The adipocyte microenvironment and cancer.

Many epithelial tumors grow in the vicinity of or metastasize to adipose tissue. As tumors develop, crosstalk between adipose tissue and cancer cells leads to changes in adipocyte function and paracrine signaling, promoting a microenvironment that supports tumor growth. Over the last decade, it became clear that tumor cells co-opt adipocytes in the tumor microenvironment, converting them into cancer-associated adipocytes (CAA). As adipocytes and cancer cells engage, a metabolic symbiosis ensues that is driven by bi-directional signaling. Many cancers (colon, breast, prostate, lung, ovarian cancer, and hematologic malignancies) stimulate lipolysis in adipocytes, followed by the uptake of fatty acids (FA) from the surrounding adipose tissue. The FA enters the cancer cell through specific fatty acid receptors and binding proteins (e.g., CD36, FATP1) and are used for membrane synthesis, energy metabolism (ß-oxidation), or lipid-derived cell signaling molecules (derivatives of arachidonic and linolenic acid). Therefore, blocking adipocyte-derived lipid uptake or lipid-associated metabolic pathways in cancer cells, either with a single agent or in combination with standard of care chemotherapy, might prove to be an effective strategy against cancers that grow in lipid-rich tumor microenvironments.

Imaging acute effects of bevacizumab on tumor vascular kinetics in a preclinical orthotopic model of U251 glioma.

The effect of a human vascular endothelial growth factor antibody on the vasculature of human tumor grown in rat brain was studied. Using dynamic contrast-enhanced magnetic resonance imaging, the effects of intravenous bevacizumab (Avastin; 10 mg/kg) were examined before and at postadministration times of 1, 2, 4, 8, 12 and 24 h (N = 26; 4-5 per time point) in a rat model of orthotopic, U251 glioblastoma (GBM). The commonly estimated vascular parameters for an MR contrast agent were: (i) plasma distribution volume (vp ), (ii) forward volumetric transfer constant (Ktrans ) and (iii) reverse transfer constant (kep ). In addition, extracellular distribution volume (VD ) was estimated in the tumor (VD-tumor ), tumor edge (VD-edge ) and the mostly normal tumor periphery (VD-peri ), along with tumor blood flow (TBF), peri-tumoral hydraulic conductivity (K) and interstitial flow (Flux) and tumor interstitial fluid pressure (TIFP). Studied as % changes from baseline, the 2-h post-treatment time point began showing significant decreases in vp , VD-tumor, VD-edge and VD-peri , as well as K, with these changes persisting at 4 and 8 h in vp , K, VD-tumor, -edge and -peri (t-tests; p < 0.05-0.01). Decreases in Ktrans were observed at the 2- and 4-h time points (p < 0.05), while interstitial volume fraction (ve ; = Ktrans /kep ) showed a significant decrease only at the 2-h time point (p < 0.05). Sustained decreases in Flux were observed from 2 to 24 h (p < 0.01) while TBF and TIFP showed delayed responses, increases in the former at 12 and 24 h and a decrease in the latter only at 12 h. These imaging biomarkers of tumor vascular kinetics describe the short-term temporal changes in physical spaces and fluid flows in a model of GBM after Avastin administration.

Lysophosphatidic acid induces tumor necrosis factor-alpha to regulate a pro-inflammatory cytokine network in ovarian cancer.

