Intracranial Growth Research Articles

Aneurysmal Parent Artery-Specific Inflow Conditions for Complete and Incomplete Circle of Willis Configurations.

Hemodynamics are thought to play a role in intracranial aneurysm growth and rupture. Computational fluid dynamics is frequently performed to assess intra-aneurysmal hemodynamics, using generalized flow waveforms of healthy volunteers as inflow boundary conditions. The purpose of this study was to assess differences in inflow conditions for different aneurysmal parent artery locations and variations of circle of Willis configurations. In a series of 96 patients with 103 aneurysms, velocity measurements were acquired using 2D phase-contrast MR imaging perpendicular to the aneurysmal parent arteries in the circle of Willis. Circle of Willis configurations were inspected for variations using multiple overlapping thin-slab-acquisition MRAs. Flow rates, velocity magnitudes, and pulsatility indices were calculated for each parent artery location in subgroups of complete and incomplete circle of Willis configurations. Flow rates, velocity magnitudes, and pulsatility indices were significantly different among aneurysmal parent arteries. Incomplete circle of Willis configurations were observed in 24% of the cases. Significantly lower basilar artery flow rates were observed in configurations with hypoplastic P1 segments. Significantly higher A1 flow rates were observed in configurations with a hypoplastic contralateral A1 segment. Inflow conditions vary substantially between aneurysmal parent arteries and circle of Willis configurations. We have created a collection of parent artery-specific inflow conditions tailored to the patient-specific circle of Willis configuration that can be used in future computational fluid dynamics studies analyzing intra-aneurysmal hemodynamics.

PHASES and ELAPSS Scores Are Associated with Aneurysm Growth: A Study of 431 Unruptured Intracranial Aneurysms

Understanding risk factors for intracranial aneurysm growth is important for patient management. We performed a retrospective study examining risk factors for the growth of unruptured intracranial aneurysms followed at our institution, evaluating both traditional risk factors and the PHASES (Population, Hypertension, Age, Size, Earlier Subarachnoid Hemorrhage, Site) score. We retrospectively reviewed a consecutive series of unruptured intracranial aneurysms followed at our institution for a minimum of 6 months over a 15-year period. The primary outcome of this study was aneurysm growth, defined as a ≥1-mm increase in maximum diameter. Risk factors studied included PHASES score, ELAPSS (Earlier Subarachnoid Hemorrhage, Location of Aneurysm, Age, Population, Size, and Shape) score, demographics, multiple aneurysms, previous subarachnoid hemorrhage, family history of aneurysm or subarachnoid hemorrhage, smoking, hypertension, and aneurysm shape, size, and location. The χ2 test was used for comparison of categorical variables, and the Student t test was used for continuous variables. The study cohort comprised 352 patients with a total of 431 unruptured intracranial aneurysms. The mean duration of follow-up was 4.8 years, and there was a total of 2100 aneurysm-years of follow-up. Forty aneurysms (9.3%) grew, for an annualized growth rate of 2.0% of aneurysms/year. Current smoking status was the sole modifiable risk factor associated with growth (growth rate of 5.1%/year compared with 1.5%/year for never smokers; P= 0.0004). Increasing size (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.11-1.33; P < 0.0001), ELAPSS score (OR, 1.10; 95% CI, 1.09-1.11; P < 0.0001), and PHASES score (OR, 1.24; 95% CI, 1.20-1.28; P < 0.0001) were associated with growth as well. Age, location, previous subarachnoid hemorrhage, and hypertension were not independently associated with aneurysm growth. Our retrospective study suggests that aneurysm size, smoking status, PHASES score, and ELAPSS score are associated with aneurysm growth.

Is there any intra-aneuvrysmal blood marker of aneuvrysm wall inflammation? Crossed analysis between transcriptomic and proteomic data

Background and purpose Intracranial aneurysm formation, growth and rupture are incompletely understood. Inflammation plays a key role in the formation and rupture of intracranial aneurysms. Inflammation is mediated through several factors such as cytokines, chemokines and growth factors. The purpose of this study was to determine if these inflammatory proteins were increased in the lumen of human intracranial aneurysm and correlate these data with gene expression regulation (transcriptomic) at tissue level. Methods The concentration of 27 inflammatory proteins in blood samples drawn from the lumen of human intracranial unruptured aneurysms of 21 patients were compared with blood samples from the femoral arteries of the same patients. We compared these proteomic data from intra-aneurysmal blood with transcriptomic data obtained by RNA sequencing of 7 human unruptured aneurysm walls and 6 human controls cortical arteries. Results The mean serum concentration of Il-1ra, IL-2, IL-5, IL-6 FGF-basic, GM-CSF, MCP-1, TNF-I± and MIP-1I± was significantly higher in samples taken from cerebral aneurysms compared to femoral arteries. In our transcriptomic analysis, we found a significant upregulation of IL-2 gene and IL-5 gene (coding for IL-2 and IL-5) in aneurysm walls compared with controls cortical arteries. Conclusion Higher concentration of inflammatory proteins was found in intra-aneurysmal sampling compared with femoral sampling. Transcriptomic data showed an upregulation of IL-2 gene and IL-5 gene in aneurysm walls compared with controls cortical arteries. Our findings suggest that we may detect intra-aneurysmal blood marker of aneurysm wall inflammation.

