Differential gene regulation by a synthetic vitamin D receptor ligand and active vitamin D in human cells.

Vitamin D (VD) exerts a wide variety of biological functions including calcemic activity. VD nutritional status is closely associated with the onset and development of chronic diseases. To develop a VD analog with the desired VD activity but without calcemic activity, we screened synthetic VDR antagonists. We identified 1α,25-dihydroxyvitamin D3-26-23-lactams (DLAM)-2a-d (DLAM-2s) as nuclear vitamin D receptor (VDR) ligands in a competitive VDR binding assay for 1α,25(OH)2 vitamin D3 (1α,25(OH)2D3), and DLAM-2s showed an antagonistic effect on 1α,25(OH)2 D3-induced cell differentiation in HL60 cells. In a luciferase reporter assay in which human VDR was exogenously expressed in cultured COS-1 cells, DLAM-2s acted as transcriptional antagonists. Consistently, DLAM-2s had an antagonistic effect on the 1α,25(OH)2D3-induced expression of a known VD target gene [Cytochrome P450 24A1 (CYP24A1)], and VDR bound DLAM-2s was recruited to an endogenous VD response element in chromatin in human keratinocytes (HaCaT cells) endogenously expressing VDR. In an ATAC-seq assay, the effects of 1α,25(OH)2 D3 and DLAM-2b on chromatin reorganization were undetectable in HaCaT cells, while the effect of an androgen receptor (AR) antagonist (bicalutamide) was confirmed in prostate cancer cells (LNCaP) expressing endogenous AR. However, whole genome analysis using RNA-seq and ATAC (Assay for Transposase Accessible Chromatin)-seq revealed differential gene expression profiles regulated by DLAM-2b versus 1α,25(OH)2D3. The upregulated and downregulated genes only partially overlapped between cells treated with 1α,25(OH)2D3 and those treated with DLAM-2b. Thus, the present findings illustrate a novel VDR ligand with gene regulatory activity differing from that of 1α,25(OH)2D3.

Advances in the Administration of Vitamin D Analogues to Support Bone Health and Treat Chronic Diseases.

Vitamin D (VD) exerts a wide variety of biological actions in addition to its well-known roles in calcium homeostasis. Nutritional VD deficiency induces rachitic abnormalities in growing children and osteomalacia in adults, and it has been proposed to underlie the onset and development of multiple non-communicable chronic diseases. Therefore, the administration of VD or synthetic VD analogues represents a promising therapeutic strategy; indeed, VD and a VD agonist have shown clinical promise in mitigating osteoporosis and symptoms of insufficient calcium intake. However, even though high doses of VD analogues have shown pre-clinical efficacy against several diseases, including cancers, they have not yet had wide-spread clinical success. This difference may be due to limitation of clinical doses in light of the inherent calcemic action of VD. An approach to overcome this problem involves the development of VD analogues with lower calcemic activity, which could be administered in high doses to attenuate the onset and progress of disease. In a similar strategy, selective estrogen receptor modulators have had success as anti-osteoporosis drugs, and they have shown benefit for other estrogen target organs by serving as partial antagonists or agonists of estrogen receptor α. It is thus conceivable to generate synthetic partial antagonists or agonists for the VD receptor (VDR) that would exert beneficial effects on bone and other VD target organs. In this review, we discuss the molecular basis of the development of such synthetic VDR ligands from the viewpoint of roles of VDR in gene regulation.

The epigenetic function of androgen receptor in prostate cancer progression.

Androgen and androgen deprivation (castration) therapies, including androgen receptor antagonists, are clinically used to treat patients with prostate cancer. However, most hormone-dependent prostate cancer patients progress into a malignant state with loss of hormone-dependency, known as castration (drug)-resistant prostate cancer (CRPC), after prolong androgen-based treatments. Even in the CRPC state with irreversible malignancy, androgen receptor (AR) expression is detectable. An epigenetic transition to CRPC induced by the action of AR-mediated androgen could be speculated in the patients with prostate cancer. Androgen receptors belongs to the nuclear receptor superfamily with 48 members in humans, and acts as a ligand-dependent transcriptional factor, leading to local chromatin reorganization for ligand-dependent gene regulation. In this review, we discussed the transcriptional/epigenetic regulatory functions of AR, with emphasis on the clinical applications of AR ligands, AR protein co-regulators, and AR RNA coregulator (enhancer RNA), especially in chromatin reorganization, in patients with prostate cancer.

