new therapies for MB G3. The platform incorporates optimized and validated 2D and 3D efficacy and toxicity models, that account for tumor heterogenicity, limited efficacy and unacceptable toxicity from the very early stage of drug discovery. The platform has been validated by conducting a pilot HTS campaign with a 1280 lead-like compound library. Results showed 8 active compounds, targeting MB reported targets and several are currently approved or in clinical trials for pediatric patients with PBTs, including MB. Moreover, hits were combined to avoid tumor resistance, identifying 3 synergistic pairs, one of which is currently under clinical study for recurrent MB and other PBTs.

PTCH1-mutant human cerebellar organoids exhibit altered neural development and recapitulate early medulloblastoma tumorigenesis.

Patched 1 (PTCH1) is the primary receptor for the sonic hedgehog (SHH) ligand and negatively regulates SHH signalling, an essential pathway in human embryogenesis. Loss-of-function mutations in PTCH1 are associated with altered neuronal development and the malignant brain tumour medulloblastoma. As a result of differences between murine and human development, molecular and cellular perturbations that arise from human PTCH1 mutations remain poorly understood. Here, we used cerebellar organoids differentiated from human induced pluripotent stem cells combined with CRISPR/Cas9 gene editing to investigate the earliest molecular and cellular consequences of PTCH1 mutations on human cerebellar development. Our findings demonstrate that developmental mechanisms in cerebellar organoids reflect in vivo processes of regionalisation and SHH signalling, and offer new insights into early pathophysiological events of medulloblastoma tumorigenesis without the use of animal models.

SALL4 is a CRL3REN/KCTD11 substrate that drives Sonic Hedgehog-dependent medulloblastoma.

The Sonic Hedgehog (SHH) pathway is crucial regulator of embryonic development and stemness. Its alteration leads to medulloblastoma (MB), the most common malignant pediatric brain tumor. The SHH-MB subgroup is the best genetically characterized, however the molecular mechanisms responsible for its pathogenesis are not fully understood and therapeutic benefits are still limited. Here, we show that the pro-oncogenic stemness regulator Spalt-like transcriptional factor 4 (SALL4) is re-expressed in mouse SHH-MB models, and its high levels correlate with worse overall survival in SHH-MB patients. Proteomic analysis revealed that SALL4 interacts with REN/KCTD11 (here REN), a substrate receptor subunit of the Cullin3-RING ubiquitin ligase complex (CRL3REN) and a tumor suppressor lost in ~30% of human SHH-MBs. We demonstrate that CRL3REN induces polyubiquitylation and degradation of wild type SALL4, but not of a SALL4 mutant lacking zinc finger cluster 1 domain (ΔZFC1). Interestingly, SALL4 binds GLI1 and cooperates with HDAC1 to potentiate GLI1 deacetylation and transcriptional activity. Notably, inhibition of SALL4 suppresses SHH-MB growth both in murine and patient-derived xenograft models. Our findings identify SALL4 as a CRL3REN substrate and a promising therapeutic target in SHH-dependent cancers.

Tumor-associated astrocytes promote tumor progression of Sonic Hedgehog medulloblastoma by secreting lipocalin-2.

Sonic Hedgehog (SHH) subgroup of medulloblastoma (MB) accounts for about 25% of all subgroups of MB. Tumor microenvironment (TME) may play a key role in the tumor progression and therapeutic resistance. Tumor-associated astrocytes (TAAs) are reshaped to drive tumor progression through multiple paracrine signals. However, the mechanism by which TAAs modulate MB cells remains elusive. Here, we illuminated that TAAs showed a specific and dynamic pattern during SHH-MB development. Most TAAs gathered to the tumor margin during the tumor progression, rather than evenly distributed in the early-stage tumors. We further demonstrated that lipocalin-2 (LCN2) secreted by TAAs could promote the tumor growth and was correlated with the poor prognosis of MB patients. Knocking down LCN2 in TAAs in vitro impeded the proliferation and migration abilities of MB cells. In addition, we identified that TAAs accelerated the tumor growth by secreting LCN2 via STAT3 signaling pathway. Accordingly, blockade of STAT3 signaling by its inhibitor WP1066 and AAV-Lcn2 shRNA, respectively, in TAAs abrogated the effects of LCN2 on tumor progression in vitro and in vivo. In summary, we for the first time clarified that LCN2, secreted by TAAs, could promote MB tumor progression via STAT3 pathway and has potential prognostic value. Our findings unveiled a new sight in reprogramming the TME of SHH-MB and provided a potential therapeutic strategy targeting TAAs.

