bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic Resonance Imaging Defines Cervicovaginal Anatomy, Cancer, and VEGF Trap Antiangiogenic Efficacy in Estrogen-Treated K14-HPV16 Transgenic Mice
Authors: Garbow Joel R. , Santeford Andrea C. , Anderson Jeff R. , Engelbach John A. , Arbeit Jeffrey M.
Published: September 2009

Noninvasive detection of dysplasia provides a potential platform for monitoring the efficacy of chemopreventive therapy of premalignancy, imaging the tissue compartments comprising dysplasia: epithelium, microvasculature, and stromal inflammatory cells. Here, using respiratory-gated magnetic resonance imaging (MRI), the anatomy of premalignant and malignant stages of cervical carcinogenesis in estrogen-treated K14-HPV16 transgenic mice was noninvasively defined. Dynamic contrast enhanced (DCE)-MRI was used to quantify leakage across premalignant dysplastic microvasculature. Vascular permeability as measured by DCE-MRI, Ktrans, was similar in transgenic (0.053 ± 0.020 min−1; n = 32 mice) and nontransgenic (0.056 ± 0.029 min−1; n = 17 mice) animals despite a 2-fold increase in microvascular area in the former compared with the latter. DCE-MRI did detect a significant decrease in vascular permeability accompanying diminution of dysplastic microvasculature by the antiangiogenic agent, vascular endothelial growth factor Trap (Ktrans = 0.052 ± 0.013 min−1 pretreatment; n = 6 mice versus Ktrans = 0.019 ± 0.008 min−1 post-treatment; n = 5 mice). Thus, we determined that the threshold of microvessel leakage associated with cervical dysplasia was <17 kDa and highlighted the potential of DCE-MRI to noninvasively monitor the efficacy of antiangiogenic drugs or chemoprevention regimens targeting the vasculature in premalignant cervical dysplasia. [Cancer Res 2009;69(20):7945–52]
Immutable Functional Attributes of Histologic Grade Revealed by Context-Independent Gene Expression in Primary Breast Cancer Cells
Authors: Dairkee Shanaz H. , Sayeed Aejaz , Luciani Gloria , Champion Stacey , Meng Zhenhang , Jakkula Lakshmi R. , Feiler Heidi S. , Gray Joe W. , Moore Dan H.
Published: September 2009

Inherent cancer phenotypes that are independent of fluctuating cross-talk with the surrounding tissue matrix are highly desirable candidates for targeting tumor cells. Our novel study design uses epithelial cell lines derived from low versus high histologic grade primary breast cancer to effectively diminish the breadth of transient variability generated within the tumor microenvironment of the host, revealing a “paracrine-independent expression of grade-associated” (PEGA) gene signature. PEGA members extended beyond “proliferation-driven” signatures commonly associated with aggressive, high-grade breast cancer. The calcium-binding protein S100P was prominent among PEGA genes overexpressed in high-grade tumors. A three-member fingerprint of S100P-correlated genes, consisting of GPRC5A, FXYD3, and PYCARD, conferred poor outcome in multiple breast cancer data sets, irrespective of estrogen receptor status but dependent on tumor size (P < 0.01). S100P silencing markedly diminished coregulated gene transcripts and reversed aggressive tumor behavior. Exposure to pathway-implicated agents, including the calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, phenothiazine, and chlorpromazine, resulted in rapid apoptotic cell death in high-grade tumor cells resistant to the chemotherapeutic drug cisplatin. This is the first comprehensive study describing molecular phenotypes intimately associated with histologic grade whose expression remains relatively fixed despite an unavoidably changing environment to which tumor cells are invariably exposed. [Cancer Res 2009;69(19):7826–34]
The Insulin-like Growth Factor-1 Receptor–Targeting Antibody, CP-751,871, Suppresses Tumor-Derived VEGF and Synergizes with Rapamycin in Models of Childhood Sarcoma
Authors: Kurmasheva Raushan T. , Dudkin Lorina , Billups Catherine , Debelenko Larisa V. , Morton Christopher L. , Houghton Peter J.
Published: September 2009

Signaling through the type 1 insulin-like growth factor receptor (IGF-1R) occurs in many human cancers, including childhood sarcomas. As a consequence, targeting the IGF-1R has become a focus for cancer drug development. We examined the antitumor activity of CP-751,871, a human antibody that blocks IGF-1R ligand binding, alone and in combination with rapamycin against sarcoma cell lines in vitro and xenograft models in vivo. In Ewing sarcoma (EWS) cell lines, CP751,871 inhibited growth poorly (<50%), but prevented rapamycin-induced hyperphosphorylation of AKT(Ser473) and induced greater than additive apoptosis. Rapamycin treatment also increased secretion of IGF-1 resulting in phosphorylation of IGF-1R (Tyr1131) that was blocked by CP751,871. In vivo CP-751,871, rapamycin, or the combination were evaluated against EWS, osteosarcoma, and rhabdomyosarcoma xenografts. CP751871 induced significant growth inhibition [EFS(T/C) >2] in four models. Rapamycin induced significant growth inhibition [EFS(T/C) >2] in nine models. Although neither agent given alone caused tumor regressions, in combination, these agents had greater than additive activity against 5 of 13 xenografts and induced complete remissions in one model each of rhabdomyosarcoma and EWS, and in three of four osteosarcoma models. CP751,871 caused complete IGF-1R down-regulation, suppression of AKT phosphorylation, and dramatically suppressed tumor-derived vascular endothelial growth factor (VEGF) in some sarcoma xenografts. Rapamycin treatment did not markedly suppress VEGF in tumors and synergized only in tumor lines where VEGF was dramatically inhibited by CP751,871. These data suggest a model in which blockade of IGF-1R suppresses tumor-derived VEGF to a level where rapamycin can effectively suppress the response in vascular endothelial cells. [Cancer Res 2009;69(19):7662–71]
Haplotype and Cell Proliferation Analyses of Candidate Lung Cancer Susceptibility Genes on Chromosome 15q24-25.1
Authors: Liu Yan , Liu Pengyuan , Wen Weidong , James Michael A. , Wang Yian , Bailey-Wilson Joan E. , Amos Christopher I. , Pinney Susan M. , Yang Ping , de Andrade Mariza , Petersen Gloria M. , Wiest Jonathan S. , Fain Pamela R. , Schwartz Ann G. , Gazdar Adi , Gaba Colette , Rothschild Henry , Mandal Diptasri , Kupert Elena , Lee Juwon , Seminara Daniela , Minna John , Anderson Marshall W. , You Ming
Published: September 2009

