bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4218: Potential roles of NF-kappa B pathways in breast cancer-initiating cells
Authors: Hinohara Kunihiko , Murohashi Michiko , Kuroda Masahiko , Isagawa Takayuki , Tsuji Shingo , Kobayashi Seiichiro , Umezawa Kazuo , Tojo Arinobu , Aburatani Hiroyuki , Gotoh Noriko
Published: February 2011

Accumulating evidence suggests that Tumor-initiating cells (TICs) or cancer stem cells_which make up only a small proportion of heterogeneous tumor cells_possess a greater ability to maintain tumor formation than other tumor cell types. In human breast cancers, a population characterized by the expression of cell surface markers, CD24−/low/CD44+, was reported to be highly enriched in TICs as compared to CD24+/CD44+ cell populations. However, the signaling pathways activated in TICs that contribute to tumorigenesis are not fully understood. We observed various expression levels of CD24 and CD44 among 8 human breast cancer cell lines. The CD24−/low/CD44+ cell populations of HCC1954 and MCF7, breast cancer cell lines, generated significantly larger tumors than the CD24+/CD44+ cell populations in a xenograft model, suggesting that the CD24−/low/CD44+ cell populations have the properties of TICs at some extent. To identify expressed genes that were highly enriched in CD24−/low/CD44+ cell populations, we next performed DNA microarray analysis using HCC1954, MCF7, and HCC70 cell lines that have small populations of CD24−/low/CD44+ cells. We then applied a powerful analytical method called Gene Set Enrichment Analysis (GSEA) for interpreting gene expression data. GSEA revealed that the CD24−/low/CD44+ cell populations are enriched for genes involved in a tumor necrosis factor (TNF) or interferon (IFN) response pathway. TNF or IFN response pathway is involved in the expression of many inflammatory cytokines/chemokines, including IL8 and CCL5. We measured expression levels of IL8 and CCL5 by quantitative RT-PCR (qRT-PCR) and confirmed that they were expressed at significantly higher levels in CD24−/low/CD44+ cell populations compared with the CD24+/CD44+ cell populations. Moreover, we found the relatively high nuclear factor kappa B (NF-kappa B) activity in the CD24−/low/CD44+ cell populations. In addition, NF-kappa B inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) prevented tumorigenesis of CD24−/low/CD44+ cell populations in vivo. Our findings suggest that NF-kappa B play a crucial role for orchestration of transcription factors regulating breast cancer stem cell biology. Further studies will be presented about the mechanism of NF-kappa B activation and its role in breast TICs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4218.
Abstract 4230: The pro-inflammatory secretory phenotype and selection of stem-like cells in RAS-transformed ovarian epithelial cells
Authors: Shan Weiwei , Yang Gong , Mercado-Uribe Imelda , Liu Jinsong
Published: February 2011

Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer in the United States. Previously, our laboratory has successfully transformed human ovarian epithelial cells with oncogenic RAS carrying an activating mutation at valine12 (HRASV12) (T29H cells). By cDNA expression microarray we found that T29H cells exhibited marked activation of a wide spectrum of inflammatory genes and generated a pro-inflammatory phenotype. In this report, we identified a much more malignant phenotype in ovarian tumor explants derived from T29H (hereby denoted T29HT) cells, manifested by a significantly shorter latency of tumor onset after inoculation of T29HT cells back into nude mice than that of the parental T29H cells, suggesting that the T29H cells underwent a selective process in vivo that was favorable to the enhancement of tumorigenicity. By examining the ability of cells to form spheroids in suspension culture and staining spheroids with stem cell marker CD44, we showed that T29HT cells may contain a larger population of potential stem-like cells than do T29H cells. Western blot analysis confirmed higher expression levels of CD44 and genes involved in epithelial mesenchymal transition (EMT) in T29HT cells than in T29H cells. Our results suggest that T29H cells may acquire augmented malignancy in vivo by expanding the pool of potential cancer stem-like cells, and HRASV12-induced pro-inflammatory factors may play pivotal roles in mediating this effect.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4230.
Abstract 4246: Granulin-epithelin precursor (GEP) is an oncofetal protein involved in fetal liver development and liver cancer
Authors: Cheung Phyllis Fung Yi , Cheung Siu Tim
Published: February 2011

Background and objectives:

Granulin-epithelin precursor (GEP) is a novel pluripotent growth factor regulating embryo development, wound repair and tumorigenesis. Our group previously has showed that GEP was over-expressed in over 70% of liver cancer. Besides, functional studies demonstrated that GEP controlled liver cancer proliferation, invasion and tumorigenicity. In this study, we aim to examine the time-frame of GEP expression during fetal liver development, and to characterize the properties of GEP-expressing liver cells.

