bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conditional Expression of the CTCF-Paralogous Transcriptional Factor BORIS in Normal Cells Results in Demethylation and Derepression of MAGE-A1 and Reactivation of Other Cancer-Testis Genes
Authors: Vatolin Sergei , Abdullaev Ziedulla , Pack Svetlana D. , Flanagan Patrick T. , Custer Mary , Loukinov Dmitri I. , Pugacheva Elena , Hong Julie A. , Morse Herbert , Schrump David S. , Risinger John I. , Barrett J. Carl , Lobanenkov Victor V. 
Published: July 2017

Abstract
Brother of the Regulator of Imprinted Sites (BORIS) is a mammalian CTCF paralog with the same central 11Zn fingers (11ZF) that mediate specific interactions with varying ∼50-bp target sites. Regulated in vivo occupancy of such sites may yield structurally and functionally distinct CTCF/DNA complexes involved in various aspects of gene regulation, including epigenetic control of gene imprinting and X chromosome inactivation. The latter functions are mediated by meCpG-sensitive 11ZF binding. Because CTCF is normally present in all somatic cells, whereas BORIS is active only in CTCF- and 5-methylcytosine–deficient adult male germ cells, switching DNA occupancy from CTCF to BORIS was suggested to regulate site specificity and timing of epigenetic reprogramming. In addition to 11ZF-binding paternal imprinting control regions, cancer-testis gene promoters also undergo remethylation during CTCF/BORIS switching in germ cells. Only promoters of cancer testis genes are normally silenced in all somatic cells but activated during spermatogenesis when demethylated in BORIS-positive germ cells and are found aberrantly derepressed in various tumors. We show here that BORIS is also expressed in multiple cancers and is thus itself a cancer-testis gene and that conditional expression of BORIS in normal fibroblasts activates cancer-testis genes selectively. We tested if replacement of CTCF by BORIS on regulatory DNA occurs in vivo on activation of a prototype cancer-testis gene, MAGE-A1. Transition from a hypermethylated/silenced to a hypomethylated/activated status induced in normal cells by 5-aza-2′-deoxycytidine (5-azadC) was mimicked by conditional input of BORIS and is associated with complete switching from CTCF to BORIS occupancy at a single 11ZF target. This site manifested a novel type of CTCF/BORIS 11ZF binding insensitive to CpG methylation. Whereas 5-azadC induction of BORIS takes only few hours, derepression of MAGE-A1 occurred 1 to 2 days later, suggesting that BORIS mediates cancer-testis gene activation by 5-azadC. Indeed, infection of normal fibroblasts with anti-BORIS short hairpin RNA retroviruses before treatment with 5-azadC blocked reactivation of MAGE-A1. We suggest that BORIS is likely tethering epigenetic machinery to a novel class of CTCF/BORIS 11ZF target sequences that mediate induction of cancer-testis genes.
A Novel Method for Viral Gene Delivery in Solid Tumors
Authors: Wang Yong , Liu Shanling , Li Chuan-Yuan , Yuan Fan 
Published: July 2017

Abstract
Intratumoral infusion is the most commonly used method for viral gene delivery in clinical trials for cancer treatment. However, a potential problem in this approach is that viral vectors may disseminate from tumor to normal tissues during and after the infusion. To reduce the dissemination, we developed a novel method based on a biocompatible polymer, poloxamer 407, which could significantly increase the viscosity of virus suspension when the temperature was changed from 4°C to 37°C. With this method, we could significantly increase transgene expression in solid tumors and reduce virus dissemination by 2 orders of magnitude after intratumoral infusion of adenoviral vectors. The mechanism of reduction was likely to be that the viscous poloxamer solution blocked convection of viral vectors in the interstitial space and the lumen of microvessels in the vicinity of the infusion site. This method has a potential to be used in the clinic for enhancing efficacy and reducing toxicity in viral gene therapy.
Galectin-3 Inhibits Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand–Induced Apoptosis by Activating Akt in Human Bladder Carcinoma Cells
Authors: Oka Natsuo , Nakahara Susumu , Takenaka Yukinori , Fukumori Tomoharu , Hogan Victor , Kanayama Hiro-omi , Yanagawa Takashi , Raz Avraham 
Published: July 2017

