bluuebunny/crossref_metadata_2025 huggingface dataset:
AZD1152 Rapidly and Negatively Affects the Growth and Survival of Human Acute Myeloid Leukemia Cells In vitro and In vivo
Authors: Oke Adedayo , Pearce Daniel , Wilkinson Robert W. , Crafter Claire , Odedra Rajesh , Cavenagh Jamie , Fitzgibbon Jude , Lister Andrew T. , Joel Simon , Bonnet Dominique
Published: April 2009

Aurora kinases play a critical role in regulating mitosis and cell division, and their overexpression has been implicated in the survival and proliferation of human cancer. In this study, we report the in vitro and in vivo activities of AZD1152, a compound that has selectivity for aurora B kinase, in acute myeloid leukemia (AML) cell lines, primary AML samples, and cord blood cells. AZD1152 exerted antiproliferative or cytotoxic effects in all cell lines studied, inhibited the phosphorylation of histone H3 (pHis H3) on Ser10 in a dose-dependent manner, and resulted in cells with >4N DNA content. THP-1 cells treated with AZD1152 accumulated in a state of polyploidy and showed a senescent response to the drug, in contrast to the apoptotic response seen in other cell lines. Accordingly, AZD1152 profoundly affected the growth of AML cell lines and primary AML in an in vivo xenotransplantation model. However, concentration-dependent effects on cell growth, apoptosis, and cell cycle progression were also observed when human cord blood and primary lineage–negative stem and progenitor cells were analyzed in vitro and in vivo. These data suggest that the inhibition of aurora B kinase may be a useful therapeutic strategy in the treatment of AML and that further exploration of dosing and treatment schedules is warranted in clinical trials. [Cancer Res 2009;69(10):4150–8]
Pharmacologic Abrogation of the Mitotic Spindle Checkpoint by an Indolocarbazole Discovered by Cellular Screening Efficiently Kills Cancer Cells
Authors: Stolz Ailine , Vogel Celia , Schneider Verena , Ertych Norman , Kienitz Anne , Yu Hongtao , Bastians Holger
Published: April 2009

The mitotic spindle checkpoint represents a signal transduction pathway that prevents the onset of anaphase until all chromosomes are properly aligned on a metaphase plate. Partial inactivation of this checkpoint allows premature separation of sister chromatids and results in aneuploidy, which might contribute to tumorigenesis. Unlike other cell cycle checkpoints, the spindle checkpoint is essential for cell viability, giving rise to the idea that the spindle checkpoint itself might represent a valuable target for anticancer therapy. We used a cell-based screen and identified the indolocarbazole compound Gö6976 as a pharmacologic inhibitor of the spindle checkpoint. Gö6976 potently overrides a spindle checkpoint–mediated mitotic arrest by abrogating the phosphorylation and kinetochore localization of several spindle checkpoint proteins. We identified the Aurora-A and Aurora-B kinases, which have been previously implicated in proper mitotic progression and spindle checkpoint function, as targets for Gö6976. Accordingly, Gö6976 treatment causes severe mitotic abnormalities and chromosome alignment defects, which are not properly detected by the drug-inactivated spindle checkpoint. This results in an aberrant progression of mitosis, leading to apoptosis in various human cancer cell lines, including spindle checkpoint–compromised cancer cells. Thus, our work describes a novel and promising strategy for anticancer treatment that targets the mitotic spindle checkpoint. [Cancer Res 2009;69(9):3874–83]
SCUBE2 Suppresses Breast Tumor Cell Proliferation and Confers a Favorable Prognosis in Invasive Breast Cancer
Authors: Cheng Chien-Jui , Lin Yuh-Charn , Tsai Ming-Tzu , Chen Ching-Shyang , Hsieh Mao-Chih , Chen Chi-Long , Yang Ruey-Bing
Published: April 2009

Signal peptide-CUB-epidermal growth factor–like domain-containing protein 2 (SCUBE2), originally identified from the endothelium and several nonendothelial primary cell types, was recently shown to be expressed in invasive breast carcinomas. However, the protein localization and biological significance of SCUBE2 in breast cancer are unknown. In this report, we show by anti-SCUBE2 immunostaining that SCUBE2 is mainly expressed in vascular endothelial and mammary ductal epithelial cells in normal breast tissue. In addition, we observed positive staining for SCUBE2 in 55% (86 of 156) of primary breast tumors. Patients with positive SCUBE2 protein–expressing tumors had better prognosis than those with negative SCUBE2 protein–expressing tumors in terms of disease-free survival. Multivariate analysis confirmed SCUBE2 protein expression as an independent prognostic factor for disease-free survival. Furthermore, overexpression of ectopic SCUBE2 protein resulted in suppression of MCF-7 breast cancer cell proliferation and reduced MCF-7 xenograft tumor growth in nude mice. Molecular and biochemical analyses revealed that the COOH terminal region of SCUBE2 directly bound to and antagonized bone morphogenetic protein activity. Together, our results show for the first time that altered SCUBE2 expression is important in breast cancer progression and SCUBE2 may serve as a useful prognostic marker. [Cancer Res 2009;69(8):3634–41]
Multiparameter Computational Modeling of Tumor Invasion
Authors: Bearer Elaine L. , Lowengrub John S. , Frieboes Hermann B. , Chuang Yao-Li , Jin Fang , Wise Steven M. , Ferrari Mauro , Agus David B. , Cristini Vittorio
Published: April 2009

Clinical outcome prognostication in oncology is a guiding principle in therapeutic choice. A wealth of qualitative empirical evidence links disease progression with tumor morphology, histopathology, invasion, and associated molecular phenomena. However, the quantitative contribution of each of the known parameters in this progression remains elusive. Mathematical modeling can provide the capability to quantify the connection between variables governing growth, prognosis, and treatment outcome. By quantifying the link between the tumor boundary morphology and the invasive phenotype, this work provides a quantitative tool for the study of tumor progression and diagnostic/prognostic applications. This establishes a framework for monitoring system perturbation towards development of therapeutic strategies and correlation to clinical outcome for prognosis.[Cancer Res 2009;69(10):4493–501]