Nonsphericity Index and Size Ratio Identify Morphologic Differences between Growing and Stable Aneurysms in a Longitudinal Study of 93 Cases.

Recent studies have strongly associated intracranial aneurysm growth with increased risk of rupture. Identifying aneurysms that are likely to grow would be beneficial to plan more effective monitoring and intervention strategies. Our hypothesis is that for unruptured intracranial aneurysms of similar size, morphologic characteristics differ between aneurysms that continue to grow and those that do not. From aneurysms in our medical center with follow-up imaging dates in 2015, ninety-three intracranial aneurysms (23 growing, 70 stable) were selected. All CTA images for the aneurysm diagnosis and follow-up were collected, a total of 348 3D imaging studies. Aneurysm 3D geometry for each imaging study was reconstructed, and morphologic characteristics, including volume, surface area, nonsphericity index, aspect ratio, and size ratio were calculated. Morphologic characteristics were found to differ between growing and stable groups. For aneurysms of <3 mm, nonsphericity index (P < .001); 3-5 mm, nonsphericity index (P < .001); 5-7 mm, size ratio (P = .003); >7 mm, volume (P < .001); surface area (P < .001); and nonsphericity index (P = .002) were significant. Within the anterior communicating artery, the nonsphericity index (P = .008) and, within the posterior communicating artery, size ratio (P = .004) were significant. The nonsphericity index receiver operating characteristic area under the curve was 0.721 for discriminating growing and stable cases on the basis of initial images. Among aneurysms with similar sizes, morphologic characteristics appear to differ between those that are growing and those that are stable. The nonsphericity index, in particular, was found to be higher among growing aneurysms. The size ratio was found to be the second most significant parameter associated with growth.

Association of functional MMP-2 gene variant with intracranial aneurysms: case-control genetic association study and meta-analysis

Introduction: Abnormalities in Matrix Metalloproteinase (MMP) genes, which are important in extracellular matrix (ECM) maintenance and therefore arterial wall integrity are a plausible underlying mechanism of intracranial aneurysm (IA) formation, growth and subsequent rupture. We investigated whether the rs243865 C > T SNP (single nucleotide polymorphism) within the MMP-2 gene (which influences gene transcription) is associated with IA compared to matched controls.Materials and Methods: We conducted a case-control genetic association study, adjusted for known IA risk factors (smoking and hypertension), in a UK Caucasian population of 1409 patients with intracranial aneurysms (IA), and 1290 matched controls, to determine the association of the rs243865 C > T functional MMP-2 gene SNP with IA (overall, and classified as ruptured and unruptured). We also undertook a meta-analysis of two previous studies examining this SNP.Results: The rs243865 T allele was associated with IA presence in univariate (OR 1.18 [95% CI 1.04–1.33], p = .01) and in multi-variable analyses adjusted for smoking and hypertension status (OR 1.16 [95% CI 1.01-1.35], p = .042). Subgroup analysis demonstrated an association of the rs243865 SNP with ruptured IA (OR 1.18 [95% CI 1.03–1.34] p = .017), but, not unruptured IA (OR 1.17 [95% CI 0.97–1.42], p = .11).Conclusions: Our study demonstrated an association between the functional MMP-2 rs243865 variant and IAs. Our findings suggest a genetic role for altered extracellular matrix integrity in the pathogenesis of IA development and rupture.

Abstract CT151: CNS activity of ensartinib in ALK-positive non-small cell lung cancer patients