Identification of cell cycle-associated and -unassociated regulators for expression of a hepatocellular carcinoma oncogene cyclin-dependent kinase inhibitor 3.

Human cyclin-dependent kinase inhibitor 3 (CDKN3) is a known oncogene in hepatocellular carcinoma (HCC) and its expression is promoted during tumor development. CDKN3 serves as a cell cycle regulator and its dysregulation is considered to be a causal factor for tumor progression. However, the molecular basis of the regulation of CDKN3 expression remains largely elusive. Using in silico approach, we identified CDKN3SE, a super enhancer (SE), and enhancer RNA (eRNA) candidates transcribed from this SE. Among the eRNA candidates, the expression of CDKN3eRNA was detected in the human HCC model cell line HepG2, and was found to facilitate the expression of CDKN3 without affecting the cell proliferation rate. In silico screening revealed two DNA-binding transcription factors, upstream stimulatory factor (USF) 1 and 2, involved in the regulation of CDKN3eRNA expression on CDKN3SE. A knock-down of USF1/USF2 expression in the HepG2 cells did not affect CDKN3eRNA expression, while the expression of CDKN3 was down-regulated. In a USF2 dominant negative HepG2 cell line generated by genome editing, a drastically altered cell shape and lowered cell proliferation rate were found; however, the expression of CDKN3eRNA appeared unaffected. Thus, the present study illustrated two regulators for CDKN3 expression: USF2, as a cell cycle-associated protein regulator, and CDKN3eRNA, as a cell cycle-unassociated RNA regulator.

A long non-coding RNA as a direct vitamin D target transcribed from the antisense strand of the human HSD17B2 locus.

Vitamin D (VD) exerts a wide variety of actions via gene regulation mediated by the nuclear vitamin D receptor (VDR) under physiological and pathological settings. However, the known target genes of VDR appear unlikely to account for all VD actions. We used in silico and transcriptomic approaches in human cell lines to search for non-coding RNAs transcriptionally regulated by VD directly. Four long non-coding RNAs (lncRNAs), but no microRNAs (miRNAs), were found, supported by the presence of consensus VDR-binding motifs in the coding regions. One of these lncRNAs (AS-HSD17ß2) is transcribed from the antisense strand of the HSD17ß2 locus, which is also a direct VD target. AS-HSD17ß2 attenuated HSD17ß2 expression. Thus, AS-HSD17ß2 represents a direct lncRNA target of VD.

Antagonistic action of a synthetic androgen ligand mediated by chromatin remodeling in a human prostate cancer cell line.

The clinical use of androgen receptor (AR) antagonists has been successful in treating prostate cancer patients, inducing remission of androgen-dependent tumors. However, a couple of years after treatment, prostate tumors transition into an androgen-independent state with altered gene expression profiles, but the molecular basis is not understood. Since the AR antagonists trigger this transition, we assessed whether AR antagonists induce chromatin reorganization in an androgen-dependent prostate cancer cell line (LNCaP). Treatment of LNCaP cells with two clinically used AR antagonists (bicalutamide [Bic] and enzalutamide [Enz]) expectedly resulted in antagonistic effects on cell proliferation, AR transactivation, and dihydrotestosterone (DHT)-induced expression of AR target genes. Thus, the antagonists expectedly acted to antagonize the transactivation function of AR activated by androgen binding. By ChIP-qPCR assay, AR bound to Bic, but not Enz, was recruited to an endogenous consensus AR-binding site within the kallikrein-related peptidase 3 gene promoter after treatment with Bic, similar to the effect of DHT. By ATAC-seq analysis of the cells after long-term treatment for 5 days, Bic and dihydrotestosterone DHT induced different chromatin reorganization patterns and gene expression profiles, suggesting that Bic exhibited a distinct action from that by DHT. Thus, these results suggest that the action of a known AR antagonist is mediated by chromatin reorganization in a prostate cancer cell line.

Skeletal and gene-regulatory functions of nuclear sex steroid hormone receptors.

The wide variety of sex hormone actions underlie bone growth and health, and their actions mediate gene regulation by the cognate nuclear receptors. Nuclear androgen and estrogen receptors (AR, and ERα/ERß) are hormone-dependent and DNA binding- transcription regulatory factors, and gene regulation by sex hormones often accompany with chromatin remodeling under aid of a number of co-regulators. As sex hormone biosynthesis is under highly regulated systemic and local regulations, the skeletal actions of sex hormones could be inferred from only the phenotypic abnormalities in skeleton in mouse genetic models deficient of nuclear receptors selectively in specific types of bone cells as well as at specific cell differentiation stages. Anabolic androgen actions and anti-bone resorptive estrogen actions are discussed here from the phenotypic abnormalities in such model mice. Though rapid gene regulation by sex hormones may not require chromatin reorganization, dynamic chromatin reconfiguration looks to facilitate profound and long-term hormonal actions. In this review, we focus the recent findings in gene regulation at a chromatin level, particularly of the function of enhancer RNAs transcribed from strong enhancers, and in the role of liquid-liquid phase separation state in transcription initiation through chromatin reconfiguration.