Epithelial ovarian carcinoma tissues express high levels of tumor necrosis factor-alpha (TNF-α) and other inflammatory cytokines. The underlying mechanism leading to the abnormal TNF-α expression in ovarian cancer remains poorly understood. In the current study, we demonstrated that lysophosphatidic acid (LPA), a lipid mediator present in ascites of ovarian cancer patients, induced expression of TNF-α mRNA and release of TNF-α protein in ovarian cancer cells. LPA also induced expression of interleukin-1ß (IL-1ß) mRNA but no significant increase in IL-1ß protein was detected. LPA enhanced TNF-α mRNA through NF-κB-mediated transcriptional activation. Inactivation of ADAM17, a disintegrin and metalloproteinase, with a specific inhibitor TMI-1 or by shRNA knockdown prevented ovarian cancer cells from releasing TNF-α protein in response to LPA, indicating that LPA-mediated TNF-α production relies on both transcriptional upregulations of the TNF-α gene and the activity of ADAM17, the membrane-associated TNF-α-converting enzyme. Like many other biological responses to LPA, induction of TNF-α by LPA also depended on the transactivation of the epidermal growth factor receptor (EGFR). Interestingly, our results revealed that ADAM17 was also the shedding protease responsible for the transactivation of EGFR by LPA in ovarian cancer cells. To explore the biological outcomes of LPA-induced TNF-α, we examined the effects of a TNF-α neutralizing antibody and recombinant TNF-α soluble receptor on LPA-stimulated expression of pro-tumorigenic cytokines and chemokines overexpressed in ovarian cancer. Blockade of TNF-α signaling significantly reduced the production of IL-8, IL-6, and CXCL1, suggesting a hierarchy of mechanisms contributing to the robust expression of the inflammatory mediators in response to LPA in ovarian cancer cells. In contrast, TNF-α inhibition did not affect LPA-dependent cell proliferation. Taken together, our results establish that the bioactive lipid LPA drives the expression of TNF-α to regulate an inflammatory network in ovarian cancer.

Unusual Case of Progressive Multifocal Leukoencephalopathy in a Patient With Sjögren Syndrome.

ABSTRACT: Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating disease caused by reactivation of John Cunningham virus affecting typically subcortical and periventricular white matter of immunocompromised hosts (human immunodeficiency virus infection, hematologic malignancies). Cerebral hemispheric white matter is most commonly affected by lytic infections, leading to progressive damage to oligodendrocytes in the central nervous system. Neuroimaging usually highlights scattered foci of white matter hypodensity not attributable to contrast enhancement or mass effect. In contrast, we present an unusual case of PML predominantly affecting cervical spinal cord and brainstem in an immunocompetent host. This is a rare subset of PML case that can occur in association with connective tissue disorders (Sjögren Syndrome in this case), systemic lupus erythematosus being the most common. Progressive multifocal leukoencephalopathy should be considered in the differential diagnosis of spinal cord or brainstem lesions, particularly in the patients with connective tissue disorders.

Multi-tasking Sulf1/Sulf2 enzymes do not only facilitate extracellular cell signalling but also participate in cell cycle related nuclear events.

This study demonstrates highly dynamic spatial and temporal pattern of SULF1/SULF2 expression in a number of neuronal cell types growing in normal culture medium that included their transient nuclear mobilisation. Their nuclear translocation became particularly apparent during cell proliferation as both SULF1/SULF2 demonstrated not only cell membrane associated expression, their known site of function but also transient nuclear mobilisation during nuclear cell division. Nuclear localisation was apparent not only by immunocytochemical staining but also confirmed by immunoblotting staining of isolated nuclear fractions of C6, U87 and N2A cells. Immunocytochemical analysis demonstrated rapid nuclear exit of both SULF1/SULF2 following cell division that was slightly delayed but not blocked in a fraction of the polyploid cells observed in C6 cells. The overexpression of both Sulf1 and Sulf2 genes in C6 and U87 cells markedly promoted in vitro growth of these cells accompanied by nuclear mobilisation while inhibition of both these genes inhibited cell proliferation with little or no nuclear SULF1/SULF2 mobilisation. SULF1/SULF2 activity in these cells thus demonstrated a clear co-ordination of extracellular cell signalling with nuclear events related to cell proliferation.

Metformin inhibits ovarian cancer growth and increases sensitivity to paclitaxel in mouse models.