Abstract Background: Ensartinib (X-396) is a novel, potent anaplastic lymphoma kinase (ALK) small molecule tyrosine kinase inhibitor (TKI) with additional activity against MET, ABL, Axl, EPHA2, LTK, ROS1 and SLK. In animal studies, brain concentration of ensartinib in mice given at the therapeutic dose was 4 times higher than the IC50 for growth inhibition of ALK positive cells in vitro. Ensartinib was significantly more effective than crizotinib at inhibiting the intracranial growth of the SH-SY5Y neuroblastoma model harboring the F1174L mutation. We subsequently evaluated the CNS activity of ensartinib in patients with ALK positive non-small cell lung cancer (NSCLC). Methods: In this multicenter phase I/II study, patients (pts) with advanced solid tumors were enrolled and given ensartinib orally on a continuous 28-day schedule (NCT01625234). Doses from 25 mg up to 250 mg once daily were evaluated and 225 mg was selected for further evaluation in the phase II expansion. We report on patients enrolled with CNS metastases (with or without systemic disease) who were ALK TKI naïve or had received prior crizotinib or a second generation ALK TKI. Patients with untreated asymptomatic CNS metastases were allowed to enroll. All pts were assessed for adverse events using CTCAE version 4.03, and response to therapy was assessed using RECIST 1.1. Patients with only CNS disease had to have at least one measurable target lesion ≥ 3 mm in diameter. Results: As of the December 13, 2016 data cutoff, 26 pts with ALK+ NSCLC and baseline CNS metastases have been treated at ≥ 200 mg. Of the 26 pts, 13 pts had baseline target lesions (8 of which also had non-target lesions) and 13 pts had baseline non-target lesions only. Median age is 52 (21-72) years and the majority of patients had ECOG performance status of 1 (69%). CNS responses have been observed in both ALK TKI naïve pts and pts that received prior crizotinib. In the 13 pts with baseline target CNS lesions, intracranial response was achieved in 9 pts (69%), including 1 CR, and 4 pts (31%) had SD, a 100% disease control rate. In the 13 pts with non-target baseline lesions only, 1 CR was achieved and 8 pts had SD. All 3 (100%) ALK TKI naïve pts with baseline target lesions achieved CR or PR, and 5/8 pts (62%) that received prior crizotinib only and had baseline target lesions responded. The median duration of intracranial response in the 10 pts who responded (9 with target lesions, 1 with non-target lesions only) is 5.8+ months, with the longest duration being 24 months. Conclusions: Our clinical findings support the preclinical results that the use of ensartinib at doses generally well-tolerated in the clinic may result in favorable therapeutic outcomes in pts with ALK+ NSCLC with baseline CNS metastases. The ongoing phase III eXalt3 study will assess CNS response rate and time to CNS progression in pts receiving first-line ensartinib vs crizotinib (NCT02767804 and NCT01625234). Citation Format: Leora Horn, Karen L. Reckamp, Sandip Patel, George Blumenschein, Joel W. Neal, Barbara Gitlitz, Saiama Waqar, Geoffrey Oxnard, Christina Brzezniak, Gary Dukart, Fenlai Tan, Kimberly Harrow, Chris Liang, James Gibbons, Heather A. Wakelee. CNS activity of ensartinib in ALK-positive non-small cell lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT151. doi:10.1158/1538-7445.AM2017-CT151

Dipeptidyl Peptidase-4 Inhibitor Anagliptin Prevents Intracranial Aneurysm Growth by Suppressing Macrophage Infiltration and Activation.

BackgroundChronic inflammation plays a key role in the pathogenesis of intracranial aneurysms (IAs). DPP‐4 (dipeptidyl peptidase‐4) inhibitors have anti‐inflammatory effects, including suppressing macrophage infiltration, in various inflammatory models. We examined whether a DPP‐4 inhibitor, anagliptin, could suppress the growth of IAs in a rodent aneurysm model.Methods and Results IAs were surgically induced in 7‐week‐old male Sprague Dawley rats, followed by oral administration of 300 mg/kg anagliptin. We measured the morphologic parameters of aneurysms over time and their local inflammatory responses. To investigate the molecular mechanisms, we used lipopolysaccharide‐treated RAW264.7 macrophages. In the anagliptin‐treated group, aneurysms were significantly smaller 2 to 4 weeks after IA induction. Anagliptin inhibited the accumulation of macrophages in IAs, reduced the expression of MCP‐1 (monocyte chemotactic protein 1), and suppressed the phosphorylation of p65. In lipopolysaccharide‐stimulated RAW264.7 cells, anagliptin treatment significantly reduced the production of tumor necrosis factor α, MCP‐1, and IL‐6 (interleukin 6) independent of GLP‐1 (glucagon‐like peptide 1), the key mediator in the antidiabetic effects of DPP‐4 inhibitors. Notably, anagliptin activated ERK5 (extracellular signal–regulated kinase 5), which mediates the anti‐inflammatory effects of statins, in RAW264.7 macrophages. Preadministration with an ERK5 inhibitor blocked the inhibitory effect of anagliptin on MCP‐1 and IL‐6 expression. Accordingly, the ERK5 inhibitor also counteracted the suppression of p65 phosphorylation in vitro.ConclusionsA DPP‐4 inhibitor, anagliptin, prevents the growth of IAs via its anti‐inflammatory effects on macrophages.

Targeting glioma stem cells in vivo by a G-quadruplex-stabilizing synthetic macrocyclic hexaoxazole

G-quadruplex (G4) is a higher-order nucleic acid structure that is formed by guanine-rich sequences. G4 stabilization by small-molecule compounds called G4 ligands often causes cytotoxicity, although the potential medicinal impact of this effect has not been fully established. Here we demonstrate that a synthetic G4 ligand, Y2H2-6M(4)-oxazole telomestatin derivative (6OTD), limits the growth of intractable glioblastoma (grade IV glioma) and glioma stem cells (GSCs). Experiments involving a human cancer cell line panel and mouse xenografts revealed that 6OTD exhibits antitumor activity against glioblastoma. 6OTD inhibited the growth of GSCs more potently than it did the growth of differentiated non-stem glioma cells (NSGCs). 6OTD caused DNA damage, G1 cell cycle arrest, and apoptosis in GSCs but not in NSGCs. These DNA damage foci tended to colocalize with telomeres, which contain repetitive G4-forming sequences. Compared with temozolomide, a clinical DNA-alkylating agent against glioma, 6OTD required lower concentrations to exert anti-cancer effects and preferentially affected GSCs and telomeres. 6OTD suppressed the intracranial growth of GSC-derived tumors in a mouse xenograft model. These observations indicate that 6OTD targets GSCs through G4 stabilization and promotion of DNA damage responses. Therefore, G4s are promising therapeutic targets for glioblastoma.

