bluuebunny/crossref_metadata_2025_split huggingface dataset:
OPTIMAL TRIANGULATIONS OF POINTS AND SEGMENTS WITH STEINER POINTS
Authors: ARONOV BORIS , ASANO TETSUO , FUNKE STEFAN 
Published: March 2010

Consider a set X of points in the plane and a set E of non-crossing segments with endpoints in X. One can efficiently compute the triangulation of the convex hull of the points, which uses X as the vertex set, respects E, and maximizes the minimum internal angle of a triangle. In this paper we consider a natural extension of this problem: Given in addition a Steiner pointp, determine the optimal location of p and a triangulation of X ∪ {p} respecting E, which is best among all triangulations and placements of p in terms of maximizing the minimum internal angle of a triangle. We present a polynomial-time algorithm for this problem and then extend our solution to handle any constant number of Steiner points.
Preclinical Evaluation of Radiation and Perifosine in a Genetically and Histologically Accurate Model of Brainstem Glioma
Authors: Becher Oren J. , Hambardzumyan Dolores , Walker Talia R. , Helmy Karim , Nazarian Javad , Albrecht Steffen , Hiner Rebecca L. , Gall Sarah , Huse Jason T. , Jabado Nada , MacDonald Tobey J. , Holland Eric C. 
Published: March 2010

AbstractBrainstem gliomas (BSG) are a rare group of central nervous system tumors that arise mostly in children and usually portend a particularly poor prognosis. We report the development of a genetically engineered mouse model of BSG using the RCAS/tv-a system and its implementation in preclinical trials. Using immunohistochemistry, we found that platelet-derived growth factor (PDGF) receptor α is overexpressed in 67% of pediatric BSGs. Based on this observation, we induced low-grade BSGs by overexpressing PDGF-B in the posterior fossa of neonatal nestin tv-a mice. To generate high-grade BSGs, we overexpressed PDGF-B in combination with Ink4a-ARF loss, given that this locus is commonly lost in high-grade pediatric BSGs. We show that the likely cells of origin for these mouse BSGs exist on the floor of the fourth ventricle and cerebral aqueduct. Irradiation of these high-grade BSGs shows that although single doses of 2, 6, and 10 Gy significantly increased the percent of terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling (TUNEL)–positive nuclei, only 6 and 10 Gy significantly induce cell cycle arrest. Perifosine, an inhibitor of AKT signaling, significantly induced TUNEL-positive nuclei in this high-grade BSG model, but in combination with 10 Gy, it did not significantly increase the percent of TUNEL-positive nuclei relative to 10 Gy alone at 6, 24, and 72 hours. Survival analysis showed that a single dose of 10 Gy significantly prolonged survival by 27% (P = 0.0002) but perifosine did not (P = 0.92). Perifosine + 10 Gy did not result in a significantly increased survival relative to 10 Gy alone (P = 0.23). This PDGF-induced BSG model can serve as a preclinical tool for the testing of novel agents. Cancer Res; 70(6); 2548–57
Oncogenic Potential of Retinoic Acid Receptor-γ in Hepatocellular Carcinoma
Authors: Yan Ting-Dong , Wu Hua , Zhang Hai-Ping , Lu Na , Ye Ping , Yu Feng-Hai , Zhou Hu , Li Wen-Gang , Cao Xihua , Lin Ya-Yu , He Jia-You , Gao Wei-Wei , Zhao Yi , Xie Lei , Chen Jie-bo , Zhang Xiao-kun , Zeng Jin-Zhang 
Published: March 2010

Abstract
Retinoic acid receptors (RAR; α, β, and γ), members of the nuclear receptor superfamily, mediate the pleiotropic effects of the vitamin A metabolite retinoic acid (RA) and derivatives (retinoids) in normal and cancer cells. Abnormal expression and function of RARs are often involved in the growth and development of cancer. However, the underlying molecular mechanisms remain largely elusive. Here, we report that levels of RARγ were significantly elevated in tumor tissues from a majority of human hepatocellular carcinoma (HCC) and in HCC cell lines. Overexpression of RARγ promoted colony formation by HCC cells in vitro and the growth of HCC xenografts in animals. In HepG2 cells, transfection of RARγ enhanced, whereas downregulation of RARγ expression by siRNA approach impaired, the effect of RA on inducing the expression of α-fetoprotein, a protein marker of hepatocarcinogenesis. In studying the possible mechanism by which overexpression of RARγ contributed to liver cancer cell growth and transformation, we observed that RARγ resided mainly in the cytoplasm of HCC cells, interacting with the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K). The interaction between RARγ and p85α resulted in activation of Akt and NF-κB, critical regulators of the growth and survival of cancer cells. Together, our results show that overexpression of RARγ plays a role in the growth of HCC cells through nongenomic activation of the PI3K/Akt and NF-κB signaling pathways. Cancer Res; 70(6); 2285–95
Downregulation of Notch Pathway by a γ-Secretase Inhibitor Attenuates AKT/Mammalian Target of Rapamycin Signaling and Glucose Uptake in an ERBB2 Transgenic Breast Cancer Model
Authors: Efferson Clay L. , Winkelmann Christopher T. , Ware Christopher , Sullivan Timothy , Giampaoli Saverio , Tammam Jennifer , Patel Shailendra , Mesiti Giuseppe , Reilly John F. , Gibson Raymond E. , Buser Carolyn , Yeatman Timothy , Coppola Domenico , Winter Christopher , Clark Edwin A. , Draetta Giulio F. , Strack Peter R. , Majumder Pradip K. 
Published: March 2010