OBJECTIVE: There is increasing preclinical evidence indicating that metformin, a medication commonly used for type 2 diabetes mellitus, may protect against cancer. Motivated by this emerging evidence we asked 2 questions: (1) can metformin prevent ovarian cancer growth by altering metabolism and (2) will metformin increase sensitivity to chemotherapy. STUDY DESIGN: The effect of metformin in ovarian cancer was tested in vitro and with 2 different mouse models. In vitro, cell lines (n = 6) were treated with metformin (10-40 mmol/L) or phosphate-buffered saline solution and cellular proliferation and metabolic alterations (adenosine monophosphate-activated protein kinase activity, glycolysis, and lipid synthesis) were compared between the 2 groups. In mouse models, a prevention study was performed by treating mice with metformin (250 mg/kg/d intraperitoneally) or placebo for 2 weeks followed by intraperitoneal injection of the SKOV3ip1 human ovarian cancer cell line, and the mean number of tumor implants in each treatment group was compared. In a treatment study, the LSL-K-ras(G12D/+)/PTEN(floxP/floxP) genetic mouse model of ovarian cancer was used. Mice were treated with placebo, paclitaxel (3 mg/kg/wk intraperitoneally for 7 weeks), metformin (100 mg/kg/d in water for 7 weeks), or paclitaxel plus metformin, and tumor volume was compared among treatment groups. RESULTS: In vitro, metformin decreased proliferation of ovarian cancer cell lines and induced cell cycle arrest, but not apoptosis. Further analysis showed that metformin altered several aspects of metabolism including adenosine monophosphate-activated protein kinase activity, glycolysis, and lipid synthesis. In the prevention mouse model, mice that were pretreated with metformin had 60% fewer tumor implants compared with controls (P < .005). In the treatment study, mice that were treated with paclitaxel plus metformin had a 60% reduction in tumor weight compared with controls (P = .02), which is a level of tumor reduction greater than that resulting from either paclitaxel or metformin alone. CONCLUSION: Based on these results, we conclude that metformin alters metabolism in ovarian cancer cells, prevents tumor growth, and increases sensitivity to chemotherapy in vitro and in mouse models. These preclinical findings suggest that metformin warrants further investigation for use as an ovarian cancer therapeutic.

Homologous and heterologous desensitization of guanylyl cyclase-B signaling in GH3 somatolactotropes.

The guanylyl cyclases, GC-A and GC-B, are selective receptors for atrial and C-type natriuretic peptides (ANP and CNP, respectively). In the anterior pituitary, CNP and GC-B are major regulators of cGMP production in gonadotropes and yet mouse models of disrupted CNP and GC-B indicate a potential role in growth hormone secretion. In the current study, we investigate the molecular and pharmacological properties of the CNP/GC-B system in somatotrope lineage cells. Primary rat pituitary and GH3 somatolactotropes expressed functional GC-A and GC-B receptors that had similar EC50 properties in terms of cGMP production. Interestingly, GC-B signaling underwent rapid homologous desensitization in a protein phosphatase 2A (PP2A)-dependent manner. Chronic exposure to either CNP or ANP caused a significant down-regulation of both GC-A- and GC-B-dependent cGMP accumulation in a ligand-specific manner. However, this down-regulation was not accompanied by alterations in the sub-cellular localization of these receptors. Heterologous desensitization of GC-B signaling occurred in GH3 cells following exposure to either sphingosine-1-phosphate or thyrotrophin-releasing hormone (TRH). This heterologous desensitization was protein kinase C (PKC)-dependent, as pre-treatment with GF109203X prevented the effect of TRH on CNP/GC-B signaling. Collectively, these data indicate common and distinct properties of particulate guanylyl cyclase receptors in somatotropes and reveal that independent mechanisms of homologous and heterologous desensitization occur involving either PP2A or PKC. Guanylyl cyclase receptors thus represent potential novel therapeutic targets for treating growth-hormone-associated disorders.

Osimertinib-Induced Myositis in a Patient With Metastatic Non-small Cell Lung Cancer With Epidermal Growth Factor Receptor Mutation.