Major Findings We apply a biologically founded, multiscale, mathematical model to identify and quantify tumor biologic and molecular properties relating to clinical and morphological phenotype and to demonstrate that tumor growth and invasion are predictable processes governed by biophysical laws, and regulated by heterogeneity in phenotypic, genotypic, and microenvironmental parameters. This heterogeneity drives migration and proliferation of more aggressive clones up cell substrate gradients within and beyond the central tumor mass, while often also inducing loss of cell adhesion. The model predicts that this process triggers a gross morphologic instability that leads to tumor invasion via individual cells, cell chains, strands, or detached clusters infiltrating into adjacent tissue producing the typical morphologic patterns seen, e.g., in the histopathology of glioblastoma multiforme. The model further predicts that these different morphologies of infiltration correspond to different stages of tumor progression regulated by heterogeneity.
Quantitative Metrics of Net Proliferation and Invasion Link Biological Aggressiveness Assessed by MRI with Hypoxia Assessed by FMISO-PET in Newly Diagnosed Glioblastomas
Authors: Szeto Mindy D. , Chakraborty Gargi , Hadley Jennifer , Rockne Russ , Muzi Mark , Alvord Ellsworth C. , Krohn Kenneth A. , Spence Alexander M. , Swanson Kristin R.
Published: April 2009

Glioblastoma multiforme (GBM) are aggressive and uniformly fatal primary brain tumors characterized by their diffuse invasion of the normal-appearing parenchyma peripheral to the clinical imaging abnormality. Hypoxia, a hallmark of aggressive tumor behavior often noted in GBMs, has been associated with resistance to therapy, poorer survival, and more malignant tumor phenotypes. Based on the existence of a set of novel imaging techniques and modeling tools, our objective was to assess a hypothesized quantitative link between tumor growth kinetics [assessed via mathematical models and routine magnetic resonance imaging (MRI)] and the hypoxic burden of the tumor [assessed via positron emission tomography (PET) imaging]. Our biomathematical model for glioma kinetics describes the spatial and temporal evolution of a glioma in terms of concentration of malignant tumor cells. This model has already been proven useful as a novel tool to dynamically quantify the net rates of proliferation (ρ) and invasion (D) of the glioma cells in individual patients. Estimates of these kinetic rates can be calculated from routinely available pretreatment MRI in vivo. Eleven adults with GBM were imaged preoperatively with 18F-fluoromisonidazole (FMISO)–PET and serial gadolinium-enhanced T1- and T2-weighted MRIs to allow the estimation of patient-specific net rates of proliferation (ρ) and invasion (D). Hypoxic volumes were quantified from each FMISO-PET scan following standard techniques. To control for tumor size variability, two measures of hypoxic burden were considered: relative hypoxia (RH), defined as the ratio of the hypoxic volume to the T2-defined tumor volume, and the mean intensity on FMISO-PET scaled to the blood activity of the tracer (mean T/B). Pearson correlations between RH and the net rate of cell proliferation (ρ) reached significance (P < 0.04). Moreover, highly significant positive correlations were found between biological aggressiveness ratio (ρ/D) and both RH (P < 0.00003) and the mean T/B (P < 0.0007). [Cancer Res 2009;69(10):4502–9]

Major Findings Overall, biological aggressiveness assessed by serial MRI is linked with hypoxic burden assessed on FMISO-PET using a novel biomathematical model for glioma growth and invasion. This study suggests that patient-specific modeling of growth kinetics can provide novel and valuable insight into the quantitative connections between disparate information provided by multimodality imaging.
Global Histone Modifications in Breast Cancer Correlate with Tumor Phenotypes, Prognostic Factors, and Patient Outcome
Authors: Elsheikh Somaia E. , Green Andrew R. , Rakha Emad A. , Powe Des G. , Ahmed Rabab A. , Collins Hilary M. , Soria Daniele , Garibaldi Jonathan M. , Paish Claire E. , Ammar Amr A. , Grainge Matthew J. , Ball Graham R. , Abdelghany Magdy K. , Martinez-Pomares Luisa , Heery David M. , Ellis Ian O.
Published: April 2009

Post-translational histone modifications are known to be altered in cancer cells, and loss of selected histone acetylation and methylation marks has recently been shown to predict patient outcome in human carcinoma. Immunohistochemistry was used to detect a series of histone lysine acetylation (H3K9ac, H3K18ac, H4K12ac, and H4K16ac), lysine methylation (H3K4me2 and H4K20me3), and arginine methylation (H4R3me2) marks in a well-characterized series of human breast carcinomas (n = 880). Tissue staining intensities were assessed using blinded semiquantitative scoring. Validation studies were done using immunofluorescence staining and Western blotting. Our analyses revealed low or absent H4K16ac in the majority of breast cancer cases (78.9%), suggesting that this alteration may represent an early sign of breast cancer. There was a highly significant correlation between histone modifications status, tumor biomarker phenotype, and clinical outcome, where high relative levels of global histone acetylation and methylation were associated with a favorable prognosis and detected almost exclusively in luminal-like breast tumors (93%). Moderate to low levels of lysine acetylation (H3K9ac, H3K18ac, and H4K12ac), lysine (H3K4me2 and H4K20me3), and arginine methylation (H4R3me2) were observed in carcinomas of poorer prognostic subtypes, including basal carcinomas and HER-2-positive tumors. Clustering analysis identified three groups of histone displaying distinct pattern in breast cancer, which have distinct relationships to known prognostic factors and clinical outcome. This study identifies the presence of variations in global levels of histone marks in different grades, morphologic types, and phenotype classes of invasive breast cancer and shows that these differences have clinical significance. [Cancer Res 2009;69(9):3802–9]
DNA Cross-Links in Human Tumor Cells Exposed to the Prodrug PR-104A: Relationships to Hypoxia, Bioreductive Metabolism, and Cytotoxicity
Authors: Singleton Rachelle S. , Guise Christopher P. , Ferry Dianne M. , Pullen Susan M. , Dorie Mary J. , Brown J. Martin , Patterson Adam V. , Wilson William R.
Published: April 2009

