Astroblastoma: A molecularly defined entity, its clinico-radiological & pathological analysis of eight cases and review of literature.

Astroblastoma, a unique entity of glial tumor, predominantly occur in young women with distinctive MN1 rearrangement, Given its limited documentation in existing literature, we report eight cases of astroblastoma, detailing their clinical, radiological, and histopathological characteristics along with molecular analysis. We conducted a retrospective analysis of our neuropathology archive database spanning the past 8 years. We included all cases that underwent Magnetic Resonance Imaging (MRI), surgical resection, histopathological examination, molecular testing, and follow-up. Histopathological examination involving immunohistochemistry and Fluorescence In Situ Hybridization (FISH) was carried out for all cases. All tumors were found to be located in the supratentorial region (cerebral hemisphere). The median age of the group was 35.1 years, with a female-to-male ratio of 1.6:1. The most common clinical presentation was headache. Morphologically, all tumors exhibited astroblastic features with pseudorosettes and perivascular hyalinization. Immunohistochemistry consistently revealed positivity for EMA and variable immunoreactivity for GFAP, OLIG2, and D2-40. Fluorescence In Situ Hybridization (FISH) analysis conducted for all cases showed MN1 rearrangement in 7 cases. The mean follow-up period was 45 months (ranging from 12 to 105 months). Radiotherapy was administered for high-grade and recurrent astroblastomas. All patients are currently alive and in good health. Astroblastomas are uncommon central nervous system (CNS) tumors with characteristics morphology and molecular signatures. They typically carry a favorable prognosis. High level suspicion is required for their diagnosis and molecular analysis is must to distinguish them from other morphological mimics.

Clinical utility of plasma cell-free DNA (cfDNA) in diffuse gliomas for the detection of IDH1 R132H mutation.

Liquid biopsy for CNS tumors is in its nascent phase, hindered by the low levels of circulating tumor DNA (ctDNA). Overcoming this challenge requires highly sensitive molecular techniques. DD-PCR emerges as a standout technique due to its ability to identify rare mutations, copy number variations, and circulating nucleic acids, making it one of the best methods for identifying somatic mutations in cell-free DNA (cfDNA). Despite promising results from various studies demonstrating the feasibility of obtaining informative ctDNA profiles from liquid biopsy samples, challenges persist, including the need to standardize sample collection, storage, and processing methods, define clear assay positivity thresholds, and address the overall low assay sensitivity. Our two-phase study began by assessing DD-PCR efficacy in FFPE tissues, revealing robust concordance with immunohistochemistry. In Phase 1 (85 cases), DD-PCR on FFPE tissues demonstrated 100 % sensitivity and specificity for IDH1 R132H mutations. In Phase 2 (100 cases), analysis extended to cfDNA, maintaining high specificity (100 %) with moderate sensitivity (44.2 %). Overall concordance with immunohistochemistry was 61 %, highlighting liquid biopsy's potential in glioma management. The findings emphasized DD-PCR's clinical utility in both tissue and liquid biopsy, underscoring its role in early detection, diagnosis, and therapeutic monitoring of diffuse gliomas.

Evaluation of prognostic biomarkers in meningiomas and their clinical implications in settings with limited resources.

Background: The 5th edition of the World Health Organization (WHO) Central Nervous System (CNS) tumor classification for meningiomas acknowledges the clinical relevance of genomic profiling studies and emphasizes the importance of incorporating molecular information alongside histopathological features, leading to more accurate diagnoses and improved patient care. Methods: We analyzed 206 meningioma samples (108 histological grade 1, 89 grade 2, and 9 grade 3) to study pTERT mutations, CDKN2A/B homozygous deletion, loss of H3K27me3, and p16 expression. The association of these molecular markers with survival outcomes was also assessed. Results: pTERT mutation was found in 4.85% of cases, predominantly occurring in histological grade 2 (11.24%), while none of the histological grade 1 or 3 meningiomas exhibited this mutation. CDKN2A/B gene deletion was absent in grade 1 and detected in 2.24% of grade2, and 33.3% of histological grade 3 cases. There was a significant increase in loss of H3K27me3 with higher tumor grades, while p16 loss was observed in over 50% of cases across all histological grades. The presence of pTERT mutation and CDKN2A/B homozygous deletion resulted in the reclassification of 5.33% (11/206) of meningiomas as integrated grade 3. pTERT mutation and CDKN2A/B deletion, emerged as prognostically relevant markers, showing significant differences in progression-free survival (PFS) between integrated grade 3 and histological grade 2 meningiomas (P = .0002). Conclusions: pTERT mutations are the most clinically relevant genetic alterations in meningiomas. Routine testing for pTERT mutations can identify high-risk cases of histologically grade 2 meningiomas, providing crucial prognostic information for treatment planning. CDKN2A/B alteration is rare and not cost-effective in assessing meningiomas. Immunohistochemical assessment of p16 and H3K27me3 expression lacks significant prognostic value. Assessment of pTERT mutations offers a cost-effective and valuable diagnostic tool for meningiomas.