Abstract 147: Role of Nicotine in the Development of Intracranial Aneurysm Rupture

Background: Nicotine is one of main chemicals of tobacco smoke and promotes atherosclerosis and stroke. Tobacco smoke is considered an independent risk factor for intracranial aneurysm formation, growth, and rupture. There are mainly 5 subtypes of nicotine receptors. Roles of alpha7 nicotinic acetylcholine receptor (α7nAChR) in inflammation and vascular remodeling are diverse and context-dependent. Notably, endothelial α7nAChR is considered to mediate nicotine-induced inflammation. Activation of endothelial α7nAChR by nicotine may promote aneurysm rupture by increasing the aneurysm wall inflammation. Using a mouse model of intracranial aneurysm, we examined effects of nicotine in aneurysm rupture. Moreover we investigated potential roles of α7nAChR stimulation by nicotine in the pathophysiology of intracranial aneurysms. Methods: Intracranial aneurysms were induced by a combination of elastase injection into the cerebrospinal fluid and deoxycorticosteron acetate-salt (DOCA-salt) hypertension in male mice. Mice were treated with (1) nicotine (5 mg/kg/day, n=25); (2) saline sc (n=22) for three weeks after aneurysm induction. To investigate the effect of α7nAChR, mice were treated with (1) saline sc + saline ip (n=11); (2) saline sc + α7nAChR antagonist (Methyllycaconitine, MLA 5mg/kg/day) ip (n=13); (3) nicotine (5 mg/kg/day, sc, 28 days) + saline ip (n=18); (4) nicotine sc + MLA ip (n=18). Results: Nicotine alone significantly increased aneurysmal rupture compared with saline treatment (89% vs 46%, p=0.009). While α7nAChR antagonist did not affect the incidence of aneurysm or rupture rates, the α7nAChR antagonist significantly reduced the deleterious effect of nicotine as indicated by the reduction of the rupture rates (41% vs 100%: nicotine sc + MLA ip group vs nicotine sc + saline ip group, p=0.027). Conclusion: Our data indicate the promotion of aneurysm rupture by nicotine may be mediated by its stimulation of alpha7nAChR.

Abstract 190: Prediction of Intracranial Aneurysm Growth Based on Morphology

Introduction: Recent studies have strongly associated intracranial aneurysm growth with increased risk of rupture. To plan more effective monitoring and intervention strategies, it would be beneficial to identify aneurysms which are likely to grow. Hypothesis: Morphological characteristics at initial diagnosis differ between unruptured intracranial aneurysms that will grow and those that are stable. Methods: A total of 58 cases of aneurysms in our medical center with follow-up imaging dates in 2015 were selected. All CTA images for the aneurysms were collected, for a total of 250 image sets. Aneurysm 3D geometry was reconstructed and morphological characteristics, including volume, surface area, and non-sphericity index (NSI) were calculated. NSI was calculated as 1 - (18π) 1/3 V 2/3 /S, where V and S represent aneurysm volume and surface area, respectively. Statistical comparisons were made using a two-tailed t-test with an assumption of unequal variance (Welch’s t-test). Results: Aneurysms were followed for an average of 50.5±50.9 months, with an average of 3.29±2.66 follow-up imaging dates. 9 aneurysms exhibited a size increase (&gt;0.6mm) and the remaining 49 aneurysms did not. Based on their maximum diameter, no significant difference was found between initial aneurysm size between the growth (3.80±1.72 mm) and non-growth (4.26±2.00 mm) groups (p=0.13). Likewise, no significant differences in volume or surface area were found (p=0.33, p=0.36, respectively). However, initial NSI was found to be significantly higher in the growth (0.32±0.11) vs. the non-growth (0.23±0.08) group (p=0.049). Conclusions: Among aneurysms with similar size, NSI may be useful for identifying aneurysms which are more likely to grow and planning monitoring strategies accordingly. Higher initial NSI in the aneurysms which eventually grew is consistent with previous findings that higher NSI correlates with increased risk of rupture.