Differential Signaling Pathways in Medulloblastoma: Nano-biomedicine Targeting Non-coding Epigenetics to Improve Current and Future Therapeutics.

BACKGROUND: Medulloblastomas (MDB) are malignant, aggressive brain tumors that primarily affect children. The survival rate for children under 14 is approximately 72%, while for ages 15 to 39, it is around 78%. A growing body of evidence suggests that dysregulation of signaling mechanisms and noncoding RNA epigenetics play a pivotal role in this disease. METHODOLOGY: This study conducted an electronic search of articles on websites like PubMed and Google. The current review also used an in silico databases search and bioinformatics analysis and an extensive comprehensive literature search for original research articles and review articles as well as retrieval of current and future medications in clinical trials. RESULTS: This study indicates that several signaling pathways, such as sonic hedgehog, WNT/ß-catenin, unfolded protein response mediated ER stress, notch, neurotrophins and TGF-ß and ERK, MAPK, and ERK play a crucial role in the pathogenesis of MDB. Gene and ncRNA/protein are also involved as an axis long ncRNA to sponge micro-RNAs that affect downstream signal proteins expression and translation affection disease pathophysiology, prognosis and present potential target hit for drug repurposing. Current treatment options include surgery, radiation, and chemotherapy; unfortunately, the disease often relapses, and the survival rate is less than 5%. Therefore, there is a need to develop more effective treatments to combat recurrence and improve survival rates. CONCLUSION: This review describes various MDB disease hallmarks, including the signaling mechanisms involved in pathophysiology, related-causal genes, epigenetics, downstream genes/epigenes, and possibly the causal disease genes/non-protein coding (nc)RNA/protein axis. Additionally, the challenges associated with MDB treatment are discussed, along with how they are being addressed using nano-technology and nano-biomedicine, with a listing of possible treatment options and future potential treatment modalities.

Mitochondrial subtype MB-G3 contains potential novel biomarkers and therapeutic targets associated with prognosis of medulloblastoma.

BACKGROUND: Medulloblastoma is the most common malignant brain tumor in children. There are four groups, each with different causal mutations, affected pathways and prognosis. Here, we investigated the role of mitochondria in medulloblastoma and whether there are differences between the different groups. METHODS: We compared the gene expression levels in the four different medulloblastoma groups (MB-WNT, MB-SHH, MB-G3 and MB-G4), with the focus on genes associated with mitochondria. We used several tools including Salmon, Tximeta, DESeq2, BiomaRt, STRING, Ggplot2, EnhancedVolcano, Venny 2.1 and Metscape. RESULTS: A total of 668 genes were differentially expressed and the most abundant genes were associated with cell division pathway followed by modulation of chemical synaptic transmission. We also identified several genes (ABAT, SOX9, ALDH5A, FOXM1, ABL1, NHLH1, NEUROD1 and NEUROD2) known to play vital role in medulloblastoma. Comparative expression analysis revealed OXPHOS complex-associated proteins of mitochondria. The most significantly expressed genes in the MB-SHH and MB-G4 groups were AHCYL1 and SFXN5 while PAICS was significantly upregulated in MB-WNT group. Notably, MB-G3 contained the most downregulated genes from the OXPHOS complexes, except COX6B2 which was strongly upregulated. CONCLUSIONS: We show the importance of mitochondria and compare their role in the four different medulloblastoma groups.

A preliminary study on the mechanism of VASH2 in childhood medulloblastoma.