Imaging and MR Spectroscopy in Papillary Craniopharyngioma.

Sellar-suprasellar masses exhibit a diverse range of differential diagnoses and it is feasible to establish a preliminary diagnosis before surgery by evaluating conventional CT scans and contrast-enhanced MRI results. Nevertheless, certain cases may present with inconclusive findings, making it challenging to anticipate the underlying tissue composition accurately through imaging alone. Researchers have explored the application of Proton MR spectroscopy in analyzing suprasellar tumors, and their investigations have revealed that it can complement traditional MRI by enhancing the accuracy of preoperative diagnoses. In this context, we report three biopsy-proven cases of suprasellar papillary craniopharyngioma where the MRS spectra derived from the solid component exhibited noticeable lipid peaks alongside reduced levels of choline and NAA. These findings played a pivotal role in facilitating the correct preoperative identification of papillary craniopharyngioma.

Novel EGFR mutations in diffuse midline gliomas using cost-effective strategies: A report of 2 cases.

Background: Diffuse midline gliomas (DMGs) are malignant tumors predominantly affecting children, often leading to poor outcomes. The 2021 World Health Organization classification identifies 3 subtypes of DMGs, all characterized by the loss of H3K27 trimethylation. Here, we report 2 cases of DMG with Epidermal Growth Factor Receptor (EGFR) mutations within exon 20, contributing to the understanding of the molecular complexity of these pediatric brain tumors. Methods: An economical immunohistochemical panel was designed to aid in the diagnosis of most DMGs in resource-constrained regions. Sanger sequencing was employed to identify rare EGFR mutations in exon 20 of 2 cases. Results: Molecular analyses of 2 cases of DMG revealed novel EGFR mutations within exon 20. These mutations were identified using cost-effective diagnostic approaches. The presence of EGFR mutations expands the molecular landscape of DMGs and highlights the genetic heterogeneity within this tumor entity. Conclusions: These findings underscore the molecular heterogeneity of DMGs and the significance of identifying novel mutations, such as EGFR mutations in exon 20. Further research into the molecular mechanisms underlying DMGs is warranted to advance therapeutic strategies and improve outcomes for pediatric patients.

Evaluation of KIAA1549::BRAF fusions and clinicopathological insights of pilocytic astrocytomas.

BACKGROUND: Pilocytic astrocytoma (PAs) represents a significant portion of childhood primary brain tumors, with distinct histological and radiological features. The prevalence of KIAA1549::BRAF fusion in PAs has been well-established, this study aims to assess the prevalence of KIAA1549::BRAF fusions and explore their associations with tumor characteristics, radiological findings, and patient outcomes in PAs. METHODS: Histologically confirmed cases of PAs from a 5-year period were included in the study. Demographic, histopathological, and radiological data were collected, and immunohistochemistry was performed to characterize tumor markers. FISH and qRT-PCR assays were employed to detect KIAA1549::BRAF fusions. Statistical analyses were conducted to examine associations between fusion status and various other parameters. RESULTS: Histological analysis revealed no significant differences in tumor features based on fusion status. However, younger age groups showed higher fusion prevalence. Radiologically, fusion-positive cases were distributed across different tumor subtypes SE, CWE and NCWE. Survival analysis did not demonstrate a significant impact of fusion status on overall survival, however most cases with recurrence and death harboured KIAA1549::BRAF fusion. Of 200 PAs, KIAA1549::BRAF fusions were detected in 64 % and 74 % of cases via qRT-PCR and FISH, respectively. Concordance between the two platforms was substantial (86 %). CONCLUSION: KIAA1549::BRAF fusions are prevalent in PAs and can be reliably detected using both FISH and qRT-PCR assays. Cost considerations suggest qRT-PCR as a more economical option for fusion detection in routine clinical practice.