Abstract
The antiapoptotic molecule galectin-3 was previously shown to regulate CD95, a member of the tumor necrosis factor (TNF) family of proteins in the apoptotic signaling pathway. Here, we question the generality of the phenomenon by studying a different member of this family of proteins [e.g., TNF-related apoptosis-inducing ligand (TRAIL), which induces apoptosis in a wide variety of cancer cells]. Overexpression of galectin-3 in J82 human bladder carcinoma cells rendered them resistant to TRAIL-induced apoptosis, whereas phosphatidylinositol 3-kinase (PI3K) inhibitors (wortmannin and LY-294002) blocked the galectin-3 protecting effect. Because Akt is a major downstream PI3K target reported to play a role in TRAIL-induced apoptosis, we questioned the possible relationship between galectin-3 and Akt. Parental J82 and the control vector–transfected J82 cells (barely detectable galectin-3) exhibit low level of constitutively active Akt, resulting in sensitivity to TRAIL. On the other hand, J82 cells overexpressing galectin-3 cells expressed a high level of constitutively active Akt and were resistant to TRAIL. Moreover, the blockage of TRAIL-induced apoptosis in J82 cells seemed to be mediated by Akt through the inhibition of BID cleavage. These results suggest that galectin-3 involves Akt as a modulator molecule in protecting bladder carcinoma cells from TRAIL-induced apoptosis.
Insertion of Myc into Igh Accelerates Peritoneal Plasmacytomas in Mice
Authors: Park Sung Sup , Shaffer Arthur L. , Kim Joong Su , duBois Wendy , Potter Michael , Staudt Louis M. , Janz Siegfried 
Published: July 2017

Abstract
Gene-targeted mice that contain a His6-tagged mouse c-Myc cDNA, MycHis, inserted head to head into different sites of the mouse immunoglobulin heavy-chain locus, Igh, mimic the chromosomal T(12;15)(Igh-Myc) translocation that results in the activation of Myc in the great majority of mouse plasmacytomas. Mice carrying MycHis just 5′ of the intronic heavy-chain enhancer Eμ (strain iMycEμ) provide a specific model of the type of T(12;15) found in a subset (∼20%) of plasmacytomas that develop “spontaneously” in the gut-associated lymphoid tissue (GALT) of interleukin-6 transgenic BALB/c (C) mice. Here we show that the transfer of the iMycEμ transgene from a mixed genetic background of segregating C57BL/6 × 129/SvJ alleles to the background of C increased the incidence of GALT plasmacytomas by a factor of 2.5 in first-generation backcross mice (C.iMycEμ N1). Third-generation backcross mice (C.iMycEμ N3, ∼94% C alleles) were hypersusceptible to inflammation-induced peritoneal plasmacytomas (tumor incidence, 100%; mean tumor onset, 86 ± 28 days) compared with inbred C mice (tumor incidence, 5% on day 150 after tumor induction). Peritoneal plasmacytomas of C.iMycEμ N3 mice overexpressed MycHis, produced monoclonal immunoglobulin, and exhibited a unique plasma cell signature upon gene expression profiling on mouse Lymphochip cDNA microarrays. These findings indicated that the iMycEμ transgene accelerates plasmacytoma development by collaborating with tumor susceptibility alleles of strain C and circumventing the requirement for tumor precursors to acquire deregulated Myc by chromosomal translocation.
Mitochondrial DNA G10398A Polymorphism and Invasive Breast Cancer in African-American Women
Authors: Canter Jeffrey A. , Kallianpur Asha R. , Parl Fritz F. , Millikan Robert C. 
Published: July 2017

Abstract
Mitochondria generate oxygen-derived free radicals that damage mitochondrial DNA (mtDNA) as well as nuclear DNA and in turn promote carcinogenesis. The mtDNA G10398A polymorphism alters the structure of Complex I in the mitochondrial electron transport chain, an important site of free radical production. This polymorphism is associated with several neurodegenerative disorders. We hypothesized that the 10398A allele is also associated with breast cancer susceptibility. African mitochondria harbor the 10398A allele less frequently than Caucasian mitochondria, which predominantly carry this allele. Mitochondrial genotypes at this locus were therefore determined in two separate populations of African-American women with invasive breast cancer and in controls. A preliminary study at Vanderbilt University (48 cases, 54 controls) uncovered an association between the 10398A allele and invasive breast cancer in African-American women, [odds ratio (OR), 2.90; 95% confidence interval (95% CI), 0.61-18.3; P = 0.11]. We subsequently validated this finding in a large, population-based, case-control study of breast cancer, the Carolina Breast Cancer Study at the University of North Carolina (654 cases, 605 controls). African-American women in this study with the 10398A allele had a significantly increased risk of invasive breast cancer (OR, 1.60; 95% CI, 1.10-2.31; P = 0.013). The 10398A allele remained an independent risk factor after adjustment for other well-accepted breast cancer risk factors. No association was detectable in white women (879 cases, 760 controls; OR, 1.03; 95% CI, 0.81-1.31; P = 0.81). This study provides novel epidemiologic evidence that the mtDNA 10398A allele influences breast cancer susceptibility in African-American women. mtDNA polymorphisms may be underappreciated factors in breast carcinogenesis.
An Essential Role for the Tumor-Suppressor Merlin in Regulating Fatty Acid Synthesis
Authors: Stepanova Dina S. , Semenova Galina , Kuo Yin-Ming , Andrews Andrew J. , Ammoun Sylwia , Hanemann C. Oliver , Chernoff Jonathan 
Published: July 2017