Recent genome-wide association studies have linked the chromosome 15q24-25.1 locus to nicotine addiction and lung cancer susceptibility. To refine the 15q24-25.1 locus, we performed a haplotype-based association analysis of 194 familial lung cases and 219 cancer-free controls from the Genetic Epidemiology of Lung Cancer Consortium (GELCC) collection, and used proliferation and apoptosis analyses to determine which gene(s) in the 15q24-25.1 locus mediates effects on lung cancer cell growth in vitro. We identified two distinct subregions, hapL (P = 3.20 × 10−6) and hapN (P = 1.51 × 10−6), which were significantly associated with familial lung cancer. hapL encompasses IREB2, LOC123688, and PSMA4, and hapN encompasses the three nicotinic acetylcholine receptor subunit genes CHRNA5, CHRNA3, and CHRNB4. Examination of the genes around hapL revealed that PSMA4 plays a role in promoting cancer cell proliferation. PSMA4 mRNA levels were increased in lung tumors compared with normal lung tissues. Down-regulation of PSMA4 expression decreased proteasome activity and induced apoptosis. Proteasome dysfunction leads to many diseases including cancer, and drugs that inhibit proteasome activity show promise as a form of cancer treatment. Genes around hapN were also investigated, but did not show any direct effect on lung cancer cell proliferation. We concluded that PSMA4 is a strong candidate mediator of lung cancer cell growth, and may directly affect lung cancer susceptibility through its modulation of cell proliferation and apoptosis. [Cancer Res 2009;69(19):7844–50]
Mutant p53 Disrupts the Stress MAPK Activation Circuit Induced by ASK1-Dependent Stabilization of Daxx
Authors: Kitamura Tetsuya , Fukuyo Yayoi , Inoue Masahiro , Horikoshi Nobuko T. , Shindoh Masanobu , Rogers Buck E. , Usheva Anny , Horikoshi Nobuo
Published: September 2009

Daxx is a regulatory protein for apoptosis signal–regulating kinase 1 (ASK1) which activates c-Jun NH2-terminal kinase (JNK) and p38 pathways in response to stressors such as tumor necrosis factor-α (TNFα). Here, we show that TNFα treatment induces the accumulation of Daxx protein through ASK1 activation by preventing its proteasome-dependent degradation. ASK1 directly phosphorylates Daxx at Ser176 and Ser184 and Daxx is required for the sustained activation of JNK. Tumorigenic mutant p53, which binds to Daxx and inhibits Daxx-dependent activation of ASK1, prevents Daxx phosphorylation and stabilization. When mutant p53 was depleted in cancer cells, Daxx was accumulated and the cell-killing effect of TNFα was restored. Our results indicate that Daxx not only activates ASK1 but also is a downstream target of ASK1 and that accumulated Daxx further activates ASK1. Thus, the Daxx-ASK1 positive feedback loop amplifying JNK/p38 signaling plays an important role in the cell-killing effects of stressors, such as TNFα. Tumorigenic mutant p53 disrupts this circuit and makes cells more tolerable to stresses, as its gain-of-function mechanism. [Cancer Res 2009;69(19):7681–8]
Phosphorylation-Dependent Lys63-Linked Polyubiquitination of Daxx Is Essential for Sustained TNF-α–Induced ASK1 Activation
Authors: Fukuyo Yayoi , Kitamura Tetsuya , Inoue Masahiro , Horikoshi Nobuko T. , Higashikubo Ryuji , Hunt Clayton R. , Usheva Anny , Horikoshi Nobuo
Published: September 2009

Apoptosis signal–regulating kinase 1 (ASK1) is a key regulatory kinase in the proapoptotic response to various stresses. ASK1 phosphorylation of Daxx, an ASK1 activator protein, increases Daxx accumulation in cells and further enhances ASK1 activity through a positive feedback mechanism. Here, we show that ASK1-dependent phosphorylation of Daxx induces Lys63 (K63)-linked polyubiquitination on Lys122 of Daxx. Polyubiquitination is dispensable for Daxx accumulation or Daxx interaction with ASK1 because mutant Daxx deficient in polyubiquitin still exhibits ASK1-dependent accumulation and interaction with cellular ASK1. However, K63-linked Daxx polyubiquitination is required for tumor necrosis factor-α (TNF-α)–induced activation of ASK1. Therefore, K63-linked polyubiquitination of Daxx functions as a molecular switch to initiate and amplify the stress kinase response in the TNF-α signaling pathway. [Cancer Res 2009;69(19):7512–7]
Phase II Study of Neoadjuvant Imatinib in Glioblastoma: Evaluation of Clinical and Molecular Effects of the Treatment
Authors: Razis Evangelia , Selviaridis Panayotis , Labropoulos Stephanos , Norris Jeremy L. , Zhu Mei-Jun , Song David D. , Kalebic Thea , Torrens Michael , Kalogera-Fountzila Anna , Karkavelas George , Karanastasi Sofia , Fletcher Jonathan A. , Fountzilas George
Published: September 2009

Purpose: Phase I-II studies indicate that imatinib is active in glioblastoma multiforme. To better understand the molecular and clinical effects of imatinib in glioblastoma multiforme, we conducted a neoadjuvant study of imatinib with pretreatment and posttreatment biopsies.

