Rapid detection of the MYD88 L265P mutation for pre- and intra-operative diagnosis of primary central nervous system lymphoma.

The myeloid differentiation primary response gene 88 (MYD88) L265P mutation is a disease-specific mutation of primary central nervous system lymphoma (PCNSL) among the central nervous system tumors. Accordingly, this mutation is considered a reliable diagnostic molecular marker of PCNSL. As the intra-operative diagnosis of PCNSL is sometimes difficult to achieve using histological examinations alone, intra-operative detection of the MYD88 L265P mutation could be effective for the accurate diagnosis of PCNSL. Herein, we aimed to develop a novel rapid genotyping system (GeneSoC) using real-time polymerase chain reaction (PCR) based on microfluidic thermal cycling technology. This real-time PCR system shortened the analysis time, which enabled the detection of the MYD88 L265P mutation within 15 min. Rapid detection of the MYD88 L265P mutation was performed intra-operatively using GeneSoC in 24 consecutive cases with suspected malignant brain tumors, including 10 cases with suspected PCNSL before surgery. The MYD88 L265P mutation was detected in eight cases in which tumors were pathologically diagnosed as PCNSL after the operation, while wild-type MYD88 was detected in 16 cases. Although two of the 16 cases with wild-type MYD88 were pathologically diagnosed as PCNSL after the operation, MYD88 L265P could be detected in all eight PCNSL cases harboring MYD88 L265P. The MYD88 L265P mutation could also be detected using cell-free DNA derived from the cerebrospinal fluid of two PCNSL cases. Detection of the MYD88 L265P mutation using GeneSoC might not only improve the accuracy of intra-operative diagnosis of PCNSL but also help the future pre-operative diagnosis through liquid biopsy of cerebrospinal fluid.

Lack of presence of the human cytomegalovirus in human glioblastoma.

Recent reports have indicated human cytomegalovirus (HCMV) to be associated with human glioblastoma carcinogenesis. In established examples of viral carcinogenesis, viral DNA and one or more of its products have been detected in most tumor cells of biopsies in the majority of cases. To test whether HCMV is associated with human glioblastoma based on this criterion, we measured the number of viral DNA molecules per cell in both frozen and paraffin-embedded tumor biopsies from 58 patients using real-time quantitative PCR (QPCR). Immunohistochemical and fluorescence in situ hybridization (FISH) to detect HCMV proteins and genome was performed in 10 cases using formalin-fixed paraffin-embedded glioblastoma tissues. Southern blotting using DNA extracted from four glioblastoma cell lines together with immunoblotting using the four cell lines and five glioblastoma tissue samples were also performed. We further confirmed the immunoblot bands using liquid chromatography-tandem mass spectrometry assay. As a result, HCMV DNA was not detected in the tumor cells from any of the glioblastoma cases by QPCR detecting two different HCMV genes, in clear contrast to samples from patients with HCMV infection. Southern blotting and immunoblotting of cell lines and FISH using paraffin sections were all negative. However, immunoblotting and immunohistochemistry using tissue samples were partly positive, but HCMV proteins were not detected by proteomic analysis, suggesting false positivity of the analyses. As our QPCR analysis could detect 10 copies of HCMV DNA mixed with DNA extracted from 10(4) HCMV-negative cells, we conclude that HCMV is not persistent, at least in the tumor cells, of developed human glioblastoma.

Papillary glioneuronal tumor with a high proliferative component and minigemistocytes in a child.

Papillary glioneuronal tumor (PGNT) is a rare type of primary brain tumor. Although PGNT has traditionally been defined as a clinically indolent neoplasm, several cases with high proliferative activity and tumor recurrence have recently been reported. We report a case of PGNT in a 12-year-old boy who presented with epilepsy and harbored a 64 mm cystic tumor with a high proliferative component in the right temporal lobe. (11) C-methionine positron emission tomography (PET) showed high uptake in the solid mass. Gross total resection of the tumor mass was achieved and the patient became seizure-free without any neurological deficits. Histologically, the tumor contained two distinct areas of a vasocentric papilliform structure and a desmoplastic component. Minigemistocytic cells and small necrotic regions were observed adjacent to the pseudopapillae. Immunohistochemical analyses revealed both glial and neuronal differentiation. The Ki-67 proliferation index was high (14%) in the area corresponding to the high uptake region in the (11) C-methionine PET. No tumor recurrence was observed 20 months after surgery. High proliferative PGNTs are rare and to our knowledge this is only the third pediatric case of PGNT with atypical features reported in the literature. Hence, we here review the reported cases of PGNT and discuss the clinical, radiological and histological features of this malignancy.

Speech-language Pathology Rehabilitation in a Case of Jefferson Fracture Complicated with Lower Cranial Nerve Palsies.