To study the differences in VASH2 expression in pediatric medulloblastoma (MB) tumor tissues of different molecular subtypes, to analyze the correlation between VASH2 and the molecular subtypes of medulloblastoma, clinicopathological data, and prognosis, and to explore the specific mechanism of VASH2's role in SHH medulloblastoma cell lines DAOY. We analyzed 47 pediatric medulloblastoma cases admitted to the Department of Pediatric Neurosurgery of the First Affiliated Hospital of Xinjiang Medical University from January 2011 to December 2019, and the expression levels of YAP1 and GAB1 in these tumor tissues were detected by immunohistochemistry (IHC) and molecularly typed (WNT-type, SHH-type, and non-WNT/SHH-type). The correlation between VASH2 and molecular typing of medulloblastoma was analyzed. We also analyzed the medulloblastoma dataset in the GEO database (GSE30074 and GSE202043) to explore the correlation between VASH2 and the prognosis of medulloblastoma patients, as well as performed a comprehensive GO enrichment analysis specifically for the VASH2 gene to reveal the underlying biological pathways of its complex molecular profile. We used vasopressin 2 (VASH2) as a research target and overexpressed and knocked down VASH2 in SHH medulloblastoma cell lines DAOY by lentiviral vectors in vitro, respectively, to investigate its role in SHH medulloblastoma cell lines DAOY cell proliferation, apoptosis, migration, invasion and biological roles in the cell cycle. (1) Among 47 pediatric medulloblastoma cases, 8 were WNT type, 29 were SHH type, and 10 were non-WNT/SHH type. the positive rate of VASH2 was highest in the SHH type with a 68.97% positive rate, followed by non-WNT/SHH and lowest in the WNT type. The results of the multifactorial analysis showed that positive expression of VASH2 was associated with medulloblastoma molecular subtype (SHH type), site of tumor development (four ventricles), and gender (male), P < 0.05. (2) The results of cellular experiments showed that overexpression of VASH2 increased the invasion and migration ability of medulloblast Daoy, while knockdown of VASH2 inhibited the invasion and Overexpression of VASH2 upregulated the expression of Smad2 + 3, Smad4, Mmp2 and the apoptotic indicators Bcl-2 and Caspase3, while knockdown of VASH2 suppressed the expression of Smad2 + 3 and Mmp2, and silenced the expression of Smad4 and the apoptotic indicators Bcl2, Caspase3 expression. Flow cytometric cycle analysis showed that VASH2 overexpression increased the S phase in the Daoy cell cycle, while VASH2 knockdown decreased the S phase in the SHH medulloblastoma cell lines DAOY cell cycle. Bioinformatics analysis showed that there was no statistically significant difference between the expression of VASH2 genes in the GSE30074 and GSE202043 datasets and the prognosis of the patients, but the results of this dataset analysis suggested that we need to continue to expand the sample size of the study in the future. The results of the GO enrichment analysis showed that the angiogenic pathway was the most significantly enriched, and the PPI interactions network of VASH2 was obtained from the STRING database. Using the STRING database, we obtained the PPI interaction network of VASH2, and the KEGG enrichment analysis of VASH2-related genes showed that VASH2-related genes were related to the apoptosis pathway, and therefore it was inferred that VASH2 also affects the development of tumors through apoptosis. We found for the first time that the positive expression rate of VASH2 was closely associated with SHH-type pediatric medulloblastoma and that VASH2 was involved in the invasion, migration, cell cycle, and apoptotic capacity of SHH medulloblastoma cell lines DAOY by affecting downstream indicators of the TGF-ß pathway. This suggests that it is involved in the progression of pediatric medulloblastoma, and VASH2 is expected to be a diagnostic and therapeutic target for SHH-type pediatric medulloblastoma.

Subtyping of Group 3/4 medulloblastoma as a potential prognostic biomarker among patients treated with reduced dose of craniospinal irradiation: a Japanese Pediatric Molecular Neuro-Oncology Group study.

