Early High-Grade Transformation of IDH-Mutant Central Nervous System WHO Grade 2 Astrocytoma: A Case Report.

High-grade transformation of low-grade gliomas has long been a poor prognostic factor during therapy. In 2016, the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS) adopted isocitrate dehydrogenase (IDH) mutation status in the classification of diffuse astrocytomas. The 2021 classification denoted glioblastomas as IDH-wildtype and graded IDH-mutant astrocytomas as 2, 3, or 4. Gemistocytic morphology, a large proportion of residual tumor, the patient's age, and recurrence after radiotherapy were previously mentioned as risk factors for high-grade transformation of low-grade gliomas. We report a 34-year-old male patient initially diagnosed with IDH-mutant grade 2 astrocytoma according to the 2021 WHO classification of CNS tumors. As the first surgical resection achieved gross total resection on postoperative MRI, no adjuvant therapy was given and regular follow-up was planned. On 1-year follow-up MRI, two new enhancing nodular lesions appeared at the ipsilateral brain parenchyma abutting the surgical resection cavity. Salvage craniotomy achieved gross total resection, and the pathologic diagnosis was IDH-mutant WHO grade 4 astrocytoma. We describe this tumor in terms of the previous WHO classification to evaluate the risk of high-grade transformation and discuss possible risk factors leading to high-grade transformation of low-grade astrocytoma.

Malignant Transformation of Meningioma With TERT Promoter Mutation: A Case Report.

High-grade meningiomas make up a relatively minor proportion of meningiomas, which are one of the most common types of primary intracranial tumors in adults. Though rare, a considerable portion of high-grade meningiomas arise from malignant transformation of benign meningiomas. The 2021 World Health Organization (WHO) classification criteria introduced molecular markers in the diagnosis and grading of central nervous system (CNS) tumors and assigned certain genomic mutations to grade 3 meningiomas. We report a case of a 54-year-old male patient who underwent stepwise malignant transformation of meningioma from WHO grade 1 to grade 3 within 10 years, during the course of five surgeries followed by adjuvant stereotactic radiosurgery and radiotherapy. We performed next-generation sequencing (NGS) on the most recent grade 3 meningioma specimen and found that it carried a telomerase reverse transcriptase promoter (TERTp) mutation (c.-124C>T) in accordance with the 2021 WHO criteria for grade 3 meningiomas. We then retrospectively examined the previous grade 1 and 2 specimens and found them to have the same mutation. We reviewed the significance of molecular markers in the diagnosis of meningiomas, possible genetic alterations associated with their malignant transformation, and what measures could be taken to effectively manage meningiomas considering NGS findings.

Enhanced efficacy of glycoengineered rice cell-produced trastuzumab.

For several decades, a plant-based expression system has been proposed as an alternative platform for the production of biopharmaceuticals including therapeutic monoclonal antibodies (mAbs), but the immunogenicity concerns associated with plant-specific N-glycans attached in plant-based biopharmaceuticals has not been completely solved. To eliminate all plant-specific N-glycan structure, eight genes involved in plant-specific N-glycosylation were mutated in rice (Oryza sativa) using the CRISPR/Cas9 system. The glycoengineered cell lines, PhytoRice®, contained a predominant GnGn (G0) glycoform. The gene for codon-optimized trastuzumab (TMab) was then introduced into PhytoRice® through Agrobacterium co-cultivation. Selected cell lines were suspension cultured, and TMab secreted from cells was purified from the cultured media. The amino acid sequence of the TMab produced by PhytoRice® (P-TMab) was identical to that of TMab. The inhibitory effect of P-TMab on the proliferation of the BT-474 cancer cell line was significantly enhanced at concentrations above 1 µg/mL (****P < 0.0001). P-TMab bound to a FcγRIIIa variant, FcγRIIIa-F158, more than 2.7 times more effectively than TMab. The ADCC efficacy of P-TMab against Jurkat cells was 2.6 times higher than that of TMab in an in vitro ADCC assay. Furthermore, P-TMab demonstrated efficient tumour uptake with less liver uptake compared to TMab in a xenograft assay using the BT-474 mouse model. These results suggest that the glycoengineered PhytoRice® could be an alternative platform for mAb production compared to current CHO cells, and P-TMab has a novel and enhanced efficacy compared to TMab.