PR-104, currently in clinical trial, is converted systemically to the dinitrobenzamide nitrogen mustard prodrug PR-104A, which is reduced selectively in hypoxic cells to cytotoxic hydroxylamine (PR-104H) and amine (PR-104M) metabolites. Here, we evaluate the roles of this reductive metabolism, and DNA interstrand cross-links (ICL), in the hypoxic and aerobic cytotoxicity of PR-104. Using a panel of 9 human tumor cell lines, cytotoxicity was determined by clonogenic assay after a 2-hour aerobic or hypoxic exposure to PR-104A. PR-104H and PR-104M were determined by high performance liquid chromatography/mass spectrometry, and ICL with the alkaline comet assay. Under hypoxia, the relationship between ICL and cell killing was similar between cell lines. Under aerobic conditions, there was a similar relationship between ICL and cytotoxicity, except in lines with very low rates of aerobic reduction of PR-104A (A2780, C33A, H1299), which showed an ICL-independent mechanism of PR-104A cytotoxicity. Despite this, in xenografts from the same lines, the frequency of PR-104–induced ICL correlated with clonogenic cell killing (r2 = 0.747) with greatest activity in the fast aerobic metabolizers. In addition, changing levels of hypoxia in SiHa tumors modified both ICL frequency and tumor growth delay in parallel. We conclude that both aerobic and hypoxic nitroreduction of PR-104A contribute to the monotherapy antitumor activity of PR-104 in human tumor xenografts, and that ICL are responsible for its antitumor activity and represent a broadly applicable biomarker for tumor cell killing by this novel prodrug. [Cancer Res 2009;69(9):3884–91]
Computationally Guided Photothermal Tumor Therapy Using Long-Circulating Gold Nanorod Antennas
Authors: von Maltzahn Geoffrey , Park Ji-Ho , Agrawal Amit , Bandaru Nanda Kishor , Das Sarit K. , Sailor Michael J. , Bhatia Sangeeta N.
Published: April 2009

Plasmonic nanomaterials have the opportunity to considerably improve the specificity of cancer ablation by i.v. homing to tumors and acting as antennas for accepting externally applied energy. Here, we describe an integrated approach to improved plasmonic therapy composed of multimodal nanomaterial optimization and computational irradiation protocol development. We synthesized polyethylene glycol (PEG)–protected gold nanorods (NR) that exhibit superior spectral bandwidth, photothermal heat generation per gram of gold, and circulation half-life in vivo (t1/2, ∼17 hours) compared with the prototypical tunable plasmonic particles, gold nanoshells, as well as ∼2-fold higher X-ray absorption than a clinical iodine contrast agent. After intratumoral or i.v. administration, we fuse PEG-NR biodistribution data derived via noninvasive X-ray computed tomography or ex vivo spectrometry, respectively, with four-dimensional computational heat transport modeling to predict photothermal heating during irradiation. In computationally driven pilot therapeutic studies, we show that a single i.v. injection of PEG-NRs enabled destruction of all irradiated human xenograft tumors in mice. These studies highlight the potential of integrating computational therapy design with nanotherapeutic development for ultraselective tumor ablation. [Cancer Res 2009;69(9):3892–900]
Ligand-Dependent Platelet-Derived Growth Factor Receptor (PDGFR)-α Activation Sensitizes Rare Lung Cancer and Sarcoma Cells to PDGFR Kinase Inhibitors
Authors: McDermott Ultan , Ames Rachel Y. , Iafrate A. John , Maheswaran Shyamala , Stubbs Hannah , Greninger Patricia , McCutcheon Kaitlin , Milano Randy , Tam Angela , Lee Diana Y. , Lucien Laury , Brannigan Brian W. , Ulkus Lindsey E. , Ma Xiao-Jun , Erlander Mark G. , Haber Daniel A. , Sharma Sreenath V. , Settleman Jeffrey
Published: April 2009

Platelet-derived growth factor (PDGF) receptors (PDGFR) and their ligands play critical roles in several human malignancies. Sunitinib is a clinically approved multitargeted tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor, c-KIT, and PDGFR, and has shown clinical activity in various solid tumors. Activation of PDGFR signaling has been described in gastrointestinal stromal tumors (PDGFRA mutations) as well as in chronic myeloid leukemia (BCR-PDGFRA translocation), and sunitinib can yield clinical benefit in both settings. However, the discovery of PDGFR activating mutations or gene rearrangements in other tumor types could reveal additional patient populations who might benefit from treatment with anti-PDGFR therapies, such as sunitinib. Using a high-throughput cancer cell line screening platform, we found that only 2 of 637 tested human tumor-derived cell lines show significant sensitivity to single-agent sunitinib exposure. These two cell lines [a non–small-cell lung cancer (NSCLC) and a rhabdomyosarcoma] showed expression of highly phosphorylated PDGFRA. In the sunitinib-sensitive adenosquamous NSCLC cell line, PDGFRA expression was associated with focal PFGRA gene amplification, which was similarly detected in a small fraction of squamous cell NSCLC primary tumor specimens. Moreover, in this NSCLC cell line, focal amplification of the gene encoding the PDGFR ligand PDGFC was also detected, and silencing PDGFRA or PDGFC expression by RNA interference inhibited proliferation. A similar codependency on PDGFRA and PDGFC was observed in the sunitinib-sensitive rhabdomyosarcoma cell line. These findings suggest that, in addition to gastrointestinal stromal tumors, rare tumors that show PDGFC-mediated PDGFRA activation may also be clinically responsive to pharmacologic PDGFRA or PDGFC inhibition. [Cancer Res 2009;69(9):3937–46]
Gonadotropin-Releasing Hormone Type II Induces Apoptosis of Human Endometrial Cancer Cells by Activating GADD45α
Authors: Wu Hsien-Ming , Cheng Jung-Chien , Wang Hsin-Shih , Huang Hong-Yuan , MacCalman Colin D. , Leung Peter C.K.
Published: April 2009