Experimental Design: Patients underwent a computerized tomography-guided biopsy of their brain tumors. If diagnosed with glioblastoma multiforme, they were immediately treated with 7 days of imatinib 400 mg orally twice daily followed by either definitive surgery or re-biopsy. Pretreatment and posttreatment tissue specimens were tested by immunohistochemistry for Ki67 and microvessel destiny, and posttreatment specimens were analyzed for the presence of intact imatinib in tissue. Furthermore, pretreatment and posttreatment pairs were analyzed by Western blotting for activation of platelet-derived growth factor receptor, epidermal growth factor receptor (EGFR), phosphoinositide 3-kinase/AKT, and mitogen-activated protein kinase signaling pathways. Pharmacokinetic studies were also done.

Results: Twenty patients were enrolled. Median survival was 6.2 months. Intact imatinib was detected in the posttreatment tissue specimens using mass spectrometry. There was no evidence of a drug effect on proliferation, as evidenced by a change in Ki67 expression. Biochemical evidence of response, as shown by decreased activation of AKT and mitogen-activated protein kinase or increased p27 level, was detected in 4 of 11 patients with evaluable, matched pre- and post-imatinib biopsies. Two patients showed high-level EGFR activation and homozygous EGFR mutations, whereas one patient had high-level platelet-derived growth factor receptor-B activation.

Conclusions: Intact imatinib was detected in glioblastoma multiforme tissue. However, the histologic and immunoblotting evaluations suggest that glioblastoma multiforme proliferation and survival mechanisms are not substantially reduced by imatinib therapy in most patients. (Clin Cancer Res 2009;15(19):6258–66)
A Phase II Study of SGN-30 in Cutaneous Anaplastic Large Cell Lymphoma and Related Lymphoproliferative Disorders
Authors: Duvic Madeleine , Reddy Sunil A. , Pinter-Brown Lauren , Korman Neil J. , Zic John , Kennedy Dana A. , Lorenz Jennie , Sievers Eric L. , Kim Youn H.
Published: September 2009

Purpose: An open-label, multicenter, phase II study was conducted to define the safety and antitumor activity of the monoclonal antibody SGN-30 in patients with CD30+ primary cutaneous anaplastic large cell lymphoma (pc-ALCL), lymphomatoid papulosis (LyP), or transformed mycosis fungoides (T-MF).

Experimental Design: In the initial course (six doses), patients received i.v. SGN-30 every 3 weeks; eligible patients could receive two additional courses. The initial dose level of 4 mg/kg was increased to 12 mg/kg by protocol amendment.

Results: The overall objective response rate [complete response (CR) + partial response (PR)] was 70% (16 of 23 patients): 10 patients achieved a CR and another 6 patients achieved a PR. Overall, clinical benefit of SGN-30, as assessed by achieving a response to therapy or stable disease (CR + PR + stable disease), was shown by 87% of patients during the study, including all patients with pc-ALCL or LyP and two thirds of patients with T-MF or with multiple clinical diagnoses. Nine of the 10 patients who achieved a CR and 5 of the 6 patients who achieved a PR were in remission at their follow-up evaluation (median duration, 84 days). Fifteen of 23 patients (65%) experienced at least one adverse event during the study, most of which were mild or moderate.

Conclusions: SGN-30 was clinically active in 16 of 23 patients with heavily pretreated pc-ALCL, LyP, and T-MF and was well tolerated in this study. (Clin Cancer Res 2009;15(19):6217–24)
CEACAM5-Targeted Therapy of Human Colonic and Pancreatic Cancer Xenografts with Potent Labetuzumab-SN-38 Immunoconjugates
Authors: Govindan Serengulam V. , Cardillo Thomas M. , Moon Sung-Ju , Hansen Hans J. , Goldenberg David M.
Published: September 2009

Purpose: To improve the efficacy and reduce the gastrointestinal toxicity of the cancer prodrug, CPT-11, we have developed immunoconjugates of its active form, SN-38, and an anti-CEACAM5 antibody for targeted chemotherapy.

Experimental Design: SN-38 conjugates of the anti-CEACAM5 monoclonal antibody, labetuzumab (hMN-14), varying in the nature of the cross-linker attachment at the drug's 20-hydroxyl position, were evaluated in vitro, in metastatic and/or s.c. human colonic and pancreatic cancer xenografts in nude mice using appropriate controls, and in a CEACAM5-negative tumor model.

Results: A pilot study in a s.c. LS174T model of human colonic carcinoma established the relative effectiveness of different conjugates. In the lung metastatic model of GW-39 human colonic carcinoma in nude mice, therapy with two specific labetuzumab-SN-38 conjugates, using 0.25 mg SN-38 equivalent/kg, q4d × 8, significantly extended median survival time versus controls (P < 0.002). In an expanded evaluation in the s.c. LS174T xenograft model, specific SN-38 conjugates produced significant tumor growth control and increases in median survival time versus other controls, including CPT-11 at a 33-fold greater cumulative dose (P < 0.01). An improvement was also observed in the therapy of a s.c. human pancreatic tumor xenograft. In a CEACAM5-negative systemic lymphoma xenograft, one labetuzumab-SN-38 conjugate examined was ineffective, whereas the conjugate specific for the tumor model produced 100% survival.

Conclusions: The promising labetuzumab-SN-38 conjugates developed showed selective therapeutic efficacy in human tumor models at nontoxic doses that were a fraction of the CPT-11 doses used. (Clin Cancer Res 2009;15(19):6052–61)
An miR-502–Binding Site Single-Nucleotide Polymorphism in the 3′-Untranslated Region of the SET8 Gene Is Associated with Early Age of Breast Cancer Onset
Authors: Song Fengju , Zheng Hong , Liu Ben , Wei Sheng , Dai Hongji , Zhang Lina , Calin George A. , Hao Xishan , Wei Qingyi , Zhang Wei , Chen Kexin
Published: September 2009

Purpose: MicroRNAs regulate gene expression by binding to the 3′-untranslated region (UTR) of target genes. Single-nucleotide polymorphisms of critical genes may affect their regulation by microRNAs. We have identified a single-nucleotide polymorphism within the miR-502 seed binding region in the 3′-UTR of the SET8 gene. SET8 methylates TP53 and regulates genome stability. We investigated the role of this SET8 single-nucleotide polymorphism and in concert with the TP53 codon 72 single-nucleotide polymorphism in the propensity for onset of breast cancer.