Excessively Delayed Radiation Changes After Proton Beam Therapy for Brain Tumors: Report of Two Cases.

Delayed cerebral necrosis is a well-known complication of radiation therapy (RT). Because of its irreversible nature, it should be avoided if possible, but avoidance occurs at the expense of potentially compromised tumor control, despite the use of the modern advanced technique of conformal RT that minimizes radiation to normal brain tissue. Risk factors for radiation-induced cerebral necrosis include a higher dose per fraction, larger treatment volume, higher cumulative dose, and shorter time interval (for re-irradiation). The same principle can be applied to proton beam therapy (PBT) to avoid delayed cerebral necrosis. However, conversion of PBT radiation energy into conventional RT is still short of clinical support, compared to conventional RT. Herein, we describe two patients with excessively delayed cerebral necrosis after PBT, in whom follow-up MRI showed no RT-induced changes prior to 3 years after treatment. One patient developed radiation necrosis at 4 years after PBT to the resection cavity of an astroblastoma, and the other developed brainstem necrosis that became symptomatic 6 months after its first appearance on the 3-year follow-up brain MRI. We also discuss possible differences between radiation changes after PBT versus conventional RT.

Extracellular Vesicles from Cerebrospinal Fluid of Leptomeningeal Metastasis Patients Deliver MiR-21 and Induce Methotrexate Resistance in Lung Cancer Cells.

Leptomeningeal metastasis (LM) is a common and fatal complication of advanced non-small cell lung cancer (NSCLC) caused by the spread of malignant cells to the leptomeninges and cerebrospinal fluid (CSF). While intra-CSF methotrexate (MTX) chemotherapy can improve prognosis, eventual MTX resistance deters continued chemotherapy. Recent studies have shown that increased miRNA-21 (miR-21) expression in the CSF of patients with LM after intraventricular MTX-chemotherapy is associated with poor overall survival; however, the molecular mechanisms underlying this resistance are poorly understood. Here, we confirm, in 36 patients with NSCLC-LM, that elevated miR-21 expression prior to treatment correlates with poor prognosis. MiR-21 overexpression or sponging results in a corresponding increase or decrease in MTX resistance, demonstrating that cellular miR-21 expression correlates with drug resistance. MiR-21-monitoring sensor and fluorescent extracellular vesicle (EV) staining revealed that EV-mediated delivery of miR-21 could modulate MTX resistance. Moreover, EVs isolated from the CSF of LM patients containing miR-21 could enhance the cell proliferation and MTX resistance of recipient cells. These results indicate that miR-21 can be transferred from cell-to-cell via EVs and potentially modulate MTX sensitivity, suggesting that miR-21 in CSF EVs may be a prognostic and therapeutic target for overcoming MTX resistance in patients with NSCLC-LM.

Spontaneous Regression of Glioma-Mimicking Brainstem Lesion in a Child: A Case Report.

