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Background: Ependymomas, rare glial brain tumors, account for <5% of all brain tumors. Interestingly, over 60% of ependymomas occur in the spinal cord of adults, including those originating from the filum terminale, while the rest are found within the brain. The World Health Organization (WHO) categorizes ependymomas into three grades: subependymomas and myxopapillary ependymomas ([MEPNs]; WHO grade I), classic ependymomas (WHO grade II), and anaplastic ependymomas (WHO grade III). Spinal ependymomas generally exhibit a more favorable prognosis compared to their intracranial counterparts and are primarily treated through gross total resection, which is considered the most effective surgical approach. As such, they are recognized as a distinct clinical entity that demands tailored management strategies. MEPNs, which constitute 13% of ependymomas, typically occur in the cauda equina and sometimes extend into the conus medullaris. Most other spinal ependymomas are of the classic type and predominantly arise in the cervical and thoracic regions of the spine. The mean age at diagnosis is 45 years of age. While prognosis varies based on molecular subtypes, complete resection is associated with improved survival., Case Description: Here, we demonstrate the technical nuances to safely achieve gross total resection of a giant spinal ependymoma in a 29-year-old female with a medical history notable for sept-optic dysplasia, and panhypopituitarism. The patient presented with progressive neck pain, upper and lower extremity weakness, and numbness for 1 year. On physical examination, she demonstrated mild weakness in her left arm. The preoperative magnetic resonance imaging revealed a cervicothoracic intramedullary mass extending from C4 to T2 with an associated syrinx at C4. Under intraoperative neural monitoring (somatosensory evoked potentials, motor-evoked potentials, and epidural direct wave recordings), the patient underwent a C4 - T2 laminectomy. In addition, spinal ultrasonography helped differentiate solid tumor mass from syrinx formation, thus guiding the focus and extent of the decompression ., Conclusion: Gross total resection was achieved; at 18 postoperative months, the patient had mild residual motor deficit. The pathological evaluation revealed a WHO grade II ependymoma. Subsequent sequential enhanced MR studies at 3, 6, and 12 months confirmed no tumor recurrence., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Surgical Neurology International.)

Objective: Clear cell meningiomas (CCM) are an uncommon meningioma subtype marked by aggressive growth and high rates of recurrence despite initial resection. The present study evaluates the adjuvant benefit of stereotactic radiosurgery (SRS) for residual or recurrent tumors., Methods: After review of our prospectively maintained database, we identified 6 patients (3 female) with histologically confirmed Grade 2 CCMs. The median age of the patients at the time of SRS was 45 years. Five patients had undergone prior gross total surgical resection and 1 patient had subtotal resection before SRS. The median SRS treatment volume was 4.7 cc and the median radiosurgical margin dose was 13 Gy (range: 10-15 Gy)., Results: The median follow-up time was 35.5 months (range 6-168 months). Three patients achieved tumor control after the first SRS procedure. Three patients experienced tumor progression at 4, 22, and 32 months after initial SRS. Tumor control was obtained in 2 of these patients after additional SRS. One patient with multiple SRS procedures had suspected adverse radiation effect that was successfully treated with corticosteroids followed by bevacizumab., Conclusions: Tumor control was maintained in 5 of 6 patients after one or more SRS procedures. SRS should be considered for early intervention after surgical resection of CCM. To maximize the tumor control rate, patients with diagnosed CCM should be treated more generously and higher margin dose should be prescribed. Patients with CCM should be counselled that more than one SRS may be necessary to provide sustained tumor control., (Copyright © 2024. Published by Elsevier Inc.)

Although histology still plays a critical role in diagnosing diffuse gliomas, additional ancillary testing is an essential tool for VA pathology laboratories., Competing Interests: AUTHOR DISCLOSURES The authors report no actual or potential conflicts of interest with regard to this article.