Gonadotropin-releasing hormone type II (GnRH-II) has an antiproliferative effect on human endometrial cancer cells. Apoptosis in cancer cells may play a critical role in regulating cell proliferation. However, more studies are necessary to elucidate the underlying molecular mechanisms and develop potential applications of GnRH-II. Therefore, we explored the mechanisms of GnRH-II–induced apoptosis and the effects of GnRH-II on GADD45α activation in human endometrial cancer cell lines. GnRH-II decreased cell viability in a dose- and time-dependent manner. Apoptosis was induced with increased terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling apoptotic cells after GnRH-II treatment. Knockdown of the endogenous GnRH-I receptor with small interfering RNA (siRNA) rescued the cells from GnRH-II–mediated cell growth inhibition and abolished the induction of apoptosis. GnRH-II activated extracellular signal–regulated kinase (ERK)-1/2 and p38 mitogen-activated protein kinase (MAPK) in a time-dependent manner, and the activation was abolished by GnRH-I receptor siRNA and MAPK inhibitors. Cells pretreated with MAPK inhibitors were rescued from GnRH-II–mediated cell growth inhibition. Moreover, both inhibitors abolished GnRH-II–induced apoptosis. GnRH-II induced GADD45α expression, which was abolished by knockdown of endogenous GnRH-I receptors and MAPK inhibitors. GnRH-II–stimulated cell growth inhibition was rescued by knockdown of endogenous GADD45α with siRNA. Cells treated with GADD45α siRNA were refractory to GnRH-II–induced apoptosis. Thus, GnRH-II inhibits cell growth by inducing apoptosis through binding of the GnRH-I receptor, activation of the ERK1/2 and p38 MAPK pathways, and induction of GADD45α signaling. This finding may provide a new concept relating to the mechanism of GnRH-II–induced antiproliferation and apoptosis in endometrial cancer cells, indicating the possibility of GnRH-II as a promising therapeutic intervention for human endometrial cancer. [Cancer Res 2009;69(10):4202–8]
Silibinin Feeding Alters the Metabolic Profile in TRAMP Prostatic Tumors: 1H-NMRS–Based Metabolomics Study
Authors: Raina Komal , Serkova Natalie J. , Agarwal Rajesh
Published: April 2009

Herein, we evaluated for the first time silibinin efficacy on prostate cancer (PCa) metabolism in transgenic adenocarcinoma of the mouse prostate (TRAMP) model using quantitative high-resolution proton nuclear magnetic resonance spectroscopy metabolomics. Prostate tissues were from mice fed control or silibinin diet for 20 weeks. Comparative metabolic profiling indicated that antitumor effect of silibinin is accompanied by alteration in metabolic profile of TRAMP prostatic tumors as indicated by 6-fold (P = 0.016) increase in glucose content and 48% (P = 0.015) reduction in lactate levels. Increase in citrate use by prostate tissue also reversed with silibinin, as indicated by 3-fold (P = 0.01) increase in citrate levels in silibinin-fed group. Also, 61% and 50% (P < 0.01) decrease in cholesterol and phosphatidylcholine levels, respectively, was observed with silibinin. These results corroborate our earlier findings regarding PCa chemopreventive potential of silibinin in TRAMP model and warrant additional metabolic profiling in other silibinin-fed PCa tumor model tissues. This will help identify specific metabolic biomarkers altered during silibinin treatment, which when detected in clinical biopsies or noninvasive magnetic resonance spectroscopic studies could help monitor silibinin effectiveness against PCa malignancy. [Cancer Res 2009;69(9):3731–5]
Identification of Potential Driver Genes in Human Liver Carcinoma by Genomewide Screening
Authors: Woo Hyun Goo , Park Eun Sung , Lee Ju-Seog , Lee Yun-Han , Ishikawa Tsuyoshi , Kim Yoon Jun , Thorgeirsson Snorri S.
Published: April 2009

Genomic copy number aberrations and corresponding transcriptional deregulation in the cancer genome have been suggested to have regulatory roles in cancer development and progression. However, functional evaluation of individual genes from lengthy lists of candidate genes from genomic data sets presents a significant challenge. Here, we report effective gene selection strategies to identify potential driver genes based on systematic integration of genome scale data of DNA copy numbers and gene expression profiles. Using regional pattern recognition approaches, we discovered the most probable copy number–dependent regions and 50 potential driver genes. At each step of the gene selection process, the functional relevance of the selected genes was evaluated by estimating the prognostic significance of the selected genes. Further validation using small interference RNA–mediated knockdown experiments showed proof-of-principle evidence for the potential driver roles of the genes in hepatocellular carcinoma progression (i.e., NCSTN and SCRIB). In addition, systemic prediction of drug responses implicated the association of the 50 genes with specific signaling molecules (mTOR, AMPK, and EGFR). In conclusion, the application of an unbiased and integrative analysis of multidimensional genomic data sets can effectively screen for potential driver genes and provides novel mechanistic and clinical insights into the pathobiology of hepatocellular carcinoma. [Cancer Res 2009;69(9):4059–66]
The Lack of Epithelial Interleukin-7 and BAFF/BLyS Gene Expression in Prostate Cancer as a Possible Mechanism of Tumor Escape from Immunosurveillance
Authors: Di Carlo Emma , D'Antuono Tommaso , Pompa Paolo , Giuliani Rossella , Rosini Sandra , Stuppia Liborio , Musiani Piero , Sorrentino Carlo
Published: April 2009

Purpose: The human prostate is endowed with intraepithelial and stromal lymphocytes, which may develop lymphoid follicles (LF) and allow a local immune response. We sought to investigate whether interleukin (IL)-7 and BAFF/BLyS, two fundamental survival factors for T and B cells, are expressed in the normal and neoplastic prostate and affect intraprostatic lymphocyte homeostasis.

