bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Level TOP2A Amplification in Prostate Cancer Is Associated with HER2 Duplication, Androgen Resistance, and Decreased Survival
Authors: Murphy Amanda J. , Hughes Caroline A. , Barrett Ciara , Magee Hilary , Loftus Barbara , O'Leary John J. , Sheils Orla
Published: March 2007

HER2 and TOP2A genes, located on 17q, can be coamplified in cancer. Overexpression of both genes has been reported in high-grade, androgen-resistant prostate cancer. Both genes have not been compared in a single prostate cancer study and the frequency of TOP2A amplifications in prostate cancer is unknown. Using tissue microarrays, we did immunohistochemistry and fluorescence in situ hybridization for HER2 and TOP2A in 100 prostate cancers (41 localized and 59 advanced) and 42 cases of benign prostatic hyperplasia (BPH). Amplification was defined as a target/centromere signal ratio of ≥1.5. HER2 immunohistochemistry was scored from 0 to 3+. Percentage nuclei staining for topoisomerase IIα (topoIIα) was recorded; overexpression was defined as ≥5% cells staining. Eighteen (31%) advanced prostate cancers showed topoIIα overexpression; 12 (26%) showed TOP2A low-level amplification; 9 (16%) expressed HER2; and 6 (13%) showed HER2 low-level amplification. No high-level amplification of either gene (target/centromere signal ratio of ≥3.0) was detected. TOP2A coexpression and coamplification were seen in 75% and 66% of HER2-positive cases, respectively. Localized prostate cancer or BPH showed no gene amplification or topoIIα overexpression. Gene amplification or overexpression correlated with high stage and Gleason score. The presence of TOP2A amplification in advanced cancer was associated with androgen resistance and decreased survival by multivariate analysis. This is the first study to document low-level TOP2A amplification in prostate cancer and an association with reduced survival. TOP2A amplification may occur with or without HER2 duplication and is often associated with topoIIα expression. Therapies directed against topoIIα (and HER2) in such patients may improve survival. [Cancer Res 2007;67(6):2893–8]
Destabilized Adhesion in the Gastric Proliferative Zone and c-Src Kinase Activation Mark the Development of Early Diffuse Gastric Cancer
Authors: Humar Bostjan , Fukuzawa Ryuji , Blair Vanessa , Dunbier Anita , More Helen , Charlton Amanda , Yang Han Kwang , Kim Woo Ho , Reeve Anthony E. , Martin Iain , Guilford Parry
Published: March 2007

The initial development of diffuse gastric cancer (DGC) is poorly understood. The study of E-cadherin (CDH1) germ line mutation carriers predisposed to DGC provides a rare opportunity to elucidate the genetic and biological events surrounding disease initiation. Samples from various stages of hereditary and sporadic DGC were investigated to determine general mechanisms underlying early DGC development. Paraffin-embedded tissues from 13 CDH1 mutation carriers and from 10 sporadic early DGC cases were analyzed. Immunofluorescence and immunohistochemistry using differentiation, proliferation, and adhesion markers showed that DGC initiation seems to occur at the proliferative zone (the upper neck) of the gastric epithelium and correlates with absent or reduced expression of junctional proteins (β-actin, p120, Lin-7). Slow proliferation of neoplastic cells at the upper gastric neck leads to the formation of intramucosal signet-ring cell carcinoma (SRCC) displaying differentiated features. As shown by immunolabeling, invasion from SRCC lesions beyond the gastric mucosa is associated with poor differentiation, increased proliferation, activation of the c-Src system, and an epithelial-mesenchymal transition. Our results provide a molecular description of the early development of DGC and explain the relationship between the two main DGC types, poorly differentiated carcinoma and SRCC: both share their origin, but SRCC develops following cancer cell differentiation and seems relatively indolent in its intramucosal stage. [Cancer Res 2007;67(6):2480–9]
15-Deoxy-Δ12,14-Prostaglandin J2 Inhibits Transcriptional Activity of Estrogen Receptor-α via Covalent Modification of DNA-Binding Domain
Authors: Kim Han-Jong , Kim Joon-Young , Meng Zhaojing , Wang Li Hua , Liu Fa , Conrads Thomas P. , Burke Terrence R. , Veenstra Timothy D. , Farrar William L.
Published: March 2007

The cyclopentenone 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) inhibits proliferation of cancer cells, including breast cancers, by peroxisome proliferator-activated receptor-γ (PPARγ)–dependent and PPARγ-independent mechanisms. However, little is known about its effect on the transcriptional activity of estrogen receptor-α (ERα) that plays vital roles in the growth of breast cancers. Here, we show that 15d-PGJ2 inhibits both 17β-estradiol (E2)–dependent and E2-independent ERα transcriptional activity by PPARγ-independent mechanism. In addition, 15d-PGJ2 directly modifies ERα protein via its reactive cyclopentenone moiety, evidenced by incorporation of biotinylated 15d-PGJ2 into ERα, both in vitro and in vivo. Nanoflow reverse-phase liquid chromatography tandem mass spectrometry analysis identifies two cysteines (Cys227 and Cys240) within the COOH-terminal zinc finger of ERα DNA-binding domain (DBD) as targets for covalent modification by 15d-PGJ2. Gel mobility shift and chromatin immunoprecipitation assays show that 15d-PGJ2 inhibits DNA binding of ERα and subsequent repression of ERα target gene expression, such as pS2 and c-Myc. Therefore, our results suggest that 15d-PGJ2 can block ERα function by covalent modification of cysteine residues within the vulnerable COOH-terminal zinc finger of ERα DBD, resulting in fundamental inhibition of both hormone-dependent and hormone-independent ERα transcriptional activity. [Cancer Res 2007;67(6):2595–602]
Therapy of Established Tumors in a Novel Murine Model Transgenic for Human Carcinoembryonic Antigen and HLA-A2 with a Combination of Anti-idiotype Vaccine and CTL Peptides of Carcinoembryonic Antigen
Authors: Saha Asim , Chatterjee Sunil K. , Foon Kenneth A. , Celis Esteban , Bhattacharya-Chatterjee Malaya
Published: March 2007