Abstract
Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by the development of multiple tumors in the central nervous system, most notably schwannomas, and meningiomas. Mutational inactivation of the NF2 gene encoding the protein Merlin is found in most sporadic and inherited schwannomas, but the molecular mechanisms underlying neoplastic changes in schwannoma cells remain unclear. We report here that Nf2-deficient cells display elevated expression levels of key enzymes involved in lipogenesis and that this upregulation is caused by increased activity of Torc1. Inhibition or knockdown of fatty acid synthase (FASN), the enzyme that catalyzes the formation of palmitic acid from malonyl-CoA, drove NF2-deficient cells into apoptosis. Treatment of NF2-mutant cells with agents that inhibit the production of malonyl-CoA reduced their sensitivity to FASN inhibitors. Collectively, these results suggest that the altered lipid metabolism found in NF2-mutant cells renders them sensitive to elevated levels of malonyl-CoA, as occurs following blockade of FASN, suggesting new targeted strategies in the treatment of NF2-deficient tumors. Cancer Res; 77(18); 5026–38. ©2017 AACR.
MYC-Regulated Mevalonate Metabolism Maintains Brain Tumor–Initiating Cells
Authors: Wang Xiuxing , Huang Zhi , Wu Qiulian , Prager Briana C. , Mack Stephen C. , Yang Kailin , Kim Leo J.Y. , Gimple Ryan C. , Shi Yu , Lai Sisi , Xie Qi , Miller Tyler E. , Hubert Christopher G. , Song Anne , Dong Zhen , Zhou Wenchao , Fang Xiaoguang , Zhu Zhe , Mahadev Vaidehi , Bao Shideng , Rich Jeremy N. 
Published: July 2017

Abstract
Metabolic dysregulation drives tumor initiation in a subset of glioblastomas harboring isocitrate dehydrogenase (IDH) mutations, but metabolic alterations in glioblastomas with wild-type IDH are poorly understood. MYC promotes metabolic reprogramming in cancer, but targeting MYC has proven notoriously challenging. Here, we link metabolic dysregulation in patient-derived brain tumor–initiating cells (BTIC) to a nexus between MYC and mevalonate signaling, which can be inhibited by statin or 6-fluoromevalonate treatment. BTICs preferentially express mevalonate pathway enzymes, which we find regulated by novel MYC-binding sites, validating an additional transcriptional activation role of MYC in cancer metabolism. Targeting mevalonate activity attenuated RAS-ERK–dependent BTIC growth and self-renewal. In turn, mevalonate created a positive feed-forward loop to activate MYC signaling via induction of miR-33b. Collectively, our results argue that MYC mediates its oncogenic effects in part by altering mevalonate metabolism in glioma cells, suggesting a therapeutic strategy in this setting. Cancer Res; 77(18); 4947–60. ©2017 AACR.
Mathematical Modeling of Tumor–Tumor Distant Interactions Supports a Systemic Control of Tumor Growth
Authors: Benzekry Sebastien , Lamont Clare , Barbolosi Dominique , Hlatky Lynn , Hahnfeldt Philip 
Published: July 2017