Experimental Design: We have used real-time reverse transcription-PCR of microdissected prostatic glands and confocal microscopy to detect cytokine production, combined with immunohistochemistry to characterize intraprostatic lymphocytes.

Results: Prostatic epithelia constitutively produce IL-7 and, to a lesser extent, BAFF/BLyS. Indeed, we show that IL-7 receptor α is expressed by intraepithelial T lymphocytes and parafollicular T cells, whereas BAFF-R is found on periglandular B lymphocytes and mantle zone B cells of LFs. Prostate-homing B and T lymphocytes are scarcely proliferating, whereas most of them express the antiapoptotic protein bcl-2 and reveal a low apoptotic index in the terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling assay. The transition from normal to neoplastic glands in prostate cancer (PCa) is marked by a dramatic decline of IL-7 and BAFF/BLyS production. Accordingly, PCa is characterized by a significant reduction of intraepithelial lymphocytes and loss of LFs. B-cell and T-cell expression of bcl-2 decrease, whereas the apoptotic events increase. The remaining PCa-infiltrating lymphocytes are mostly CD8+ T cells that lack terminal differentiation and barely penetrate neoplastic glands.

Conclusions: These results suggest that epithelial IL-7 and BAFF/BLyS production support intraprostatic lymphocyte survival. Its loss in PCa is associated with a severe depletion of prostate-associated lymphocytes and points to a novel tumor escape mechanism.
Prostate Cancer–Associated Gene Expression Alterations Determined from Needle Biopsies
Authors: Qian David Z. , Huang Chung-Ying , O'Brien Catherine A. , Coleman Ilsa M. , Garzotto Mark , True Lawrence D. , Higano Celestia S. , Vessella Robert , Lange Paul H. , Nelson Peter S. , Beer Tomasz M.
Published: April 2009

Purpose: To accurately identify gene expression alterations that differentiate neoplastic from normal prostate epithelium using an approach that avoids contamination by unwanted cellular components and is not compromised by acute gene expression changes associated with tumor devascularization and resulting ischemia.

Experimental Design: Approximately 3,000 neoplastic and benign prostate epithelial cells were isolated using laser capture microdissection from snap-frozen prostate biopsy specimens provided by 31 patients who subsequently participated in a clinical trial of preoperative chemotherapy. cDNA synthesized from amplified total RNA was hybridized to custom-made microarrays composed of 6,200 clones derived from the Prostate Expression Database. Expression differences for selected genes were verified using quantitative reverse transcription-PCR.

Results: Comparative analyses identified 954 transcript alterations associated with cancer (q < 0.01%), including 149 differentially expressed genes with no known functional roles. Gene expression changes associated with ischemia and surgical removal of the prostate gland were absent. Genes up-regulated in prostate cancer were statistically enriched in categories related to cellular metabolism, energy use, signal transduction, and molecular transport. Genes down-regulated in prostate cancers were enriched in categories related to immune response, cellular responses to pathogens, and apoptosis. A heterogeneous pattern of androgen receptor expression changes was noted. In exploratory analyses, androgen receptor down-regulation was associated with a lower probability of cancer relapse after neoadjuvant chemotherapy followed by radical prostatectomy.

Conclusions: Assessments of tumor phenotypes based on gene expression for treatment stratification and drug targeting of oncogenic alterations may best be ascertained using biopsy-based analyses where the effects of ischemia do not complicate interpretation.
Supplementation with Branched-chain Amino Acids Inhibits Azoxymethane-induced Colonic Preneoplastic Lesions in Male C57BL/KsJ-db/db Mice
Authors: Shimizu Masahito , Shirakami Yohei , Iwasa Junpei , Shiraki Makoto , Yasuda Yoichi , Hata Kazuya , Hirose Yoshinobu , Tsurumi Hisashi , Tanaka Takuji , Moriwaki Hisataka
Published: April 2009

Purpose: Obesity and related metabolic abnormalities, including insulin resistance and activation of the insulin-like growth factor (IGF)/IGF-I receptor (IGF-IR) axis, are risk factors for colon cancer. Supplementation with branched-chain amino acids (BCAA) reduces the risk of liver cancer in cirrhotic patients who are obese, and this has been associated with an improvement of insulin resistance. The present study examined the effects of BCAA on the development of azoxymethane (AOM)-initiated colonic premalignant lesions in C57BL/KsJ-db/db (db/db) mice that were obese and had hyperinsulinemia.

Experimental Design: Male db/db mice were given 4 weekly s.c. injections of AOM (15 mg/kg of body weight) and then they were fed a diet containing 3.0% BCAA or casein, a nitrogenc content–matched control diet, for 7 weeks.