Induction of potent and sustained antitumor immunity depends on the efficient activation of CD8+ and CD4+ T cells. Immunization using dendritic cells loaded with tumor antigens constitute a powerful platform for stimulating cellular immunity. Our previous studies suggested that vaccination with an anti-idiotype antibody 3H1, which mimics a specific epitope of carcinoembryonic antigen (CEA), has the potential to break immune tolerance to CEA and induce anti-CEA antibody as well as CEA-specific CD4+ T-helper responses in colon cancer patients as well as in mice transgenic for human CEA. Here, we have combined the anti-idiotype 3H1 with the CTL peptides of CEA to augment both T-helper and CTL responses in a clinically relevant mouse model, which is transgenic for both CEA and HLA-A2. We have evaluated the potential of two different HLA-A2–restricted epitopes of CEA pulsed into dendritic cells in a therapeutic setting. The overall immune responses and survival were enhanced in groups of mice immunized with agonist peptide for CEA691 (YMIGMLVGV)–pulsed dendritic cells or CAP1-6D (YLSGADLNL, agonist peptide for CAP-1)–pulsed dendritic cells. Mice immunized with peptide-pulsed dendritic cells along with 3H1-pulsed dendritic cells resulted in significant increase in survival compared with mice immunized with peptide-pulsed dendritic cells alone (P < 0.02). IFN-γ ELISPOT and 51Cr-release assays showed that HLA-A2–restricted, CEA-specific CTL responses were augmented by combined dendritic cell vaccinations. The combined vaccination strategy resulted in increased antigen-specific proliferation of splenocytes and secretion of Th1 cytokines by CD4+ T cells that correlated with increased survival. These results suggest the potential use of this vaccination strategy for future clinical applications. [Cancer Res 2007;67(6):2881–92]
A Target Cell–Specific Activatable Fluorescence Probe for In vivo Molecular Imaging of Cancer Based on a Self-Quenched Avidin-Rhodamine Conjugate
Authors: Hama Yukihiro , Urano Yasuteru , Koyama Yoshinori , Kamiya Mako , Bernardo Marcelino , Paik Ronald S. , Shin In Soo , Paik Chang H. , Choyke Peter L. , Kobayashi Hisataka
Published: March 2007

A target cell–specific activation strategy for improved molecular imaging of peritoneal implants has been proposed, in which fluorophores are activated only in living targeted cells. A current example of an activatable fluorophore is one that is normally self-quenched by attachment to a peptide backbone but which can be activated by specific proteases that degrade the peptide resulting in “dequenching.” In this study, an alternate fluorescence activation strategy is proposed whereby self-quenching avidin-rhodamine X, which has affinity for lectin on cancer cells, is activated after endocytosis and degradation within the lysosome. Using this approach in a mouse model of peritoneal ovarian metastases, we document target-specific molecular imaging of submillimeter cancer nodules with minimal contamination by background signal. Cellular internalization of receptor-ligand pairs with subsequent activation of fluorescence via dequenching provides a generalizable and highly sensitive method of detecting cancer microfoci in vivo and has practical implications for assisting surgical and endoscopic procedures. [Cancer Res 2007;67(6):2791–9]
Dikkopf-1 as a Novel Serologic and Prognostic Biomarker for Lung and Esophageal Carcinomas
Authors: Yamabuki Takumi , Takano Atsushi , Hayama Satoshi , Ishikawa Nobuhisa , Kato Tatsuya , Miyamoto Masaki , Ito Tomoo , Ito Hiroyuki , Miyagi Yohei , Nakayama Haruhiko , Fujita Masahiro , Hosokawa Masao , Tsuchiya Eiju , Kohno Nobuoki , Kondo Satoshi , Nakamura Yusuke , Daigo Yataro
Published: March 2007

Gene expression profile analysis of lung and esophageal carcinomas revealed that Dikkopf-1 (DKK1) was highly transactivated in the great majority of lung cancers and esophageal squamous cell carcinomas (ESCC). Immunohistochemical staining using tumor tissue microarrays consisting of 279 archived non–small cell lung cancers (NSCLC) and 280 ESCC specimens showed that a high level of DKK1 expression was associated with poor prognosis of patients with NSCLC as well as ESCC, and multivariate analysis confirmed its independent prognostic value for NSCLC. In addition, we identified that exogenous expression of DKK1 increased the migratory activity of mammalian cells, suggesting that DKK1 may play a significant role in progression of human cancer. We established an ELISA system to measure serum levels of DKK1 and found that serum DKK1 levels were significantly higher in lung and esophageal cancer patients than in healthy controls. The proportion of the DKK1-positive cases was 126 of 180 (70.0%) NSCLC, 59 of 85 (69.4%) SCLC, and 51 of 81 (63.0%) ESCC patients, whereas only 10 of 207 (4.8%) healthy volunteers were falsely diagnosed as positive. A combined ELISA assays for both DKK1 and carcinoembryonic antigen increased sensitivity and classified 82.2% of the NSCLC patients as positive whereas only 7.7% of healthy volunteers were falsely diagnosed to be positive. The use of both DKK1 and ProGRP increased sensitivity to detect SCLCs up to 89.4%, whereas false-positive rate in healthy donors was only 6.3%. Our data imply that DKK1 should be useful as a novel diagnostic/prognostic biomarker in clinic and probably as a therapeutic target for lung and esophageal cancer. [Cancer Res 2007;67(6):2517–25]
p53-Independent Abrogation of a Postmitotic Checkpoint Contributes to Human PapillomavirusE6-Induced Polyploidy
Authors: Liu Yingwang , Heilman Susan A. , Illanes Diego , Sluder Greenfield , Chen Jason J.
Published: March 2007