Clinicoradiological Parameters and Biochemical and Molecular Alterations Predicting Remission and Recurrence After Surgical Treatment of Corticotroph Adenomas-Cushing Disease.

OBJECTIVE: Endonasal endoscopic transsphenoidal surgery (TSS) and resection of pituitary adenomas are considered the gold standard treatment for Cushing disease (CD). Even with various recent advances in management, disease persistence and recurrence are common in these patients. The remission rate in the global population after surgery has been reported to vary widely from 64% to 93%. This study aims to determine the various clinical, biochemical, radiological, and histological factors that correlate with persistence and recurrence in patients with CD. This study also aims to understand the clinicopathological significance of EGFR-MAPK, NF-κB, and SHH pathway activation and to study the protein expression of activation markers of these pathways (i.e., c-Fos, c-Jun, GLI-1, pMEK, NR4A1, and p44) in functioning corticotroph pituitary adenomas. METHODS: From January 2009 to September 2022, the clinical data of 167 patients who underwent surgical treatment (n = 174 surgeries) for CD with a median follow-up of 8.1 years (range, 1-13.29 years) were ambispectively analyzed. The preoperative clinical, biochemical, and radiological features, operative findings, postoperative clinical and biochemical data, and histopathological and molecular profiles were retrieved from the electronic medical records. The patients were followed up to assess their remission status. RESULTS: Among the 174 surgeries performed, 140 were primary surgeries, 22 were revision surgeries, 24 surgeries were for pediatric patients, and 12 surgeries were for patients with Nelson syndrome. In the primary surgery cohort, 74.3% were female, and the average age was 28.73 ± 10.15 years. Of the primary surgery cohort, 75% of the patients experienced remission compared with 47.4% after revision surgery. The remission rate for the pediatric patients was 55.5%. The postoperative day 1 plasma cortisol (P < 0.001; area under the curve, 0.8894; range, 0.8087-0.9701) and adrenocorticotropic hormone (P < 0.001; area under the curve, 0.9; range, 0.7386-1) levels were seen to be strong independent predictors of remission in the primary surgery cohort. The remission rate after endoscopic TSS was greater than that after microscopic TSS in patients undergoing primary surgery (81.08% vs. 57.14%; P = 0.008). The presence of adenoma on histopathological examination (HPE) was also a strong predictor of disease remission (P = 0.020). On stratifying by surgical approach and HPE, microscopically operated patients without histopathological evidence of adenoma had significantly higher odds of nonremission (odds ratio, 38.1; 95% confidence interval, 4.2-348.3) compared with endoscopically operated patients with adenoma found on HPE. A lower immunoreactivity score for NR4A1 was found to correlate with higher remission rates (P = 0.074). However, none of the molecular markers studied (i.e., c-Fos, c-Jun, GLI-1, pMEK, and p44) showed a significant correlation with the preoperative cortisol values. CONCLUSIONS: The remission rate after primary surgery is higher than that after revision surgery and is lower for pediatric patients than for adults. The postoperative day 1 plasma cortisol and adrenocorticotropic hormone levels are strong independent predictors of remission in the primary surgery cohort. An endoscopic approach with histopathological evidence of adenoma is associated with a higher remission rate; thus, endoscopy should be the approach of choice for these patients with the goal of identification of an adenoma on HPE.

STAT1 mediated downregulation of the tumor suppressor gene PDCD4, is driven by the atypical cadherin FAT1, in glioblastoma.