Purpose: TMEM16A is a calcium-activated chloride channel that is amplified in a variety of cancers, including 30% of head and neck squamous cell carcinomas (HNSCCs), raising the possibility of an anti-apoptotic role in malignant cells. This study investigated this using a multimodal, translational investigation. Experimental Design: Combination of (i) in vitro HNSCC cell culture experiments assessing cell viability, apoptotic activation, and protein expression (ii) in vivo studies assessing similar outcomes, and (iii) molecular and staining analysis of human HNSCC samples. Results: TMEM16A expression was found to correlate with greater tumor size, increased Erk 1/2 activity, less Bim expression, and less apoptotic activity overall in human HNSCC. These findings were corroborated in subsequent in vitro and in vivo studies and expanded to include a cisplatin-resistant phenotype with TMEM16A overexpression. A cohort of 41 patients with laryngeal cancer demonstrated that cases that recurred after chemoradiation failure were associated with a greater TMEM16A overexpression rate than HNSCC that did not recur. Conclusions: Ultimately, this study implicates TMEM16A as a contributor to tumor progression by limiting apoptosis and as a potential biomarker of more aggressive disease. Clin Cancer Res; 23(23); 7324-32. ©2017 AACR ., (©2017 American Association for Cancer Research.)

ANO1 is a calcium-activated chloride channel that is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and other cancers. While ANO1 expression negatively correlates with survival in several cancers, its epigenetic regulation is poorly understood. We analyzed HNSCC samples from TCGA and a separate dataset of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) samples to identify differentially methylated regions. E6 and E7 transfected normal oral keratinocytes (NOK) were used to induce hypermethylation of the ANO1 promoter. We found three CpG islands that correlated with ANO1 expression, including two positively correlated with expression. Using two HNSCC datasets with differential expression of ANO1, we showed hypermethylation of positively correlated CpG islands potentiates ANO1 expression. E7 but not E6 transfection of NOK cells led to hypermethylation of a positively correlated CpG island without a change in ANO1 expression. ANO1 promoter methylation was also correlated with patient survival. Our results are the first to show the contribution of positively correlated CpG's for regulating gene expression in HNSCC. Hypermethylation of the ANO1 promoter was strongly correlated with but not sufficient to increase ANO1 expression, suggesting methylation of positively correlated CpG's likely serves as an adjunct to other mechanisms of ANO1 activation.

Introduction: We examined mutational testing of the epidermal growth factor gene (EGFR) and erlotinib treatment among veterans diagnosed with non-small-cell lung cancer in the United States Department of Veterans Affairs (VA). Our objectives were to identify the prevalence of clinically actionable EGFR mutations, to determine whether testing and treatment were guideline concordant, to evaluate the impact of testing and treatment on survival, and to estimate the rate of testing., Patients and Methods: Test results were linked to electronic health records from VA Corporate Data Warehouse and the VA Central Cancer Registry. We analyzed patient demographic and clinical characteristics, prevalence of EGFR mutations, and timing of EGFR mutational testing and erlotinib treatment based on pharmacy records. Overall survival was assessed by Kaplan-Meier analysis., Results: Among 973 patients tested at 70 VA medical centers between 2011 and 2013, 64 (7%) had sensitizing EGFR mutations, 694 (71%) were EGFR wild type, and 168 (17%) had clinically insignificant polymorphisms or variants of unknown significance. Results were not documented in 47 tests (5%). Erlotinib administration was in agreement with test results in 843 cases (87%)., Conclusion: Veterans have a much lower rate of sensitizing EGFR mutations than the reported average of 10% to 15%, which correlates with a high rate of smoking among veterans. This may partially explain clinicians' reluctance to prescribe EGFR testing, which results in underutilization. Although test results appear to have influenced erlotinib treatment decisions, we documented a substantial number of cases where treatment was not applied in accordance with clinical guidelines, potentially resulting in worse outcomes and unnecessary cost., (Published by Elsevier Inc.)