Experimental Design: We measured the SET8 single-nucleotide polymorphisms in a case-control study on 1,110 breast cancer cases and 1,097 controls.

Results: The SET8 CC and TP53 GG genotypes were independently associated with an earlier age of breast cancer onset in an allele-dose-dependent manner (for SET8, 52.2 years for TT, 51.4 for TC, and 49.5 for CC; and for TP53, 53.1 years for CC, 51.5 for GC, 50.7 for GG). Individuals with combined SET8 CC and TP53 GG genotypes developed cancer at a median age of 47.7 years as compared with 54.6 years for individuals with combined SET8 TT and TP53 CC genotypes. In the 51 breast cancer tissue samples tested, the SET8 CC genotype was associated with reduced SET8, but not miR-502, transcript levels.

Conclusions: These data suggest that the miR-502–binding site single-nucleotide polymorphism in the 3′-UTR of SET8 modulates SET8 expression and contributes to the early development of breast cancer, either independently or together with the TP53 codon 72 single-nucleotide polymorphism. Larger studies with multiethnic groups are warranted to validate our findings. (Clin Cancer Res 2009;15(19):6292–300)
Translocator Protein Blockade Reduces Prostate Tumor Growth
Authors: Fafalios Arlee , Akhavan Ardavan , Parwani Anil V. , Bies Robert R. , McHugh Kevin J. , Pflug Beth R.
Published: September 2009

Purpose: The transmembrane molecule, translocator protein (TSPO), has been implicated in the progression of epithelial tumors. TSPO gene expression is high in tissues involved in steroid biosynthesis, neurodegenerative disease, and in cancer, and overexpression has been shown to contribute to pathologic conditions including cancer progression in several different models. The goal of our study was to examine the expression and biological relevance of TSPO in prostate cancer and show that the commonly prescribed benzodiazepine lorazepam, a ligand for TSPO, exhibits anticancer properties.

Experimental Design: Immunohistochemical analysis using tissue microarrays was used to determine the expression profile of TSPO in human prostate cancer tissues. To show the effect of TSPO ligands (lorazepam and PK11195) in prostate cancer, we used cell proliferation assays, apoptosis ELISA, prostate cancer xenograft study, and immunohistochemistry.

Results: TSPO expression is increased in prostatic intraepithelial neoplasia, primary prostate cancer, and metastases compared with normal prostate tissue and benign prostatic hyperplasia. Furthermore, TSPO expression correlates with disease progression, as TSPO levels increased with increasing Gleason sum and stage with prostate cancer metastases demonstrating the highest level of expression among all tissues examined. Functionally, we have shown that lorazepam has antiproliferative and proapoptotic properties in vitro and in vivo. Additionally, we have shown that TSPO overexpression in nontumorigenic cells conferred susceptibility to lorazepam-induced growth inhibition.

Conclusion: These data suggest that blocking TSPO function in tumor cells induces cell death and denotes a survival role for TSPO in prostate cancer and provides the first evidence for the use of benzodiazepines in prostate cancer therapeutics. (Clin Cancer Res 2009;15(19):6177–84)
Targeted Radioiodine Therapy of Neuroblastoma Tumors following Systemic Nonviral Delivery of the Sodium Iodide Symporter Gene
Authors: Klutz Kathrin , Russ Verena , Willhauck Michael J. , Wunderlich Nathalie , Zach Christian , Gildehaus Franz Josef , Göke Burkhard , Wagner Ernst , Ogris Manfred , Spitzweg Christine
Published: September 2009

Purpose: We recently reported the significant therapeutic efficacy of radioiodine therapy in various tumor mouse models following transcriptionally targeted sodium iodide symporter (NIS) gene transfer. These studies showed the high potential of NIS as a novel diagnostic and therapeutic gene for the treatment of extrathyroidal tumors. As a next crucial step towards clinical application of NIS-mediated radionuclide therapy we aim at systemic delivery of the NIS gene to target extrathyroidal tumors even in the metastatic stage.

Experimental Design: In the current study, we used synthetic polymeric vectors based on pseudodendritic oligoamines with high intrinsic tumor affinity (G2-HD-OEI) to target a NIS-expressing plasmid (CMV-NIS-pcDNA3) to neuroblastoma (Neuro2A) cells.

Results: Incubation with NIS-containing polyplexes (G2-HD-OEI/NIS) resulted in a 51-fold increase in perchlorate-sensitive iodide uptake activity in Neuro2A cells in vitro. Through 123I-scintigraphy and ex vivo gamma counting Neuro2A tumors in syngeneic A/J mice were shown to accumulate 8% to 13% ID/g 123I with a biological half-life of 13 hours, resulting in a tumor-absorbed dose of 247 mGy/MBq 131I after i.v. application of G2-HD-OEI/NIS. Nontarget organs, including liver, lung, kidneys, and spleen revealed no significant iodide uptake. Moreover, two cycles of systemic NIS gene transfer followed by 131I application (55.5 MBq) resulted in a significant delay in tumor growth associated with markedly improved survival.

Conclusions: In conclusion, our data clearly show the high potential of novel pseudodendritic polymers for tumor-specific NIS gene delivery after systemic application, opening the prospect of targeted NIS-mediated radionuclide therapy of nonthyroidal tumors even in metastatic disease. (Clin Cancer Res 2009;15(19):6079–86)
Spectrum of Phosphatidylinositol 3-Kinase Pathway Gene Alterations in Bladder Cancer
Authors: Platt Fiona M. , Hurst Carolyn D. , Taylor Claire F. , Gregory Walter M. , Harnden Patricia , Knowles Margaret A.
Published: September 2009

Purpose: The phosphatidylinositol 3-kinase (PI3K) pathway can be activated by alterations affecting several pathway components. For rational application of targeted therapies, detailed understanding of tumor biology and approaches to predict efficacy in individual tumors are required. Our aim was to assess the frequency and distribution of pathway alterations in bladder cancer.