Osimertinib is a third-generation tyrosine kinase inhibitor (TKI) that has emerged as a standard treatment in non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation. While it is generally well tolerated, milder side effects of diarrhea, cytopenia, and cutaneous rashes are common. Osimertinib-induced myositis and rhabdomyolysis are exceedingly rare, and only a few cases have been documented in the literature to date. In this report, we present a case of a 59-year-old female with metastatic NSCLC who experienced myalgia following the initiation of osimertinib. Blood work revealed elevated creatine kinase (CK), serum creatinine (Cr), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Initially, her myalgia improved, and lab work normalized after drug discontinuation and supportive care. However, rechallenge with a 50% dose resulted in recurrence of symptoms and elevated serum CK, Cr, ALT, and AST. MRI findings suggested diffuse inflammation and a muscle biopsy revealed necrotizing myopathy. Symptoms ameliorated upon complete cessation of the drug and use of steroids. This case highlights the importance of recognizing this rare adverse effect of osimertinib and a guide for managing these associated symptoms.

Lysophosphatidic acid activates lipogenic pathways and de novo lipid synthesis in ovarian cancer cells.

One of the most common molecular changes in cancer is the increased endogenous lipid synthesis, mediated primarily by overexpression and/or hyperactivity of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC). The changes in these key lipogenic enzymes are critical for the development and maintenance of the malignant phenotype. Previous efforts to control oncogenic lipogenesis have been focused on pharmacological inhibitors of FAS and ACC. Although they show anti-tumor effects in culture and in mouse models, these inhibitors are nonselective blockers of lipid synthesis in both normal and cancer cells. To target lipid anabolism in tumor cells specifically, it is important to identify the mechanism governing hyperactive lipogenesis in malignant cells. In this study, we demonstrate that lysophosphatidic acid (LPA), a growth factor-like mediator present at high levels in ascites of ovarian cancer patients, regulates the sterol regulatory element binding protein-FAS and AMP-activated protein kinase-ACC pathways in ovarian cancer cells but not in normal or immortalized ovarian epithelial cells. Activation of these lipogenic pathways is linked to increased de novo lipid synthesis. The pro-lipogenic action of LPA is mediated through LPA(2), an LPA receptor subtype overexpressed in ovarian cancer and other malignancies. Downstream of LPA(2), the G(12/13) and G(q) signaling cascades mediate LPA-dependent sterol regulatory element-binding protein activation and AMP-activated protein kinase inhibition, respectively. Moreover, inhibition of de novo lipid synthesis dramatically attenuated LPA-induced cell proliferation. These results demonstrate that LPA signaling is causally linked to the hyperactive lipogenesis in ovarian cancer cells, which can be exploited for development of new anti-cancer therapies.

Adipocytes reprogram cancer cell metabolism by diverting glucose towards glycerol-3-phosphate thereby promoting metastasis.

In the tumor microenvironment, adipocytes function as an alternate fuel source for cancer cells. However, whether adipocytes influence macromolecular biosynthesis in cancer cells is unknown. Here we systematically characterized the bidirectional interaction between primary human adipocytes and ovarian cancer (OvCa) cells using multi-platform metabolomics, imaging mass spectrometry, isotope tracing and gene expression analysis. We report that, in OvCa cells co-cultured with adipocytes and in metastatic tumors, a part of the glucose from glycolysis is utilized for the biosynthesis of glycerol-3-phosphate (G3P). Normoxic HIF1α protein regulates the altered flow of glucose-derived carbons in cancer cells, resulting in increased glycerophospholipids and triacylglycerol synthesis. The knockdown of HIF1α or G3P acyltransferase 3 (a regulatory enzyme of glycerophospholipid synthesis) reduced metastasis in xenograft models of OvCa. In summary, we show that, in an adipose-rich tumor microenvironment, cancer cells generate G3P as a precursor for critical membrane and signaling components, thereby promoting metastasis. Targeting biosynthetic processes specific to adipose-rich tumor microenvironments might be an effective strategy against metastasis.

Detection of diagnostic and prognostic methylation-based signatures in liquid biopsy specimens from patients with meningiomas.