Methods:

GEP expression was examined by immunofluorescence using flow cytometry and immunohistochemistry. The properties of GEP-expressing cells were characterized by measuring the co-expression of GEP and various stem/progenitor cell markers using immunofluorescence and flow cytometry. Correlation of GEP level with the expression of stem/progenitor markers was studied by transfection experiments.

Results:

In murine model, GEP expression was observed to increase gradually from embryonic day (E) 11 to E17, with up to 49% fetal liver cells were GEP positive. Immediately after birth, GEP expression decreased abruptly from day 1, and by day 7, less than 1% neonatal liver cells were GEP positive, and GEP was not detectable in adult liver. In human, fetal liver at 10 weeks old were demonstrated to express GEP protein, while normal adult livers were devoid of GEP-expressing cells. GEP expression was up-regulated in liver cancer cells compared with the adjacent non-tumor liver cells. Moreover, we showed that GEP co-expressed with hematopoietic stem/progenitor cell marker CD34, liver cancer stem cell marker CD326, and stem cell-related signaling molecules β-catenin and Oct4, suggesting a stem/progenitor cell feature of the GEP-expressing cells. Furthermore, up-regulation of GEP level enhanced the expression of β-catenin and Oct4, and suppression of GEP level resulted in decreased expression of these molecules.

Conclusion:

The present data suggests that GEP is an oncofetal protein, and GEP regulates the expression of stem cell-related signaling molecules. This information advances our knowledge on the fundamental role of GEP in fetal liver development and liver carcinogenesis, and provides valuable insights on the use of GEP as a therapeutic target in the treatment of liver cancer.

Category: Tumor Biology

Sub-classification: TB2: stem cell biology/cancer stem cells/developmental oncobiology

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4246.
Abstract 4250: Cigarette smoke induces expression of the putative stem cell marker ABCG2 in cultured esophageal adenocarcinoma cells
Authors: Mathur Aarti , Rao Mahadev , Zhang Yuwei , Zhang Mary , Kemp Clint D. , Ripley Robert T. , Hong Julie , Liu Fang , Avital Itzhak , Schrump David S.
Published: February 2011

Limited information is available regarding epigenetic mechanisms by which cigarette smoke mediates initiation and progression of esophageal cancer. In order to examine this issue, esophageal adenocarcinoma cell (EsC) lines (NCI-EsC1 and NCI-EsC2) were cultured in normal media (NM) with or without cigarette smoke condensate (CSC) under clinically relevant exposure conditions. Microarray analysis revealed that CSC exposure significantly upregulated expression of ABCG2, which encodes a xenobiotic pump protein believed to be highly expressed in cancer stem cells, and recently shown to correlate with aggressive phenotype of primary esophageal squamous cell carcinomas. Analysis revealed an average of 11 fold upregulation of ABCG2 as well as a 4 fold upregulation of another ABC transporter, ABCC3. Quantitative reverse transcription-PCR (RT-PCR), western blot, and immunohistochemistry experiments confirmed upregulation of ABCG2 in esophageal cancer cells exposed to CSC. Interestingly, basal as well as CSC-induced levels of ABCG2 were considerably higher in NCI-EsC2 derived from a smoker, relative to NCI-EsC1, which was established from a never-smoker. Time course experiments revealed that induction of ABCG2 commenced approximately 8 hours and peaked 48 hours following initiation of CSC exposure; thereafter, ABCG2 expression was sustained at these levels with continuous CSC exposure. HDAC inhibitors such as TSA and depsipeptide repressed basal levels of ABCG2 expression, and reduced CSC-mediated induction of ABCG2 in EsC cells. HDAC inhibitors in combination with verapamil (a ABCC3 inhibitor) and Depsipeptide virtually abolished basal, as well as CSC-induced ABCG2 expression in these cells. Preliminary pyrosequencing and chromatin immunoprecipitation (ChIP) experiments revealed that CSC-mediated ABCG2 induction was independent of promoter DNA demethylation, and coincided with hyperacetylation of H3K9 within the ABCG2 promoter. Flow cytometry analysis utilizing hoescht dye with and without fumitremorgin C, an ABCG2 inhibitor, revealed an increased side population in CSC-treated ESC cells relative to untreated controls. Experiments are in progress to further delineate the mechanisms by which CSC induces ABCG2 expression, and to ascertain if ABCG2 induction enhances the malignant phenotype of esophageal adenocarcinoma cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4250.
Abstract 427: Targeted inhibition of the mTOR complex components, RAPTOR and RICTOR, attenuates progression of colorectal cancer
Authors: Pat Gulhati , Bowen Kanika A. , Liu Jianyu , Li Jing , Qiu Suimin , Weiss Heidi L. , Gao Tianyan , Evers B. Mark
Published: February 2011

