Citations

OBJECT Mild traumatic brain injury (TBI) has been proposed as a risk factor for the development of Alzheimer’s disease, Parkinson’s disease, depression, and other illnesses. This study’s objective was to determine the association of prior mild TBI with the subsequent diagnosis (that is, at least 1 year postinjury) of neurological or psychiatric disease. METHODS All studies from January 1995 to February 2012 reporting TBI as a risk factor for diagnoses of interest were identified by searching PubMed, study references, and review articles. Reviewers abstracted the data and assessed study designs and characteristics. RESULTS Fifty-seven studies met the inclusion criteria. A random effects meta-analysis revealed a significant association of prior TBI with subsequent neurological and psychiatric diagnoses. The pooled odds ratio (OR) for the development of any illness subsequent to prior TBI was 1.67 (95% CI 1.44–1.93, p < 0.0001). Prior TBI was independently associated with both neurological (OR 1.55, 95% CI 1.31–1.83, p < 0.0001) and psychiatric (OR 2.00, 95% CI 1.50–2.66, p < 0.0001) outcomes. Analyses of individual diagnoses revealed higher odds of Alzheimer’s disease, Parkinson’s disease, mild cognitive impairment, depression, mixed affective disorders, and bipolar disorder in individuals with previous TBI as compared to those without TBI. This association was present when examining only studies of mild TBI and when considering the influence of study design and characteristics. Analysis of a subset of studies demonstrated no evidence that multiple TBIs were associated with higher odds of disease than a single TBI. CONCLUSIONS History of TBI, including mild TBI, is associated with the development of neurological and psychiatric illness. This finding indicates that either TBI is a risk factor for heterogeneous pathological processes or that TBI may contribute to a common pathological mechanism.

ObjectivesTo assess technical performance learning curves of teams performing transfemoral transcatheter aortic valve replacement (TF‐TAVR).BackgroundTF‐TAVR is a new procedure for treating severe aortic stenosis. The number of cases required for procedural efficiency is unknown.MethodsIn the PARTNER‐I trial, 1,521 patients underwent TF‐TAVR from 4/2007–2/2012. Learning curve analysis of technical performance metrics was performed using institution‐specific patient sequence number, interval between procedures, and institutional trial entry date. Learning curve characteristics were assessed using semi‐parametric and parametric mixed‐effects models.ResultsAs patient sequence number increased, average procedure time decreased from 154 to 85 minutes (P < 0.0001), and fluoroscopy time from 28 to 20 minutes (P < 0.0001). Procedure time plateaued at an average of 83 minutes (range 52–140). Procedure time plateau was dynamic during the course of the trial, averaging 25 cases (range 21–52) by its end. The later institutions enrolled in the trial, the shorter the initial procedure time. During the trial, percutaneous rather than surgical access increased from 7.9% to 69%.ConclusionsTechnical performance learning curves exist for TF‐TAVR; procedural efficiency increased with experience, with concomitant decreases in radiation and contrast media exposure. The number of cases needed to achieve efficiency decreased progressively, with optimal procedural performance reached after approximately 25 cases for late‐entering institutions. Knowledge and experience accumulated by early TF‐TAVR institutions were disseminated, shortening the learning curve of late‐entering institutions. Technological advances resulting from learning during the trial moved the field from initial conservative surgical cut‐down to percutaneous access for most patients. © 2015 Wiley Periodicals, Inc.

Abstract Patient derived xenografts (PDX) mouse models for many types of cancer have demonstrated therapeutic responses similar to those seen in patients. Thus, resected patient tumor tissue directly implanted into immune compromised mice followed by therapy and tumor growth analysis is thought to be the closest preclinical model to predict patient therapeutic responses. To date, few models are available for the different histotypes of thyroid cancer derived from follicular thyrocytes; these include papillary, follicular, Hurthle cell, squamous and anaplastic thyroid carcinoma. We have developed eight PDX models in athymic nude mice representing all of these subtypes. The models have been extensively characterized for mutational status (i.e. BRAF, telomerase, RAS, PTEN, TP53, RB, etc) as well as validation by short tandem repeat (STR) analysis to match that of the originating patient tumor tissue. Squamous and anaplastic thyroid cancers are rare tumor types with no FDA approved therapies. Each model demonstrated their own unique responses to radiation, cytotoxic or molecular targeted therapies such as doxorubicin, sorafenib (tyrosine kinase inhibitor), cisplatin, paclitaxel, sunitinib (tyrosine kinase inhibitor), erlotinib (EGFR inhibitor), trametinib (MEK inhibitor) and vemurafenib (BRAF inhibitor). We expect that these models may provide useful in vivo models for thyroid cancer research as well as models for therapeutic guidance based upon histotype, mutational status and response to therapies. Citation Format: Laura A. Marlow, Adam C. Mathias, Louis K. Dawson, William F. Durham, Kenneth A. Meshaw, Robert J. Mullin, Daniel L. Small, Aidan J. Synnott, Dragana Milosevic, Brian C. Netzel, Stefan K. Grebe, Kevin Wu, Robert C. Smallridge, John A. Copland. Characterization of novel thyroid PDX models and their response to combination therapies. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1458. doi:10.1158/1538-7445.AM2015-1458