Profiling of Androgen-Dependent Enhancer RNAs Expression in Human Prostate Tumors: Search for Malignancy Transition Markers.

INTRODUCTION: Although the ability of androgens to promote prostate cancer development has been known for decades, the molecular mechanisms of androgen receptor (AR) signaling in the tumorigenesis remain unclear. Enhancer RNAs (eRNAs) transcribed from strong enhancers, or super-enhancers (SEs), have recently emerged as a novel class of regulatory non-coding RNAs (ncRNAs) that facilitate transcription, including that of androgen target genes, through chromatin looping to position enhancers proximate to the promoters. The aim of this study was to assess androgen-dependent transcription in prostate tumors of eRNAs (designated as KLK3eRNAs) from the SE of the KLK3 gene encoding the prostate-specific antigen (PSA) protein, a clinical marker of prostate carcinogenesis. MATERIALS AND METHODS: The androgen-induced KLK3eRNAs were identified in the LNCaP human prostate cancer cell line. The expressions of these KLK3eRNAs together with KLK3 and AR mRNA transcripts were assessed by qRT-PCR in prostate tumor samples from five prostate cancer patients. RESULTS: Androgen-induced KLK3eRNAs have been identified in the LNCaP cells, and their expression was further analyzed in tumors of prostate cancer patients. Transcripts of the tested KLK3eRNAs have been detected in all clinical samples, but their expression patterns differed between individual tumor specimens. We found a statistically significant correlation between the levels of the KLK3 and AR mRNAs with those of the previously reported KLK3eRNAs, while such correlation was not observed for novel KLK3eRNAs described in our recent report. CONCLUSION: Presented data suggest that prostate tumor development may associate with epigenetic reorganization in the KLK3 genomic regulatory elements reflected by changes of the KLK3eRNA expression. Our findings support a potential of eRNAs profiling to be used as diagnostic marker.

Androgen-dependent and DNA-binding-independent association of androgen receptor with chromatic regions coding androgen-induced noncoding RNAs.

Androgen induces the binding of its receptor (AR) to androgen-responsive elements (AREs), while genome-wide studies showed that most androgen-induced AR binding sites on chromatin were unrelated to AREs. Enhancer RNAs (eRNAs), a class of noncoding RNAs (ncRNAs), are transcribed from superenhancers (SEs) and trigger the formation of large ribonucleoprotein condensates of transcription factors. By in silico search, an SE is found to be located on the locus of KLK3 that encodes prostate specific antigen. On the KLK3 SE, androgen-induced expression of ncRNAs was detected and designated as KLK3eRNAs in LNCaP cells, and androgen-induced association of AR and FOXA1 on the KLK3eRNA coding regions was detected. Such androgen-induced association of an AR mutant lacking DNA binding activity on the KLK3eRNA coding regions was undetectable on an exogenous ARE. Thus, the present findings suggest a molecular basis of androgen-induced association of AR with chromatin on ARE-unrelated sequences.

A case report of a perigraft inflammatory reaction to a Viabahn stent-graft: diagnosis with MRI and treatment with steroids.

BACKGROUND: Perigraft inflammatory reactions to prosthetic graft materials in vascular surgery have been reported; however, to our knowledge, this is the first report of a perigraft inflammatory reaction to a Viabahn stent-graft used in a superficial femoral artery occlusion lesion. CASE PRESENTATION: A 76-year-old man with right leg claudication was diagnosed with a right superficial femoral artery occlusion via contrast-enhanced computed tomography. Endovascular treatment included intravascular ultrasound for passing through the true lumen. A 25-cm Viabahn stent-graft (diameter 5 mm) was implanted. The patient developed pain and local swelling of the right thigh 5 days after endovascular treatment. Blood analysis revealed elevated inflammatory marker levels. Magnetic resonance imaging revealed extensive soft-tissue edema and a high perivascular T2 signal around the right superficial femoral artery. Clinical symptoms resolved within 7 days after initiating steroid therapy, which was gradually decreased and halted after 3 weeks. Follow-up magnetic resonance imaging demonstrated substantially reduced inflammation over the following months. CONCLUSIONS: Perigraft inflammatory reaction to a Viabahn stent-graft implant can be immediately diagnosed via magnetic resonance imaging and treated with steroids to reduce the possibility of stent-graft occlusion.