Experimental Design: We examined the pathway components (PIK3CA, PTEN, TSC1, RHEB, and LKB1) and putative upstream regulators (FGFR3 and RAS genes) for mutation, allelic loss, copy number alteration, and expression in bladder tumors and cell lines.

Results: No mutations were found in RHEB and only a single mutation in LKB1. PIK3CA mutations were detected in 25% of tumors and 26% of cell lines with a significant excess of helical domain mutations (E542K and E545K). There was over-representation but not amplification of the gene. Loss of heterozygosity of the PTEN region and homozygous deletion were found in 12% and 1.4% of tumors, and reduced expression in 49%. Forty-six percent of cell lines showed alterations that implicated PTEN. Sixteen percent of tumors and 11% of cell lines showed TSC1 mutation, and 9q loss of heterozygosity was common (57%). Pathway alterations were independently distributed, suggesting that the mutation of two pathway members may have additive or synergistic effects through noncanonical functions.

Conclusions: PI3K pathway alterations are common in bladder cancer. The lack of redundancy of alterations suggests that single-agent PI3K-targeted therapy may not be successful in these cancers. This study provides a well-characterized series of cell lines for use in preclinical studies of targeted agents. (Clin Cancer Res 2009;15(19):6008–17)
High-Throughput Cell-Based Screening of 4910 Known Drugs and Drug-like Small Molecules Identifies Disulfiram as an Inhibitor of Prostate Cancer Cell Growth
Authors: Iljin Kristiina , Ketola Kirsi , Vainio Paula , Halonen Pasi , Kohonen Pekka , Fey Vidal , Grafström Roland C. , Perälä Merja , Kallioniemi Olli
Published: September 2009

Purpose: To identify novel therapeutic opportunities for patients with prostate cancer, we applied high-throughput screening to systematically explore most currently marketed drugs and drug-like molecules for their efficacy against a panel of prostate cancer cells.

Experimental Design: We carried out a high-throughput cell-based screening with proliferation as a primary end-point using a library of 4,910 drug-like small molecule compounds in four prostate cancer (VCaP, LNCaP, DU 145, and PC-3) and two nonmalignant prostate epithelial cell lines (RWPE-1 and EP156T). The EC50 values were determined for each cell type to identify cancer selective compounds. The in vivo effect of disulfiram (DSF) was studied in VCaP cell xenografts, and gene microarray and combinatorial studies with copper or zinc were done in vitro for mechanistic exploration.

Results: Most of the effective compounds, including antineoplastic agents, were nonselective and found to inhibit both cancer and control cells in equal amounts. In contrast, histone deacetylase inhibitor trichostatin A, thiram, DSF, and monensin were identified as selective antineoplastic agents that inhibited VCaP and LNCaP cell proliferation at nanomolar concentrations. DSF reduced tumor growth in vivo, induced metallothionein expression, and reduced DNA replication by downregulating MCM mRNA expression. The effect of DSF was potentiated by copper in vitro.

Conclusions: We identified three novel cancer-selective growth inhibitory compounds for human prostate cancer cells among marketed drugs. We then validated DSF as a potential prostate cancer therapeutic agent. These kinds of pharmacologically well-known molecules can be readily translated to in vivo preclinical studies and clinical trials. (Clin Cancer Res 2009;15(19):6070–8)
Vorinostat Inhibits Brain Metastatic Colonization in a Model of Triple-Negative Breast Cancer and Induces DNA Double-Strand Breaks
Authors: Palmieri Diane , Lockman Paul R. , Thomas Fancy C. , Hua Emily , Herring Jeanne , Hargrave Elizabeth , Johnson Matthew , Flores Natasha , Qian Yongzhen , Vega-Valle Eleazar , Taskar Kunal S. , Rudraraju Vinay , Mittapalli Rajendar K. , Gaasch Julie A. , Bohn Kaci A. , Thorsheim Helen R. , Liewehr David J. , Davis Sean , Reilly John F. , Walker Robert , Bronder Julie L. , Feigenbaum Lionel , Steinberg Seth M. , Camphausen Kevin , Meltzer Paul S. , Richon Victoria M. , Smith Quentin R. , Steeg Patricia S.
Published: September 2009

Purpose: As chemotherapy and molecular therapy improve the systemic survival of breast cancer patients, the incidence of brain metastases increases. Few therapeutic strategies exist for the treatment of brain metastases because the blood-brain barrier severely limits drug access. We report the pharmacokinetic, efficacy, and mechanism of action studies for the histone deactylase inhibitor vorinostat (suberoylanilide hydroxamic acid) in a preclinical model of brain metastasis of triple-negative breast cancer.

Experimental Design: The 231-BR brain trophic subline of the MDA-MB-231 human breast cancer cell line was injected into immunocompromised mice for pharmacokinetic and metastasis studies. Pharmacodynamic studies compared histone acetylation, apoptosis, proliferation, and DNA damage in vitro and in vivo.

Results: Following systemic administration, uptake of [14C]vorinostat was significant into normal rodent brain and accumulation was up to 3-fold higher in a proportion of metastases formed by 231-BR cells. Vorinostat prevented the development of 231-BR micrometastases by 28% (P = 0.017) and large metastases by 62% (P < 0.0001) compared with vehicle-treated mice when treatment was initiated on day 3 post-injection. The inhibitory activity of vorinostat as a single agent was linked to a novel function in vivo: induction of DNA double-strand breaks associated with the down-regulation of the DNA repair gene Rad52.