Targeting NF-KB Activation in Novel Intracranial Models of CNS Lymphoma

Among the clinical subtypes of diffuse large B-cell lymphoma, central nervous system (CNS) lymphomas, both primary (PCNSL) and secondary (SCNSL), are generally associated with the worst prognosis. Moreover, PCNSL typically exhibits multifocal dissemination, prompting its description as a whole brain disease. An accumulation of genomic data suggests that aberrant NF-kB pro-survival signaling may be a critical factor in the pathogenesis of CNS lymphoma. To date, however, there has been an absence of mechanistic studies to interrogate the mediators and significance of NF-kB activation in CNS lymphoma invasion. Recently our lab derived the first panel of xenografts yet established from PCNSL patients (n=7), and defined their invasive properties in murine models. These novel model systems provide a unique opportunity to study key regulatory mechanisms as well as novel targeted therapies of CNS lymphoma invasion and growth within the brain.We determined that the intracranial growth patterns of the xenografts can be classified based upon reproducible patterns of invasiveness. Two xenografts derived from SCNSL failed to infiltrate brain parenchyma or to migrate to the contralateral hemisphere; instead these tumors exhibited solely a meningeal dissemination pattern, largely growing in the ventricles. By contrast, five of the xenografts exhibited diffuse brain invasion into bilateral hemispheres. In addition, we noted that CNS lymphoma xenografts with an invasive phenotype can be sub-divided phenotypically into moderately vs. highly invasive tumors. After standard injection of 200,000 tumor cells/brain, the highly invasive lymphomas were reproducibly lethal to mice within 3 weeks post-implantation and yielded ~ 1X106 lymphoma cells/brain at necropsy. Under identical conditions, the moderately-invasive lymphoma xenografts were lethal to mice within 1-3 months and yielded between 3-5 X106lymphoma cells/brain. Notably each of the highly invasive CNS lymphoma xenografts were derived from CNS lymphomas that contained the activating L265P mutation of MYD88 (activator of NF-kB via IRAK1/4) and/or Y196H mutation of CD79B (activator of NF-kB), whereas the non-invasive xenografts contained wild type MYD88 and CD79B.We analyzed RNA-seq expression data of these xenograft samples to evaluate relationship of individual genes and signaling pathways with the distinct subclasses of CNS lymphomas in terms of invasiveness. Upregulated signatures in the pro-invasive phenotype are significantly enriched with NF-kB target genes (http://lymphochip.nih.gov/signaturedb/) (FDR<3e-4). For example, as expected, the most invasive xenografts derived from CNS lymphoma specimens expressed high RelA (p65) and NFKB1, core components of the NF-kB multimeric complex. The invasive CNS lymphoma xenografts also exhibited upregulation of MYD88, SYK and PIM1/2, inducers of NF-kB activation. Conversely, the non-invasive xenografts expressed a signature of predominantly non-NF-kB-induced genes including SPRY1/2 (negative regulators of receptor tyrosine kinases) and TIMP2 (negative regulator of invasion). Gene set enrichment analysis confirmed a similar pattern of transcripts expressed in highly invasive PCNSL isolated from diagnostic specimens in patients (N=23; FDR <0.017).Given that the L265P mutation of MYD88 represents a candidate key driver of NF-kB activation in CNS lymphoma, we evaluated the preclinical efficacy of AZ1495, a novel and potent inhibitor of IRAKs. We demonstrated CNS penetration of AZ1495 after PO administration to mice with intracranial lymphoma xenografts, yielding a mean brain/plasma partition coefficient of 0.8. AZ1495 potently antagonized NF-kB activation as demonstrated by p-p65 immunoblot analysis of tumor lysates isolated from murine CNS lymphoma xenografts, within 3 hrs of administration. AZ1495 monotherapy resulted in > 2-fold delay in both intracranial plus spinal progression in a dissemination model of CNS lymphoma using L265P mutant OCI-LY10 cells engineered for bioluminescence (p<0.01). Finally, AZ1495 treatment resulted in a >2-fold increase in median OS in a patient-derived model of L265P mutant PCNSL. These results support the preclinical utility of these models to dissect impact of NF-kB inhibition on CNS lymphoma progression as well as the clinical potential of IRAK antagonism as a means to target NF-kB activation in L265P mutant CNS lymphomas. DisclosuresAnjum:Astra Zeneca: Employment. Drew:Astra Zeneca: Employment. Degorce:Astra Zeneca: Employment. Dillman:Astra Zeneca: Employment. Mayo:Astra Zeneca: Employment. Rubenstein:Celgene: Research Funding; Genentech: Research Funding.

Abstract C28: Platelet-derived growth factor receptor-β (PDGFRβ) in the breast metastatic tumor microenvironment