A 68-year-old man presented with a Jefferson fracture leading to lower cranial nerve palsies affecting the ninth, tenth, and twelfth cranial nerves with a traumatic basilar impression. On the X day, the patient underwent occipitocervical posterior fixation surgery; the surgery was uneventful. However, just after the surgery, epipharyngeal palsy and airway obstruction occurred. Consequently, tracheostomy was needed. On the X+8 day, speech-language pathology (SLP) therapy was initiated for decannulation. On the X+21 day, the patient could clear all the checkpoints and was decannulated. On the X+36 day, the patient was discharged home and SLP therapy was continued. On the X+171 day, his SLP therapy was halted. However, the patient continued to complain that he could not speak as fast as before, and his quality of life remained compromised. Some studies reported that lower cranial nerve palsies affecting the ninth to the twelfth cranial nerve occur in conjunction with Jefferson fractures. Thus, SLP therapy is crucial for Jefferson fracture cases.

Surgical management of brain metastasis as a part of systematic metastases from adenoid cystic carcinoma of the external auditory canal: illustrative case.

BACKGROUND: Adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) is a rare tumor that accounts for approximately 5% of all EAC tumors. ACC is generally known as a slow-growing tumor, but patients often experience recurrence or distant metastasis in the long clinical course. While the major pattern of recurrence is pulmonary metastasis, brain metastasis of ACC of the EAC is rare. OBSERVATIONS: The authors describe the case of a 72-year-old male who was diagnosed with ACC of the EAC. Approximately 7 years later, brain magnetic resonance imaging revealed an intra-axial homogenously enhancing mass lesion that had no direct connection with the skull base in the left frontal lobe. The patient underwent tumor resection and histopathological examination revealed a mixture of cribriform and tubular patterns. The image and pathological characteristics of the tumor were similar to those of primary ACC or ACC from other sites of origin. LESSONS: While patients with ACC of the EAC often experience recurrence or distant metastasis in the long clinical course, they survive for a relatively long period of time, even though an optimal treatment has not been established. The authors therefore recommend surgical resection for brain metastasis of ACC of the EAC to improve neurological symptoms.

Newly established patient-derived organoid model of intracranial meningioma.

BACKGROUND: Recent comprehensive studies have revealed several molecular alterations that are frequently found in meningiomas. However, effective treatment reagents targeting specific molecular alterations have not yet been identified because of the limited number of representative research models of meningiomas. METHODS: We performed organoid cultures using meningioma cells and meningioma tumor tissues. Using immunohistochemistry and molecular analyses consisting of whole-exome sequencing, RNA-seq, and DNA methylation analyses, we compared the histological findings and molecular profiling of organoid models with those of parental tumors. Further, using these organoid models together with a public database of meningiomas, we explored molecular alterations, which are a potent treatment target for meningioma. RESULTS: We established 18 organoid models comprising of two malignant meningioma cells (HKBMM and IOMM-Lee), 10 benign meningiomas, four malignant meningiomas, and two solitary fibrous tumors (SFTs). The organoids exhibited consistent histological features and molecular profiles with those of the parental tumors. Using a public database, we identified that upregulated forkhead box M1 (FOXM1) was correlated with increased tumor proliferation. Overexpression of FOXM1 in benign meningioma organoids increased organoid proliferation; depletion of FOXM1 in malignant organoids decreased proliferation. Additionally, thiostrepton, a FOXM1 inhibitor combined with radiation therapy, significantly inhibited the proliferation of malignant meningioma organoid models. CONCLUSIONS: An organoid model for meningioma enabled us to elucidate the tumor biology of meningioma along with potent treatment targets for meningioma.

CD8+ T-cell-Mediated Immunoediting Influences Genomic Evolution and Immune Evasion in Murine Gliomas.

PURPOSE: Cancer immunoediting shapes tumor progression by the selection of tumor cell variants that can evade immune recognition. Given the immune evasion and intratumor heterogeneity characteristic of gliomas, we hypothesized that CD8+ T cells mediate immunoediting in these tumors. EXPERIMENTAL DESIGN: We developed retrovirus-induced PDGF+ Pten -/- murine gliomas and evaluated glioma progression and tumor immunogenicity in the absence of CD8+ T cells by depleting this immune cell population. Furthermore, we characterized the genomic alterations present in gliomas that developed in the presence and absence of CD8+ T cells. RESULTS: Upon transplantation, gliomas that developed in the absence of CD8+ T cells engrafted poorly in recipients with intact immunity but engrafted well in those with CD8+ T-cell depletion. In contrast, gliomas that developed under pressure from CD8+ T cells were able to fully engraft in both CD8+ T-cell-depleted mice and immunocompetent mice. Remarkably, gliomas developed in the absence of CD8+ T cells exhibited increased aneuploidy, MAPK pathway signaling, gene fusions, and macrophage/microglial infiltration, and showed a proinflammatory phenotype. MAPK activation correlated with macrophage/microglia recruitment in this model and in the human disease. CONCLUSIONS: Our studies indicate that, in these tumor models, CD8+ T cells influence glioma oncogenic pathways, tumor genotype, and immunogenicity. This suggests immunoediting of immunogenic tumor clones through their negative selection by CD8+ T cells during glioma formation.

Induction of synthetic lethality in IDH1-mutated gliomas through inhibition of Bcl-xL.