Abstract
Interactions between different tumors within the same organism have major clinical implications, especially in the context of surgery and metastatic disease. Three main explanatory theories (competition, angiogenesis inhibition, and proliferation inhibition) have been proposed, but precise determinants of the phenomenon remain poorly understood. Here, we formalized these theories into mathematical models and performed biological experiments to test them with empirical data. In syngeneic mice bearing two simultaneously implanted tumors, growth of only one of the tumors was significantly suppressed (61% size reduction at day 15, P &lt; 0.05). The competition model had to be rejected, whereas the angiogenesis inhibition and proliferation inhibition models were able to describe the data. Additional models including a theory based on distant cytotoxic log-kill effects were unable to fit the data. The proliferation inhibition model was identifiable and minimal (four parameters), and its descriptive power was validated against the data, including consistency in predictions of single tumor growth when no secondary tumor was present. This theory may also shed new light on single cancer growth insofar as it offers a biologically translatable picture of how local and global action may combine to control local tumor growth and, in particular, the role of tumor-tumor inhibition. This model offers a depiction of concomitant resistance that provides an improved theoretical basis for tumor growth control and may also find utility in therapeutic planning to avoid postsurgery metastatic acceleration. Cancer Res; 77(18); 5183–93. ©2017 AACR.
Insurance Clearance for Early-Phase Oncology Clinical Trials Following the Affordable Care Act
Authors: Kehl Kenneth L. , Fullmer Cheryl P. , Fu Siqing , George Goldy C. , Hess Kenneth R. , Janku Filip , Karp Daniel D. , Kato Shumei , Kizer Cynthia K. , Kurzrock Razelle , Naing Aung , Pant Shubham , Piha-Paul Sarina A. , Subbiah Vivek , Tsimberidou Apostolia M. , Hong David S. 
Published: July 2017

Abstract
Purpose: The Affordable Care Act (ACA) required that private insurance plans allow clinical trial participation and cover standard-of-care costs, but the impact of this provision has not been well-characterized. We assessed rates of insurance clearance for trial participation within our large early-phase clinical trials program, before and after implementation of the requirement.
Experimental Design: We analyzed the departmental database for the Clinical Center for Targeted Therapy (CCTT) at MD Anderson Cancer Center (Houston, TX). Among patients referred for sponsored trials, we described rates of insurance clearance and prolonged time to clearance (at least 14 days) from July 2012 to June 2013 (baseline), July 2013–December 2013 (following CCTT staffing changes in July 2103), and January 2014–June 2015 (following implementation of the ACA). We used multivariable logistic regression models to compare rates across these time periods.
Results: We identified 2,404 referrals for insurance clearance. Among privately insured patients, insurance clearance rates were higher for those referred from January 2014 to June 2015 than for those referred from July 2012 to June 2013 (OR, 4.72; 95% CI, 2.96–7.51). There was no association between referral period and clearance rates for Medicare/Medicaid patients (P = 0.25). Referral from January 2014 to June 2015 was associated with lower rates of prolonged clearance among both privately insured (OR 0.57; 95% CI, 0.38–0.86) and Medicare/Medicaid patients (OR 0.39; 95% CI, 0.19–0.83).
Conclusions: Within our large early-phase clinical trials program, insurance clearance rates among privately insured patients improved following implementation of the ACA's requirement for coverage of standard-of-care costs. Clin Cancer Res; 23(15); 4155–62. ©2017 AACR.
Quercetin Targets hnRNPA1 to Overcome Enzalutamide Resistance in Prostate Cancer Cells
Authors: Tummala Ramakumar , Lou Wei , Gao Allen C. , Nadiminty Nagalakshmi 
Published: July 2017

Abstract
Prostate cancer remains dependent on androgen receptor signaling even after castration. Aberrant androgen receptor signaling in castration-resistant prostate cancer is mediated by mechanisms such as alterations in the androgen receptor and activation of interacting signaling pathways. Clinical evidence confirms that resistance to the next-generation antiandrogen, enzalutamide, may be mediated to a large extent by alternative splicing of the androgen receptor to generate constitutively active splice variants such as AR-V7. The splice variants AR-V7 and ARv567es have been implicated in the resistance to not only enzalutamide, but also to abiraterone and other conventional therapeutics such as taxanes. Numerous studies, including ours, suggest that splicing factors such as hnRNPA1 promote the generation of AR-V7, thus contributing to enzalutamide resistance in prostate cancer cells. In the present study, we discovered that quercetin, a naturally occurring polyphenolic compound, reduces the expression of hnRNPA1, and consequently, that of AR-V7. The suppression of AR-V7 by quercetin resensitizes enzalutamide-resistant prostate cancer cells to treatment with enzalutamide. Our results indicate that quercetin downregulates hnRNPA1 expression, downregulates the expression of AR-V7, antagonizes androgen receptor signaling, and resensitizes enzalutamide-resistant prostate cancer cells to enzalutamide treatment in vivo in mouse xenografts. These findings demonstrate that suppressing the alternative splicing of the androgen receptor may have important implications in overcoming the resistance to next-generation antiandrogen therapy. Mol Cancer Ther; 16(12); 2770–9. ©2017 AACR.
Autophagy Inhibition Improves Sunitinib Efficacy in Pancreatic Neuroendocrine Tumors via a Lysosome-dependent Mechanism
Authors: Wiedmer Tabea , Blank Annika , Pantasis Sophia , Normand Lea , Bill Ruben , Krebs Philippe , Tschan Mario P. , Marinoni Ilaria , Perren Aurel 
Published: July 2017