STAT1 (Signal Transducer and Activator of Transcription 1), belongs to the STAT protein family, essential for cytokine signaling. It has been reported to have either context dependent oncogenic or tumor suppressor roles in different tumors. Earlier, we demonstrated that Glioblastoma multiforme (GBMs) overexpressing FAT1, an atypical cadherin, had poorer outcomes. Overexpressed FAT1 promotes pro-tumorigenic inflammation, migration/invasion by downregulating tumor suppressor gene, PDCD4. Here, we demonstrate that STAT1 is a novel mediator downstream to FAT1, in downregulating PDCD4 in GBMs. In-silico analysis of GBM databases as well as q-PCR analysis in resected GBM tumors showed positive correlation between STAT1 and FAT1 mRNA levels. Kaplan-Meier analysis showed poorer survival of GBM patients having high FAT1 and STAT1 expression. SiRNA-mediated knockdown of FAT1 decreased STAT1 and increased PDCD4 expression in glioblastoma cells (LN229 and U87MG). Knockdown of STAT1 alone resulted in increased PDCD4 expression. In silico analysis of the PDCD4 promoter revealed four putative STAT1 binding sites (Site1-Site4). ChIP assay confirmed the binding of STAT1 to site1. ChIP-PCR revealed decrease in the binding of STAT1 on the PDCD4 promoter after FAT1 knockdown. Site directed mutagenesis of Site1 resulted in increased PDCD4 luciferase activity, substantiating STAT1 mediated PDCD4 inhibition. EMSA confirmed STAT1 binding to the Site 1 sequence. STAT1 knockdown led to decreased expression of pro-inflammatory cytokines and EMT markers, and reduced migration/invasion of GBM cells. This study therefore identifies STAT1 as a novel downstream mediator of FAT1, promoting pro-tumorigenic activity in GBM, by suppressing PDCD4 expression.

Disseminated phaeohyphomycosis due to Cladophialophora bantiana in an immunocompetent child.

A 3-year-old boy presented with acute headache, vomiting and right focal clonic seizures without history of fever, joint pain or altered sensorium. Neuroimaging showed multifocal contrast enhancing lesions with significant perilesional edema. CECT chest and abdomen showed multiple variable sized nodules in the lungs and hypodense lesion in liver with mesenteric lymphadenopathy. There was persistent eosinophilia with maximum upto 35 %. Liver biopsy and brain biopsy revealed Cladophialophora bantiana. He was treated with IV liposomal amphotericin and voriconazole for 6 weeks with repeat neuroimaging showing more than 50 % resolution of the intracranial lesions. He was transitioned to oral combination of flucytosine and voriconazole. At 14 months follow-up, he remained symptom free with complete radiological resolution of the lesions and no eosinophilia. High suspicion, an aggressive approach in obtaining microbiological diagnosis and timely combination antifungal therapy may give satisfactory outcome without surgery.

The role of susceptibility-weighted imaging & contrast-enhanced MRI in the diagnosis of primary CNS vasculitis: a large case series.

Primary CNS Vasculitis (PCNSV) is a rare, diverse, and polymorphic CNS blood vessel inflammatory condition. Due to its rarity, clinical variability, heterogeneous imaging results, and lack of definitive laboratory markers, PCNSV diagnosis is challenging. This retrospective cohort analysis identified patients with histological diagnosis of PCNSV. Demographic data, clinical presentation, neuroimaging studies, and histopathologic findings were recorded. We enrolled 56 patients with a positive biopsy of CNS vasculitis. Most patients had cerebral hemisphere or brainstem symptoms. Most brain MRI lesions were bilateral, diffuse discrete to confluent white matter lesions. Frontal lobe lesions predominated, followed by inferior cerebellar lesions. Susceptibility-weighted imaging (SWI) hemorrhages in 96.4% (54/56) of patients, either solitary microhemorrhages or a combination of micro and macrohemorrhages. Contrast-enhanced T1-WIs revealed parenchymal enhancement in 96.3% (52/54 patients). The most prevalent pattern of enhancement observed was dot-linear (87%), followed by nodular (61.1%), perivascular (25.9%), and patchy (16.7%). Venulitis was found in 19 of 20 individuals in cerebral DSA. Hemorrhages in SWI and dot-linear enhancement pattern should be incorporated as MINOR diagnostic criteria to diagnose PCNSV accurately within an appropriate clinical context. Microhemorrhages in SWI and venulitis in DSA, should be regarded as a potential marker for PCNSV.

A gain of function mutation in AKT1 increases hexokinase 2 and diminishes oxidative stress in meningioma.