Conclusions: We report the first preclinical data for the prevention of brain metastasis of triple-negative breast cancer. Vorinostat is brain permeable and can prevent the formation of brain metastases by 62%. Its mechanism of action involves the induction of DNA double-strand breaks, suggesting rational combinations with DNA active drugs or radiation. (Clin Cancer Res 2009;15(19):6148–57)
Antiglioma Immunological Memory in Response to Conditional Cytotoxic/Immune-Stimulatory Gene Therapy: Humoral and Cellular Immunity Lead to Tumor Regression
Authors: Ghulam Muhammad A.K.M. , Candolfi Marianela , King Gwendalyn D. , Yagiz Kader , Foulad David , Mineharu Yohei , Kroeger Kurt M. , Treuer Katherine A. , Nichols W. Stephen , Sanderson Nicholas S. , Yang Jieping , Khayznikov Maksim , Van Rooijen Nico , Lowenstein Pedro R. , Castro Maria G.
Published: September 2009

Purpose: Glioblastoma multiforme is a deadly primary brain cancer. Because the tumor kills due to recurrences, we tested the hypothesis that a new treatment would lead to immunological memory in a rat model of recurrent glioblastoma multiforme.

Experimental Design: We developed a combined treatment using an adenovirus (Ad) expressing fms-like tyrosine kinase-3 ligand (Flt3L), which induces the infiltration of immune cells into the tumor microenvironment, and an Ad expressing herpes simplex virus-1–thymidine kinase (TK), which kills proliferating tumor cells in the presence of ganciclovir.

Results: This treatment induced immunological memory that led to rejection of a second glioblastoma multiforme implanted in the contralateral hemisphere and of an extracranial glioblastoma multiforme implanted intradermally. Rechallenged long-term survivors exhibited anti-glioblastoma multiforme–specific T cells and displayed specific delayed-type hypersensitivity. Using depleting antibodies, we showed that rejection of the second tumor was dependent on CD8+ T cells. Circulating anti-glioma antibodies were observed when glioblastoma multiforme cells were implanted intradermally in naïve rats or in long-term survivors. However, rats bearing intracranial glioblastoma multiforme only exhibited circulating antitumoral antibodies upon treatment with Ad-Flt3L + Ad-TK. This combined treatment induced tumor regression and release of the chromatin-binding protein high mobility group box 1 in two further intracranial glioblastoma multiforme models, that is, Fisher rats bearing intracranial 9L and F98 glioblastoma multiforme cells.

Conclusions: Treatment with Ad-Flt3L + Ad-TK triggered systemic anti–glioblastoma multiforme cellular and humoral immune responses, and anti–glioblastoma multiforme immunological memory. Release of the chromatin-binding protein high mobility group box 1 could be used as a noninvasive biomarker of therapeutic efficacy for glioblastoma multiforme. The robust treatment efficacy lends further support to its implementation in a phase I clinical trial. (Clin Cancer Res 2009;15(19):6113–27)
Nuclear NF-κB p65 Phosphorylation at Serine 276 by Protein Kinase A Contributes to the Malignant Phenotype of Head and Neck Cancer
Authors: Arun Pattatheyil , Brown Matthew S. , Ehsanian Reza , Chen Zhong , Van Waes Carter
Published: September 2009

Purpose: Aberrant nuclear activation and phosphorylation of the canonical NF-κB subunit RELA/p65 at Serine-536 by inhibitor κB kinase is prevalent in head and neck squamous cell carcinoma (HNSCC), but the role of other kinases in NF-κB activation has not been well defined. Here, we investigated the prevalence and function of p65-Ser276 phosphorylation by protein kinase A (PKA) in the malignant phenotype and gene transactivation, and studied p65-Ser276 as a potential target for therapy.

Experimental Design: Phospho and total p65 protein expression and localization were determined in HNSCC tissue array and in cell lines. The effects of the PKA inhibitor H-89 on NF-κB activation, downstream gene expression, cell proliferation and cell cycle were examined. Knockdown of PKA by specific siRNA confirmed the specificity.

Results: NF-κB p65 phosphorylated at Ser276 was prevalent in HNSCC and adjacent dysplastic mucosa, but localized to the cytoplasm in normal mucosa. In HNSCC lines, tumor necrosis factor-α (TNF-α) significantly increased, whereas H-89 inhibited constitutive and TNF-α–induced nuclear p65 (Ser276) phosphorylation, and significantly suppressed NF-κB and target gene IL-8 reporter activity. Knockdown of PKA by small interfering RNA inhibited NF-κB, IL-8, and BCL-XL reporter gene activities. H-89 suppressed cell proliferation, induced cell death, and blocked the cell cycle in G1-S phase. Consistent with its biological effects, H-89 down-modulated expression of NF-κB–related genes Cyclin D1, BCL2, BCL-XL, COX2, IL-8, and VEGF, as well as induced cell cycle inhibitor p21CIP1/WAF1, while suppressing proliferative marker Ki67.

Conclusions: NF-κB p65 (Ser276) phosphorylation by PKA promotes the malignant phenotype and holds potential as a therapeutic target in HNSCC. (Clin Cancer Res 2009;15(19):5974–84)
MicroRNA Expression in Squamous Cell Carcinoma and Adenocarcinoma of the Esophagus: Associations with Survival
Authors: Mathé Ewy A. , Nguyen Giang Huong , Bowman Elise D. , Zhao Yiqiang , Budhu Anuradha , Schetter Aaron J. , Braun Rosemary , Reimers Mark , Kumamoto Kensuke , Hughes Duncan , Altorki Nasser K. , Casson Alan G. , Liu Chang-Gong , Wang Xin Wei , Yanaihara Nozomu , Hagiwara Nobutoshi , Dannenberg Andrew J. , Miyashita Masao , Croce Carlo M. , Harris Curtis C.
Published: September 2009

Purpose: The dismal outcome of esophageal cancer patients highlights the need for novel prognostic biomarkers, such as microRNAs (miRNA). Although recent studies have established the role of miRNAs in esophageal carcinoma, a comprehensive multicenter study investigating different histologic types, including squamous cell carcinoma (SCC) and adenocarcinoma with or without Barrett's, is still lacking.