Abstract
Increasing the efficacy of approved systemic treatments in metastasized pancreatic neuroendocrine tumors (PanNET) is an unmet medical need. The antiangiogenic tyrosine kinase inhibitor sunitinib is approved for PanNET treatment. In addition, sunitinib is a lysosomotropic drug and such drugs can induce lysosomal membrane permeabilization as well as autophagy. We investigated sunitinib-induced autophagy as a possible mechanism of PanNET therapy resistance. Sunitinib accumulated in lysosomes and induced autophagy in PanNET cell lines. Adding the autophagy inhibitor chloroquine reduced cell viability in cell lines and in primary cells isolated from PanNET patients. The same treatment combination reduced tumor burden in the Rip1Tag2 transgenic PanNET mouse model. The combination of sunitinib and chloroquine reduced recovery and induced apoptosis in vitro, whereas single treatments did not. Knockdown of key autophagy proteins in combination with sunitinib showed similar effect as chloroquine. Sunitinib also induced lysosomal membrane permeabilization, which further increased in the presence of chloroquine or knockdown of lysosome-associated membrane protein (LAMP2). Both combinations led to cell death. Our data indicate that chloroquine increases sunitinib efficacy in PanNET treatment via autophagy inhibition and lysosomal membrane permeabilization. We suggest that adding chloroquine to sunitinib treatment will increase efficacy of PanNET treatment and that such patients should be included in respective ongoing clinical trials. Mol Cancer Ther; 16(11); 2502–15. ©2017 AACR.
The IGF1R/INSR Inhibitor BI 885578 Selectively Inhibits Growth of IGF2-Overexpressing Colorectal Cancer Tumors and Potentiates the Efficacy of Anti-VEGF Therapy
Authors: Sanderson Michael P. , Hofmann Marco H. , Garin-Chesa Pilar , Schweifer Norbert , Wernitznig Andreas , Fischer Stefan , Jeschko Astrid , Meyer Reiner , Moll Jürgen , Pecina Thomas , Arnhof Heribert , Weyer-Czernilofsky Ulrike , Zahn Stephan K. , Adolf Günther R. , Kraut Norbert 
Published: July 2017

Abstract
Clinical studies of pharmacologic agents targeting the insulin-like growth factor (IGF) pathway in unselected cancer patients have so far demonstrated modest efficacy outcomes, with objective responses being rare. As such, the identification of selection biomarkers for enrichment of potential responders represents a high priority for future trials of these agents. Several reports have described high IGF2 expression in a subset of colorectal cancers, with focal IGF2 amplification being responsible for some of these cases. We defined a novel cut-off value for IGF2 overexpression based on differential expression between colorectal tumors and normal tissue samples. Analysis of two independent colorectal cancer datasets revealed IGF2 to be overexpressed at a frequency of 13% to 22%. An in vitro screen of 34 colorectal cancer cell lines revealed IGF2 expression to significantly correlate with sensitivity to the IGF1R/INSR inhibitor BI 885578. Furthermore, autocrine IGF2 constitutively activated IGF1R and Akt phosphorylation, which was inhibited by BI 885578 treatment. BI 885578 significantly delayed the growth of IGF2-high colorectal cancer xenograft tumors in mice, while combination with a VEGF-A antibody increased efficacy and induced tumor regression. Besides colorectal cancer, IGF2 overexpression was detected in more than 10% of bladder carcinoma, hepatocellular carcinoma and non-small cell lung cancer patient samples. Meanwhile, IGF2-high non-colorectal cancer cells lines displayed constitutive IGF1R phosphorylation and were sensitive to BI 885578. Our findings suggest that IGF2 may represent an attractive patient selection biomarker for IGF pathway inhibitors and that combination with VEGF-targeting agents may further improve clinical outcomes. Mol Cancer Ther; 16(10); 2223–33. ©2017 AACR.