Increasing evidence suggests the oncogenic role of missense mutation (AKT1-E17K) of AKT1 gene in meningiomas. Upon investigating the connection between the pro-tumorigenic role of AKT1-E17K and cellular metabolic adaptations, elevated levels of glycolytic enzyme hexokinase 2 (HK2) was observed in meningioma patients with AKT1-E17K compared to patients harboring wild-type AKT1. In vitro experiments also suggested higher HK2 levels and its activity in AKT1-E17K cells. Treatment with the conventional drug of choice AZD5363 (a pan AKT inhibitor) enhanced cell death and diminished HK2 levels in AKT1 mutants. Given the role of AKT phosphorylation in eliciting inflammatory responses, we observed increased levels of inflammatory mediators (IL-1ß, IL6, IL8, and TLR4) in AKT1-E17K cells compared to AKT1-WT cells. Treatment with AKT or HK2 inhibitors dampened the heightened levels of inflammatory markers in AKT1-E17K cells. As AKT and HK2 regulates redox homeostasis, diminished ROS generation concomitant with increased levels of NF-E2- related factor 2 (Nrf2) and superoxide dismutase 1 (SOD1) were observed in AKT1-E17K cells. Increased sensitivity of AKT1-E17K cells to AZD5363 in the presence of HK2 inhibitor Lonidamine was reversed upon treatment with ROS inhibitor NAC. By affecting metabolism, inflammation, and redox homeostasis AKT1-E17K confers a survival advantage in meningioma cells. Our findings suggest that targeting AKT-HK2 cross-talk to induce ROS-dependent cell death could be exploited as novel therapeutic approach in meningiomas.

MYCN immunohistochemistry as surrogate marker for MYCN-amplified spinal ependymomas.

MYCN (master regulator of cell cycle entry and proliferative metabolism) gene amplification defines a molecular subgroup of spinal cord ependymomas that show high-grade morphology and aggressive behavior. Demonstration of MYCN amplification by DNA methylation or fluorescence-in situ hybridization (FISH) is required for diagnosis. We aimed to (i) assess prevalence and clinicopathological features of MYCN-amplified spinal ependymomas and (ii) evaluate utility of immunohistochemistry (IHC) for MYCN protein as a surrogate for molecular testing. A combined retrospective-prospective study spanning 8 years was designed during which all spinal cord ependymomas with adequate tissue were subjected to MYCN FISH and MYCN IHC. Among 77 spinal cord ependymomas included, MYCN amplification was identified in 4 samples from 3 patients (3/74, 4%) including two (1st and 2nd recurrences) from the same patient. All patients were adults (median age at diagnosis of 32 years) including two females and one male. The index tumors were located in thoracic (n = 2) and lumbar (n = 1) spinal cord. One of the female patients had neurofibromatosis type 2 (NF2). All four tumors showed anaplastic histology. Diffuse expression of MYCN protein was seen in all four MYCN-amplified samples but in none of the non-amplified cases, thus showing 100% concordance with FISH results. On follow-up, the NF2 patient developed widespread spinal dissemination while another developed recurrence proximal to the site of previous excision. To conclude, MYCN-amplified spinal ependymomas are rare tumors, accounting for ~ 4% of spinal cord ependymomas. Within the limitation of small sample size, MYCN IHC showed excellent concordance with MYCN gene amplification.

Malignancy arising in adamantinomatous craniopharyngioma: Report of a rare case with unusual morphologic features.

Adamantinomatous craniopharyngioma is a grade 1 tumor that arises in a sellar/suprasellar location. Despite being a grade 1 tumor, there is high recurrence and endocrinal insufficiency. Malignancy arising in craniopharyngioma is extremely rare, has a dismal prognosis, and is currently not included as a separate entity in the World Health Organization Classification of Central Nervous System 5th edition. Here we describe a case of adamantinomatous craniopharyngioma and its malignant counterpart. The malignant part had unique histomorphology and basaloid cells with pseudoglandular architecture and a myxoid background. It bore a striking resemblance to adenoid cystic carcinoma. Both the benign and malignant counterparts were beta-catenin and SOX-2 positive, providing proof of the malignant part arising from the benign part. Tumors like squamous cell carcinoma and odontogenic ghost cell carcinoma have been described in cranipharyngioma. This case study is the first to describe this unique morphology of adenoid cystic carcinoma-like features. The possibility of adenoid cystic carcinoma was excluded by immunohistochemistry.