Results: Feeding with BCAA caused a significant reduction in the number of total aberrant crypt foci and β-catenin accumulated crypts, both of which are premalignant lesions of the colon, compared with the control diet–fed groups. BCAA supplementation caused a marked decrease in the expression of IGF-IR, the phosphorylated form of IGF-IR, phosphorylated glycogen synthase kinase 3β, phosphorylated Akt, and cyclooxygenase-2 proteins on the colonic mucosa of AOM-treated mice. The serum levels of insulin, IGF-I, IGF-II, triglyceride, total cholesterol, and leptin were also decreased by supplementation with BCAA.

Conclusion: BCAA supplementation in diet improves insulin resistance and inhibits the activation of the IGF/IGF-IR axis, thereby preventing the development of colonic premalignancies in an obesity-related colon cancer model that was also associated with hyperlipidemia and hyperinsulinemia. BCAA, therefore, may be a useful chemoprevention modality for colon cancer in obese people.
A Potent, Imaging Adenoviral Vector Driven by the Cancer-selective Mucin-1 Promoter That Targets Breast Cancer Metastasis
Authors: Huyn Steven T. , Burton Jeremy B. , Sato Makoto , Carey Michael , Gambhir Sanjiv S. , Wu Lily
Published: April 2009

Purpose: With breast cancer, early detection and proper staging are critical, and will often influence both the treatment regimen and the therapeutic outcome for those affected with this disease. Improvements in these areas will play a profound role in reducing mortality from breast cancer.

Experimental Design: In this work we developed a breast cancer–targeted serotype 5 adenoviral vector, utilizing the tumor-specific mucin-1 promoter in combination with the two-step transcriptional amplification system, a system used to augment the activity of weak tissue–specific promoters.

Results: We showed the strong specificity of this tumor-selective adenovirus to express the luciferase optical imaging gene, leading to diagnostic signals that enabled detection of sentinel lymph node metastasis of breast cancer. Furthermore, we were able to target hepatic metastases following systemic administration of this mucin-1 selective virus.

Conclusions: Collectively, we showed that the amplified mucin-1 promoter–driven vector is able to deliver to and selectively express a desirable transgene in metastatic lesions of breast tumors. This work has strong clinical relevance to current diagnostic staging approaches, and could add to targeted therapeutic strategies to advance the fight against breast cancer.
Evaluation of 8q24 and 17q Risk Loci and Prostate Cancer Mortality
Authors: Penney Kathryn L. , Salinas Claudia A. , Pomerantz Mark , Schumacher Fredrick R. , Beckwith Christine A. , Lee Gwo-Shu , Oh William K. , Sartor Oliver , Ostrander Elaine A. , Kurth Tobias , Ma Jing , Mucci Lorelei , Stanford Janet L. , Kantoff Philip W. , Hunter David J. , Stampfer Meir J. , Freedman Matthew L.
Published: April 2009

Purpose: Variants at chromosomal loci 8q24 and 17q are established risk factors for prostate cancer. Many studies have confirmed the findings for risk, but few have examined aggressiveness and other clinical variables in detail. Additionally, Gleason score is typically used as a surrogate for the primary end point of prostate cancer mortality. We investigated whether the 8q24 and 17q risk variants are associated with clinical variables as well as prostate cancer mortality.

Experimental Design: In the Physicians' Health Study (1,347 cases and 1,462 controls), the Dana-Farber Harvard Cancer Center Specialized Program of Research Excellence (Gelb Center; 3,714 cases), and the Fred Hutchinson Cancer Research Center King County Case-Control Studies (1,308 cases and 1,266 controls), we examined eight previously identified 8q24 and 17q risk variants for association with prostate cancer mortality in men of European ancestry. We considered associations with other surrogate markers of prostate cancer aggressiveness, such as Gleason score, pathologic stage, prostate-specific antigen at diagnosis, and age at diagnosis.

Results: Six of the eight variants were confirmed as prostate cancer risk factors. Several variants were nominally associated with age at diagnosis; when totaling all alleles for single nucleotide polymorphisms significantly associated with risk, each additional allele decreased age at diagnosis by an average of 6 months in the Physicians' Health Study (P = 0.0005) and 4 months in the Dana-Farber Harvard Cancer Center Specialized Program of Research Excellence (Gelb Center) cohort (P = 0.0016). However, there were no statistically significant associations with prostate cancer mortality.

Conclusions: Our results suggest that the 8q24 and 17q prostate cancer risk variants may influence age at diagnosis but not disease aggressiveness.
Mutation-Specific Antibodies for the Detection of EGFR Mutations in Non–Small-Cell Lung Cancer
Authors: Yu Jian , Kane Susan , Wu Jiong , Benedettini Elisa , Li Daiqiang , Reeves Cynthia , Innocenti Gregory , Wetzel Randy , Crosby Katherine , Becker Alison , Ferrante Michelle , Cheung Wan Cheung , Hong Xiqiang , Chirieac Lucian R. , Sholl Lynette M. , Haack Herbert , Smith Bradley L. , Polakiewicz Roberto D. , Tan Yi , Gu Ting-Lei , Loda Massimo , Zhou Xinmin , Comb Michael J.
Published: April 2009

Purpose: Activating mutations within the tyrosine kinase domain of epidermal growth factor receptor (EGFR) are found in approximately 10% to 20% of non–small-cell lung cancer (NSCLC) patients and are associated with response to EGFR inhibitors. The most common NSCLC-associated EGFR mutations are deletions in exon 19 and L858R mutation in exon 21, together accounting for 90% of EGFR mutations. To develop a simple, sensitive, and reliable clinical assay for the identification of EGFR mutations in NSCLC patients, we generated mutation-specific rabbit monoclonal antibodies against each of these two most common EGFR mutations and aimed to evaluate the detection of EGFR mutations in NSCLC patients by immunohistochemistry.

Experimental Design: We tested mutation-specific antibodies by Western blot, immunofluorescence, and immunohistochemistry. In addition, we stained 40 EGFR genotyped NSCLC tumor samples by immunohistochemistry with these antibodies. Finally, with a panel of four antibodies, we screened a large set of NSCLC patient samples with unknown genotype and confirmed the immunohistochemistry results by DNA sequencing.