BACKGROUND: One of the most significant challenges in patients with medulloblastoma is reducing the dose of craniospinal irradiation (CSI) to minimize neurological sequelae in survivors. Molecular characterization of patients receiving lower than standard dose of CSI therapy is important to facilitate further reduction of treatment burden. METHODS: We conducted DNA methylation analysis using an Illumina Methylation EPIC array to investigate molecular prognostic markers in 38 patients with medulloblastoma who were registered in the Japan Pediatric Molecular Neuro-Oncology Group and treated with reduced-dose CSI. RESULTS: Among the patients, 23 were classified as having a standard-risk and 15 as high-risk according to the classic classification based on tumor resection rate and presence of metastasis, respectively. The median follow-up period was 71.5 months (12.0-231.0). The median CSI dose was 18 Gy (15.0-24.0) in both groups, and 5 patients in the high-risk group received a CSI dose of 18.0 Gy. Molecular subgrouping revealed that the standard-risk cohort included 5 WNT, 2 SHH, and 16 Group 3/4 cases; all 15 patients in the high-risk cohort had Group 3/4 medulloblastoma. Among the patients with Group 3/4 medulloblastoma, 9 of the 31 Group 3/4 cases were subclassified as subclass II, III, and V, which were known to an association with poor prognosis according to the novel subtyping among the subgroups. Patients with poor prognostic subtype showed worse prognosis than that of others (5-year progression survival rate 90.4% vs. 22.2%; p < 0.0001). The result was replicated in the multivariate analysis (hazard ratio12.77, 95% confidence interval for hazard ratio 2.38-99.21, p value 0.0026 for progression-free survival, hazard ratio 5.02, 95% confidence interval for hazard ratio 1.03-29.11, p value 0.044 for overall survival). CONCLUSION: Although these findings require validation in a larger cohort, the present findings suggest that novel subtyping of Group 3/4 medulloblastoma may be a promising prognostic biomarker even among patients treated with lower-dose CSI than standard treatment.

Mapping pediatric brain tumors to their origins in the developing cerebellum.

BACKGROUND: Distinguishing the cellular origins of childhood brain tumors is key for understanding tumor initiation and identifying lineage-restricted, tumor-specific therapeutic targets. Previous strategies to map the cell-of-origin typically involved comparing human tumors to murine embryonal tissues, which is potentially limited due to species-specific differences. The aim of this study was to unravel the cellular origins of the 3 most common pediatric brain tumors, ependymoma, pilocytic astrocytoma, and medulloblastoma, using a developing human cerebellar atlas. METHODS: We used a single-nucleus atlas of the normal developing human cerebellum consisting of 176 645 cells as a reference for an in-depth comparison to 4416 bulk and single-cell transcriptome tumor datasets, using gene set variation analysis, correlation, and single-cell matching techniques. RESULTS: We find that the astroglial cerebellar lineage is potentially the origin for posterior fossa ependymomas. We propose that infratentorial pilocytic astrocytomas originate from the oligodendrocyte lineage and MHC II genes are specifically enriched in these tumors. We confirm that SHH and Group 3/4 medulloblastomas originate from the granule cell and unipolar brush cell lineages. Radiation-induced gliomas stem from cerebellar glial lineages and demonstrate distinct origins from the primary medulloblastoma. We identify tumor genes that are expressed in the cerebellar lineage of origin, and genes that are tumor specific; both gene sets represent promising therapeutic targets for future study. CONCLUSION: Based on our results, individual cells within a tumor may resemble different cell types along a restricted developmental lineage. Therefore, we suggest that tumors can arise from multiple cellular states along the cerebellar "lineage of origin."

Smurf1 and Smurf2 mediated polyubiquitination and degradation of RNF220 suppresses Shh-group medulloblastoma.