Polyploidy is often an early event during cervical carcinogenesis, and it predisposes cells to aneuploidy, which is thought to play a causal role in tumorigenesis. Cervical and anogenital cancers are induced by the high-risk types of human papillomavirus (HPV). The HPV E6 oncoprotein induces polyploidy in human keratinocytes, yet the mechanism is not known. It was believed that E6 induces polyploidy by abrogating the spindle checkpoint after mitotic stress. We have tested this hypothesis using human keratinocytes in which E6 expression induces a significant amount of polyploidy. We found that E6 expression does not affect the spindle checkpoint. Instead, we provide direct evidence that E6 is capable of abrogating the subsequent G1 arrest after adaptation of the mitotic stress. E6 targets p53 for degradation, and previous studies have shown an important role for p53 in modulation of the G1 arrest after mitotic stress. Importantly, we have discovered that E6 mutants defective in p53 degradation also induce polyploidy, although with lower efficiency. These results suggest that E6 is able to induce polyploidy via both p53-dependent and p53-independent mechanisms. Therefore, our studies highlight a novel function of HPV E6 that may contribute to HPV-induced carcinogenesis and improve our understanding of the onset of the disease. [Cancer Res 2007;67(6):2603–10]
Dasatinib Inhibits Migration and Invasion in Diverse Human Sarcoma Cell Lines and Induces Apoptosis in Bone Sarcoma Cells Dependent on Src Kinase for Survival
Authors: Shor Audrey C. , Keschman Elizabeth A. , Lee Francis Y. , Muro-Cacho Carlos , Letson G. Douglas , Trent Jonathan C. , Pledger W. Jack , Jove Richard
Published: March 2007

Sarcomas are rare malignant mesenchymal tumors for which there are limited treatment options. One potential molecular target for sarcoma treatment is the Src tyrosine kinase. Dasatinib (BMS-354825), a small-molecule inhibitor of Src kinase activity, is a promising cancer therapeutic agent with p.o. bioavailability. Dasatinib exhibits antitumor effects in cultured human cell lines derived from epithelial tumors, including prostate and lung carcinomas. However, the action of dasatinib in mesenchymally derived tumors has yet to be shown. Based on our previous findings of Src activation in human sarcomas, we evaluated the effects of dasatinib in 12 cultured human sarcoma cell lines derived from bone and soft tissue sarcomas. Dasatinib inhibited Src kinase activity at nanomolar concentrations in these sarcoma cell lines. Downstream components of Src signaling, including focal adhesion kinase and Crk-associated substrate (p130CAS), were also inhibited at similar concentrations. This inhibition of Src signaling was accompanied by blockade of cell migration and invasion. Moreover, apoptosis was induced in the osteosarcoma and Ewing's subset of bone sarcomas at nanomolar concentrations of dasatinib. Inhibition of Src protein expression by small interfering RNA also induced apoptosis, indicating that these bone sarcoma cell lines are dependent on Src activity for survival. These results show that dasatinib inhibits migration and invasion of diverse sarcoma cell types and selectively blocks the survival of bone sarcoma cells. Therefore, dasatinib may provide therapeutic benefit by preventing the growth and metastasis of sarcomas in patients. [Cancer Res 2007;67(6):2800–8]
Histone H2AX Is a Mediator of Gastrointestinal Stromal Tumor Cell Apoptosis following Treatment with Imatinib Mesylate
Authors: Liu Ying , Tseng Michelle , Perdreau Sophie A. , Rossi Ferdinand , Antonescu Cristina , Besmer Peter , Fletcher Jonathan A. , Duensing Stefan , Duensing Anette
Published: March 2007

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and are caused by activating mutations of the KIT or platelet-derived growth factor receptor α (PDGFRA) tyrosine kinases. GISTs can be successfully treated with imatinib mesylate, a selective small-molecule protein kinase inhibitor that was first clinically approved to target the oncogenic BCR-ABL fusion protein kinase in chronic myelogenous leukemia, but which also potently inhibits KIT and PDGFR family members. The mechanistic events by which KIT/PDGFRA kinase inhibition leads to clinical responses in GIST patients are not known in detail. We report here that imatinib triggers GIST cell apoptosis in part through the up-regulation of soluble histone H2AX, a core histone H2A variant. We found that untreated GIST cells down-regulate H2AX in a pathway that involves KIT, phosphoinositide-3-kinase, and the ubiquitin/proteasome machinery, and that the imatinib-mediated H2AX up-regulation correlates with imatinib sensitivity. Depletion of H2AX attenuated the apoptotic response of GIST cells to imatinib. Soluble H2AX was found to sensitize GIST cells to apoptosis by aberrant chromatin aggregation and a transcriptional block. Our results underscore the importance of H2AX as a human tumor suppressor protein, provide mechanistic insights into imatinib-induced tumor cell apoptosis and establish H2AX as a novel target in cancer therapy. [Cancer Res 2007;67(6):2685–92]
Genome-Wide, High-Resolution Detection of Copy Number, Loss of Heterozygosity, and Genotypes from Formalin-Fixed, Paraffin-Embedded Tumor Tissue Using Microarrays
Authors: Jacobs Sharoni , Thompson Ella R. , Nannya Yasuhito , Yamamoto Go , Pillai Raji , Ogawa Seishi , Bailey Dione K. , Campbell Ian G.
Published: March 2007

Formalin-fixed, paraffin-embedded (FFPE) material tends to yield degraded DNA and is thus suboptimal for use in many downstream applications. We describe an integrated analysis of genotype, loss of heterozygosity (LOH), and copy number for DNA derived from FFPE tissues using oligonucleotide microarrays containing over 500K single nucleotide polymorphisms. A prequalifying PCR test predicted the performance of FFPE DNA on the microarrays better than age of FFPE sample. Although genotyping efficiency and reliability were reduced for FFPE DNA when compared with fresh samples, closer examination revealed methods to improve performance at the expense of variable reduction in resolution. Important steps were also identified that enable equivalent copy number and LOH profiles from paired FFPE and fresh frozen tumor samples. In conclusion, we have shown that the Mapping 500K arrays can be used with FFPE-derived samples to produce genotype, copy number, and LOH predictions, and we provide guidelines and suggestions for application of these samples to this integrated system. [Cancer Res 2007;67(6):2544–51]
Angiotensin-(1-7) Inhibits Growth of Human Lung Adenocarcinoma Xenografts in Nude Mice through a Reduction in Cyclooxygenase-2
Authors: Menon Jyotsana , Soto-Pantoja David R. , Callahan Michael F. , Cline J. Mark , Ferrario Carlos M. , Tallant E. Ann , Gallagher Patricia E.
Published: March 2007