Abstract
ERBB2/neu and Notch signaling are known to be deregulated in many human cancers. However, pathway cross-talk and dependencies are not well understood. In this study, we use an ERBB2-transgenic mouse model of breast cancer (neuT) to show that Notch signaling plays a critical role in tumor maintenance. Inhibition of the Notch pathway with a γ-secretase inhibitor (GSI) decreased both the Notch and the mammalian target of rapamycin/AKT pathways. Antitumor activity resulting from GSI treatment was associated with decreased cell proliferation as measured by Ki67 and decreased expression of glucose transporter Glut1. Positron emission tomography (PET) imaging showed that the functional consequences of decreased Glut1 translated to reduced glucose uptake and correlated with antitumor effects as measured by micro-computed tomography imaging. The decrease of Glut1 in neuT tumors was also observed in several human breast cancer cell lines following GSI treatment. We provide evidence that ∼27% of ERBB2-positive human breast cancer specimens display high expression of HES1, phospho-S6RP, and GLUT1. Together, these results suggest that pathways downstream of Notch signaling are, at least in part, responsible for promoting tumor growth in neuT and also active in both neuT and a subset of human breast cancers. These findings suggest that GSI may provide therapeutic benefit to a subset of ERBB2-positive breast cancers and that [18F]FDG-PET imaging may be useful in monitoring clinical response. Cancer Res; 70(6); 2476–84
Hsp27 Promotes Insulin-Like Growth Factor-I Survival Signaling in Prostate Cancer via p90Rsk-Dependent Phosphorylation and Inactivation of BAD
Authors: Zoubeidi Amina , Zardan Anousheh , Wiedmann Romina M. , Locke Jennifer , Beraldi Eliana , Fazli Ladan , Gleave Martin E. 
Published: March 2010

Abstract
Hsp27 is highly expressed in castrate-resistant prostate cancer. Although its overexpression confers resistance to androgen ablation and chemotherapy, the mechanisms by which Hsp27 inhibits treatment-induced apoptosis are incompletely defined. Castrate-resistance often correlates with increased activity of autocrine and/or paracrine growth/survival stimulatory loops including the mitogen-activated protein kinase (MAPK) and Akt pathways and insulin-like growth factor (IGF) axis components. Because Hsp27 can be activated by both MAPK and Akt pathways, it is possible that interactions between IGF-I signaling and Hsp27 phosphoactivation function to promote castrate-resistant progression. Here, we report that Hsp27 expression and phosphorylation levels correlate with IGF-I signaling and castrate-resistant progression in human prostate cancer specimens and cell lines. IGF-I induces Hsp27 phosphorylation in a time- and dose-dependent manner via p90Rsk, which interacts directly with and phosphorylates Hsp27 in vitro and in vivo. Conversely, p90Rsk inhibition using short interfering RNA or a dominant negative mutant abolishes IGF-I–induced Hsp27 phosphorylation. Hsp27 overexpression increases IGF-I–induced phosphorylation of Erk, p90Rsk, and Akt. Conversely, Hsp27 knockdown abrogates IGF-I–induced phosphorylation of Erk, p90Rsk, and Akt, thereby destabilizing Bad/14-3-3 complexes and increasing apoptotic rates. These data elucidate the interactions between Hsp27 phosphorylation and the IGF-I receptor signaling pathway and support targeting Hsp27 as a therapeutic strategy for castrate-resistant prostate cancer. Cancer Res; 70(6); 2307–17
Jun Proteins Are Starvation-Regulated Inhibitors of Autophagy
Authors: Yogev Orli , Goldberg Rachel , Anzi Shira , Yogev Ohad , Shaulian Eitan 
Published: March 2010