Colorectal cancer (CRC) is the second leading cause of cancer deaths in the USA. The mammalian target of rapamycin (mTOR) acts downstream of PI3K to regulate cell growth, proliferation and survival. The mTOR kinase nucleates two distinct complexes, mTORC1 and mTORC2. The mTOR-RAPTOR complex (mTORC1) regulates translation initiation through the effectors S6K and 4E-BP1, while the mTOR-RICTOR complex (mTORC2) regulates the actin cytoskeleton and activates Akt, a key regulator of cell survival. Rapamycin inhibits the kinase activity of mTORC1; prolonged rapamycin treatment also inhibits mTORC2 assembly and Akt activation in certain cells. The purpose of the present study was to determine the effect of targeting mTORC1 and mTORC2 upon progression of CRCs. METHODS. HCT116 and SW480 human colon cancer cells were treated with rapamycin. Cells were also transfected with shRNA directed against RAPTOR or RICTOR. Effects on migration (measured by wound healing assay) and invasion (measured by transwell matrigel assay) were analyzed. Changes in actin cytoskeleton and cell-cell contacts were determined by immunofluorescence microscopy. RESULTS. (i) Immunohistochemical analysis showed that the mTORC1 and mTORC2 components, mTOR, RAPTOR and RICTOR, are overexpressed in primary CRCs and matched liver metastases compared to normal colonic tissue. (ii) Treatment with rapamycin significantly decreased the migration and invasion of HCT116 and SW480 cells. (iii) Stable shRNA-mediated knockdown of RAPTOR and RICTOR significantly decreased the migration and invasion of HCT116 and SW480 cells. (iv) Stable shRNA-mediated knockdown of RAPTOR and RICTOR leads to mesenchymal-to-epithelial transition, as evidenced by increased E-cadherin and decreased vimentin levels. (v) Stable shRNA-mediated knockdown of RAPTOR and RICTOR leads to characteristic rearrangements in actin cytoskeleton as well as increased cell-cell contact. CONCLUSIONS. The mTORC1 and mTORC2 components, mTOR, RAPTOR and RICTOR, are overexpressed in both primary CRCs as well as matched liver metastases. Although the mTOR signaling axis is primarily associated with growth of normal and cancer cells, we demonstrate that stable inhibition of both mTORC1 and mTORC2 decreases migration and invasion capabilities of CRC cells as well as causing a mesenchymal-to-epithelial change in phenotype. The mechanism for this decrease in migration and invasion may be via modulation of actin cytoskeletal rearrangement and cell-cell contact. Thus, targeted inhibition of mTOR signaling represents a novel therapeutic strategy to attenuate the progression and metastasis of CRCs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 427.
Abstract 4290: The smoothened antagonist NVP-LDE225 targets stroma and cancer stem cells in primary human pancreatic tumor xenografts
Authors: Buonamici Silvia , Ospina Beatriz E. , Zhu Julia Xing , Yuan Jing , Hsiao Kathy , Vattay Anthony , Li Fang , Deeds James , Ostrom Lance , Monahan John , Williams Juliet , Kelleher Joseph , Peukert Stefan , Pan Shifeng , Wu Xu , Warmuth Markus , Mosher Rebecca , Yao Yung-mae , Sellers William R. , Dorsch Marion
Published: February 2011