Abstract A role for the tumor microenvironment (TME) in cancer progression is irrefutable and our laboratory has been at the forefront of this field providing evidence for both tumor suppressive and oncogenic roles of the TME. The PDGF pathway is an exemplar for the study of tumor-stroma interaction as PDGF receptors (PDGFR) are frequently expressed in the fibroblasts and pericytes within the tumor-associated stroma of epithelial tumors including breast cancer. In contrast, PDGF ligands are expressed by the epithelial tumor cells themselves. However, beyond a few descriptive studies, the role of interactive PDGFRβ signaling in the TME during breast cancer initiation, progression and metastases is not understood. This can be attributed in part to limited in vivo models to study the complex TME, especially for breast cancer associated metastases. To overcome this limitation, we have established a transgenic knock-in mouse model that expresses constitutively active PDGFRβ in the stroma of the mammary gland as well in the lung and the brain, two common sites of metastatic breast cancer dissemination. We have found that these mice develop mammary gland hyperplasia highlighting the importance of PDGFRβ in the TME in driving mammary epithelial cell growth. To test whether activation of mutant PDGFRβ in either the lung or the brain increases metastatic growth at either site, two experimental metastases assays were performed: (1) tail vein and (2) intracranial injections to test for lung and brain metastatic outgrowth, respectively. Tail vein injection of the non-metastatic murine mammary cancer cell line DB7 cells led to pronounced lung metastases in PDGFRβ knock-in mice in less than 4 weeks. No macrometastases were seen in the control at this same time point. Similar to the surge in lung metastasis, intracranial injection of DB7 cells led to an increase in tumor growth in brains of the mutant versus wild type controls, revealing an important role for PDGFRβ signaling in the breast cancer metastatic microenvironment. In addition, knockdown of PDGF-B in mammary cancer cells represses intracranial growth in wild type animals. Combined these data support a role for PDGFRβ signaling in the breast cancer metastatic microenvironment. Ongoing investigation is aimed to delineate how activated PDGF-B to PDGFRβ signaling primes the metastatic niche. Citation Format: Gina Sizemore, Anisha Mathur, Katie Thies, Chelsea Bolyard, Steven Sizemore, Raleigh Kladney, Anthony Trimboli, Balveen Kaur, Gustavo Leone, Michael Ostrowski. Platelet-derived growth factor receptor-β (PDGFRβ) in the breast metastatic tumor microenvironment. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C28.

Tumour-processed osteopontin and lactadherin drive the protumorigenic reprogramming of microglia and glioma progression.

Tumour tissue is infiltrated by myeloid cells that are reprogrammed into alternatively activated/regenerative (M2) macrophages. The contribution of major signalling pathways and their modulators/targets involved in the macrophage reprogramming is poorly known. Glioblastoma (malignant brain tumour) attracts and reprograms brain-resident microglia and peripheral macrophages into cells that increase invasion, angiogenesis and suppress antitumour immunity. Using a 'function-first' approach and glioma secretome proteomics we identified osteopontin and lactadherin as proteins that cooperatively activate amoeboid transformation, phagocytosis and motility of primary microglia cultures via integrins and FAK-Akt (focal adhesion kinase-Akt) signalling. A synthetic peptide interfering with integrin ligands blocks glioma-microglia communication, functional activation and M2 gene expression. We found that osteopontin/secreted phosphoprotein 1 (Spp1) produced by non-transformed cells acts as a proinflammatory factor inducing inflammatory signalling and M1 genes, and counteracts the action of lactadherin. Using constructs encoding functional mutants of osteopontin, we demonstrated sequential processing of Spp1 by thrombin and matrix metalloproteinase-3 and/or -7 (MMP-3 and/or -7) in glioma cells, which generates a microglia-activating form devoid of the inflammatory activity, while retaining the M2 reprogramming potential. A similar form of osteopontin is secreted by human glioma cells but not normal human astrocytes. Knockdown of osteopontin or lactadherin in glioma cells reduces intracranial glioma growth, blocks amoeboid transformation of myeloid cells and affects M2 reprogramming of microglia/macrophages. Our findings demonstrate how glioma cells misuse macrophage-activating signals and redesign primarily proinflammatory signals towards their advantage to induce M2 reprogramming of tumour-infiltrating brain macrophages.

Abstract A22: NEO212: A novel temozolomide-perillyl alcohol conjugate exhibits superior activity against temozolomide resistant gliomas and intracranial triple negative breast cancer metastasis

Abstract Although the alkylating agent temozolomide (TMZ) has become the standard of care in the treatment of malignant gliomas, its overall efficacy is still limited by development of drug resistance, limited blood brain barrier (BBB) penetrance, and myelotoxicity. Recently, we have synthesized a TMZ analog where the monoterpene perillyl alcohol (POH) is covalently linked to TMZ via a carbamide bond. This new compound (NEO212) has been tested in two situations: TMZ resistant gliomas and breast cancer intracranial metastasis. Glioma cell lines (U251TR, LN229TR2, T98G) determined to be TMZ resistant based on base excision repair (BER) pathway, mismatch repair (MMR) deficiency, or overexpression of O6 methyl-guanine-DNA methyltransferase (MGMT) were evaluated in-vitro. In vivo experiments were performed using intracranial implant of luciferase labeled TMZ resistant cell lines. Triple negative breast cancer lines were tested, and implanted intracranially for in-vivo model. NEO212 was administered in both cases using subcutaneous injection using 10 day treatment, 7 day rest cycles did not have significant toxicity on normal astrocytes and brain endothelial cells. NEO212 induced cell death appeared to be independent of the mechanism of DNA repair resistance. In vivo experiments using intracranial implant of luciferase labeled TMZ resistant cell lines demonstrated that NEO212 crossed the BBB, reduced intracranial growth, and increased animal survival significantly compared to TMZ, without significant toxicity (including bone marrow). NEO212 was also effective in TMZ resistant breast cancer lines. In an intracranial mouse tumor model with triple-negative breast cancer, NEO212 revealed considerably greater therapeutic efficacy than TMZ, where a single cycle of treatment (10 days) extended median survival benefit from 6 days (in the case of TMZ) to 28 days, with good tolerance. NEO212 appears to be a promising well tolerated new agent with similar mechanism of cytotoxicity to TMZ. Its increased potency is most likely multi-factorial: 1) increased DNA damage, involving a broader scope of DNA repair mechanisms. 2) linkage with POH, resulting in longer biological half-life and greater opportunity for placement of cytotoxic DNA lesions. 3) increased lipophilicity, allowing for better penetration of the BBB, and possibly cell membrane. Preliminary results demonstrate that it can safely be administered systemically; more detailed toxicity studies are currently underway. Citation Format: Thomas C. Chen, Axel H. Schonthal, Weijun Wang, Heeyon Cho, Florence H. Hofman. NEO212: A novel temozolomide-perillyl alcohol conjugate exhibits superior activity against temozolomide resistant gliomas and intracranial triple negative breast cancer metastasis. [abstract]. In: Proceedings of the AACR Special Conference: Advances in Brain Cancer Research; May 27-30, 2015; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2015;75(23 Suppl):Abstract nr A22.