[Pneumopericardium 4 Years after Surgery of Thymic Cancer].

A 67-year-old man had undergone thymectomy with partial resection of the left upper lobe and pericardium for thymic cancer. Four years later, he visited our hospital due to chest pain. Chest computed tomography revealed pneumopericardium. Nine months later, surgical treatment was performed due to the development of the left pneumothorax. Air leak was found from the bulla which was partially incarcerated into the pericardial space.

Early and Mid-Term Vascular Responses to Optical Coherence Tomography-Guided Everolimus-Eluting Stent Implantation in Stable Coronary Artery Disease.

BACKGROUND: Analysis of pooled clinical data has shown the safety of 3 months of dual antiplatelet therapy with everolimus-eluting cobalt-chromium stents (Co-Cr EESs). This study evaluated early and mid-term vascular responses to Co-Cr EESs in patients with stable coronary artery disease. METHODS: The Multicenter Comparison of Early and Late Vascular Responses to Everolimus-Eluting Cobalt-Chromium Stent and Platelet Aggregation Studies in Patients With Stable Angina Managed as Elective Case (MECHANISM-Elective) study (NCT02014818) is a multicenter optical coherence tomography (OCT) registry. Enrolled patients were evaluated by OCT immediately after everolimus-eluting stent implantation were prospectively allocated to 1 month (n = 50) or 3 months (n = 50) OCT follow-up and then received a 12-month OCT evaluation. The incidences of intrastent thrombus (IS-Th) and irregular protrusion (IRP) were also assessed. RESULTS: The percentage of uncovered struts was 6.4% ± 10.3% at 1 month (P < 0.001 vs. postprocedure) and 0.5% ± 0.9% at 12 months (P < 0.001 vs. 1 month). The corresponding values in the 3-month cohort were 2.0% ± 2.5% (P < 0.001 vs. postprocedure) and 0.5% ± 1.5% (P < 0.001 vs. 3 months). The incidence of IS-Th was 32.7% at 1 month, 5.4% at 3 months, and 2.0% at 12 months. IRP was observed in 21.8% of patients post-EES but had totally resolved at 1, 3, and 12 months. CONCLUSION: Early and mid-term vascular reactions after Co-Cr EES implantation in stable patients with coronary artery disease in the MECHANISM-Elective included dynamic resolution of IS-Th and IRP and rapid decrease in uncovered struts. Thus, EES may allow shortening of dual antiplatelet therapy duration less than 3 months in this patient subset.

Clinical and immune profiling for cancer of unknown primary site.

BACKGROUND: Immune checkpoint inhibitors (ICIs) confer a survival benefit in many cancer types. Given that the survival outcome for cancer of unknown primary site (CUP) remains poor, we investigated the potential of CUP for immunotherapy. METHODS: A total of 164 patients with CUP (favorable subset, 34 patients; unfavorable subset, 130 patients) who were treated between January 2009 and March 2017 was identified from a review of medical records at Kindai University Hospital. They included 92 patients for whom pretreatment tumor tissue was available both for determination of programmed cell death-ligand 1 expression and tumor-infiltrating lymphocyte (TIL) density by immunohistochemistry (IHC) and for immune-related gene expression profiling (irGEP). The results of irGEP for CUP were compared with published data for ICI-treated solid cancers classified into progressive disease (PD) and non-PD subsets according to their best response to ICIs. RESULTS: The median overall survival of all CUP patients was 29.3 months (95% confidence interval [CI], 15.7-not reached) and 7.1 months (95% CI, 5.0-9.4) for favorable and unfavorable subsets, respectively. IHC and irGEP revealed that pretreatment immune activity-including expression of immune checkpoint molecules-for CUP was similar to that for ICI-responsive malignancies (antitumor immune cell signatures: CUP versus PD, P = 0.002-0.067; CUP versus non-PD, P = 0.591-0.999), although VEGFA expression was associated with suppression of antitumor immunity in CUP (P = 0.008, false discovery rate = 0.010). In addition, one case of CUP in the unfavorable subset that was associated with prominent PD-L1 expression on TILs and showed a durable response to nivolumab is presented. CONCLUSIONS: The survival outcome of CUP remains unsatisfactory. However, our clinical and immune profiling of CUP has revealed a potential to benefit from immunotherapy, with ICIs thus being a potential option for CUP treatment.