Sonic hedgehog (Shh)-group medulloblastoma (MB) (Shh-MB) encompasses a clinically and molecularly distinct group of cancers originating from the developing nervous system with aberrant high Shh signaling as a causative driver. We recently reported that RNF220 is required for sustained high Shh signaling during Shh-MB progression; however, how high RNF220 expression is achieved in Shh-MB is still unclear. In this study, we found that the ubiquitin E3 ligases Smurf1 and Smurf2 interact with RNF220, and target it for polyubiquitination and degradation. In MB cells, knockdown or overexpression of Smurf1 or Smurf2 promotes or inhibits cell proliferation, colony formation and xenograft growth, respectively, by controlling RNF220 protein levels, and thus modulating Shh signaling. Furthermore, in clinical human MB samples, the protein levels of Smurf1 or Smurf2 were negatively correlated with those of RNF220 or GAB1, a Shh-MB marker. Overall, this study highlights the importance of the Smurf1- and Smurf2-RNF220 axes during the pathogenesis of Shh-MB and provides new therapeutic targets for Shh-MB treatment.

A case of discordant histology and expression of programmed death ligand 1 between primary tumor and brain metastases in adenosquamous carcinoma of the lung.

A patient presented with vomiting and gait disturbance. Investigation revealed a single cerebellar tumor and another tumor in the upper lobe of the left lung. Based on the severe vomiting and gait disturbance, we removed the cerebellar tumor first, achieving resolution of symptoms. The cerebellar tumor was pathologically diagnosed as metastatic lung adenocarcinoma. No other metastases were identified, including in the mediastinal lymph nodes. We therefore resected the primary lung tumor. On final pathological analysis, the tumor in the upper lobe of the left lung was diagnosed as adenosquamous carcinoma with no lymph node metastasis. PD-L1 expression was low in the primary lung adenosquamous carcinoma and high in the cerebellar metastasis. Furthermore, both tumors were KRASG12C -positive. Tumor PD-L1 expression is considered important for immune escape. In this case, adenocarcinoma cells in the primary adenosquamous carcinoma may have migrated to form a cerebellar metastasis. In advanced lung cancer, tumor growth may be observed in some lesions even when many other lesions are controlled by chemo- or immunotherapy. Biopsy to confirm histology and PD-L1 expression is worth considering, depending on the location of the metastases and the invasiveness of the biopsy procedure.

Cytotoxicity of poly-guanidine in medulloblastoma cell lines.

Medulloblastoma (MB) is the most common pediatric brain tumor. The therapy frequently causes serious side effects, and new selective therapies are needed. MB expresses hyper sialylation, a possible target for selective therapy. The cytotoxic efficacy of a poly guanidine conjugate (GuaDex) incubated with medulloblastoma cell cultures (DAOY and MB-LU-181) was investigated. The cells were incubated with 0.05-8 µM GuaDex from 15 min to 72 h. A fluorometric cytotoxicity assay (FMCA) measured the cytotoxicity. Labeled GuaDex was used to study tumor cell interaction. FITC-label Sambucus nigra confirmed high expression of sialic acid (Sia). Immunofluorescence microscopy was used to visualize the cell F-actin and microtubules. The cell interactions were studied by confocal and fluorescence microscopy. Annexin-V assay was used to detect apoptosis. Cell cycle analysis was done by DNA content determination. A wound-healing migration assay determined the effects on the migratory ability of DAOY cells after GuaDex treatment. IC50 for GuaDex was 223.4 -281.1 nM. FMCA showed potent growth inhibition on DAOY and MB-LU-181 cells at 5 uM GuaDex after 4 h of incubation. GuaDex treatment induced G2/M phase cell cycle arrest. S. nigra FITC-label lectin confirmed high expression of Sia on DAOY medulloblastoma cells. The GuaDex treatment polymerized the cytoskeleton (actin filaments and microtubules) and bound to DNA, inducing condensation. The Annexin V assay results were negative. Cell migration was inhibited at 0.5 µM GuaDex concentration after 24 h of incubation. GuaDex showed potent cytotoxicity and invasion-inhibitory effects on medulloblastoma cells at low micromolar concentrations. GuaDex efficacy was significant and warrants further studies.