Angiotensin-(1-7) [Ang-(1-7)] is an endogenous peptide of the renin-angiotensin system with vasodilator and antiproliferative properties. Our previous studies showed that Ang-(1-7) reduced serum-stimulated growth of human lung cancer cells in vitro through activation of a unique AT(1-7) receptor. The current study investigates the effect of Ang-(1-7) on lung tumor growth in vivo, using a human lung tumor xenograft model. Athymic mice with tumors resulting from injection of A549 human lung cancer cells were treated for 28 days with either i.v. saline or Ang-(1-7), delivered by implanted osmotic mini-pumps. Treatment with Ang-(1-7) reduced tumor volume by 30% compared with the size before treatment; in contrast, tumor size in the saline-treated animals increased 2.5-fold. These results correlate with a reduction in the proliferation marker Ki67 in the Ang-(1-7)–infused tumors when compared with the saline-infused tumor tissues. Treatment with Ang-(1-7) significantly reduced cyclooxygenase-2 (COX-2) mRNA and protein in tumors of Ang-(1-7)–infused mice when compared with mice treated with saline as well as in the parent A549 human lung cancer cells in tissue culture. These results suggest that Ang-(1-7) may decrease COX-2 activity and proinflammatory prostaglandins to inhibit lung tumor growth. In contrast, the heptapeptide had no effect on COX-1 mRNA in xenograft tumors or A549 cells. Because Ang-(1-7), a peptide with antithrombotic properties, reduces growth through activation of a selective AT(1-7) receptor, our results suggest that the heptapeptide represents a novel treatment for lung cancer by reducing COX-2. [Cancer Res 2007;67(6):2809–15]
Betulinic Acid Inhibits Prostate Cancer Growth through Inhibition of Specificity Protein Transcription Factors
Authors: Chintharlapalli Sudhakar , Papineni Sabitha , Ramaiah Shashi K. , Safe Stephen
Published: March 2007

Betulinic acid is a pentacyclic triterpene natural product initially identified as a melanoma-specific cytotoxic agent that exhibits low toxicity in animal models. Subsequent studies show that betulinic acid induces apoptosis and antiangiogenic responses in tumors derived from multiple tissues; however, the underlying mechanism of action is unknown. Using LNCaP prostate cancer cells as a model, we now show that betulinic acid decreases expression of vascular endothelial growth (VEGF) and the antiapoptotic protein survivin. The mechanism of these betulinic acid–induced antiangiogenic and proapoptotic responses in both LNCaP cells and in tumors is due to activation of selective proteasome-dependent degradation of the transcription factors specificity protein 1 (Sp1), Sp3, and Sp4, which regulate VEGF and survivin expression. Thus, betulinic acid acts as a novel anticancer agent through targeted degradation of Sp proteins that are highly overexpressed in tumors. [Cancer Res 2007;67(6):2816–23]
Identification of a Fibroblast Growth Factor Receptor 1 Splice Variant That Inhibits Pancreatic Cancer Cell Growth
Authors: Liu Zhanbing , Neiss Nicola , Zhou Shaoxia , Henne-Bruns Doris , Korc Murray , Bachem Max , Kornmann Marko
Published: March 2007

Fibroblast growth factor receptors (FGFR) play important roles in many biological processes. Nothing is presently known about possible roles of the human FGFR1-IIIb mRNA splice variant. In this study, we characterized for the first time the effects of FGFR1-IIIb expression on the transformed phenotype of human pancreatic cancer cells. The full-length FGFR1-IIIb cDNA was generated and stably expressed in PANC-1 and MIA PaCa-2 pancreatic cancer and TAKA-1 pancreatic ductal cells. FGFR1-IIIb–expressing cells synthesized a glycosylated 110-kDa protein enhancing tyrosine phosphorylation of FGFR substrate-2 on FGF-1 stimulation. The basal anchorage-dependent and anchorage-independent cell growth was significantly inhibited. These effects were associated with a marked reduction of p44/42 mitogen-activated protein kinase (MAPK) phosphorylation in combination with enhanced activity of p38 MAPK and c-Jun NH2-terminal kinase. FGFR1-IIIb expression inhibited single-cell movement and in vitro invasion as determined by time-lapse microscopy and Boyden chamber assay as well as in vivo tumor formation and growth in nude mice. Microscopic analysis of the xenograft tumors revealed a reduced Ki-67 labeling and a lower amount of tumor necrosis in FGFR1-IIIb–expressing tumors. Our results show that FGFR1-IIIb is a functional FGFR that inhibits the transformed phenotype of human pancreatic cancer cells. [Cancer Res 2007;67(6):2712–9]
Sensitization of Mesothelioma Cells to Tumor Necrosis Factor–Related Apoptosis–Inducing Ligand–Induced Apoptosis by Heat Stress via the Inhibition of the 3-Phosphoinositide-Dependent Kinase 1/Akt Pathway
Authors: Pespeni Melissa H. , Hodnett Maki , Abayasiriwardana Keith S. , Roux Jérémie , Howard Marybeth , Broaddus V. Courtney , Pittet Jean-François
Published: March 2007