Abstract Patient derived xenografts (PDX) mouse models for many types of cancer have been developed recapitulating therapeutic responses in the patient for which the PDX model was derived. Essentially, live surgically resected or biopsy tumor tissues are directly implanted into immune incompetent mice to develop in vivo models to test therapies, follow tumor progression (gene mutations that occur with patient tumor progression do so in mice) or to better understand drug resistance. However, the use of PDX models also has its limitations and challenges. Our laboratory has attempted to develop PDX models in athymic nude mice for numerous cancer histotypes such as bladder, brain, breast, colon, kidney, lung, melanoma, ovarian, pancreas, sarcoma and thyroid. While melanoma and colon cancers have very high tumor take rates (73 - 100%), the other cancer histotypes do not (14 - 50%). We share our experience for each cancer histotype and the techniques used to enhance the success rates in athymic nude mice. We also address the other challenges that include expansion of tumors after cryopreservation and conversion of human tumors to mouse tumors and spontaneous lymphomas. We provide methods to test for human versus mouse content that include QPCR and immunohistochemistry Citation Format: Laura A. Marlow, James L. Miller, Brandy Edenfield, Adam C. Mathias, Louis K. Dawson, William F. Durham, Robert J. Mullin, Daniel L. Small, Aidan J. Synnott, Kevin Wu, John A. Copland. Methods for developing patient derived xenografts in athymic nude mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1453. doi:10.1158/1538-7445.AM2015-1453

Abstract We have developed the use of reovirus as a systemically delivered oncolytic agent in both pre-clinical models and in early Phase clinical trials. Reovirus has direct oncolytic activity against many human/murine tumor cells, partly because of disruption of the PKR-mediated anti-viral response in malignant cells. In addition however, we have shown that anti-tumor therapy is directly associated with immune activation by virus replication in tumors. The immune mechanisms of therapy include both innate immune activation against virally infected tumor cells, as well as the generation of adaptive anti tumor immune responses as a result of in vivo priming against tumor associated antigens released during that killing. Therefore, to exploit the immune components of reovirus anti-tumor therapy, we hypothesized that the combination of reovirus therapy with systemic checkpoint inhibition would augment therapeutic efficacy. To test the hypothesis, we used C57Bl/6 mice, an immune-competent murine model, with established subcutaneous (s.c.) B16 melanomas. In this model, intra-tumoral injection of reovirus into s.c. tumors generated moderate therapy. Provision of systemic anti-PD-1 antibody along with i.t. reovirus, significantly enhanced survival compared to i.t. reovirus alone (p&lt;0.01) and led to &gt;40% of mice being cured long term. Immune analysis suggested that the enhanced therapeutic benefit of reovirus plus checkpoint inhibition is contributed by at least two factors. First, blockade of PD-1 significantly enhanced the ability of NK cells to recognize (TNF-α secretion), and kill, reovirus-infected target tumor cells. Second, anti PD-1 antibody led to a significant reduction in Treg activity in reovirus-treated mice, with the overall effect of increasing the adaptive CD8+ anti-tumor T cell response. Furthermore, in vivo depletion studies demonstrated that NK cells had a dramatic effect in reducing the therapeutic efficacy of reovirus plus anti-PD-1 therapy. Overall, the results indicate that combination therapy of reovirus with PD-1 blockade confers significant survival benefit, by augmenting tumor-specific NK responses and specifically attenuating tumor-specific immunosuppression. These data also suggest that combination of PD-1 inhibition therapy with reovirus oncolytic/immunotherapy represents a readily translatable method to enhance the therapeutic efficacy. Citation Format: Karishma Rajani, Christopher Parrish, Kevin Shim, Liz Ilett, Fiona Errington-Mais, Jill Thompson, Tim Kottke, Rosa Maria-Diaz, Peter Selby, Hardev Pandha, Kevin Harrington, Alan Melcher, Matt Coffey, Shane Zaidi, Richard Vile. Combination therapy of reovirus and PD-1 blockade effectively establishes tumor control via innate and adaptive immune responses. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1360. doi:10.1158/1538-7445.AM2015-1360