Recurrence of meningiomas is unpredictable by current invasive methods based on surgically removed specimens. Identification of patients likely to recur using noninvasive approaches could inform treatment strategy, whether intervention or monitoring. In this study, we analyze the DNA methylation levels in blood (serum and plasma) and tissue samples from 155 meningioma patients, compared to other central nervous system tumor and non-tumor entities. We discover DNA methylation markers unique to meningiomas and use artificial intelligence to create accurate and universal models for identifying and predicting meningioma recurrence, using either blood or tissue samples. Here we show that liquid biopsy is a potential noninvasive and reliable tool for diagnosing and predicting outcomes in meningioma patients. This approach can improve personalized management strategies for these patients.

Synexpression group analyses identify new functions of FSTL3, a TGFß ligand inhibitor.

Follistatin-like 3 (FSTL3) is a secreted glycoprotein that forms inactive complexes with and acts as an endogenous inhibitor of TGFß ligands such as activin, myostatin and GDF11. FSTL3 gene deleted mice (FSTL3 KO) are viable, fertile and show a constellation of metabolic abnormalities, including those involving glucose and lipid homoeostasis, suggesting a role for FSTL3 and TGFß ligand signaling in these systems. To identify additional roles of FSTL3 and the ligands it inhibits we have used a synexpression analysis strategy. By mining microarray RNA expression data we have identified a group of 9 genes, the expression of which closely follow that of FSTL3 in both mouse and human tissues. After classifying the tissues studied according to physiological systems we found that within each system the expression of a majority, but not all, of the genes are strongly correlated with FSTL3 expression. Further, the best correlation of expression was seen in the cardiovascular system. Importantly, the promoter regions of a number of these synexpression genes have putative SMAD binding elements and in cultured embryonic fibroblasts the expression of a subset of these genes are induced in the absence of FSTL3 or in WT cells upon activin treatment. Taken together, we have identified a group of activin responsive genes the expression of which is closely related to and regulated by FSTL3. These findings link FSTL3 and TGFß ligand signaling and a novel subset of the synexpression group of genes to organ/tissue-specific regulatory pathways.

Health information seeking in the information society.

This article is the second student contribution to the Dissertations into Practice feature. It reports on a study that investigated the everyday health information-seeking practices of a small group of the 'general public' and the implications for information-seeking theory and health information provision. The first student article, about the implementation of radio frequency identification (RFID) in a hospital library, was very different, and the two articles illustrate the broad spectrum of possible subjects for the Dissertations into Practice feature. This study was conducted in summer 2011 by Abir Mukherjee for his MSc dissertation in the Library and Information Sciences programme at City University London. Further information and copies of the full dissertation may be obtained from Abir Mukherjee or David Bawden. AM.

Isolation of Primary Normal and Cancer-Associated Adipocytes from the Omentum.

The omentum is the metastatic site for intra-abdominal cancers such as colon, stomach, and ovarian (where it is the primary site for metastasis). Adipocytes are the primary cell type of the omentum, and they aid in cancer cell proliferation, migration, and invasion. Therefore, systematic characterization of adipocyte-cancer cell interactions will help in understanding the metastatic spread of intra-abdominal cancer. Here, a detailed mechanical-enzymatic digestion method describes the isolation of both normal and cancer-associated adipocyte from omental tissues.

The Hospital Frailty Risk Score (HFRS) applied to primary data: protocol for a systematic review.

INTRODUCTION: Frailty is characterised by vulnerability to adverse health outcomes and increases with age. Many frailty risk scores have been developed. One important example is the Hospital Frailty Risk Score (HFRS) which has the potential to be widely used and automatically calculated which will provide accurate assessment of frailty in a time/cost-effective manner. This systematic review, therefore, seeks to describe the HFRS use since its publication in 2018. METHODS AND ANALYSIS: The proposed systematic review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We will include published original peer-reviewed articles, preprints, conference proceedings and letters to the editor reporting primary data where there is an English language abstract available from 1 January 2018 to 30 June 2022. Databases to be searched are MEDLINE, EMBASE and Web of Science. Additional studies from, for example, the reference of the included studies will be identified and assessed for potential inclusion. Two independent reviewers will perform and assess the following: (1) eligibility of the included studies, (2) critical appraisal using the Cochrane Risk of Bias in Non-randomized Studies of Interventions tool, and (3) data extraction using a predefined form. Disagreements will be resolved through discussions or by involvement of a third reviewer. It may be possible to undertake a meta-analysis if there are sufficient studies reporting effect measures in homogenous populations and/or settings. Effect sizes will be calculated using meta-analysis methods and expressed as risk ratios or ORs with 95% CIs. ETHICS AND DISSEMINATION: No ethical approval is required for this systematic review as it will use secondary data only. The results of the systematic review will be submitted for publication in recognised peer-reviewed journals related to frailty and geriatric care and will be widely disseminated through conferences, congresses, seminars, symposia and scientific meetings.