Analysis of Histomorphologic/Molecular Association and Immune Checkpoint Regulators in Epithelioid Glioblastoma and Pleomorphic Xanthoastrocytoma: Are These Tumors Potential Candidates for Immune Checkpoint Blockade?

Accurate diagnosis of Epithelioid glioblastoma (eGB) and pleomorphic xanthoastrocytoma (PXA) is sometimes challenging owing to overlapping histologic and genetic features. There are limited reports on the immune profile of these tumors. In this study, we assessed 21 PXA [15 PXA Grade 2 (PXAG2); 6 PXA Grade 3 (PXAG3)] and 14 eGB for their histopathological and molecular association. Further, their immune profile was compared with GB, IDH1 wild-type (wt) (n-18). Morphologically, PXAG2 mostly differed from eGB; however, it was occasionally difficult to differentiate PXAG3 from eGB due to their epithelioid pattern and less obvious degenerative features. PXAG2 showed predominantly diffuse, whereas variable positivity for epithelial and glial markers was seen in PXAG3 and eGB. All cases showed retained nuclear ATRX and INI-1 . H3K27M or IDH1 mutation was seen in none. P53 mutation was more common in eGB, followed by PXAG3, and least common in PXAG2. BRAF V600E mutation was observed in 66.67% PXAG2, 33.33% PXAG3, and 50% eGB, with 100% concordance between immunohistochemistry (IHC) and sequencing. Thirty-six percent eGB, 33% PXAG3, and 61% PXAG2 harbored CDKN2A homozygous deletion. EGFR amplification was observed in 14% eGB and 66% of GB, IDH wt. PDL1 and CTLA-4 expression was higher in eGB (71.4% and 57.1%), PXAG3 (66.6% and100%), and PXAG2 (60% & 66.7%) as compared with GB, IDH wt (38.8% and 16.7%). Tumor-infiltrating lymphocytes were also observed in a majority of eGB and PXA (90% to 100%) in contrast to GB, IDH wt (66%). This analysis highlights the homogenous molecular and immune profile of eGB and PXA, suggesting the possibility that histologically and molecularly, these two entities represent 2 ends of a continuous spectrum with PXAG3 lying in between. Higher upregulation of PDL1, CTLA-4, and increased tumor infiltrating lymphocytes in these tumors as compared with GB, IDH wt suggests potential candidature for immunotherapy.

Current status of DNA methylation profiling in neuro-oncology as a diagnostic support tool: A review.

Over the last 2 decades, high throughput genome-wide molecular profiling has revealed characteristic genetic and epigenetic alterations associated with different types of central nervous system (CNS) tumors. DNA methylation profiling has emerged as an important molecular platform for CNS tumor classification with improved diagnostic accuracy and patient risk stratification in comparison to the standard of care histopathological analysis and any single molecular tests. The emergence of DNA methylation arrays have also played a crucial role in refining existing types and the discovery of new tumor types or subtypes. The adoption of methylation data into neuro-oncology has been greatly aided by the development of a freely accessible machine learning-based classifier. In this review, we discuss methylation workflow, address the utility of DNA methylation profiling in CNS tumors in a routine diagnostic setting, and provide an overview of the methylation-based tumor types and new types or subtypes identified with this platform.

Pathological Spectrum and ß-APP Immunoreactivity as a Diagnostic Tool of Diffuse Axonal Injury following Traumatic Brain Injury: A Novel Classification.

Aim Different deposition patterns and grading systems used to define and identify DAI remain discordant and to date these are a challenge in clinical practice. Our main objective was to study the post-mortem axonal changes and develop a grading system to identify DAI on the basis of histopathological and immunoreactive ß-amyloid precursor protein (ß-APP) observations in severe TBI cases. Methods Prospective study with 35 decedents with sTBI (GCS score ≤ 8) was conducted and samples were collected from three different sites-corpus callosum, thalamus and brain stem. Serial sections from each site were stained with hematoxylin and eosin (H&E), and immunohistochemistry (IHC) of ß-APP. Results We developed a grading system based on histopathological characteristics to assess the overall damage of axonal injury. We found maximum histopathological changes in cases with prolonged stay. Corpus callosum showed maximum changes in both gradings. Curiously, we also detected axonal swellings with H&E staining. Usually neglected, the thalamus also showed significant histopathological and immunoreactive changes for sTBI. Conclusion Our study based on histopathological and ß-APP scoring system to define and identify DAI thus facilitates accurate diagnosis of DAI post mortem, which has forensic implications, and may further contribute toward survival and improvement of quality of life of sTBI patients.