Experimental Design: miRNA expression was measured in cancerous and adjacent noncancerous tissue pairs collected from 100 adenocarcinoma and 70 SCC patients enrolled at four clinical centers from the United States, Canada, and Japan. Microarray-based expression was measured in a subset of samples in two cohorts and was validated in all available samples.

Results: In adenocarcinoma patients, miR-21, miR-223, miR-192, and miR-194 expression was elevated, whereas miR-203 expression was reduced in cancerous compared with noncancerous tissue. In SCC patients, we found elevated miR-21 and reduced miR-375 expression levels in cancerous compared with noncancerous tissue. When comparing cancerous tissue expression between adenocarcinoma and SCC patients, miR-194 and miR-375 were elevated in adenocarcinoma patients. Significantly, elevated miR-21 expression in noncancerous tissue of SCC patients and reduced levels of miR-375 in cancerous tissue of adenocarcinoma patients with Barrett's were strongly associated with worse prognosis. Associations with prognosis were independent of tumor stage or nodal status, cohort type, and chemoradiation therapy.

Conclusions: Our multicenter-based results highlight miRNAs involved in major histologic types of esophageal carcinoma and uncover significant associations with prognosis. Elucidating miRNAs relevant to esophageal carcinogenesis is potentially clinically useful for developing prognostic biomarkers and identifying novel drug targets and therapies. (Clin Cancer Res 2009;15(19):6192–200)
Inhibiting the Hypoxia Response for Cancer Therapy: The New Kid on the Block
Authors: Koh Mei Yee , Spivak-Kroizman Taly R. , Powis Garth
Published: September 2009

The hypoxia-inducible transcription factor (HIF)-1α inhibitor KC7F2 described in this issue of Clinical Cancer Research is the newest addition to an emerging class of antitumor agents targeting the hypoxia response. Here, we discuss the proposed mechanism of action of KC7F2 and its potential strengths and limitations in comparison with other promising HIF-1α inhibitors. (Clin Cancer Res 2009;15(19):5945–6)
A Pooled Analysis of Continued Prophylactic Efficacy of Quadrivalent Human Papillomavirus (Types 6/11/16/18) Vaccine against High-grade Cervical and External Genital Lesions
Authors: Kjaer Susanne K. , Sigurdsson Kristján , Iversen Ole-Erik , Hernandez-Avila Mauricio , Wheeler Cosette M. , Perez Gonzalo , Brown Darron R. , Koutsky Laura A. , Tay Eng Hseon , García Patricia , Ault Kevin A. , Garland Suzanne M. , Leodolter Sepp , Olsson Sven-Eric , Tang Grace W.K. , Ferris Daron G. , Paavonen Jorma , Lehtinen Matti , Steben Marc , Bosch F. Xavier , Dillner Joakim , Joura Elmar A. , Majewski Slawomir , Muñoz Nubia , Myers Evan R. , Villa Luisa L. , Taddeo Frank J. , Roberts Christine , Tadesse Amha , Bryan Janine , Maansson Roger , Lu Shuang , Vuocolo Scott , Hesley Teresa M. , Saah Alfred , Barr Eliav , Haupt Richard M.
Published: September 2009

Quadrivalent human papillomavirus (HPV) vaccine has been shown to provide protection from HPV 6/11/16/18–related cervical, vaginal, and vulvar disease through 3 years. We provide an update on the efficacy of the quadrivalent HPV vaccine against high-grade cervical, vaginal, and vulvar lesions based on end-of-study data from three clinical trials. Additionally, we stratify vaccine efficacy by several baseline characteristics, including age, smoking status, and Papanicolaou (Pap) test results. A total of 18,174 females ages 16 to 26 years were randomized and allocated into one of three clinical trials (protocols 007, 013, and 015). Vaccine or placebo was given at baseline, month 2, and month 6. Pap testing was conducted at regular intervals. Cervical and anogenital swabs were collected for HPV DNA testing. Examination for the presence of vulvar and vaginal lesions was also done. Endpoints included high-grade cervical, vulvar, or vaginal lesions (CIN 2/3, VIN 2/3, or VaIN 2/3). Mean follow-up time was 42 months post dose 1. Vaccine efficacy against HPV 6/11/16/18–related high-grade cervical lesions in the per-protocol and intention-to-treat populations was 98.2% [95% confidence interval (95% CI), 93.3-99.8] and 51.5% (95% CI, 40.6-60.6), respectively. Vaccine efficacy against HPV 6/11/16/18–related high-grade vulvar and vaginal lesions in the per-protocol and intention-to-treat populations was 100.0% (95% CI, 82.6-100.0) and 79.0% (95% CI, 56.4-91.0), respectively. Efficacy in the intention-to-treat population tended to be lower in older women, women with more partners, and women with abnormal Pap test results. The efficacy of quadrivalent HPV vaccine against high-grade cervical and external anogenital neoplasia remains high through 42 months post vaccination.
Detection of MGMT Promoter Methylation in Normal Individuals Is Strongly Associated with the T Allele of the rs16906252 MGMT Promoter Single Nucleotide Polymorphism
Authors: Candiloro Ida L.M. , Dobrovic Alexander
Published: September 2009

Methylation of the CpG island in the MGMT promoter region is a frequent event in several cancer types including colorectal cancer, lung cancer, lymphoma, and glioblastoma. A correlation between methylation and the T allele of the rs16906252 single nucleotide polymorphism (SNP) in colorectal carcinomas has previously been reported. As aberrant MGMT methylation can be an early event in tumor development, we tested the hypothesis that normal individuals possessing the T allele may be predisposed to somatic methylation at the MGMT promoter. Peripheral blood monononuclear cell DNA from 89 normal, healthy individuals was genotyped at rs1690625 and assessed for the methylation status of the MGMT promoter region using independent quantitative methodologies capable of detecting low-level methylation: MethyLight and Sensitive Melting Analysis after Real-time Methylation-Specific PCR (SMART-MSP). There was a strong association between presence of the T allele and detectable methylation (P = 0.00005) in the peripheral blood DNA. Furthermore, when a MSP assay flanking the SNP was used to amplify methylated sequences in heterozygotes, only the T allele was methylated. Thus, detectable somatic methylation of the MGMT promoter in normal individuals is strongly associated with the T allele of the rs16906252 MGMT promoter SNP.
SCN5A Mutations and the Role of Genetic Background in the Pathophysiology of Brugada Syndrome
Authors: Probst Vincent , Wilde Arthur A.M. , Barc Julien , Sacher Frederic , Babuty Dominique , Mabo Philippe , Mansourati Jacques , Le Scouarnec Solena , Kyndt Florence , Le Caignec Cedric , Guicheney Pascale , Gouas Laetitia , Albuisson Juliette , Meregalli Paola G. , Le Marec Hervé , Tan Hanno L. , Schott Jean-Jacques
Published: September 2009