Background: Infection with human immunodeficiency virus (HIV) influences the outcome and natural disease progression of hepatitis C virus (HCV) infection. While the majority of HCV mono-infected and HCV/HIV co-infected subjects develop chronic HCV infection, 20-46% of mono- and co-infected subjects spontaneously clear HCV infection. The mechanism underlying viral clearance is not clearly understood. Analysis of differential cellular gene expression (mRNA) between HIV-infected patients with persistent HCV infection or spontaneous clearance could provide a unique opportunity to decipher the mechanism of HCV clearance., Methods: Plasma RNA from HIV/HCV co-infected subjects who cleared HCV and those who remained chronically infected with HCV was sequenced using Ion Torrent technology. The sequencing results were analyzed to identify transcripts that are associated with HCV clearance by measuring differential gene expression in HIV/HCV co-infected subjects who cleared HCV and those who remained chronically infected with HCV., Results: We have identified plasma mRNA, the levels of which are significantly elevated (at least 5 fold, False Discovery Rate (FDR) <0.05) before HCV infection in subjects who cleared HCV compared to those who remained chronically infected. Upon further analysis of these differentially expressed genes, before and after HCV infection, we found that before HCV infection 12 genes were uniquely upregulated in the clearance group compared to the chronically infected group. Importantly, a number of these 12 genes and their upstream regulators (such as CCL3, IL17D, LBP, SOCS3, NFKBIL1, IRF) are associated with innate immune response functions., Conclusions: These results suggest that subjects who spontaneously clear HCV may express these unique genes associated with innate immune functions.

Head and neck squamous cell carcinoma (HNSCC) has a variety of causes. Recently, the human papilloma virus (HPV) has been implicated in the rising incidence of oropharyngeal cancer and has led to variety of studies exploring the differences between HPV-positive and HPV-negative HNSCC. The calcium-activated chloride channel TMEM16A is overexpressed in a variety of cancers, including HNSCC, but whether or not it plays different roles in HPV-positive and HPV-negative HNSCC is unknown. Here, we demonstrate that TMEM16A is preferentially overexpressed in HPV-negative HNSCC and that this overexpression of TMEM16A is associated with decreased patient survival. We also show that TMEM16A expression is decreased in HPV-positive HNSCC at the DNA, RNA, and protein levels in patient samples as well as cell lines. We demonstrate that the lower levels of TMEM16A expression in HPV-positive tumors can be attributed to both a combination of copy number alteration and promoter methylation at the DNA level. Additionally, our cellular data show that HPV-negative cell lines are more dependent on TMEM16A for survival than HPV-positive cell lines. Therefore, we suspect that the down-regulation of TMEM16A in HPV-positive HNSCC makes TMEM16A a poor therapeutic target in HPV-positive HNSCC, but a potentially useful target in HPV-negative HNSCC.

The antioxidant enzyme extracellular superoxide dismutase (EC-SOD) is highly expressed in the extracellular matrix of lung tissue and is believed to protect the lung from oxidative damage that results in diseases such as pulmonary fibrosis. This study tests the hypothesis that proteolytic removal of the heparin-binding domain of EC-SOD results in clearance of the enzyme from the extracellular matrix of pulmonary tissues and leads to a loss of antioxidant protection. Using a polyclonal antibody to mouse EC-SOD, the immunodistribution of EC-SOD in normal and bleomycin-injured lungs was examined. EC-SOD labeling was strong in the matrix of vessels, airways, and alveolar surfaces and septa in control lungs. At 2 d post-treatment, a slight increase in EC-SOD staining was evident. In contrast, lungs examined 4 or 7 d post-treatment, showed an apparent loss of EC-SOD from the matrix and surface of alveolar septa. Notably, at 7 d post-treatment, the truncated form of EC-SOD was found in the bronchoalveolar lavage fluid of bleomycin-treated mice, suggesting that EC-SOD is being removed from the extracellular matrix through proteolysis. However, loss of EC-SOD through proteolysis did not correlate with a decrease in overall pulmonary EC-SOD activity. The negligible effect on EC-SOD activity may reflect the large influx of intensely staining inflammatory cells at day 7. These results indicate that injuries leading to pulmonary fibrosis have a significant effect on EC-SOD distribution due to proteolytic removal of the heparin-binding domain and may be important in enhancing pulmonary injuries by altering the oxidant/antioxidant balance in alveolar interstitial spaces.