Results: These two antibodies specifically detect the corresponding mutant form of EGFR by Western blotting, immunofluorescence, and immunohistochemistry. Screening a panel of 340 paraffin-embedded NSCLC tumor samples with these antibodies showed that the sensitivity of the immunohistochemistry assay is 92%, with a specificity of 99% as compared with direct and mass spectrometry–based DNA sequencing.

Conclusions: This simple assay for detection of EGFR mutations in diagnostic human tissues provides a rapid, sensitive, specific, and cost-effective method to identify lung cancer patients responsive to EGFR-based therapies.
In vitro and In vivo Radiosensitization with AZD6244 (ARRY-142886), an Inhibitor of Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase 1/2 Kinase
Authors: Chung Eun Joo , Brown Aaron P. , Asano Hiroaki , Mandler Mariana , Burgan William E. , Carter Donna , Camphausen Kevin , Citrin Deborah
Published: April 2009

Purpose: The mitogen-activated protein (MAP) kinase pathway is important for cell proliferation, survival, and differentiation, and is frequently up-regulated in cancers. The MAP kinase pathway is also activated after exposure to ionizing radiation. We investigated the effects of AZD6244 (ARRY-142886), an inhibitor of MAP kinase/extracellular signal-regulated kinase 1/2, on radiation response.

Experimental Design: The effects of AZD6244 on the in vitro radiosensitivity of human cancer cell lines (A549, MiaPaCa2, and DU145) were evaluated using clonogenic assays. DNA damage repair was evaluated using γH2AX, and mitotic catastrophe was measured using nuclear fragmentation. Cell cycle effects were measured with flow cytometry. Growth delay was used to evaluate the effects of AZD6244 on in vivo tumor radiosensitivity.

Results: Exposure of each cell line to AZD6244 before irradiation resulted in an increase in radiosensitivity with dose enhancement factors at a surviving fraction of 0.1, ranging from 1.16 to 2.0. No effects of AZD6244 on radiation-induced apoptosis or persistence of γH2AX foci after irradiation were detected. Cells treated with AZD6244 had an increased mitotic index and decreased Chk1 phosphorylation at 1 and 2 hours after irradiation. Mitotic catastrophe was increased in cells receiving AZD6244 and irradiation compared with the single treatments. In vivo studies revealed that AZD6244 administration to mice bearing A549 tumor xenografts resulted in a greater than additive increase in radiation-induced tumor growth delay (dose enhancement factor of 3.38).

Conclusions: These results indicate that AZD6244 can enhance tumor cell radiosensitivity in vitro and in vivo and suggest that this effect involves an increase in mitotic catastrophe.
PIK3CA Mutations Are Not a Major Determinant of Resistance to the Epidermal Growth Factor Receptor Inhibitor Cetuximab in Metastatic Colorectal Cancer
Authors: Prenen Hans , De Schutter Jef , Jacobs Bart , De Roock Wendy , Biesmans Bart , Claes Bart , Lambrechts Diether , Van Cutsem Eric , Tejpar Sabine
Published: April 2009

Purpose: It has been reported that activating KRAS mutations negatively affect response to anti–epidermal growth factor receptor (EGFR) monoclonal antibodies in metastatic colorectal cancer. The mutation status of signaling molecules downstream of the EGFR target is thus crucial to predict clinical benefit to EGFR-targeted therapies. Other mechanisms of resistance to EGFR inhibitors could involve activating mutations of the other main EGFR effector pathway, i.e., the PI3K/PTEN/AKT pathway.

Experimental Design: We analyzed the PIK3CA and KRAS mutation status in a large group (n = 200) of chemorefractory metastatic colorectal cancers treated with cetuximab (Erbitux) in monotherapy or in combination with irinotecan, and correlated the mutation status with outcome.

Results: Twenty-three (12%) of the 200 samples carried 1 of the PIK3CA mutations included in our assay. We found no correlation between the presence of a PIK3CA mutation and impaired response to cetuximab.

Conclusions: Our findings do not provide any evidence for a strong role of PIK3CA mutations as a single marker in determining response to cetuximab in chemorefractory metastatic colorectal cancer.
An Open-Label, Multicenter, Phase I/II Study of Single-Agent AT-101 in Men with Castrate-Resistant Prostate Cancer
Authors: Liu Glenn , Kelly W. Kevin , Wilding George , Leopold Lance , Brill Kimberli , Somer Bradley
Published: April 2009

Purpose: AT-101 binds and inhibits the antiapoptotic function of Bcl-2, Bcl-xL, Mcl-1, and Bcl-w and is a potent stimulator of proapoptotic proteins. In this multi-institution phase I/II trial, we evaluated the safety and efficacy of single-agent AT-101, in men with chemotherapy naïve, castrate-resistant prostate cancer (CRPC).

Experimental Design: Patients with progressive CRPC were to be treated with escalating doses of AT-101 on a continuous daily basis until the maximally tolerated dose was achieved. At the recommended phase 2 dose, an additional 21 patients were planned to assess for preliminary evidence of efficacy.

Results: Twenty-three patients were enrolled. The phase I starting dose was 30 mg/day on a continuous basis; however, ongoing trials with AT-101 showed increased gastrointestinal toxicity with this daily schedule when given for repetitive cycles. As a result, the phase II starting dose was chosen to be 30 mg/day for 21 of 28 days. The most frequent observed adverse events (any grade) were diarrhea (43.5%), fatigue (34.8%), nausea (21.7%), anorexia (21.7%), and small intestinal obstruction (21.7%). Due to the high incidence of grade 3 small intestinal obstruction (n = 5; 21.7%), a reduction in dose to 20 mg/day for 21 of 28 days was mandated for all patients. Two patients had a confirmed ≥50% posttherapy prostate-specific antigen decline. No objective responses (Response Evaluation Criteria in Solid Tumors) were observed.