Protumorigenic role of the atypical cadherin FAT1 by the suppression of PDCD10 via RelA/miR221-3p/222-3p axis in glioblastoma.

The atypical cadherin FAT1 function either as a pro or antitumorigenic in tumors of different tissue origins. Our group previously demonstrated the protumorigenic nature of FAT1 signaling in glioblastoma (GBM). In this study, we investigated how FAT1 influences the expression of clustered oncomiRs (miR-221-3p/miR-222-3p) and their downstream effects in GBM. Through several experiments involving the measurement of specific gene/microRNA expression, gene knockdowns, protein and cellular assays, we have demonstrated a novel oncogenic signaling pathway mediated by FAT1 in glioma. These results have been verified using antimiRs and miR-mimic assays. Initially, in glioma-derived cell lines (U87MG and LN229), we observed FAT1 as a novel up-regulator of the transcription factor NFκB-RelA. RelA then promotes the expression of the clustered-oncomiRs, miR-221-3p/miR-222-3p, which in turn suppresses the expression of the tumor suppressor gene (TSG), PDCD10 (Programmed cell death protein10). The suppression of PDCD10, and other known TSG targets (PTEN/PUMA), by miR-221-3p/miR-222-3p, leads to increased clonogenicity, migration, and invasion of glioma cells. Consistent with our in-vitro findings, we observed a positive expression correlation of FAT1 and miR-221-3p, and an inverse correlation of FAT1 and the miR-targets (PDCD10/PTEN/PUMA), in GBM tissue-samples. These findings were also supported by publicly available GBM databases (The Cancer Genome Atlas [TCGA] and The Repository of Molecular Brain Neoplasia Data [Rembrandt]). Patients with tumors displaying high levels of FAT1 and miR-221-3p expression (50% and 65% respectively) experienced shorter overall survival. Similar results were observed in the TCGA-GBM database. Thus, our findings show a novel FAT1/RelA/miR-221/miR-222 oncogenic-effector pathway that downregulates the TSG, PDCD10, in GBM, which could be targeted therapeutically in a specific manner.

Alterations of oligodendrocyte progenitor cells (OPCs) with survival time in humans following high impact brain trauma.

BACKGROUND: As there is a lack of comprehensive literature regarding the molecular environment of the human brain emphasizing on oligodendrocyte progenitor cells (OPCs) following high impact brain trauma. The protagonist of OPCs post severe traumatic brain injury (sTBI) provides a significant thrust towards estimating time elapsed since trauma as well as developing novel therapeutic approaches. The present study was carried out to study post trauma alterations pertaining to myelin sheath and oligodendrocyte response with survival time. MATERIALS AND METHODS: In the present study, victims (both male and female) of sTBI (n = 64) were recruited and contrasted with age and gender matched controls (n = 12). Post mortem brain samples from corpus callosum and grey white matter interface were collected during autopsy examination. Extent of myelin degradation and response of OPC markers Olig-2 and PDGFR-α were evaluated using immunohistochemistry and qRT-PCR. STATA 14.0 statistical software was used for data analysis with P-value<0.05 considered statistically significant. RESULTS: Timewise qualitative correlation with extent of demyelination performed using LFB-PAS/IHC-MBP, IHC Olig-2 and mRNA expression revealed tendency towards remyelination in both corpus callosum and grey white matter interface. Number of Olig-2 positive cells was significantly higher in sTBI group as compared to control group (P-value: 0.0001). Moreover, mRNA expression studies of Olig-2 showed significant upregulation in sTBI patients. mRNA expression of Olig-2 and PDGFR-α in sTBI patients showed significant variation with respect to survival time (p value:0.0001). CONCLUSION: Detailed assessment of post TBI changes implementing various immunohistochemical and molecular techniques shall potentially reveal intriguing and important inferences in medicolegal practices and neurotherapeutics.