Differential diagnosis of focal brainstem lesions detected on MRI is challenging, especially in young children. Formerly, brainstem gliomas were classified mainly based on MRI features and location. However, since 2016, the World Health Organization's brainstem lesion classification requires tissue biopsy to reveal molecular characteristics. Although modern techniques of stereotactic or navigation-guided biopsy ensure accurate biopsy of the lesion with safety, biopsy of brainstem lesions is still generally not performed. Here, we report a focal brainstem lesion mimicking brainstem glioma in a 9-year-old girl. Initial MRI, MR spectroscopy, and 11C-methionine positron emission tomography (PET) features suggested low-grade glioma or diffuse intrinsic pontine glioma. However, repeated MR spectroscopy, perfusion MRI, and 18fluorodeoxyglucose PET findings suggested that it was more likely a non-tumorous lesion. As the patient presented not with a neurological manifestation but with precocious puberty, the attending oncologist chose to observe with regular follow-up MRI. The pontine lesion with high signal intensity on T2-weighted MRI regressed from the 6-month follow-up and became invisible on the 1.5-year follow-up MRI. We reviewed brainstem glioma-mimicking lesions in the literature and discussed the key points of differential diagnosis.

Disseminating Necrotizing Leukoencephalopathy Associated With Intra-CSF Methotrexate Chemotherapy: A Retrospective Observational Study.

BACKGROUND AND OBJECTIVES: Leptomeningeal metastases (LMs) are neoplasms that proliferate to membranes lining the brain and spinal cord. Intra-CSF methotrexate (MTX) chemotherapy is a prevalent treatment option. However, resultant long-term neurotoxicity can lead to irreversible disseminated necrotizing leukoencephalopathy (DNL). This study aims to determine the incidence, characteristics, risk factors, and outcomes of DNL following intra-CSF MTX chemotherapy for LM. METHODS: We retrospectively reviewed patients with LM who received intra-CSF MTX between 2001 and 2021 at the National Cancer Center of Korea. Patients with a follow-up duration of <3 months and those without follow-up MRI after MTX administration were excluded. The primary outcome was the development of DNL, evaluated based on the clinical and radiologic definitions of DNL. Logistic and Cox proportional regression models were used to assess the risk of DNL in patients with LM receiving intra-CSF MTX chemotherapy. RESULTS: Of the 577 patients included in the DNL investigation, 13 (2.3%) were identified to have irreversible DNL. The MRI features of DNL typically include necrotic changes in the bilateral anterior temporal region, extensive white matter, and/or brainstem lesions. All patients with DNL experienced fatal clinical course despite MTX cessation. Logistic regression analysis revealed that a cumulative dose of MTX significantly affected DNL occurrence. Multivariable analysis showed that the factor of ≥10 MTX rounds was significant for DNL development after adjusting for route of MTX administration and prior brain radiotherapy (odds ratio 7.32, 95% CI 1.42-37.77 at MTX rounds ≥10 vs < 10). In the Cox proportional hazards model considering time to occurrence of DNL, ≥10 rounds of MTX were identified as an independent predictor of DNL (hazard ratio 12.57, 95% CI 1.62-97.28, p = 0.015), even after adjusting for the synergistic effect of brain radiotherapy. DISCUSSION: DNL is a rare but fatal complication of intra-CSF MTX chemotherapy, and its progression cannot be prevented despite early recognition. The cumulative dose of intra-CSF MTX was an independent risk factor for DNL occurrence. Thus, intra-CSF MTX treatment for patients with LM should be administered with caution considering the possibility of the cumulative irreversible neurotoxicity.

The efficacy of slow-rate ventriculolumbar perfusion chemotherapy for leptomeningeal carcinomatosis: a phase II study.

PURPOSE: This study aimed to evaluate the symptomatic response and side effects of ventriculolumbar perfusion (VLP) methotrexate chemotherapy with a low perfusion rate in patients with leptomeningeal metastasis. METHODS: Patients in a single-arm, two-stage phase II trial based on Simon's minimax design received VLP with a reduced (15 cc/h) perfusion rate with the purpose of decreasing constitutional side effects such as nausea/vomiting, insomnia, and confusion. The primary outcome was control of increased intracranial pressure (ICP). The secondary outcome was an occurrence of side effects. The results were compared with those of a previous trial of VLP with a 20-cc/h perfusion rate. RESULTS: Total 90 patients were enrolled. Out of 65 patients with increased ICP, 32 achieved normalized ICP after VLP chemotherapy (bias-adjusted response rate = 51%). The incidence of moderate-to-severe nausea/vomiting was reduced to 46% from 64% in the previous study, and that of sleep disturbance was increased to 13% from 9%, but both failed to reach statistical significance. The incidence of moderate-to-severe confusion was significantly reduced to 12% from 23% in the previous study (p = 0.04). Median overall survival was better among patients with controlled ICP than among those who remained with increased ICP (193 days vs. 94 days, p = 0.013). CONCLUSION: Compared with a higher perfusion rate, the low perfusion rate failed to provide non-inferior ICP control or improved side effects, except for confusion. The relationship between VLP perfusion rate and ICP control needs to be evaluated in future trials adjusting for bias from uncompleted protocol due to poor general condition.