Heat stress may enhance the effect of apoptosis-inducing agents in resistant tumor cells. One such agent is the tumor necrosis factor–related apoptosis–inducing ligand (TRAIL), which has attracted intense interest for its ability to induce apoptosis in tumors without affecting nonmalignant cells. We therefore tested whether heat stress potentiates TRAIL-induced apoptosis in mesothelioma cells, its cell type being resistant to TRAIL alone. We found that heat stress enhanced the apoptosis caused by TRAIL but not by chemotherapy. To explain this potentiation, we found that heat stress decreased Akt phosphorylation via the dissociation of heat shock protein 90 (Hsp90) from its client protein 3-phosphoinositide-dependent kinase 1 (PDK-1), a major Akt kinase. The role of Hsp90 and the Akt pathway was confirmed by showing that inhibitors of Hsp90 and the phosphatidyilinositol-3 kinase/Akt pathway reproduced the effect of heat stress on TRAIL-induced apoptosis and that the effect of inhibiting Hsp90 on TRAIL-induced apoptosis could be overcome by activating the Akt pathway with a constitutively active construct of the Akt kinase PDK-1. The effect of heat stress involved multiple steps of the apoptotic machinery. Heat stress potentiated the death receptor pathway, as shown by an increase in TRAIL-induced caspase 8 cleavage. Nonetheless, knockdown of Bid, the main intermediary molecule from the death receptor pathway to the mitochondria, inhibited the effect of heat stress, showing that mitochondrial amplification was required for potentiation by heat stress. In summary, these results support the novel concept that heat stress inhibits the Akt pathway by dissociating PDK-1 from its chaperone Hsp90, leading to potentiation of TRAIL-induced apoptosis in resistant malignant cells. [Cancer Res 2007;67(6):2865–71]
Oncolytic Immunovirotherapy for Melanoma Using Vesicular Stomatitis Virus
Authors: Diaz Rosa Maria , Galivo Feorillo , Kottke Timothy , Wongthida Phonphimon , Qiao Jian , Thompson Jill , Valdes Mikael , Barber Glen , Vile Richard G.
Published: March 2007

Relatively little attention has been paid to the role of virotherapy in promoting antitumor immune responses. Here, we show that CD8+ T cells are critical for the efficacy of intratumoral vesicular stomatitis virus virotherapy and are induced against both virally encoded and tumor-associated immunodominant epitopes. We tested three separate immune interventions to increase the frequency/activity of activated antitumoral T cells. Depletion of Treg had a negative therapeutic effect because it relieved suppression of the antiviral immune response, leading to early viral clearance. In contrast, increasing the circulating levels of tumor antigen–specific T cells using adoptive T cell transfer therapy, in combination with intratumoral virotherapy, generated significantly improved therapy over either adoptive therapy or virotherapy alone. Moreover, the incorporation of a tumor-associated antigen within the oncolytic vesicular stomatitis virus increased the levels of activation of naïve T cells against the antigen, which translated into increased antitumor therapy. Therefore, our results show that strategies which enhance immune activation against tumor-associated antigens can also be used to enhance the efficacy of virotherapy. [Cancer Res 2007;67(6):2840–7]
Large-Scale CpG Methylation Analysis Identifies Novel Candidate Genes and Reveals Methylation Hotspots in Acute Lymphoblastic Leukemia
Authors: Taylor Kristen H. , Pena-Hernandez Keila E. , Davis J. Wade , Arthur Gerald L. , Duff Deiter J. , Shi Huidong , Rahmatpanah Farah B. , Sjahputera Ozy , Caldwell Charles W.
Published: March 2007

This study examined DNA methylation associated with acute lymphoblastic leukemia (ALL) and showed that selected molecular targets can be pharmacologically modulated to reverse gene silencing. A CpG island (CGI) microarray containing more than 3,400 unique clones that span all human chromosomes was used for large-scale discovery experiments and led to 262 unique CGI loci being statistically identified as methylated in ALL lymphoblasts. The methylation status of 10 clones encompassing 11 genes (DCC, DLC-1, DDX51, KCNK2, LRP1B, NKX6-1, NOPE, PCDHGA12, RPIB9, ABCB1, and SLC2A14) identified as differentially methylated between ALL patients and controls was independently verified. Consequently, the methylation status of DDX51 was found to differentiate patients with B- and T-ALL subtypes (P = 0.011, Fisher's exact test). Next, the relationship between methylation and expression of these genes was examined in ALL cell lines (NALM-6 and Jurkat) before and after treatments with 5-aza-2-deoxycytidine and trichostatin A. More than a 10-fold increase in mRNA expression was observed for two previously identified tumor suppressor genes (DLC-1 and DCC) and also for RPIB9 and PCDHGA12. Although the mechanisms that lead to the CGI methylation of these genes are unknown, bisulfite sequencing of the promoter of RPIB9 suggests that expression is inhibited by methylation within SP1 and AP2 transcription factor binding motifs. Finally, specific chromosomal methylation hotspots were found to be associated with ALL. This study sets the stage for acquiring a better biological understanding of ALL and for the identification of epigenetic biomarkers useful for differential diagnosis, therapeutic monitoring, and the detection of leukemic relapse. [Cancer Res 2007;67(6):2617–25]
Caveolin-1–Deficient Mice Have Increased Tumor Microvascular Permeability, Angiogenesis, and Growth
Authors: Lin Michelle I. , Yu Jun , Murata Takahisa , Sessa William C.
Published: March 2007

Caveolin-1 (Cav-1) is a major structural protein that is essential to the formation of the organelle, caveolae. Cav-1 knockout (KO) mice were observed to be completely devoid of caveolae yet they exhibit a hyperpermeable vasculature. Given the nature of the hyperpermeable Cav-1 KO endothelium, we sought to investigate if tumors grown in Cav-1 KO mice would be leaky and grow faster. Indeed, Lewis lung carcinoma cells implanted into Cav-1 KO mice had increased tumor vascular permeability, measured by Evans blue extravasation and fibrinogen deposition compared with tumors implanted into wild-type (WT) mice. Cav-1 KO mice also had significantly higher tumor growth rates, attributable to increased tumor angiogenesis and decreased tumor cell death. Furthermore, administration of an antipermeability peptide, cavtratin, was able to correct the tumor hyperpermeability as well as attenuate the increased tumor growth. Mechanistically, endothelial cells isolated from Cav-1 KO mice exhibited increased tyrosine phosphorylation on vascular endothelial growth factor (VEGF) receptor-2 (VEGFR-2) and decreased association with the adherens junction protein, VE-cadherin. Thus, the loss of Cav-1 increases tumor permeability and growth and that may relate to enhanced VEGF signaling due to lack of Cav-1 inhibition of VEGFR-2 or decreased VE-cadherin mediated VEGFR-2 phosphorylation. [Cancer Res 2007;67(6):2849–56]
Effect of Vascular Normalization by Antiangiogenic Therapy on Interstitial Hypertension, Peritumor Edema, and Lymphatic Metastasis: Insights from a Mathematical Model
Authors: Jain Rakesh K. , Tong Ricky T. , Munn Lance L.
Published: March 2007