Background—

Mutations in SCN5A are identified in ≈20% to 30% of probands affected by Brugada syndrome (BrS). However, in familial studies, the relationship between SCN5A mutations and BrS remains poorly understood. The aim of this study was to investigate the association of SCN5A mutations and BrS in a group of large genotyped families.

Methods and Results—

Families were included if at least 5 family members were carriers of the SCN5A mutation, which was identified in the proband. Thirteen large families composed of 115 mutation carriers were studied. The signature type I ECG was present in 54 mutation carriers (BrS-ECG+; 47%). In 5 families, we found 8 individuals affected by BrS but with a negative genotype (mutation-negative BrS-ECG+). Among these 8 mutation-negative BrS-ECG+ individuals, 3, belonging to 3 different families, had a spontaneous type I ECG, whereas 5 had a type I ECG only after the administration of sodium channel blockers. One of these 8 individuals had also experienced syncope. Mutation carriers had, on average, longer PR and QRS intervals than noncarriers, demonstrating that these mutations exerted functional effects.

Conclusions—

Our results suggest that SCN5A mutations are not directly causal to the occurrence of a BrS-ECG+ and that genetic background may play a powerful role in the pathophysiology of BrS. These findings add further complexity to concepts regarding the causes of BrS, and are consistent with the emerging notion that the pathophysiology of BrS includes various elements beyond mutant sodium channels.
Treatment of Acute Myocardial Infarction With Sirolimus-Eluting Stents Results in Chronic Endothelial Dysfunction in the Infarct-Related Coronary Artery
Authors: Obata Jyun-ei , Nakamura Takamitsu , Kitta Yoshinobu , Kodama Yasushi , Sano Keita , Kawabata Ken-Ichi , Saitoh Yukio , Fujioka Daisuke , Kobayashi Tsuyoshi , Yano Toshiaki , Watanabe Yosuke , Watanabe Kazuhiro , Kugiyama Kiyotaka
Published: September 2009

Background—

Sirolimus-eluting stent (SES) implantation aggravated endothelial vasomotor dysfunction in infarct-related coronary arteries.

Methods and Results—

This study examined the effect of SES implantation on the duration of reperfusion-induced endothelial vasomotor dysfunction in infarct-related coronary arteries and on postinfarct left ventricular dysfunction in acute myocardial infarction (AMI). Patients with a first AMI due to occlusion of the left anterior descending coronary artery and successful reperfusion using SES (n=15) or bare metal stents (BMS; n=18) were examined. The vasomotor response of the left anterior descending coronary artery to acetylcholine and left ventriculography were examined 2 weeks and 6 months after AMI. At 6 months after AMI, the impairment of epicardial coronary artery dilation and coronary blood flow increase in response to acetylcholine was recovered from 2 weeks after AMI in BMS-treated patients, whereas the responses of SES-treated patients improved but remained impaired compared with BMS-treated patients (% increase in blood flow, 77�12% in SES versus 116�15% in BMS at 10 μg/min of acetylcholine,
P
<0.01). Left ventricular regional wall dysfunction in the left anterior descending coronary artery territory improved from 2 weeks to 6 months after AMI in BMS-treated patients but not in SES-treated patients (% improvement of average SD/chord, 6% in SES versus 19% in BMS,
P
<0.05), although left ventricular global ejection fraction was similar between the groups at any time points.

Conclusions—

SES implantation may delay recovery of reperfusion-induced endothelial vasomotor dysfunction in infarct-related coronary arteries and left ventricular regional dysfunction for at least 6 months after AMI.
Transformative Choices: Leaders and the Origins of Intervention Strategy
Authors: Saunders Elizabeth N.
Published: September 2009

When and why do great powers seek to transform foreign institutions and societies through military interventions? What role does executive leadership play in influencing the choice of intervention strategy, especially the degree to which an intervention interferes in the domestic institutions of the target state? A typology of political leaders based on whether they believe that the internal characteristics of other states are the ultimate source of threats indicates that these threat perceptions shape the cost-benefit calculation leaders make when they confront intervention decisions; they also have important consequences for how states intervene. A comparison of the beliefs of President John F. Kennedy and President Lyndon B. Johnson, as well as their decision-making during the Vietnam War, illustrates how the theory operates.
China's Naval Nationalism: Sources, Prospects, and the U.S. Response
Authors: Ross Robert S.
Published: September 2009

Recent developments in Chinese politics and defense policy indicate that China will soon embark on an ambitious maritime policy that will include construction of a power-projection navy centered on an aircraft carrier. But just as nationalism and the pursuit of status encouraged past land powers to seek great power maritime capabilities, widespread nationalism, growing social instability, and the leadership's concern for its political legitimacy drive China's naval ambition. China's maritime power, however, will be limited by the constraints experienced by all land powers: enduring challenges to Chinese territorial security and a corresponding commitment to a large ground force capability will constrain China's naval capabilities and its potential challenge to U.S. maritime security. Nonetheless, China's naval nationalism will challenge U.S.-China cooperation. It will likely elicit increased U.S. naval spending and deployments, as well as politicization of China policy in the United States, challenging the United States to develop policy to manage U.S.-China naval competition to allow for continued political cooperation.