Abstract
The growing number of biological functions affected by autophagy ascribes a special significance to identification of factors regulating it. The activator protein-1 (AP-1) transcription factors are involved in most aspects of cellular proliferation, death, or survival, yet no information regarding their involvement in autophagy is available. Here, we show that the AP-1 proteins JunB and c-Jun, but not JunD, c-Fos, or Fra-1, inhibit autophagy. JunB inhibits autophagy induced by starvation, overexpression of a short form of ARF (smARF), a potent inducer of autophagy, or even after rapamycin treatment. In agreement, acute repression of JunB expression, by JunB knockdown, potently induces autophagy. As expected from autophagy-inhibiting proteins, Jun B and c-Jun expression is reduced by starvation. Decrease in JunB mRNA expression and posttranscriptional events downregulate JunB protein expression after starvation. The inhibition of autophagy by JunB is not mediated by mammalian target of rapamycin (mTOR) regulation, as it occurs also in the absence of mTOR activity, and autophagy induced by JunB knockdown is not correlated with changes in mTOR activity. Nevertheless, the transcriptional activities of c-Jun and JunB are required for autophagy inhibition, and JunB incapable of heterodimerizing is a less effective inhibitor of autophagy. Most importantly, inhibition of autophagy in starved HeLa cells by JunB enhances apoptotic cell death. We suggest that JunB and c-Jun are regulators of autophagy whose expression responds to autophagy-inducing signals. Cancer Res; 70(6); 2318–27
Plasma Homocysteine and Cysteine and Risk of Breast Cancer in Women
Authors: Lin Jennifer , Lee I-Min , Song Yiqing , Cook Nancy R. , Selhub Jacob , Manson JoAnn E. , Buring Julie E. , Zhang Shumin M. 
Published: March 2010

Abstract
Homocysteine and cysteine are associated with oxidative damage and metabolic disorders, which may lead to carcinogenesis. Observational studies assessing the association between circulating homocysteine or cysteine and breast cancer are very limited, and findings have been inconsistent. We prospectively evaluated plasma levels of homocysteine and cysteine in relation to breast cancer risk among 812 incident cases of invasive breast cancer and 812 individually matched control subjects from 28,345 women in the Women's Health Study; these women were ≥45 years old, provided blood samples, and had no history of cancer and cardiovascular disease at baseline. Logistic regression controlling for matching factors and risk factors for breast cancer was used to estimate relative risks (RR) and 95% confidence intervals (95% CI). All statistical tests were two sided. Homocysteine levels were not associated with overall risk for breast cancer. However, we observed a positive association between cysteine levels and breast cancer risk; the multivariate RR for the highest quintile group relative to the lowest quintile was 1.65 (95% CI, 1.04–2.61; P for trend = 0.04). In addition, women with higher levels of homocysteine and cysteine were at a greater risk for developing breast cancer when their folate levels were low (P for interaction = 0.04 and 0.002, respectively). Although our study offers little support for an association between circulating homocysteine and overall breast cancer risk, higher homocysteine levels may be associated with an increased risk for breast cancer among women with low folate status. The increased risk of breast cancer associated with high cysteine levels warrants further investigation. Cancer Res; 70(6); 2397–405
Mesalazine Reduces Mutations in Transforming Growth Factor β Receptor II and Activin Type II Receptor by Improvement of Replication Fidelity in Mononucleotide Repeats
Authors: Campregher Christoph , Honeder Clemens , Chung Heekyung , Carethers John M. , Gasche Christoph 
Published: March 2010