Integrated proteogenomic characterization of glioblastoma evolution.

The evolutionary trajectory of glioblastoma (GBM) is a multifaceted biological process that extends beyond genetic alterations alone. Here, we perform an integrative proteogenomic analysis of 123 longitudinal glioblastoma pairs and identify a highly proliferative cellular state at diagnosis and replacement by activation of neuronal transition and synaptogenic pathways in recurrent tumors. Proteomic and phosphoproteomic analyses reveal that the molecular transition to neuronal state at recurrence is marked by post-translational activation of the wingless-related integration site (WNT)/ planar cell polarity (PCP) signaling pathway and BRAF protein kinase. Consistently, multi-omic analysis of patient-derived xenograft (PDX) models mirror similar patterns of evolutionary trajectory. Inhibition of B-raf proto-oncogene (BRAF) kinase impairs both neuronal transition and migration capability of recurrent tumor cells, phenotypic hallmarks of post-therapy progression. Combinatorial treatment of temozolomide (TMZ) with BRAF inhibitor, vemurafenib, significantly extends the survival of PDX models. This study provides comprehensive insights into the biological mechanisms of glioblastoma evolution and treatment resistance, highlighting promising therapeutic strategies for clinical intervention.

Clinical Safety and Efficiency of the H-Port for Treatment of Leptomeningeal Metastasis.

Objective: To evaluate the usefulness of a cranial implantable chemoport, the H-port, as an alternative to the Ommaya reservoir for intraventricular chemotherapy/cerebrospinal fluid (CSF) access in patients with leptomeningeal metastasis (LM). Methods: One hundred fifty-two consecutive patients with a diagnosis of LM and who underwent H-port installation between 2015 and 2021 were evaluated. Adverse events associated with installation and intraventricular chemotherapy, and the rate of increased intracranial pressure (ICP) control via the port were evaluated for safety and efficacy. These indices were compared with published data of Ommaya (n=89), from our institution. Results: Time-to-install and installation-related complications of intracranial hemorrhage (n=2) and catheter malposition (n=5) were not significantly different between the two groups. Intraventricular chemotherapy-related complications of CSF leakage occurred more frequently in the Ommaya than in the H-port group (13/89 vs. 3/152, respectively, p<0.001). Intracranial hemorrhage during chemotherapy occurred only in the Ommaya group (n=4). The CSF infection rate was not statistically different between groups (14/152 vs. 12/89, respectively). The ICP control rate according to reservoir type revealed a significantly higher ICP control rate with the H-port (40/67), compared with the Ommaya result (12/58, p<0.001). Analyzing the ICP control rate based on the CSF drainage method, continuous extraventricular drainage (implemented only with the H-port), found a significantly higher ICP control rate than with intermittent CSF drainage (33/40 vs. 6/56, respectively, p<0.0001). Conclusion: The H-port for intraventricular chemotherapy in patients with LM was superior for ICP control; it had equal or lower complication rates than the Ommaya reservoir.

Cross-talk between PARN and EGFR-STAT3 Signaling Facilitates Self-Renewal and Proliferation of Glioblastoma Stem Cells.