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer mortality. Despite surgical intervention and treatment with Gemcitabine, the standard of care, the 5-year survival rate remains less than 5%. Because the aberrant activation of the Hedgehog (Hh) pathway in stroma cells and cancer stem cells in PDAC has become evident during the last few years, therapeutic agents able to inhibit Smoothened (Smo), the positive regulator of the pathway, are under vigorous investigation. We have developed a selective Smo antagonist, NVP-LDE225, which is orally bioavailable and potently inhibits Hh signaling in vitro and in vivo. Using a combination of in vitro and in vivo assays, we evaluated the effects of NVP-LDE225 alone or in combination with Gemcitabine in primary human tumor xenograft models. In these models, NVP-LDE225 dosed together with Gemcitibine resulted in a trend towards combination activity. Tumor samples collected at the end of the studies showed that the Hh pathway was completely inhibited in the stroma of the NVP-LDE225 treated animals. Moreover, analysis of the ratio of tumor to stroma area demonstrated no differences between the drug treated as compared to vehicle treated tumors. After subcutaneous implantation of the human tumors in mice, the mouse stroma replaces the human stroma. Using mouse and human Affymetrix analysis of tumors following in vivo treatment, we were able to differentiate the changes occurring in murine stromal cells versus human epithelial cells. This analysis revealed changes in the regulation of several key developmental and growth factor pathways in the mouse stroma. To study cancer stem cells, we isolated Aldehyde Dehydrogenase (ALDH) positive cells from untreated xenograft tumors and confirmed up regulation of the Hh pathway genes, and that ALDH positive cells were more tumorigenic than ALDH negative cells when implanted in animals. Furthermore, we used 2 different stem cell functional assays, in vitro sphere formation and in vivo serial transplantation to evaluate the effect of NVP-LDE225 on cancer stem cells. We observed that upon NVP-LDE225 treatment the cells had impaired ability to form spheres in vitro and similarly, tumor growth was delayed following in vivo serial transplantation. These experiments suggest that Smo inhibitors can have a high impact on the treatment of this very aggressive cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4290.
Abstract 4296: STAT3 is required for proliferation and tumor growth of breast cancer stem cells
Authors: Lin Li , Hutzen Brian , Peng Zhengang , Lin Huey-Jen , Li Pui-Kai , Li Chenglong , Wicha Max , Lin Jiayuh
Published: February 2011

Breast cancer is the leading type of cancer affecting women. It is estimated that breast cancer accounts for over a quarter of all newly diagnosed cancer cases in women. Despite advances in chemotherapy and hormonal treatment, at the present time, metastatic breast cancer remains an incurable disease. Although a large number of chemotherapeutic agents have been developed that are able to cause the regression of metastatic breast cancers, these tumors almost always recur following chemotherapy treatment. It is possible that breast cancer stem cells or breast cancer initiating cells are responsible for the drug-resistance, metastasis, and recurrence of cancer. Constitutive activation of Signal Transducers and Activators of Transcription 3 (STAT3) signaling is frequently detected in many types of cancers, including breast cancer, and has emerged as an attractive molecular target for cancer treatment. However, whether or not STAT3 is activated in breast cancer stem cells and what role STAT3 signaling plays in cancer stem cells is still unknown. If STAT3 is activated in breast cancer stem cells, targeting STAT3 may offer a promising opportunity to eliminate breast cancer stem cells and prevent the recurrence of cancer. We examined STAT3 activation in breast cancer stem cells, which are characterized by an aldehyde dehydrogenase (ALDH)-positive (ALDH+) and ALDH+/CD44+/CD24− subpopulations. Interestingly, we observed that the ALDH+ and ALDH+/CD44+/CD24− subpopulations of breast cancer cells expressed higher levels of phosphorylated STAT3, an active form of STAT3, as compared to the ALDH− and ALDH−/CD44+/CD24+ subpopulations and un-separated breast cancer cells, suggesting that STAT3 is activated in breast cancer stem cells. We also demonstrated that a novel STAT3 inhibitor, LLL12, inhibited STAT3 phosphorylation, cell viability, STAT3 downstream target gene expression, and induced apoptosis in breast cancer stem cells. In addition, the STAT3 inhibitors Stattic and LLL12 inhibited the tumorsphere forming capacity of breast cancer stem cells. Furthermore, in a mouse tumor model using breast cancer stem cells, we demonstrated that LLL12 can suppress tumor growth in vivo. This is the first report to demonstrate that persistent STAT3 phosphorylation is expressed in breast cancer stem cells and that this subpopulation of breast cancer stem cells is sensitive to STAT3 inhibitors. Our results suggest that STAT3 is a novel therapeutic target in breast cancer stem cells and inhibition of activated STAT3 in cancer stem cells may offer a more effective treatment for breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4296.
Abstract 4297: Selective enrichment of liver cancer stem cell by DNA methyltransferase inhibition
Authors: Raggi Chiara , Marquardt Jens U. , Andersen Jesper B. , Factor Valentina M. , Thorgeirsson Snorri S.
Published: February 2011