Preclinical and clinical evidence shows that antiangiogenic agents can decrease tumor vessel permeability and interstitial fluid pressure (IFP) in a process of vessel “normalization.” The resulting normalized vasculature has more efficient perfusion, but little is known about how tumor IFP and interstitial fluid velocity (IFV) are affected by changes in transport properties of the vessels and interstitium that are associated with antiangiogenic therapy. By using a mathematical model to simulate IFP and IFV profiles in tumors, we show here that antiangiogenic therapy can decrease IFP by decreasing the tumor size, vascular hydraulic permeability, and/or the surface area per unit tissue volume of tumor vessels. Within a certain window of antiangiogenic effects, interstitial convection within the tumor can increase dramatically, whereas fluid convection out of the tumor margin decreases. This would result in increased drug convection within the tumor and decreased convection of drugs, growth factors, or metastatic cancer cells from the tumor margin into the peritumor fluid or tissue. Decreased convection of growth factors, such as vascular endothelial growth factor-C (VEGF-C), would limit peritumor hyperplasia, and decreased VEGF-A would limit angiogenesis in sentinel lymph nodes. Both of these effects would reduce the probability of lymphatic metastasis. Finally, decreased fluid convection into the peritumor tissue would decrease peritumor edema associated with brain tumors and ascites accumulation in the peritoneal or pleural cavity, a major complication with a number of malignancies. [Cancer Res 2007;67(6):2729–35]
Genome-Wide Loss of Heterozygosity and Copy Number Analysis in Melanoma Using High-Density Single-Nucleotide Polymorphism Arrays
Authors: Stark Mitchell , Hayward Nicholas
Published: March 2007

Although a number of genes related to melanoma development have been identified through candidate gene screening approaches, few studies have attempted to conduct such analyses on a genome-wide scale. Here we use Illumina 317K whole-genome single-nucleotide polymorphism arrays to define a comprehensive allelotype of melanoma based on loss of heterozygosity (LOH) and copy number changes in a panel of 76 melanoma cell lines. In keeping with previous reports, we found frequent LOH on chromosome arms 9p (72%), 10p (55%), 10q (55%), 9q (49%), 6q (43%), 11q (43%), and 17p (41%). Tumor suppressor genes (TSGs) can be identified through homozygous deletion (HD). We detected 174 HDs, the most common of which targeted CDKN2A (n = 33). The second highest frequency of HD occurred in PTEN (n = 8), another well known melanoma TSG. HDs were also common for PTPRD (n = 7) and HDAC4 (n = 3), TSGs recently found to be mutated or deleted in other cancer types. Analysis of other HDs and regions of LOH that we have identified might lead to the characterization of further melanoma TSGs. We noted 197 regional amplifications, including some centered on the melanoma oncogenes MITF (n = 9), NRAS (n = 3), BRAF (n = 3), and CCND1 (n = 3). Other amplifications potentially target novel oncogenes important in the development of a subset of melanomas. The numerous focal amplifications and HDs we have documented here are the first step toward identifying a comprehensive catalog of genes involved in melanoma development, some of which may be useful prognostic markers or targets for therapies to treat this disease. [Cancer Res 2007;67(6):2632–42]
Oncogenic Role of KIAA0101 Interacting with Proliferating Cell Nuclear Antigen in Pancreatic Cancer
Authors: Hosokawa Masayo , Takehara Akio , Matsuda Koichi , Eguchi Hidetoshi , Ohigashi Hiroaki , Ishikawa Osamu , Shinomura Yasuhisa , Imai Kohzoh , Nakamura Yusuke , Nakagawa Hidewaki
Published: March 2007

To isolate novel diagnostic markers and therapeutic targets for pancreatic cancer, we earlier did expression profile analysis of pancreatic cancer cells using a genome-wide cDNA microarray combined with microdissection. Among dozens of trans-activated genes in pancreatic cancer cells, this study focused on KIAA0101 whose overexpression in pancreatic cancer cells was validated by immunohistochemical analysis. KIAA0101 was previously identified as p15PAF [proliferating cell nuclear antigen (PCNA)–associated factor] to bind with PCNA; however, its function remains unknown. To investigate for the biological significance of KIAA0101 overexpression in cancer cells, we knocked down KIAA0101 by small interfering RNA (siRNA) in pancreatic cancer cells and found that the reduced expression by siRNA caused drastic attenuation of their proliferation as well as significant decrease in DNA replication rate. Concordantly, exogenous overexpression of KIAA0101 enhanced cancer cell growth, and NIH3T3 derivative cells expressing KIAA0101 revealed in vivo tumor formation, implying its growth-promoting and oncogenic property. We also showed that the expression of KIAA0101 was regulated tightly by the p53-p21 pathway. To consider the KIAA0101/PCNA interaction as a therapeutic target, we designed the cell-permeable 20-amino-acid dominant-negative peptide and found that it could effectively inhibit the KIAA0101/PCNA interaction and resulted in the significant growth suppression of cancer cells. Our results clearly implicated that suppression of the KIAA0101 and PCNA oncogenic activity, or the inhibition of KIAA0101/PCNA interaction, is likely to be a promising strategy to develop novel cancer therapeutic drugs. [Cancer Res 2007;67(6)2568–76]
Metallothionein Expression Is Suppressed in Primary Human Hepatocellular Carcinomas and Is Mediated through Inactivation of CCAAT/Enhancer Binding Protein α by Phosphatidylinositol 3-Kinase Signaling Cascade
Authors: Datta Jharna , Majumder Sarmila , Kutay Huban , Motiwala Tasneem , Frankel Wendy , Costa Robert , Cha Hyuk C. , MacDougald Ormond A. , Jacob Samson T. , Ghoshal Kalpana
Published: March 2007