Detection of tumor-specific DNA methylation markers in the blood of patients with pituitary neuroendocrine tumors.

BACKGROUND: DNA methylation abnormalities are pervasive in pituitary neuroendocrine tumors (PitNETs). The feasibility to detect methylome alterations in circulating cell-free DNA (cfDNA) has been reported for several central nervous system (CNS) tumors but not across PitNETs. The aim of the study was to use the liquid biopsy (LB) approach to detect PitNET-specific methylation signatures to differentiate these tumors from other sellar diseases. METHODS: We profiled the cfDNA methylome (EPIC array) of 59 serum and 41 plasma LB specimens from patients with PitNETs and other CNS diseases (sellar tumors and other pituitary non-neoplastic diseases, lower-grade gliomas, and skull-base meningiomas) or nontumor conditions, grouped as non-PitNET. RESULTS: Our results indicated that despite quantitative and qualitative differences between serum and plasma cfDNA composition, both sources of LB showed that patients with PitNETs presented a distinct methylome landscape compared to non-PitNETs. In addition, LB methylomes captured epigenetic features reported in PitNET tissue and provided information about cell-type composition. Using LB-derived PitNETs-specific signatures as input to develop machine-learning predictive models, we generated scores that distinguished PitNETs from non-PitNETs conditions, including sellar tumor and non-neoplastic pituitary diseases, with accuracies above ~93% in independent cohort sets. CONCLUSIONS: Our results underpin the potential application of methylation-based LB profiling as a noninvasive approach to identify clinically relevant epigenetic markers to diagnose and potentially impact the prognostication and management of patients with PitNETs.

Statistical reliability of bone biopsy for the diagnosis of diabetic foot osteomyelitis.

Bone biopsy is often referred to as the reference standard for the diagnosis of diabetic foot osteomyelitis (OM), and it also serves as an important interventional tool with respect to diabetic foot infections and limb salvage. However, the phrase bone biopsy lacks a standardized definition, and the statistical reliability of the pathologic diagnosis has not been previously examined. The objective of the present study was to quantify the reliability of the histopathologic analysis of bone with respect to the diagnosis of diabetic foot OM. Four pathologists, kept unaware of the previous pathology reports and specific patient clinical characteristics, retrospectively reviewed 39 consecutive tissue specimens and were informed only that it was "a specimen of bone taken from a diabetic foot to evaluate for OM." As a primary outcome measure, the pathologists were asked to make 1 of 3 possible diagnoses: (1) no evidence of OM, (2) no definitive findings of OM, but cannot rule it out, or (3) findings consistent with OM. There was complete agreement among all 4 pathologists with respect to the primary diagnosis in 13 (33.33%) of the 39 specimens, with a corresponding kappa coefficient of 0.31. A situation of clinically significant disagreement, or in which at least 1 pathologist diagnosed "no evidence of OM," but at least 1 other pathologist diagnosed "findings consistent with OM," occurred in 16 (41.03%) of the specimens. These results indicate agreement below the level of a "reference standard" and emphasize the need for a more comprehensive diagnostic protocol for diabetic foot OM.

A muscle growth-promoting treatment based on the attenuation of activin/myostatin signalling results in long-term testicular abnormalities.