Background and Purpose— The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography–based planimetry (CTP). Methods— In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. Results— In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC ( r 2 =0.93) than with site-ABC ( r 2 =0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm 3 ; CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P <0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots. Conclusions— ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.

Abstract Methyl-lysine (Kme) recognition domains play a central role in epigenetic regulation during cellular differentiation, development, and gene transcription with more than 200 known “reader” domains in the human proteome. We describe our target-class approach to ligand design and discovery for three cancer relevant members of this large family: L3MBTL3 (a Malignant Brain Tumor (MBT) domain containing reader), 53BP1 (a tandem Tudor domain) and CBX7 (a chromo domain). The advantages of a small molecule driven approach to modulating chromatin biology are numerous: temporal resolution; mechanistic flexibility (targeting a specific activity of a protein as opposed to ablating them all with transgenic knock-outs or RNA-interference techniques); ease of delivery; and most significantly, when warranted, a small molecule tool has the potential to provide an immediate transition to a drug discovery effort, potentially cutting years off the time between target validation and therapeutic intervention. UNC1215 binds the MBT domains of L3MBTL3 with a Kd of 120 nM, competitively displacing mono- or dimethyl-lysine containing peptides. This probe is greater than 50-fold selective versus other members of the human MBT family and also demonstrates selectivity against more than 200 other Kme reader domains examined. UNC1215 increases the cellular mobility of GFP-L3MBTL3 fusion proteins and point mutants that disrupt the Kme binding function of GFP-L3MBTL3 phenocopy the effects of UNC1215. The potency, specificity, and cellular effects of UNC1215 establish it as the first cell-active antagonist of a Kme reader domain and a useful chemical probe for biological studies of the function of L3MBTL3 (James, L. I. et al. Nat Chem Biol 2013, 9, 184-191). 53BP1 is a Kme binding protein that plays a central biological role in DNA Damage Repair (DDR) pathway via its recruitment to sites of DNA double strand breaks (DSB). BRCA1 is a checkpoint and DNA damage repair gene that is required for maintenance of genomic integrity, and the inheritance of mutated BRCA1 is a major risk factor for breast and ovarian cancer. The BRCA1 knockout murine model is embryonic lethal and a conditional knockout in mammary glands results in low frequency and long latency of mammary tumor formation. It was recently reported that the BRCA1-null developmental phenotype is rescued when placed on a 53BP1-null background. Adult mice from this model, that are null for both the 53BP1 and BRCA1 genes, age normally and display a very low incidence of tumor formation. Genomic instability can be rescued in 53BP1 knockouts because the homologous recombination (HR) pathway is largely restored in cells lacking both BRCA1 and 53BP1 (Cao, L. et al. Molecular cell 2009, 35 (4), 534-41). Based on this data, small molecule antagonists of 53BP1's biological function could act as viable therapeutics to restore HR in the DDR response in humans with BRAC1 mutations. We will report the first small molecule, fragment-like ligands with selectivity for binding to 53BP1. CBX7 is a chromo domain containing Kme reader that, along with other CBX domains, recruits the PRC1 complex to histone 3, lysine 27 trimethylation sites (H3K27me3) and enables transcriptional silencing downstream of the PRC2 complex which ‘writes’ the H3K27me3 mark via the catalytic activity of EZH2. As EZH2 is a well validated drug target with inhibitors now entering the clinic for the treatment of various cancers, we hypothesize that antagonism of the PRC1 complex recognition of H3K27me3 will phenocopy and perhaps synergize with the activity of EZH2 inhibitors (Konze, K. D. et al. ACS Chemical Biology 2013, 8, 1324-1334). Progress towards a chemical probe to validate CBX7 as a therapeutic target will be presented. The pursuit of high quality chemical probes for KMe reader proteins represents an emerging area that will open new avenues of research in chromatin biology and may in time, translate to new therapeutic approaches. Antagonists of the readers of acetylated lysine (BRD4 bromo domains) derived from pioneering chemical probe efforts (Filippakopoulos, P. et al. Nature 468, 1067-73 (2010)) have recently entered the clinic for the treatment of various malignancies and we hope that our chemical probe work will help to validate Kme readers as novel and significant anti-tumor targets. Citation Format: Lindsey I. James, Jake I. Stuckey, Brandi M. Baughman, Michael T. Perfetti, Samantha G. Pattenden, Brad M. Dickson, Jacqueline L. Norris, Gaofeng Cui, Pavel Mader, Aiping Dong, Yunxiang Mu, Scott B. Rothbart, Brian D. Strahl, Jinrong Min, Peter J. Brown, Dmitri B. Kireev, William P. Janzen, Kevin M. McBride, Mark T. Bedford, Georges Mer, Cheryl H. Arrowsmith, Stephen V. Frye. Targeting chromatin regulation for cancer therapy: progress towards chemical probes for methyl-lysine readers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr SY08-03. doi:10.1158/1538-7445.AM2015-SY08-03