Targeted next-generation sequencing of cancer-related genes in thyroid carcinoma: A single institution's experience.

Thyroid carcinoma (TC) has characteristic genetic alterations, including point mutations in proto-oncogenes and chromosomal rearrangements that vary by histologic subtype. Recent developments in next-generation sequencing (NGS) technology enable simultaneous analysis of cancer-associated genes of interest, thus improving diagnostic accuracy and allowing precise personalized treatment for human cancer. A total of 50 patients who underwent thyroidectomy between 2014 and 2016 at Hokuto Hospital were enrolled. Total DNA was extracted from formalin-fixed, paraffin-embedded tissue sections and quantified. Targeted regions of 24 cancer-associated genes were amplified by PCR, barcoded and sequenced using an Illumina MiSeq platform. Subjects included 30 patients with papillary carcinoma (PC), two with PC tall cell variant (TVPC), two with PC follicular variant (FVPC), eight with follicular carcinoma, seven with poorly differentiated carcinoma (PDC), and one with anaplastic carcinoma (AC). The BRAF V600E mutation was present in 25 of 30 (83%) patients with PC, 2 of 2 (100%) patients with TVPC, 6 of 7 (86%) patients of PDC, and one patient with AC. PIK3CA mutations were present in 3 of 30 (delPV104P, A1046T and C420R; 10%) patients with PC and 1 of 7 (H1047R; 14%) patients with PDC. The TP53 mutation was present in 1 of 30 (R306*; 3.3%) patients with PC and 1 of 7 (Q152*; 14%) patients with PDC. The NRAS mutation was present in 1 of 2 (Q61K, 50%) patients with FVPC. Statistical analysis showed that patients without the BRAF V600E mutation had advanced pathologic T and N stages compared with those with the mutation (P=0.047 and P=0.019, respectively). The BRAF V600E mutation was not correlated with overall and disease-free survival in patients with PC. A patient with PC with a mutation in EGFR (K852Q) and the PIK3CA mutation had an aggressive course with multiple bone and lung metastases. Detection of mutations in cancer-associated genes using NGS could enhance the understanding of the clinical behavior of TC.

[Primary Lung Cancer Initially Suspected of Pulmonary Extranodal Marginal Zone Lymphoma of Mucosa Associated Lymphoid Tissue(MALT)].

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is associated with pre-existing infections or autoimmune disorders. We report a case of lung cancer initially suspected of MALT lymphoma. The patient was a 73-year-old woman. Complete screening examinations identified a tumor in the right middle lobe. Transbronchial lung biopsy revealed the infiltration of CD20+/CD79a+ lymphocytes invading the structure of the alveolus. MALT lymphoma was suspected, and the middle lobe was resected. The tumor was primarily invasive mucinous carcinoma, and lymphocytic infiltration was observed around the tumor. The monoclonal expansion of B cells and genetic and chromosomal abnormalities which are criteria for the diagnosis of MALT lymphoma were not demonstrated and the lesion was diagnosed as reactive lymphoid infiltrates. Marked lymphocytic infiltration regardless of neoplastic or reactive may suggest the presence of latent lesions.

Monocyte chemoattractant protein 1 expression and proliferation in primary central nervous system lymphoma.

Whether the poor prognosis of primary central nervous system lymphoma (PCNSL) compared with systemic diffuse large B cell lymphoma (DLBCL) is attributable to the immune privilege of the intracerebral location or to intrinsic differences in the biological characteristics of two types of lymphoma remains unclear. Monocyte chemoattractant protein 1 (MCP-1) is essential to support tumor cell survival and growth, and the present study aimed to compare MCP-1 expression in PCNSL and peripheral DLBCL. The present study included 19 patients with PCNSL and 16 patients with DLBCL, all of whom had tissue diagnosis and lymphoma tissue samples available for analysis. Histology included immunohistochemistry using antibodies against a panel of lymphoma markers, antibodies specific to MCP-1, and antibodies specific to tumor-associated macrophages. MCP-1 expression was quantified using immunostaining scoring. RNA extraction and reverse transcription-quantitative polymerase chain reaction were used to determine MCP-1 mRNA expression. In addition, a human brain-derived lymphoma cell line, HKBML, was stimulated with MCP-1 and cell proliferation was measured by 5-bromo-2'-deoxyuridine incorporation. The expression levels of MCP-1 mRNA and MCP-1 protein were significantly increased in PCNSL compared with peripheral DLBCL. MCP-1 induced tyrosine phosphorylation of mitogen-activated protein kinase in HKBML cells, as analyzed by western blotting. The results of the present study indicated that MCP-1 expression in PCNSL promoted cell proliferation in an autocrine manner.