Background: Evidence is growing that many solid cancers, including liver cancer, contain small subpopulations of cells with stem cell-like properties known as cancer stem cells (CSCs) that are responsible for maintaining and propagating a tumor. Major obstacles in the research on CSC biology are the paucity and lack of specific markers of CSC. We have recently shown that human liver CSC can be enriched by modulating the epigenome of liver cancer cell lines with zebularine (Zeb), a potent DNA methyltransferase inhibitor.

Objective: In this study we exploited the impact of epigenetic modulation of cancer epigenome by Zeb in conjunction with the ability of stem/progenitor cells to grow as non-adherent spheres in serum-free media to provide further enrichment of the CSC fraction.

Methods: Huh7 cells were plated in high (HD, 13×103cell/cm2) and low (LD, 2.7×103/cm2) density and treated with 100 µM Zeb for 3days. The sphere forming ability and serial sphere formation were investigated in Matrigel and suspension culture, respectively. CSC and pluripotency markers preferentially expressed in cells grown under sphere conditions were examined by qRT-PCR and surface markers by FACS.

Results: Huh7 cells grown under LD failed to form tumorspheres when placed in Matrigel or non-adherent growth conditions. In striking contrast, Zeb-treated low density cells were capable of forming spherical clonal-expanding colonies which showed the stem cell-like properties such as strong induction of the stem cell-related genes NANOG and OCT4 and did not express EpCAM. Cells grown at high density possessed a similar sphere forming ability regardless of Zeb pretreatment. However, morphological characterization revealed a predominance of smaller sized spheres suggesting reduced proliferation potential and/or differences in cell type of origin, with smaller spheres originating from the progenitors, and larger spheres from the stem cells. Consistent with this, HD spheres showed a smaller induction of NANOG and OCT4, expressed high levels of EpCAM and exhibited reduced self-renewal in serial sphere formation assay. The sphere forming ability of LD and HD cells was associated with a presence of a subpopulation of CD133-/cKit+ cells.

Conclusion: The described “double selective” approach offers an in vitro model to enrich for cells with cancer stem cell properties. Both cell density and epigenetic modulation were able to affect the sphere-forming potential of Huh7 cells. Further studies are needed to characterize this cell population in more detail, to clarify their tumorigenic potential and the capacity to propagate tumor growth in vivo.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4297.
Abstract 4310: Prospective isolation of clongenic mantle cell lymphoma initiating cells
Authors: Chen Zheng , Ayala Paul , Wang Michael , Fayad Luis , Katz Ruth L. , Romaguera Jorge , Caraway Nancy , Neelapu Sattva S. , Kwak Larry W. , Simmons Paul , Nami McCarty
Published: February 2011

We have prospectively isolated and characterized clonogenic cells with self-renewal capacities from mantle cell lymphoma (MCL), a particularly deadly form of non-hodgkin's lymphoma (NHL). Self-renewal and tumorigenic activities were enriched in MCL cell fractions that lacked expression of the prototypic B cell surface marker, CD19. CD45+CD19- cells represented a relatively small fraction of the total MCL tumor cells, however, they recapitulated the heterogeneity of original patient tumors upon transplantation into immunodeficient mice. As few as 100 of these cells displayed self-renewal capacities in secondary and tertiary recipient mice by in vivo limiting dilution assays. Similar to leukemic stem cells, CD45+CD19- MCL cells also displayed a quiescent status as determined by dye efflux assays. In summary, this study is the first to isolate subpopulations of MCL cells that have self-renewal and tumorigenic capacities. Identification and characterization of MCL-ICs is an important first step toward understanding how self-renewal and tumorigenicity are regulated in MCL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4310.
Abstract 4317: Developing near infrared (NIR) optical retinoid analogue for cancer imaging
Authors: Wang Wei , McNees Adrienne L. , Cameron Arlin G. , Wendt Juliet A. , Mawad Michel E. , Ke Shi
Published: February 2011