Abstract Genome wide association studies (GWAS) have mapped multiple independent cancer risk loci (n = 6) to a small region on chr5p15.33 for at least ten distinct cancers, including bladder, breast, glioma, lung, melanoma, non-melanoma skin, ovarian, pancreas, prostate, and testicular germ cell cancer. This region harbors two plausible target genes, TERT which encodes the catalytic subunit of telomerase reverse transcriptase which maintains chromosome ends by adding telomeres repeats, and CLPTM1L which encodes the cleft lip and palate transmembrane protein 1-like protein which promotes cancer cell growth, protect cells from apoptosis, and can induce abnormal cytokinesis. The most significant pancreatic cancer GWAS SNP on chr5p15.33 was rs401681 (P = 3.7×10−7, OR = 1.19), located in the 13th intron of the CLPTM1L gene and within the independent multi-cancer risk locus in this region most distant from TERT. Imputation and fine mapping in pancreatic cancer resolved this signal by three orders of magnitude (P = 1.4×10−10, OR = 1.30) to a set of seven highly correlated SNPs. Electrophoretic mobility shift assays (EMSA) and luciferase assays across these SNPs led us to a single SNP, rs36115365, that showed allele-specific effects in both assays and overlapped with prominent ENCODE marks indicating regulatory potential. Examining this SNP across cell lines derived from multiple types of cancer linked to this locus, specifically pancreatic, testicular, lung, and melanoma, established a consistent pattern of a specific protein binding and enhanced regulatory activity for the risk allele across eight cancer cell lines (two cell lines per cancer type). siRNA-based targeting of the putative gene regulatory-region harboring rs36115365 resulted in a strong inhibition of TERT expression (average 60%, range 45-85%) but no effect on CLPTM1L expression. This inhibition of TERT expression was stronger from the pancreatic cancer risk as compared to the protective allele. Quantitative mass spectrometry identified Zinc finger protein 148 (ZNF148) as the protein specifically binding the risk allele, further supported by direct and allele-specific binding of purified recombinant ZNF148 in EMSA assays. Lastly, siRNA-mediated knockdown of ZNF148 resulted in significant reduction of TERT but not CLPTM1L expression across multiple cancer cell lines. Our results indicate that the pancreatic cancer GWAS signal at the single independent chr5p15.33 multi-cancer risk locus most distant from TERT may be explained by a single SNP that influences TERT expression via ZNF148. Citation Format: Kevin M. Brown, Jun Fang, Jinping Jia, Zhaoming Wang, Matthew Makowski, Tongwu Zhang, Jason Hoskins, Jiyeon Choi, Younghun Han, Mingfeng Zhang, Mai Xu, Peter Kanetsky, Andresson Thorkell, Gloria M. Petersen, Katherine L. Nathanson, Christopher I. Amos, Maria T. Landi, Stephen J. Chanock, Michiel Vermeulen, Laufey T. Amundadottir. Functional characterization of a multicancer risk locus on chr5p15.33 reveals regulation of TERT by ZNF148. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4610. doi:10.1158/1538-7445.AM2015-4610