[Benign Metastasizing Leiomyoma of the Lung;Report of a Case].

A 71-year-old woman, in whom computed tomography revealed a solitary mass shadow at the base of the left lung, underwent resection of the mass. Histopathological examination showed estrogen receptor-positive leiomyoma cells growing in cords and mixed with glandular structures composed of alveolar cells. These findings led to a diagnosis of benign metastatic leiomyoma. Benign metastatic leiomyoma is a rare disease in which histologically benign uterine leiomyoma cells metastasize to different sites of the body. However, in this patient, the presence of uterine myoma was not confirmed in the past or at present. She had a history of cervical conization, which suggests that a small amount of the leiomyoma component contained in cervical tissue may have been forced into blood vessels during surgical manipulation, causing lung metastasis.

EphA4-deleted microenvironment regulates cancer development and leukemoid reaction of the isografted 4T1 murine breast cancer via reduction of an IGF1 signal.

UNLABELLED: EphA4 belongs to the largest family of receptor tyrosine kinases (RTKs). Although EphA4 is highly expressed in the central nervous system, EphA4 has also been implicated in cancer progression. Most of the studies focus on the expression and function in tumor cells. It is unknown whether EphA4-deleted microenvironment affects tumor progression. Some of cancers in animals and humans, such as 4T1 cancer cells, are known to produce a large amount of granulocyte colony-stimulating factors (G-CSF/Csf3) which can stimulate myeloproliferation, such as myeloid-derived suppressor cells (MDSCs) leading to a poor recipient prognosis. We isografted 4T1 breast cancer cells into both EphA4-knockout and control wild-type female littermate mice. The results showed that the EphA4-deleted host could inhibit primary tumor growth and tumor metastasis mainly by decreasing the amount of IGF1 synthesis in the circulation and locally tissues. The EphA4-deleted microenvironment and delayed tumor development reduced the production of G-CSF resulting in the decrease of splenomegaly and leukemoid reaction including MDSCs, which in turn inhibit the tumor progression. This inhibition can be reversed by supplying the mice with IGF1. However, an excess of IGF1 supply over demand to the control mice could not further accelerate the tumor growth and metastasis. A better understanding and re-evaluation of the main role of IGF1 in regulating tumor progression could further enhance our cognition of the tumor development niche. Our findings demonstrated that EphA4-deleted microenvironment impairs tumor-supporting conditions. CONCLUSION: Host EphA4 expression regulates cancer development mainly via EphA4-mediated IGF1 synthesis signal. Thus, targeting this signaling pathway may provide a potential therapeutic option for cancer treatment.

[Association Between the pH and Clinicopathological Characteristics of Lung Cancer Tissue].

Recent studies have shown that cancer cells surviving in a microenvironment characterized by hypoxia, low pH, and low glucose level have an ability to adapt to the adverse conditions. We measured the pH in the central tumor area of primary lung cancer, and evaluated its association with clinicopathological factors. There was a negative correlation between the tumor size and pH;with an increase in the tumor size, the pH decreased. Cancer cells grow at a markedly low pH compared with the physiological environment. There is a possibility that this low pH is a microenvironment that is appropriate rather than adverse for the growth and development of cancer cells.

Adult classical glioblastoma with a BRAF V600E mutation.

The B-Raf proto-oncogene serine/threonine kinase (B-Raf) is a member of the Raf kinase family. The BRAF V600E mutation occurs frequently in certain brain tumors such as pleomorphic xanthoastrocytoma, ganglioglioma, and pilocytic astrocytoma, and less frequently in epithelioid and giant cell glioblastoma. BRAF V600E mutation in these cases has been canonically detected using Sanger sequencing or immunohistochemistry but not with next-generation sequencing (NGS). Moreover, to our knowledge, there is no detailed report of the BRAF V600E mutation in an adult glioblastoma with classical histologic features (c-GBM). Therefore, we performed NGS analysis to determine the mutational status of BRAF of 13 glioblastomas (GBMs) (11 primary and 2 secondary cases) and detected one tumor harboring the BRAF V600E mutation. We report here the detection of the BRAF V600E mutation in a patient with c-GBM and describe the patient's clinical course as well as the results of histopathological analysis.