Clear Cell Renal Cell Carcinoma with Hemangioblastoma-Like Features: A Case Report

Abstract Background: Clear cell renal cell carcinoma (ccRCC) constitutes the most frequently encountered sporadic class of kidney cancer in adults. Recently, a rare form of clear cell kidney cancer known as ccRCC with hemangioblastoma-like features was proposed, with unique immunological characteristics and a good prognosis. The tumor expressed alpha-inhibin and carbonic anhydrase Ⅸ (CA9) as examined by immunohistochemistry. Methods: Herein, we report a clinical instance of ccRCC with hemangioblastoma-like features. A 49-year-old woman presenting with a chief complaint of hematuria underwent a comprehensive and meticulous assessment. Imaging findings indicated the presence of a mass in the right kidney. Subsequently, she underwent a partial nephrectomy. Results: Histopathological analysis of the resected specimen confirmed the presence of ccRCC with hemangioblastoma-like features. The patient was discharged from the hospital six days post-surgery and could resume her daily activities. During a one-year follow-up after surgery, no signs of recurrence were detected. Conclusions: This case demonstrates the importance of including ccRCC with hemangioblastoma-like features in the differential diagnosis of renal masses in patients with hematuria, and suggests partial nephrectomy as an effective treatment modality for this rare subtype of renal cell carcinoma. However, because of the small number of reported cases and insufficient follow-up time, further investigation is necessary to determine the optimal therapeutic approach and to identify the molecular and genetic characteristics of this tumor (AU)

Efficacy of intrathecal methotrexate in children with high-risk medulloblastoma over three years: a retrospective study from a single center.

PURPOSE: Chemotherapy is commonly used for treatment in children over three years old with high-risk medulloblastoma(MB). However, little is currently known about the therapeutic benefits and side effects of intrathecal methotrexate(MTX), warranting further research. METHODS: In this retrospective study, patients who received intrathecal MTX during chemotherapy were included in the MTX group (n = 32), and patients that only underwent cerebrospinal fluid (CSF) cytology analysis were assigned to the control group (n = 14). RESULTS: In the MTX group, 27(84.38%) patients had metastatic disease, 3(9.38%) had diffuse anaplasia, and 3(9.38%) had residual disease greater than 1.5 cm2. Molecular subgroup classification was available for 28(87.5%) patients. In the control group, 8(57.14%) patients had metastatic disease, 3(27.27%) had diffuse anaplasia, and 6(42.86%) had residual disease greater than 1.5 cm2. Molecular subgroup classification was available for 6(42.86%) patients. The 5-year progression-free survival was 70.99% and the 5-year overall survival was 72.99% for the MTX group, and the corresponding values were 41.67% and 50% for the control group, respectively. 6 (18.75%) patients in the MTX group with group 4 disease developed MTX-related acute leukoencephalopathy and one of them died. CONCLUSIONS: Our findings support the addition of intrathecal MTX during chemotherapy as the optimal management for children with group 3 and SHH high-risk MB. However, it is not recommended for group 4 MB patients, especially in resource-limited regions. TRIAL REGISTRATION NUMBER: Retrospective registered No.(2020 - 117).

[Pediatric posterior fossa tumors]. / Infratentorielle Hirntumoren bei Kindern.

CLINICAL ISSUE: Tumors of the posterior fossa account for about 50-55% of brain tumors in childhood. DIAGNOSTIC WORKUP: The most frequent tumor entities are medulloblastomas, pilocytic astrocytomas, ependymomas, diffuse midline gliomas and atypical teratoid-rhabdoid tumors. Neuroradiological differential diagnosis with magnetic resonance imaging (MRI) is of considerable importance for preoperative planning as well as planning of follow-up therapy. PERFORMANCE: Most important findings for differential diagnosis of pediatric posterior fossa tumors are tumor location, patient age and the intratumoral apparent diffusion assessed by diffusion-weighted imaging. ACHIEVEMENTS: Advanced MR techniques like MRI perfusion and MR spectroscopy can be helpful both in the initial differential diagnosis and in tumor surveillance, but exceptional characteristics of certain tumor entities should be kept in mind. PRACTICAL RECOMMENDATIONS: Standard clinical MRI sequences including diffusion-weighted imaging are the main diagnostic tool in evaluating posterior fossa tumors in children. Advanced imaging methods can be helpful, but should never be interpreted separately from conventional MRI sequences.