Although the toxin 6-hydroxydopamine (6-OHDA) is utilized extensively in animal models of Parkinson's disease, the underlying mechanism of its toxic effects on dopaminergic neurons is not completely understood. We examined the effects of 6-OHDA on the CNS-derived tyrosine hydroxylase expressing B65 cell line, with particular attention to the regulation of the extracellular signal-regulated protein kinases (ERK). 6-OHDA elicited a dose-dependent cytotoxicity in B65 cells. Toxic doses of 6-OHDA also elicited a biphasic pattern of ERK phosphorylation with a prominent sustained phase, a pattern that differed from that observed with hydrogen peroxide (H(2)O(2)) treatment. 6-OHDA-elicited ERK phosphorylation was blocked by PD98059, an inhibitor of the upstream mitogen activated protein kinase kinase (MEK) that phosphorylates and activates ERK. PD98059 also conferred protection against 6-OHDA cytotoxicity, but did not affect H(2)O(2) toxicity in B65 cells. These results suggest that ERK activation plays a direct mechanistic role in 6-OHDA toxicity, rather than representing a protective compensatory response, and raise the possibility that abnormal patterns of ERK activation may contribute to dopaminergic neuronal cell death.

Exoenzyme S of Pseudomonas aeruginosa (ExoS) is a member of the family of bacterial ADP-ribosylating exotoxins (bAREs). Site-directed mutagenesis of glutamic acids within the catalytic domain of ExoS (termed delta N222) allowed the identification of the preferential inactivation of ADP-ribosyltransferase activity by alanine substitution of E381. The specific activity of E381A mutant was 0.02% of wild-type delta N222. Delta N222(E381A) retained the requirement of factor activating exoenzyme S (FAS) activation for the expression of ADP-ribosyltransferase activity. In contrast, E387A, E399A, and E414A mutants possessed ADP-ribosyltransferase activity similar to that of wild-type delta N222. Kinetic evaluation of E381A and two other mutants, E381D and E381S, showed that their primary defect was a lower kcat in the ADP-ribosylation of soybean trypsin inhibitor (SBTI). The Km for NAD and SBTI and activation by FAS varied 2- and 10-fold relative to delta N222. In addition, the E381 mutants possessed identical protease patterns during thrombin and trypsin digestion as delta N222, which indicated that E381 mutants had retained their overall conformation. Together, these data identify E381 as contributing to the catalytic activity of exoenzyme S.

We report the purification and proteolytic characterization of the 49-kDa form of exoenzyme S and the cloning of the structural gene for the 49-kDa form of exoenzyme S (exoS). The 49-kDa form of exoenzyme S was purified from SDS-polyacrylamide gels. Conditions were established that allowed efficient trypsin digestion of the 49-kDa form of exoenzyme S. Amino acid sequence determination of the amino terminus and tryptic peptides of the 49-kDa form of exoenzyme S allowed the generation of degenerate oligonucleotides, which were used to amplify DNA encoding an amino-terminal sequence and an internal sequence of the 49-kDa form of exoenzyme S. These DNA fragments were used to clone the entire structural gene for the 49-kDa form of exoenzyme S (exoS) from a cosmid library of Pseudomonas aeruginosa strain 388. The 49-kDa form of exoenzyme S (ExoS) is predicted to be a 453 amino acid protein. The predicted amino acid sequence indicates that ExoS is secreted from Pseudomonas without cleavage of an amino-terminal sequence. BESTFIT analysis identified three regions of alignment between ExoS and the active site of Escherichia coli heat-labile enterotoxin. One region of homology appears to be shared among several members of the family of bacterial ADP-ribosyltransferases.