Abstract
Purpose: Mesalazine (5-aminosalicylic acid, 5-ASA) has chemopreventive properties in colitis-associated cancer. In vitro, it improves replication fidelity at (CA)13 microsatellites independent of mismatch repair proficiency. Therefore, 5-ASA might be advantageous in patients with hereditary nonpolyposis colorectal cancer. At this point, however, it is uncertain whether this improvement of replication fidelity is specific for (CA)13 repetitive sequences. Here, we tested the effect of 5-ASA on replication fidelity in mononucleotide, dinucleotide, and tetranucleotide repeats.
Experimental Design: HCT116 and HCT116+chr3 cells were transfected with pIREShyg2-EGFP reporter plasmids harboring the following microsatellites: A10, G10, (CA)13, (CA)26, (AAAG)17, poly-A tracts, and their flanking sequences of transforming growth factor β receptor II (TGFBR2; A10) and activin type II receptor (ACVR2; A8). Stably transfected single-cell clones were selected, characterized by Southern blotting, sorted into six-well plates, and cultured with or without 5-ASA. Frameshift mutations that shift the enhanced green fluorescence protein into its proper reading frame were quantified by flow cytometry.
Results: In HCT116, 5-ASA reduced the mutant fraction at (CA)13 by 48.3%, at A10 by 35.6-43.6%, at G10 by 74.9-83.6%, and at (AAAG)17 by 37.6-44.4%. Similar results were observed in hMLH1-proficient HCT116+chr3 cells. Moreover, the presence of 5-ASA significantly reduced mutations in TGFBR2 (A10) and ACVR2 (A8) by 39.9% and 46.2%, respectively.
Conclusions: 5-ASA increases replication fidelity in mononucleotide, dinucleotide, and tetranucleotide repeats and reduces mutations in tumor suppressor genes TGFBR2 and ACVR2, a finding that may provoke in vivo studies for the prevention of colorectal cancer in hereditary nonpolyposis colorectal cancer. Clin Cancer Res; 16(6); 1950–6
SB939, a Novel Potent and Orally Active Histone Deacetylase Inhibitor with High Tumor Exposure and Efficacy in Mouse Models of Colorectal Cancer
Authors: Novotny-Diermayr Veronica , Sangthongpitag Kanda , Hu Chang Yong , Wu Xiaofeng , Sausgruber Nina , Yeo Pauline , Greicius Gediminas , Pettersson Sven , Liang Ai Leng , Loh Yung Kiang , Bonday Zahid , Goh Kee Chuan , Hentze Hannes , Hart Stefan , Wang Haishan , Ethirajulu Kantharaj , Wood Jeanette Marjorie 
Published: March 2010

Abstract
Although clinical responses in liquid tumors and certain lymphomas have been reported, the clinical efficacy of histone deacetylase inhibitors in solid tumors has been limited. This may be in part due to the poor pharmacokinetic of these drugs, resulting in inadequate tumor concentrations of the drug. SB939 is a new hydroxamic acid based histone deacetylase inhibitor with improved physicochemical, pharmaceutical, and pharmacokinetic properties. In vitro, SB939 inhibits class I, II, and IV HDACs, with no effects on other zinc binding enzymes, and shows significant antiproliferative activity against a wide variety of tumor cell lines. It has very favorable pharmacokinetic properties after oral dosing in mice, with &gt;4-fold increased bioavailability and 3.3-fold increased half-life over suberoylanilide hydroxamic acid (SAHA). In contrast to SAHA, SB939 accumulates in tumor tissue and induces a sustained inhibition of histone acetylation in tumor tissue. These excellent pharmacokinetic properties translated into a dose-dependent antitumor efficacy in a xenograft model of human colorectal cancer (HCT-116), with a tumor growth inhibition of 94% versus 48% for SAHA (both at maximum tolerated dose), and was also effective when given in different intermittent schedules. Furthermore, in APCmin mice, a genetic mouse model of early-stage colon cancer, SB939 inhibited adenoma formation, hemocult scores, and increased hematocrit values more effectively than 5-fluorouracil. Emerging clinical data from phase I trials in cancer patients indicate that the pharmacokinetic and pharmacologic advantages of SB939 are translated to the clinic. The efficacy of SB939 reported here in two very different models of colorectal cancer warrants further investigation in patients. Mol Cancer Ther; 9(3); 642–52
Doxorubicin Resistance in a NovelIn vitroModel of Human Pleomorphic Liposarcoma Associated with Alternative Lengthening of Telomeres
Authors: Mitchell Marcy A. , Johnson Jay E. , Pascarelli Kara , Beeharry Neil , Chiourea Maria , Gagos Sarantis , Lev Dina , von Mehren Margaret , Kipling David , Broccoli Dominique 
Published: March 2010

AbstractSoft tissue sarcomas are a diverse set of fatal human tumors where few agents have demonstrable clinical efficacy, with the standard therapeutic combination of doxorubicin and ifosfamide showing only a 25% to 30% response rate in large multi-institutional trials. Although liposarcomas are the most common histologic form of adult soft tissue sarcomas, research in this area is severely hampered by the lack of experimentally tractable in vitro model systems. To this end, here we describe a novel in vitro model for human pleomorphic liposarcoma. The cell line (LS2) is derived from a pleomorphic liposarcoma that uses the alternative lengthening of telomeres (ALT) mechanism of telomere maintenance, which may be important in modulating the response of this tumor type to DNA-damaging agents. We present detailed baseline molecular and genomic data, including genome-wide copy number and transcriptome profiles, for this model compared with its parental tumor and a panel of liposarcomas covering multiple histologies. The model has retained essentially all of the detectable alterations in copy number that are seen in the parental tumor, and shows molecular karyotypic and expression profiles consistent with pleomorphic liposarcomas. We also show the utility of this model, together with two additional human liposarcoma cell lines, to investigate the relationship between topoisomerase 2A expression and the sensitivity of ALT-positive liposarcomas to doxorubicin. This model, together with its associated baseline data, provides a powerful new tool to develop treatments for this clinically poorly tractable tumor and to investigate the contribution that ALT makes to modulating sensitivity to doxorubicin. Mol Cancer Ther; 9(3); 682–92
2-Methoxyestradiol Inhibits Barrett's Esophageal Adenocarcinoma Growth and Differentiation through Differential Regulation of the β-Catenin–E-Cadherin Axis
Authors: Kambhampati Suman , Banerjee Snigdha , Dhar Kakali , Mehta Smita , Haque Inamul , Dhar Gopal , Majumder Monami , Ray Gibanananda , Vanveldhuizen Peter J. , Banerjee Sushanta K. 
Published: March 2010