Glioblastoma is the most common type of malignant primary brain tumor and displays highly aggressive and heterogeneous phenotypes. The transcription factor STAT3 has been reported to play a key role in glioblastoma malignancy. Thus, discovering targets and functional downstream networks regulated by STAT3 that govern glioblastoma pathogenesis may lead to improved treatment strategies. In this study, we identified that poly(A)-specific ribonuclease (PARN), a key modulator of RNA metabolism, activates EGFR-STAT3 signaling to support glioblastoma stem cells (GSC). Functional integrative analysis of STAT3 found PARN as the top-scoring transcriptional target involved in RNA processing in patients with glioblastoma, and PARN expression was strongly correlated with poor patient survival and elevated malignancy. PARN positively regulated self-renewal and proliferation of GSCs through its 3'-5' exoribonuclease activity. EGFR was identified as a clinically relevant target of PARN in GSCs. PARN positively modulated EGFR by negatively regulating the EGFR-targeting miRNA miR-7, and increased EGFR expression created a positive feedback loop to increase STAT3 activation. PARN depletion in GSCs reduced infiltration and prolonged survival in orthotopic brain tumor xenografts; similar results were observed using siRNA nanocapsule-mediated PARN targeting. Pharmacological targeting of STAT3 also confirmed PARN regulation by STAT3 signaling. In sum, these results suggest that a STAT3-PARN regulatory network plays a pivotal role in tumor progression and thus may represent a target for glioblastoma therapeutics. SIGNIFICANCE: A positive feedback loop comprising PARN and EGFR-STAT3 signaling supports self-renewal and proliferation of glioblastoma stem cells to drive tumor progression and can be targeted in glioblastoma therapeutics.

Molecular Biology of Brain Metastases.

Brain metastases (BMs) often occur in patients with lung cancer, breast cancer, and melanoma and are the leading cause of morbidity and mortality. The incidence of BM has increased with advanced neuroimaging and prolonged overall survival of cancer patients. With the advancement of local treatment modalities, including stereotactic radiosurgery and navigation-guided microsurgery, BM can be controlled long-term, even in cases with multiple lesions. However, radiation/chemotherapeutic agents are also toxic to the brain, usually irreversibly and cumulatively, and it remains difficult to completely cure BM. Thus, we must understand the molecular events that begin and sustain BM to develop effective targeted therapies and tools to prevent local and distant treatment failure. BM most often spreads hematogenously, and the blood-brain barrier (BBB) presents the first hurdle for disseminated tumor cells (DTCs) entering the brain parenchyma. Nevertheless, how the DTCs cross the BBB and settle on relatively infertile central nervous system tissue remains unknown. Even after successfully taking up residence in the brain, the unique tumor microenvironment is marked by restricted aerobic glycolysis metabolism and limited lymphocyte infiltration. Brain organotropism, certain phenotype of primary cancers that favors brain metastasis, may result from somatic mutation or epigenetic modulation. Recent studies revealed that exosome secretion from primary cancer or over-expression of proteolytic enzymes can "pre-condition" brain vasculoendothelial cells. The concept of the "metastatic niche," where resident DTCs remain dormant and protected from systemic chemotherapy and antigen exposure before proliferation, is supported by clinical observation of BM in patients clearing systemic cancer and experimental evidence of the interaction between cancer cells and tumor-infiltrating lymphocytes. This review examines extant research on the metastatic cascade of BM through the molecular events that create and sustain BM to reveal clues that can assist the development of effective targeted therapies that treat established BMs and prevent BM recurrence.

Leptomeningeal Metastasis in Gliomas : Clinical Characteristics and Risk Factors.