Risk Factors for Growth of Intracranial Aneurysms: A Systematic Review and Meta-Analysis.

Understanding risk factors for intracranial aneurysm growth is important for patient management. We performed a meta-analysis examining risk factors for intracranial aneurysm growth in longitudinal studies and examined the association between aneurysm growth and rupture. We searched the literature for longitudinal studies of patients with unruptured aneurysms. We examined the associations of demographics, multiple aneurysms, prior subarachnoid hemorrhage, family history of aneurysm or subarachnoid hemorrhage, smoking, and hypertension; and aneurysm shape, size, and location with aneurysm growth. We studied the association between aneurysm growth and rupture. A meta-analysis was performed by using a random-effects model by using summary statistics from included studies. Twenty-one studies including 3954 patients with 4990 aneurysms with 13,294 aneurysm-years of follow-up were included. The overall proportion of growing aneurysms was 3.0% per aneurysm-year (95% CI, 2.0%-4.0%). Patient risk factors for growth included age older than 50 years (3.8% per year versus 0.9% per year, P < .01), female sex (3.2% per year versus 1.3% per year, P < .01), and smoking history (5.5% per year versus 3.5% per year, P < .01). Characteristics associated with higher growth rates included cavernous carotid artery location (14.4% per year), nonsaccular shape (14.7% per year versus 5.2% per year for saccular, P < .01), and aneurysm size (P < .01). Aneurysm growth was associated with a rupture rate of 3.1% per year compared with 0.1% per year for stable aneurysms (P < .01). Observational evidence provided multiple clinical and anatomic risk factors for aneurysm growth, including age older than 50 years, female sex, smoking history, and nonsaccular shape. These findings should be considered when counseling patients regarding the natural history of unruptured intracranial aneurysms.

Elevated expression of the C-type lectin CD93 in the glioblastoma vasculature regulates cytoskeletal rearrangements that enhance vessel function and reduce host survival.

Glioblastoma is an aggressive brain tumor characterized by an abnormal blood vasculature that is hyperpermeable. Here, we report a novel role for CD93 in regulating angiogenesis in this setting by modulating cell-cell and cell-matrix adhesion of endothelial cells. Tissue microarray analysis demonstrated that vascular expression of CD93 was correlated with poor survival in a clinical cohort of patients with high-grade astrocytic glioma. Similarly, intracranial growth in the GL261 mouse model of glioma was delayed significantly in CD93(-/-) hosts, resulting in improved survival compared with wild-type mice. This effect was associated with increased vascular permeability and decreased vascular perfusion of tumors, indicating reduced vessel functionality in the absence of CD93. RNAi-mediated attenuation of CD93 in endothelial cells diminished VEGF-induced tube formation in a three-dimensional collagen gel. CD93 was required for efficient endothelial cell migration and proper cell polarization in vitro. Further, in endothelial cells where CD93 was attenuated, decreased cell spreading led to a severe reduction in cell adhesion, a lack of proper cell contacts, a loss of VE-cadherin, and aberrant actin stress fiber formation. Our results identify CD93 as a key regulator of glioma angiogenesis and vascular function, acting via cytoskeletal rearrangements required for cell-cell and cell-matrix adhesion.