Activin/myostatin signalling acts to induce skeletal muscle atrophy in adult mammals by inhibiting protein synthesis as well as promoting protein and organelle turnover. Numerous strategies have been successfully developed to attenuate the signalling properties of these molecules, which result in augmenting muscle growth. However, these molecules, in particular activin, play major roles in tissue homeostasis in numerous organs of the mammalian body. We have recently shown that although the attenuation of activin/myostatin results in robust muscle growth, it also has a detrimental impact on the testis. Here, we aimed to discover the long-term consequences of a brief period of exposure to muscle growth-promoting molecules in the testis. We demonstrate that muscle hypertrophy promoted by a soluble activin type IIB ligand trap (sActRIIB) is a short-lived phenomenon. In stark contrast, short-term treatment with sActRIIB results in immediate impact on the testis, which persists after the sessions of the intervention. Gene array analysis identified an expansion in aberrant gene expression over time in the testis, initiated by a brief exposure to muscle growth-promoting molecules. The impact on the testis results in decreased organ size as well as quantitative and qualitative impact on sperm. Finally, we have used a drug-repurposing strategy to exploit the gene expression data to identify a compound - N6-methyladenosine - that may protect the testis from the impact of the muscle growth-promoting regime. This work indicates the potential long-term harmful effects of strategies aimed at promoting muscle growth by attenuating activin/myostatin signalling. Furthermore, we have identified a molecule that could, in the future, be used to overcome the detrimental impact of sActRIIB treatment on the testis.

The impact of initial tumor microenvironment on imaging phenotype.

Models of human cancer, to be useful, must replicate human disease with high fidelity. Our focus in this study is rat xenograft brain tumors as a model of human embedded cerebral tumors. A distinguishing signature of such tumors in humans, that of contrast-enhancement on imaging, is often not present when the human cells grow in rodents, despite the xenografts having nearly identical DNA signatures to the original tumor specimen. Although contrast enhancement was uniformly evident in all the human tumors from which the xenografts' cells were derived, we show that long-term contrast enhancement in the model tumors may be determined conditionally by the tumor microenvironment at the time of cell implantation. We demonstrate this phenomenon in one of two patient-derived orthotopic xenograft (PDOX) models using cancer stem-like cell (CSC)-enriched neurospheres from human tumor resection specimens, transplanted to groups of immune-compromised rats in the presence or absence of a collagen/fibrin scaffolding matrix, Matrigel. The rats were imaged by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and their brains were examined by histopathology. Targeted proteomics of the PDOX tumor specimens grown from CSC implanted with and without Matrigel showed that while the levels of the majority of proteins and post-translational modifications were comparable between contrast-enhancing and non-enhancing tumors, phosphorylation of Fox038 showed a differential expression. The results suggest key proteins determine contrast enhancement and suggest a path toward the development of better animal models of human glioma. Future work is needed to elucidate fully the molecular determinants of contrast-enhancement.

A serum-based DNA methylation assay provides accurate detection of glioma.

BACKGROUND: The detection of somatic mutations in cell-free DNA (cfDNA) from liquid biopsy has emerged as a noninvasive tool to monitor the follow-up of cancer patients. However, the significance of cfDNA clinical utility remains uncertain in patients with brain tumors, primarily because of the limited sensitivity cfDNA has to detect real tumor-specific somatic mutations. This unresolved challenge has prevented accurate follow-up of glioma patients with noninvasive approaches. METHODS: Genome-wide DNA methylation profiling of tumor tissue and serum cfDNA of glioma patients. RESULTS: Here, we developed a noninvasive approach to profile the DNA methylation status in the serum of patients with gliomas and identified a cfDNA-derived methylation signature that is associated with the presence of gliomas and related immune features. By testing the signature in an independent discovery and validation cohorts, we developed and verified a score metric (the "glioma-epigenetic liquid biopsy score" or GeLB) that optimally distinguished patients with or without glioma (sensitivity: 100%, specificity: 97.78%). Furthermore, we found that changes in GeLB score reflected clinicopathological changes during surveillance (eg, progression, pseudoprogression, and response to standard or experimental treatment). CONCLUSIONS: Our results suggest that the GeLB score can be used as a complementary approach to diagnose and follow up patients with glioma.