OBJECTIVE: Our objective is to analyze the occurrence, clinical course and risk factors for glioma patients with leptomeningeal metastasis (LM) according to different metastasis patterns and clinical variables. METHODS: We retrospectively reviewed data from 376 World Health Organization (WHO) grade II-IV adult glioma patients who were treated in the National Cancer Center from 2001 to 2020. Patients who underwent surgery at other institutions, those without initial images or those with pathologically unconfirmed cases were excluded. LM was diagnosed based on magnetic resonance imaging (MRI) findings or cerebrospinal fluid (CSF) cytology. The metastasis pattern was categorized as nodular or linear according to the enhancement pattern. Tumor proximity to the CSF space was classified as involved or separated, whereas location of the tumor was dichotomized as midline, for tumors residing in the thalamus, basal ganglia and brainstem, or lateral, for tumors residing in the cerebral and cerebellar hemispheres. RESULTS: A total of 138 patients were enrolled in the study. A total of 44 patients (38%) were diagnosed with LM during a median follow-up of 9 months (range, 0-60). Among the clinical variables, tumor proximity to CSF space, the location of the tumor and the WHO grade were significant factors for LM development in univariate analysis. In multivariate analysis, the midline location of the tumor and WHO grade IV gliomas were the most significant factor for LM development. The hazard ratio was 2.624 for midline located gliomas (95% confidence interval [CI], 1.384-4.974; p=0.003) and 3.008 for WHO grade IV gliomas (95% CI, 1.379-6.561; p=0.006). CONCLUSION: Midline location and histological grading are an important factor for LM in glioma patients. The proximity to the CSF circulation pathway is also an important factor for WHO grade IV glioma LM. Patients carrying high risks should be followed up more thoroughly.

Lumboperitoneal Shunt Combined With Ommaya Reservoir Enables Continued Intraventricular Chemotherapy for Leptomeningeal Metastasis With Increased Intracranial Pressure.

BACKGROUND: Intra-cerebrospinal fluid (CSF) chemotherapy for leptomeningeal metastasis (LM) can be delivered intraventricularly via an Ommaya reservoir. However, hydrocephalus associated with LM can interfere with chemotherapeutic drug distribution, and ventriculoperitoneal shunts can prevent drug distribution to the extra-ventricular CSF space. This study examined the feasibility of combining a lumboperitoneal (LP) shunt with an Ommaya reservoir to both control intracranial pressure and allow for intraventricular chemotherapy. METHODS: We identified 16 patients with LM who received both an Ommaya reservoir and an LP shunt, either concurrently or sequentially, and subsequently received intraventricular chemotherapy. The feasibility of this combination for intraventricular chemotherapy was evaluated by assessing 1) the distribution of intraventricularly injected drugs in CSF samples collected 0, 6, and 12 h post-injection and 2) adverse events associated with the procedure and drug administration. RESULTS: Patients received a median of seven rounds (range 1-37) of intraventricular chemotherapy during a median follow-up period of 5.2 months after LP shunt insertion. Pharmacokinetic data were obtained from six patients. Baseline methotrexate (MTX) levels from Ommaya reservoirs varied from 339.9 µM to 1,523.5 µM. CSF sampled from LP shunt reservoirs revealed an elimination half-life (t1/2) of 2.63 h, and the mean ratio of MTX concentration at 12 h to that at baseline was 0.05±0.05, ensuring drug distribution from the ventricle to the spinal canal. Nine patients (56%) underwent revision surgery due to catheter migration, malfunction, or infection. Among these patients, CSF infections attributable to intraventricular chemotherapy (n=3) occurred, but no infections occurred in later cases after we began to employ a complete aseptic technique. CONCLUSION: LP shunt combined with Ommaya reservoir insertion is a feasible option for achieving both intracranial pressure control and the continuation of intraventricular chemotherapy in patients with LM.

Cerebrospinal fluid neurofilament light chain as a potential prognostic biomarker for leptomeningeal metastasis.