DDEL-13TARGETED INTERLEUKIN-13-LIPOSOMES-MAGNIVEST-DOXORUBICIN FOR DETECTION AND TREATMENT OF GLIOMA IN EARLY STAGE

Malignant glioma in central nervous system (CNS) is a challenge to detect/treat due to the blood-brain barrier (BBB) that prohibits most chemicals like anti-cancer agents to penetrate. Furthermore, to detect brain cancer, magnetic resonance image (MRI) contrast agent such as Magnevist (Gd/DTPA) is limited to the cases where the BBB is significantly compromised by the cancer because Gd-DTPA itself is not able to cross the BBB. As a result, the cancer boundary presented by Gd-DTPA-enhanced MRI reflects only the extent where BBB is compromised instead of all the cancer-infiltrated regions. For the malignant glioma in early stage when it is smaller than 2 mm, which is even none detectable by Gd-DTPA-enhanced MRI because the BBB is intact when tumor is less than 2 mm. It is critical to develop a delivery system that carries targeted MRI contrast agent with drug alongside, which could penetrate brain tissue, detect and treat glioma in early stage concomitantly. Previous work demonstrated: 1) IL-13Rα2 was over-expressed in glioma, 2) IL-13-liposomes-doxrubinsine inhibited an intracranial glioma growth and 3) IL-13-liposomes-Gd/DTPA as a MRI contrast agent enhanced and detected infiltrating glioma. Based on these findings we hypothesized that IL-13-liposome encapsulating Gd-DTPA and doxorubicin (Dox) will be a theranostic agent for detection and treatment of gliomas. To test our hypothesis, glioma U251 and glioma stem cells T3691 and athymic nude mice with intracranial glioma were selected as our in vitro and in vivo model. IL-13-liposomes-Gd/DTPA-Dox was developed and characterized. Its application in vitro and in vivo has been evaluated through targeted MRI guided drug delivery. Our results provided the evidence that corresponded with our hypothesis. We predicted that the development of IL-13-liposomes-Gd/Dox will not only lead a translation into clinical neuro-oncology, but also into treatment of other tumors like colon cancer metastasis and adrenocortical carcinoma, which overexpressed IL-13Rα2.

Maternal cocaine abuse – An evidence review

In Australia, the use of illicit substances is on the rise, with as many as two in five people admitting to having ever used an illicit substance. As illicit drug availability is becoming ever more readily available, it has been argued that maternal substance use is increasing the demands of neonatal intensive care units and special care nurseries Australia wide. Cocaine causes miscarriage due to its vasoconstrictive effects on the blood supply of the developing foetus when used during the first trimester of pregnancy. Furthermore there is an increased risk of the foetus developing congenital anomalies and insufficient intracranial growth all due to the vasoconstrictive teratogenic effects of cocaine.Within this paper, common teratogenic effects of prenatal cocaine use are explored and further supplemented with the documented associated short and long term effects of such illicit drug use as reported in recent literature.The most common short term effect of maternal substance use on the neonate is neonatal abstinence syndrome (NAS) being one of the most common reasons and possibly unavoidable for admission to a neonatal intensive care unit (NICU). Such impacts upon NICUs are explored and discussed.

Desmoplastic Fibroma of the Temporal Bone.

Background: Desmoplastic fibroma is a benign, locally aggressive, intraosseous neoplasm with a propensity for local recurrence. Desmoplastic fibroma most commonly originates within the mandible (70% of cases), and long bones with rare lesions reported in the maxillary, frontal, and parietal bones. We report two patients with desmoplastic fibroma arising within the temporal bone. Study Design: Case report and literature review. Patients: Two patients with desmoplastic fibroma with intracranial and extra cranial growth patterns are presented. Both were young females with aural fullness and decreased hearing. Interventions: Diagnostic and therapeutic. Results: Both tumors were surgically extirpated and the patients have remained disease free for 18-48 months. Neither tumor expressed estrogen or progesterone receptors. Conclusion: Desmoplastic fibroma is a highly invasive local destructive lesion which is best treated by nondestructive surgical intervention. Immunohistochemical analysis may demonstrate hormonal receptors, in which case Tamoxifen may reduce recurrence.

RNA-Sequencing Analysis of Messenger RNA/MicroRNA in a Rabbit Aneurysm Model Identifies Pathways and Genes of Interest.

Rabbit aneurysm models are used for the testing of embolization devices and elucidating the mechanisms of human intracranial aneurysm growth and healing. We used RNA-sequencing technology to identify genes relevant to induced rabbit aneurysm biology and to identify genes and pathways of potential clinical interest. This process included sequencing microRNAs, which are important regulatory noncoding RNAs. Elastase-induced saccular aneurysms were created at the origin of the right common carotid artery in 6 rabbits. Messenger RNA and microRNA were isolated from the aneurysm and from the control left common carotid artery at 12 weeks and processed by using RNA-sequencing technology. The results from RNA sequencing were analyzed by using the Ingenuity Pathway Analysis tool. A total of 9396 genes were analyzed by using RNA sequencing, 648 (6.9%) of which were found to be significantly differentially expressed between the aneurysms and control tissues (P < .05; false-discovery rate, <0.01; fold change, >2 or <.5). Of these genes, 614 were mapped successfully, 143 were down-regulated, and 471 were up-regulated in the aneurysms as compared with controls. Using the same criteria for significance, 3 microRNAs were identified as down-regulated and 5 were identified as up-regulated. Pathway analysis associated these genes with inflammatory response, cellular migration, and coagulation, among other functions and pathologies. RNA-sequencing analysis of rabbit aneurysms revealed differential regulation of some key pathways, including inflammation and antigen presentation. ANKRD1 and TACR1 were identified as genes of interest in the regulation of matrix metalloproteinases.