Reactive oxygen species (ROS) resulting from chronic inflammation cause liver injury leading to transformation of regenerating hepatocytes. Metallothioneins (MT), induced at high levels by oxidative stress, are potent scavengers of ROS. Here, we report that the levels of MT-1 and MT-2A are drastically reduced in primary human hepatocellular carcinomas (HCCs) and in diethylnitrosamine-induced liver tumors in mice, which is primarily due to transcriptional repression. Expression of the transcription factor, MTF-1, essential for MT expression, and its target gene Zn-T1 that encodes the zinc transporter-1 was not significantly altered in HCCs. Inhibitors of both phosphatidylinositol 3-kinase (PI3K) and its downstream target AKT increased expression of MT genes in HCC cells but not in liver epithelial cells. Suppression of MT-1 and MT-2A by ectopic expression of the constitutively active PI3K or AKT and their up-regulation by dominant-negative PI3K or AKT mutant confirmed negative regulation of MT expression by PI3K/AKT signaling pathway. Further, treatment of cells with a specific inhibitor of glycogen synthase kinase-3 (GSK-3), a downstream effector of PI3K/AKT, inhibited MT expression specifically in HCC cells. Short interfering RNA–mediated depletion of CCAAT/enhancer binding protein α (C/EBPα), a target of GSK-3, impeded MT expression, which could not be reversed by PI3K inhibitors. DNA binding activity of C/EBPα and its phosphorylation at T222 and T226 by GSK-3 are required for MT expression. MTF-1 and C/EBPα act in concert to increase MT-2A expression, which probably explains the high level of MT expression in the liver. This study shows the role of PI3K/AKT signaling pathway and C/EBPα in regulation of MT expression in hepatocarcinogenesis. [Cancer Res 2007;67(6):2736–46]
The Synthetic Triterpenoids CDDO-Methyl Ester and CDDO-Ethyl Amide Prevent Lung Cancer Induced by Vinyl Carbamate in A/J Mice
Authors: Liby Karen , Royce Darlene B. , Williams Charlotte R. , Risingsong Renee , Yore Mark M. , Honda Tadashi , Gribble Gordon W. , Dmitrovsky Ethan , Sporn Thomas A. , Sporn Michael B.
Published: March 2007

We report the first use of new synthetic triterpenoids to prevent lung cancer in experimental animals. Female A/J mice were treated with the mutagenic carcinogen vinyl carbamate, which induces adenocarcinoma of the lung in all animals within 16 weeks. If mice were fed either the methyl ester or the ethyl amide derivative of the synthetic triterpenoid 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO-ME and CDDO-EA, respectively), beginning 1 week after dosing with carcinogen, the number, size, and severity of lung carcinomas were markedly reduced. The mechanisms of action of CDDO-ME and CDDO-EA that are germane to these in vivo findings are the following results shown here in cell culture: (a) suppression of the ability of IFN-γ to induce de novo formation of nitric oxide synthase in a macrophage-like cell line RAW264.7, (b) induction of heme oxygenase-1 in these RAW cells, and (c) suppression of phosphorylation of the transcription factor signal transducers and activators of transcription 3 as well as induction of apoptosis in human lung cancer cell lines. [Cancer Res 2007;67(6):2414–9]
A Randomized Phase II Pharmacokinetic and Pharmacodynamic Study of Indisulam as Second-Line Therapy in Patients with Advanced Non–Small Cell Lung Cancer
Authors: Talbot Denis C. , von Pawel Joachim , Cattell Emma , Yule S. Murray , Johnston Claire , Zandvliet Anthe S. , Huitema Alwin D.R. , Norbury Chris J. , Ellis Paul , Bosquee Leon , Reck Martin
Published: March 2007

Purpose: The primary aim of this study was to measure the objective tumor response rate following treatment with indisulam [E7070; N-(3-chloro-7-indolyl)-1,4-benzenedisulfonamide] as second-line therapy in patients with advanced non–small cell lung cancer. The secondary aims were to determine progression-free survival, to assess the safety and tolerability of indisulam, and to study its pharmacokinetic and pharmacodynamic profile.

Experimental Design: Patients were randomized to receive indisulam every 3 weeks either as a single i.v. dose of 700 mg/m2 on day one (dx1) or 130 mg/m2 given on days 1 to 5 inclusive as a daily infusion (dx5). All patients had previously received platinum-based chemotherapy.

Results: Forty-four patients were randomized. Only minor responses were seen. Myelosuppression, gastrointestinal symptoms, and lethargy were the most common toxicities and were more frequent in the dx1 arm. The pharmacokinetics of indisulam in each treatment schedule were adequately described using a previously developed population pharmacokinetic model and were mostly consistent with the results of the phase I program. Flow cytometric analysis of endobronchial and metastatic disease revealed a reduction in the fraction of cycling cells and an increase in apoptosis following indisulam compared with pretreatment levels.

Conclusions: We conclude that, despite evidence of tumor-specific indisulam-induced apoptosis, neither of these treatment schedules has single-agent activity as second-line treatment of non–small cell lung cancer.
Monoclonal Antibody 4C5 Immunostains Human Melanomas and Inhibits Melanoma Cell Invasion and Metastasis
Authors: Stellas Dimitris , Karameris Andreas , Patsavoudi Evangelia
Published: March 2007

Purpose: Tumor cell metastasis constitutes a major problem in the treatment of cancer. Because the cure rate of metastatic tumors is very low, new therapeutic approaches are needed. Heat shock protein 90 (HSP90) is a molecular chaperone that is recognized as a new target for the treatment of cancer. Here, we examine the value of a monoclonal antibody (mAb) against HSP90, mAb 4C5, as a potential marker in malignant melanomas. Moreover, we investigate the possibility to use mAb 4C5 as an inhibitor of melanoma cell invasion and metastasis.