The present study aimed to evaluate whether the cerebrospinal fluid (CSF) neurofilament light chain (NfL) is a potential prognostic marker for patients with leptomeningeal metastasis (LM). NfL levels were measured in CSF using a single-molecule array assay. A total of 42 patients with LM who were treated with ventriculo-lumbar perfusion (VLP) chemotherapy and had available stored CSF samples from the lumbar subarachnoid space before VLP chemotherapy were included in the present study, in order to investigate the prognostic value of CSF NfL. The median CSF NfL level in patients with LM was 8.15 ng/ml; 30% of patients who had died at the time of analysis had CSF NfL levels higher than the calculated overall prognostic cut-off value (11 ng/ml). The median overall survival after initiation of VLP chemotherapy was significantly longer in patients with LM and low CSF NfL levels compared with in patients with LM and high CSF NfL levels (P<0.001). The statistical significance remained after adjusting for other known prognostic factors and in a subgroup analysis according to age. In conclusion, CSF NfL could be considered a putative prognostic marker in patients with LM treated with VLP chemotherapy.

Recurrent L3 Chordoma Presented as Intradural Extramedullary Mass With Distant Metastasis: A Case Report.

Here, we report a rare case of L3 chordoma progressed to an intradural extramedullary (IDEM) mass and distant metastasis to the fascia lata. A 64-year old female patient presented to a local university hospital due to back pain and received excisional biopsy for a L3 destructive bony lesion. Local radiation therapy was initially administered, assuming a malignancy of unknown origin, but she developed cerebrospinal fluid leakage during adjuvant radiation therapy, which was managed by wound revision and lumbar drainage. As the destructive lesion progressed, she visited our hospital for a second opinion 3 months after the biopsy. After review of outside pathology, we diagnosed the lesion to be a chordoma, and performed a L3 corpectomy with cage and plate fixation. One and a half years later, positron emission tomography and computed tomography (PET-CT) revealed a right tensor fascia lata hypermetabolic lesion. Excisional biopsy confirmed a distant metastasis of the chordoma. One year later, she complained of L2 radiating pain. PET-CT and CT myelogram revealed an IDEM lesion. Surgical excision confirmed the transdural invasion of the chordoma. To our knowledge, this is the first report of an iatrogenic IDEM invasion and distant metastasis to the tensor of the fascia lata by a L3 chordoma.

Different Metabolomic and Proteomic Profiles of Cerebrospinal Fluid in Ventricular and Lumbar Compartments in Relation to Leptomeningeal Metastases.

The different molecular profiles of cerebrospinal fluid (CSF) between ventricular and lumbar compartments remain elusive, especially in the context of leptomeningeal metastasis (LM), which affects CSF flow. We evaluated CSF metabolomic and proteomic profiles based on the compartments and the diagnosis of spinal LM, proved by MRI from 20 paired ventricular and lumbar CSF samples of LM patients, including 12 spinal LM (+) samples. In metabolome analysis, 9512 low-mass ions (LMIs) were identified-7 LMIs were abundant in all lumbar versus paired ventricular CSF samples, and 3 LMIs were significantly abundant in all ventricular CSF. In comparisons between spinal LM (+) CSF and LM (-) CSF, 105 LMIs were discriminative for spinal LM (+) CSF. In proteome analysis, a total of 1536 proteins were measured. A total of 18 proteins, including complement C3, were more highly expressed in all lumbar CSF, compared with paired ventricular CSF, while 82 proteins, including coagulation factor V, were higher in the ventricular CSF. Of 37 discriminative proteins, including uteroglobin and complement component C8 gamma chain, 4 were higher in all spinal LM (+) CSF versus spinal LM (-) CSF. We further evaluated metabolic pathways associated with these discriminative proteins using the Gene Ontology database. We found that 16/17 spinal LM (+) pathways, including complement activation, were associated with lumbar discriminative proteins, whereas only 2 pathways were associated with ventricular-discriminative proteins. In conclusion, we determined that metabolite and protein profiles differed between paired lumbar and ventricular CSF samples. The protein profiles of spinal LM (+) CSF showed more similarity with the lumbar CSF than the ventricular CSF. Thus, we suggest that CSF LMIs and proteins could reflect LM disease activity and that LM-associated differences in CSF are more likely to be present in the lumbar compartment.