Certain gliomas often harbor a mutation in the activity center of IDH1 (R132H), which leads to the production of the oncometabolite 2-R-2-hydroxyglutarate (2-HG). In six model systems, including patient-derived stem cell-like glioblastoma cultures, inhibition of Bcl-xL induces significantly more apoptosis in IDH1-mutated cells than in wild-type IDH1 cells. Anaplastic astrocytoma samples with mutated IDH1 display lower levels of Mcl-1 than IDH1 wild-type tumors and specific knockdown of Mcl-1 broadly sensitizes glioblastoma cells to Bcl-xL inhibition-mediated apoptosis. Addition of 2-HG to glioblastoma cultures recapitulates the effects of the IDH mutation on intrinsic apoptosis, shuts down oxidative phosphorylation and reduces ATP levels in glioblastoma cells. 2-HG-mediated energy depletion activates AMPK (Threonine 172), blunting protein synthesis and mTOR signaling, culminating in a decline of Mcl-1. In an orthotopic glioblastoma xenograft model expressing mutated IDH1, Bcl-xL inhibition leads to long-term survival. These results demonstrate that IDH1-mutated gliomas are particularly vulnerable to Bcl-xL inhibition.

A Synthetic Cell-Penetrating Dominant-Negative ATF5 Peptide Exerts Anticancer Activity against a Broad Spectrum of Treatment-Resistant Cancers.

PURPOSE: Despite significant progress in cancer research, many tumor entities still have an unfavorable prognosis. Activating transcription factor 5 (ATF5) is upregulated in various malignancies and promotes apoptotic resistance. We evaluated the efficacy and mechanisms of the first described synthetic cell-penetrating inhibitor of ATF5 function, CP-d/n-ATF5-S1. EXPERIMENTAL DESIGN: Preclinical drug testing was performed in various treatment-resistant cancer cells and in vivo xenograft models. RESULTS: CP-d/n-ATF5-S1 reduced the transcript levels of several known direct ATF5 targets. It depleted endogenous ATF5 and induced apoptosis across a broad panel of treatment-refractory cancer cell lines, sparing non-neoplastic cells. CP-d/n-ATF5-S1 promoted tumor cell apoptotic susceptibility in part by reducing expression of the deubiquitinase Usp9X and led to diminished levels of antiapoptotic Bcl-2 family members Mcl-1 and Bcl-2. In line with this, CP-d/n-ATF5-S1 synergistically enhanced tumor cell apoptosis induced by the BH3-mimetic ABT263 and the death ligand TRAIL. In vivo, CP-d/n-ATF5-S1 attenuated tumor growth as a single compound in glioblastoma, melanoma, prostate cancer, and triple receptor-negative breast cancer xenograft models. Finally, the combination treatment of CP-d/n-ATF5-S1 and ABT263 significantly reduced tumor growth in vivo more efficiently than each reagent on its own. CONCLUSIONS: Our data support the idea that CP-d/n-ATF5-S1, administered as a single reagent or in combination with other drugs, holds promise as an innovative, safe, and efficient antineoplastic agent against treatment-resistant cancers. Clin Cancer Res; 22(18); 4698-711. ©2016 AACR.

Primary peripheral T-cell lymphoma, not otherwise specified, of the central nervous system in a child.

Primary peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), is a rare disease that infrequently involves the central nervous system (CNS), and it is even rarer in pediatric patients. Here, we report of a 13-year-old male with primary CNS PTCL-NOS who exhibited a malignant clinical course with recurrence after radiochemotherapy followed by bone marrow transplantation; he died 43 months after diagnosis. Pathology revealed the proliferation of cytotoxic T-cells and clonal T-cell receptor gene rearrangements. Although the optimal therapy for PTCL remains controversial, intensive radiochemotherapy may be required for some patients.

Preclinical evaluation of an O(6)-methylguanine-DNA methyltransferase-siRNA/liposome complex administered by convection-enhanced delivery to rat and porcine brains.

The main determinant of glioblastoma (GBM) resistance to temozolomide (TMZ) is thought to be O(6)-methylguanine-DNA methyltransferase (MGMT), which is a DNA-repair enzyme that removes alkyl groups from the O(6)-position of guanine. Previously, we reported that a MGMT-siRNA/cationic liposome complex exerted a clear synergistic antitumor effect in combination with TMZ. Translation to a clinical setting might be desirable for reinforcing the efficacy of TMZ therapy for GBM. In this study, we aim to evaluate the safety of MGMT-siRNA/cationic liposome complexes and determine whether the convection-enhanced delivery of these complexes is suitable for clinical use by undertaking preclinical testing in laboratory animals. No significant adverse events were observed in rats receiving infusions of MGMT-siRNA/cationic liposome complex directly into the brain with or without TMZ administration. A pig which received the complex administered by CED also showed no evidence of neurological dysfunction or histological abnormalities. However, the complex did not appear to achieve effective distribution by CED in either the rat or the porcine brain tissue. Considering these results together, we concluded that insufficient distribution of cationic liposomes was achieved for tumor treatment by CED.