Abstract
The purpose of this study was to evaluate whether 2-methoxyestradiol (2-ME2), a promising anticancer agent, modulates Barrett's esophageal adenocarcinoma (BEAC) cell growth and behavior through a cellular pathway involving β-catenin in partnership with E-cadherin, which seems to play a critical role in the induction of antitumor responses in cancer cells. We found that 2-ME2 markedly reduced the BEAC cell proliferation through regulating apoptotic machinery such as Bcl-2 and Bax. It may nullify the aggressive behavior of the cells by reducing the migratory behavior. Expressions of β-catenin and E-cadherin and binding of these two proteins is activated in a 2-ME2–dependent fashion in Bic-1 cells. Moreover, overexpressions of these two proteins may be due to the stabilization of these proteins by 2-ME2. We found that 2-ME2–induced antimigratory effects are mediated through the β-catenin–E-cadherin signaling pathways. In view of these results, we determined whether 2-ME2 reduces BEAC tumor growth. Administration of 2-ME2 significantly decreased the growth of BEAC cells xenografted on the flank of nude mice. The evidence presented points out that the effect of 2-ME2 on β-catenin–orchestrated signal transduction plausibly plays a multifaceted functional role to inhibit the proliferation and cell migration of 2-ME2–treated malignant cells and it could be a potential candidate in novel treatment strategies for Barrett's esophageal adenocarcinoma. Mol Cancer Ther; 9(3); 523–34
Sorafenib Inhibits STAT3 Activation to Enhance TRAIL-Mediated Apoptosis in Human Pancreatic Cancer Cells
Authors: Huang Shengbing , Sinicrope Frank A. 
Published: March 2010

Abstract
Signal transducers and activators of transcription 3 (STAT3) is constitutively active in human pancreatic cancer cells and can promote cell growth and apoptosis resistance that contribute to tumorigenesis. We determined if sorafenib, a multikinase inhibitor, can induce apoptosis by targeting STAT3 signaling to enhance apoptosis induction by tumor necrosis factor–related apoptosis-inducing ligand (TRAIL). Human pancreatic cancer cell lines (PANC-1 and BxPC-3) were preincubated with sorafenib (Nexavar) alone or followed by TRAIL. Apoptosis was determined by Annexin V labeling, caspase cleavage, and Bax/Bak activation. Protein expression was analyzed by immunoblotting. Knockdown of STAT3, Mcl-1, and Bim were achieved by lentiviral small hairpin RNA. Adenoviral dominant-negative or retroviral constitutively active (CA) STAT3 were also used. Sorafenib inhibited constitutive STAT3 phosphorylation (Tyr705) and suppressed Mcl-1 and Bcl-xL proteins in a dose- and time-dependent manner. CA-STAT3 overexpression was shown to attenuate caspase-3 cleavage and suppression of Mcl-1 by sorafenib. STAT3 knockdown or a DN STAT3 was shown to downregulate Mcl-1 and Bcl-xL and to sensitize cells to TRAIL-mediated apoptosis. Treatment with sorafenib enhanced TRAIL-induced Annexin V staining and release of mitochondrial cytochrome c and AIF. Because the BH3-only Bim protein is a potent inducer of mitochondrial apoptosis, Bim knockdown was shown to attenuate caspase-3, caspase-9 cleavage, and Bax/Bak activation by sorafenib plus TRAIL. The suppression of STAT3 by genetic means or using sorafenib was shown to downregulate Mcl-1 and Bcl-xL and to sensitize cells to TRAIL-mediated apoptosis. These data indicate that targeting STAT3 may enhance treatment efficacy against pancreatic cancer. Mol Cancer Ther; 9(3); 742–50