Conclusion: AT-101 administered at 20 mg/day for 21 of 28 days was well-tolerated. Evidence of single-agent clinical activity was observed with prostate-specific antigen declines in some patients. Further investigation of AT-101 in prostate cancer is warranted and trials combining AT-101 with androgen deprivation, as well as with docetaxel chemotherapy are ongoing.
Association of Blood Lipids With Common DNA Sequence Variants at 19 Genetic Loci in the Multiethnic United States National Health and Nutrition Examination Survey III
Authors: Keebler Mary E. , Sanders Christopher L. , Surti Aarti , Guiducci Candace , Burtt Noel P. , Kathiresan Sekar
Published: April 2009

Background—

Using the genome-wide association approach in individuals of European ancestry, we and others recently identified single-nucleotide polymorphisms (SNPs) at 19 loci as associated with blood lipids; 8 of these loci were novel. Whether these same SNPs associate with lipids in a broader range of ethnicities is unknown.

Methods and Results—

We genotyped index SNPs at 19 loci in the Third United States National Health and Nutrition Examination Survey (n=7159), a population-based probability sample of the United States comprised primarily of non-Hispanic blacks, Mexican Americans, and non-Hispanic whites. We constructed ethnic-specific residual blood lipid levels after adjusting for age and gender. Ethnic-specific linear regression was used to test the association of genotype with blood lipids. To summarize the statistical evidence across 3 racial groups, we conducted a fixed-effects variance-weighted meta-analysis. After exclusions, there were 1627 non-Hispanic blacks, 1659 Mexican Americans, and 2230 non-Hispanic whites. At 5 loci (1p13 near
CELSR2/PSRC1/SORT1
,
HMGCR
,
CETP
,
LPL
, and
APOA5
), the index SNP was associated with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or triglycerides in all 3 ethnic groups. At the remaining loci, there was mixed evidence by ethnic group. In meta-analysis, we found that, at 14 of the 19 loci, SNPs exceeded a nominal
P
<0.05.

Conclusions—

At 5 loci including the recently discovered region on 1p13 near
CELSR2/PSRC1/SORT1
, the same SNP discovered in whites associates with blood lipids in non-Hispanic blacks and Mexican Americans. For the remaining loci, fine mapping and resequencing will be required to definitively evaluate the relevance of each locus in individuals of African and Hispanic ancestries.
Mechanisms Underlying Improvements in Ejection Fraction With Carvedilol in Heart Failure
Authors: Maurer Mathew S. , Sackner-Bernstein Jonathan D. , El-Khoury Rumbarger Lyna , Yushak Madeline , King Donald L. , Burkhoff Daniel
Published: April 2009

Background—

Reductions in heart rate (HR) with β-blocker therapy have been associated with improvements in ejection fraction (EF). However, the relative contributions of HR reduction, positive inotropism, afterload reduction, and reverse remodeling to improvements in EF are unknown.

Methods and Results—

Twenty-nine patients (63�12 years old) with New York Heart Association class II-III heart failure underwent serial measurements of left ventricular volumes using 3-dimensional echocardiography and blood pressures by sphygmomanometry at baseline, 2 weeks, 2, 6, and 12 months after initiation of carvedilol. From these parameters, left ventricular contractility (indexed by the end-systolic pressure-volume ratio), total peripheral resistance, and effective arterial elastance (E
a
) were derived. Overall, EF increased by 7-percentage points after 6 months of therapy (from 25�9 to 32�9,
P
<0.0001). This change was due to an increase in stroke volume (
P
<0.001) with no significant change in end-diastolic volume (
P
=0.15). The EF change correlated with increased contractility, decreased HR and decreased total peripheral resistance (
P
<0.003 in each case). In those patients whose EF increased at least 5 points, ≈60% of the increase was due to HR reduction, ≈30% was due to increased contractility, and <20% was due to the decrease in total peripheral resistance.

Conclusions—

Decreased HR, improved chamber contractility and afterload reduction each contributed significantly to improved EF with carvedilol.
Are State Non-Need, Merit-Based Scholarship Programs Impacting College Enrollment?
Authors: Farrell Patricia L. , Kienzl Gregory S.
Published: April 2009

This study examines whether non-need, merit-based scholarship programs are effective in encouraging students to enroll in postsecondary education and, more specifically, attend an in-state college. National residence and migration data from 1992 to 2004 (alternating even years) were used within a fixed effect regression framework. This approach, combined with interaction terms that capture different program implementation periods, is an attempt to enhance the current understanding of scholarship programs on college enrollment. The results suggest that these programs have a significant impact on college enrollment after controlling for state-level factors, but the effect depends on when the program was implemented, who is eligible to receive aid, and how much aid these students are awarded.
The State Role in Teacher Professional Development and Education Throughout Teachers' Careers
Authors: Loeb Susanna , Miller Luke C. , Strunk Katharine O.
Published: April 2009

Professional development and teacher education policies have the potential to greatly affect teachers' abilities to teach and, as a result, students' abilities to learn. States can play varied roles in the provision of teacher education and professional development. This policy brief summarizes states' policy approaches to teacher professional development and education throughout teachers' careers. It explores what states are currently doing in the realms of pre-service education, induction and mentoring, ongoing professional development, and teacher evaluation, as well as the existing evidence regarding the effectiveness of such policies. We find that states play disparate roles in the provision of teacher education and professional development that fall along the regulatory spectrum from highly prescriptive to rather laissez-faire. Research on the effects of such policies is still in the early stages, and more attention is needed to determine the effectiveness of states' professional development policies.