Experimental Design: Paraffin blocks of formalin-fixed human melanoma tumor tissues were used to prepare tissue microarrays. The B16 F10 melanoma cell line was used in all the in vitro experiments. To assess melanoma cell invasion, the wound-healing assay and the Matrigel invasion assay were applied. To evaluate the effect of mAb 4C5 on tumor metastasis, we used an experimental model of metastatic melanoma.

Results: Immunohistochemical studies done on a panel of malignant melanomas showed positive immunostaining with mAb 4C5 in all cases. mAb 4C5 inhibits B16 F10 cell invasion by binding to surface HSP90 because it is not internalized. mAb 4C5 significantly inhibits melanoma metastasis in C57BL/6 mice inoculated with B16 F10 cells.

Conclusions: mAb 4C5 could be potentially used as a novel specific marker for malignant melanomas. mAb 4C5 inhibits melanoma cell invasion in vitro by binding to cell surface HSP90 expressed on B16 F10 melanoma cells. Finally, this antibody significantly inhibits melanoma metastasis, thus rendering it a potential therapeutic agent for the treatment of cancer metastasis.
Clinical Implications of Fibroblast Activation Protein in Patients with Colon Cancer
Authors: Henry Leonard R. , Lee Hyung-Ok , Lee John S. , Klein-Szanto Andres , Watts Perry , Ross Eric A. , Chen Wen-Tien , Cheng Jonathan D.
Published: March 2007

Purpose: Human fibroblast activation protein (FAP)/seprase is a 97-kDa surface glycoprotein expressed on tumor associated fibroblasts in the majority of epithelial cancers including colon adenocarcinomas. FAP overexpression in human tumor cells has been shown to promote tumor growth in animal models, and clinical trials targeting FAP enzymatic activity have been initiated. The primary objective of this study was to evaluate the clinical significance of stromal FAP in human colon cancers by immunohistochemisty.

Experimental Design: Sections of paraffin-embedded resected primary human colon cancer specimens from 1996 through 2001 within the Fox Chase Cancer Center tumor bank were stained with D8 antibody directed against FAP/seprase. Xenotransplanted human colorectal tumors in mice were examined similarly for stromal FAP in tumors of different sizes. Overall percentage of stromal FAP staining of the primary tumor was assessed semiquantitatively (0, 1+, 2+, 3+) and staining intensity was also graded (none, weak, intermediate, strong). Survival time and time to recurrence data were analyzed using Kaplan-Meier plots, log-rank tests, and Cox proportional hazards models.

Results: One hundred thirty-eight patients with resected specimens were available for study (mean follow-up, 1,050 days) with 6 (4%) stage I, 52 (38%) stage II, 43 (31%) stage III, and 37 (27%) stage IV patients. FAP was detected in >93% of specimens. Semiquantitative staining was scored as 1+ in 28 (20%), 2+ in 52 (38%), and 3+ in 49 (35%). FAP staining intensity was graded as weak in 45 (33%), intermediate in 48 (35%), and dark in 36 (26%). Stromal FAP was found to correlate inversely with tumor stage (semiquantitative, P = 0.01; intensity, P = 0.009) and with tumor size of the tumor xenograft model (correlation coefficient, −0.61; P = 0.047), suggesting that stromal FAP may have a greater role in the early development of tumors. Furthermore, greater stromal FAP for patients with known metastatic disease was associated with a decreased survival.

Conclusion: Our data indicate that patients whose colon tumors have high levels of stromal FAP are more likely to have aggressive disease progression and potential development of metastases or recurrence. This study affirms the rationale for ongoing clinical investigations using FAP as a therapeutic target to disrupt FAP-driven tumor progression in patients with metastatic disease. It also suggests that the effects of FAP inhibition should be investigated in earlier-stage tumors, given its high levels and potential effect earlier in the course of the disease.
A Phase I/II Study of Arsenic Trioxide/Bortezomib/Ascorbic Acid Combination Therapy for the Treatment of Relapsed or Refractory Multiple Myeloma
Authors: Berenson James R. , Matous Jeffrey , Swift Regina A. , Mapes Russell , Morrison Blake , Yeh Howard S.
Published: March 2007

Purpose: This multicenter, open-label, phase I/II dose escalation study assessed the safety/tolerability and initial efficacy of arsenic trioxide/bortezomib/ascorbic acid (ABC) combination therapy in patients with relapsed/refractory multiple myeloma.

Experimental Design: Enrolled in six cohorts, patients were given arsenic trioxide (0.125 or 0.250 mg/kg), bortezomib (0.7, 1.0, or 1.3 mg/m2), and a fixed dose of ascorbic acid (1 g) i.v. on days 1, 4, 8, and 11 of a 21-day cycle for a maximum of eight cycles. The primary end point was safety/tolerability of the ABC regimen.

Results: Twenty-two patients (median age, 63 years) were enrolled, having failed a median of 4 (range, 3-9) prior therapies. One occurrence of grade 4 thrombocytopenia was observed. One patient had asymptomatic arrhythmia and withdrew from the study. Objective responses were observed in 6 (27%) patients, including two partial responses and four minor responses. Median progression-free survival was 5 months (95% confidence interval, 2-9 months), and median overall survival had not been reached. The 12-month progression-free survival and overall survival rates were 34% and 74%, respectively. One (minor response) of six patients receiving the lowest dose of bortezomib (0.7 mg/m2) and 5 (2 partial responses and 3 minor responses) of 16 patients receiving the higher doses (1.0 or 1.3 mg/m2) responded.

Conclusions: The ABC regimen was well tolerated by most patients, and it produced preliminary signs of efficacy with an objective response rate of 27% in this heavily pretreated study population. These findings warrant further clinical evaluation of the ABC combination for treatment of relapsed/refractory multiple myeloma.