Experimental Assessment of Leptomeningeal Metastasis Diagnosis in Medulloblastoma Using Cerebrospinal Fluid Metabolomic Profiles.

Diagnosing leptomeningeal metastasis (LM) in medulloblastoma is currently based on positive cerebrospinal fluid (CSF) cytology or magnetic resonance imaging (MRI) finding. However, the relevance of discordant results has not been established. We evaluated the diagnostic potential of CSF metabolomic profiles in the medulloblastoma LM assessment. A total of 83 CSF samples from medulloblastoma patients with documented MRI and CSF cytology results at the time of sampling for LM underwent low-mass ions (LMIs) analysis using liquid chromatography-mass spectrometry. Discriminating LMIs were selected by a summed sensitivity and specificity (>160%) and LMI discriminant equation (LOME) algorithms, evaluated by measuring diagnostic accuracy for verifying LM groups of different MRI/cytology results. Diagnostic accuracy of LM in medulloblastoma was 0.722 for cytology and 0.889 for MRI. Among 6572 LMIs identified in all sample, we identified 27 discriminative LMIs differentiating MRI (+)/cytology (+) from MRI (-)/cytology (-). Using LMI discriminant equation (LOME) analysis, we selected 9 LMIs with a sensitivity of 100% and a specificity of 93.6% for differentiating MRI (+)/cytology (+) from MRI (-)/cytology (-). Another LOME of 20 LMIs significantly differentiated sampling time relative to treatment (p = 0.007) and the presence or absence of LM-related symptoms (p = 0.03) in the MRI (+)/cytology (-) group. CSF metabolomics of medulloblastoma patients revealed significantly different profiles among LM diagnosed with different test results. We suggest that LM patients could be screened by appropriately selected LOME-generated LMIs to support LM diagnosis by either MRI or cytology alone.

Exploratory Profiling of Extracellular MicroRNAs in Cerebrospinal Fluid Comparing Leptomeningeal Metastasis with Other Central Nervous System Tumor Statuses.

The diagnosis of leptomeningeal metastasis (LM) is often difficult due to the paucity of cancer cells in cerebrospinal fluid (CSF) and nonspecific findings on neuroimaging. Investigations of extracellular microRNAs (miRNAs) in CSF could be used for both the diagnosis and study of LM pathogenesis because they reflect the activity of disseminating cancer cells. We isolated CSF extracellular miRNAs from patients (n = 65) of different central nervous system tumor statuses, including cancer control, healthy control, LM, brain metastasis (BM), and primary brain tumor (BT) groups, and performed miRNA microarrays. In unsupervised clustering analyses, all LM and two BM samples showed unique profiles. Among 30 miRNAs identified for LM-specific biomarkers via a Prediction Analysis of Microarrays, miR-335-5p and miR-34b-3p were confirmed in both the discovery and validation samples (n = 23). Next, we performed a significance analysis of the microarray (SAM) to extract discriminative miRNA profiles of two selected CSF groups, with LM samples revealing a greater number of discriminative miRNAs than BM and BT samples compared to controls. Using SAM comparisons between LM and BM samples, we identified 30 upregulated and 6 downregulated LM miRNAs. To reduce bias from different primary cancers, we performed a subset analysis with primary non-small cell lung cancer, and 12 of 13 upregulated miRNAs in LM vs. BM belonged to the upregulated miRNAs in LM. We identified possible target genes and their biological processes that could be affected by LM discriminative miRNAs in NSCLC using the gene ontology database. In conclusion, we identified a unique extracellular miRNA profile in LM CSF that was different from BM, suggesting the use of miRNAs as LM biomarkers in studies of LM pathogenesis.