Imaging technology plays an important role in early detection of cancers and improved prognoses. Among of the various imaging techniques used near infrared (NIR) optical imaging is an active and promising area for both in vitro and in vivo molecular imaging studies. However, NIR fluorophores normally only possess optical imaging properties without selectivity to diseased tissues. To address this problem, a targeting moiety can be introduced to help to deliver the imaging report to its target. It is know that retinoids, analogs of vitamin A, are assessed for multiple therapeutic uses. In practically, their potential chemopreventive and therapeutic roles in different kinds of cancers have attracted much attention. The cancer types include head and neck, lung, breast, esophagus, colon, kidney, prostate, bladder cancers and so on. Considering about important role of retinoids in cancer treatment developing retinoid derivatives as targeting imaging agents should be a useful strategy for noninvasive detection and characterization of solid tumors. Herein, we developed fluorescent retinoid derivatives for cancer imaging. Several different cancer cell lines and cancer xenograft models were used in this study. The data demonstrate that this new imaging agent can be used to imaging different kinds of cancers from cell level to whole body. Furthermore, these imaging agents have the potential to develop into special therapeutic agents that can be used for diagnosis, treatment and monitor of retinoid positive diseases.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4317.
Abstract 433: Role of AQP1 in invasion of GBM
Authors: Samuelson Gay , Feuerstein Burt , Misra Anjan , Bennett Kevin
Published: February 2011

There has been little improvement in glioblastoma multiforme (GBM) patient prognosis over the past 20 years despite advances in imaging, neurosurgery, post-operative care, radiation delivery and chemotherapy. One reason for treatment failure is the highly invasive nature of glioma cells. Thus, it is essential to understand the mechanisms underlying invasion so that therapeutic targets can be developed and their impact assessed, non-invasively, during treatment.

We have identified a trans-membrane protein, Aquaporin 1 (AQP1) whose over-expression correlates inversely with GBM survival (1,2) and drives migration of invading glioma cells (3). Our hypotheses are that the water permeation function of AQP1 drives migration and diffusion-weighted magnetic resonance imaging (DW-MRI) can be used to measure the water permeation and hence, invasion.

The goal of our work is to determine the relationship between AQP1 expression and brain tumor invasion as measured in tissue culture by wound assay, in orthotopic murine brain slices by confocal microscopy and in rodent xenografts by DW-MRI. Modulating aquaporin channels alters water diffusion through cells and these changes have been detected with DW-MRI (4,5).

We have data on 168 GBM patients that shows AQP1 overexpression correlates inversely with survival. Wound assay data indicates AQP1 overexpression drives migration and we have used an inhibitor of AQP1 water permeation, tetraethylammonium chloride (TEA) (6) to show that inhibiting water permeation also inhibits migration, We have histologic data on rodent xenografts demonstrating the aggressive invasive behavior of AQP1 overexpression compared to empty vector controls. We will present preliminary MRI results using an orthotopic rodent model where we modulate levels of AQP1 expression.

References: 1. Verkman AS et al. J Mol Med (Epub), 2008. 2. Nagashima G et al. Brain Tumor Pathol 23(1), 2006. 3. Mirvish et al. Soc Neuro-Onc, 2007. 4. Latour LL. PNAS 91(4), 1994. 5. Thewall PE et al. Magn Reson Med 48(4), 2002. 6. Detmers et al. JBiolChem. 281(20); 14207, 2006.

Supported by the Diane and Bruce Halle Fund, and the Barrow Neurological Foundation

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 433.
Abstract 4343: X-ray detection of hepatocellular carcinoma (HCC) using gold nanoparticles conjugated to HCC-specific SF25 antibodies
Authors: Ortiz Vivian , Derdak Zoltan , Liu Yanan , Diebold Gerald , Wands Jack R. , Rose-Petruck Christoph
Published: February 2011

There is widespread concern among health care professionals regarding the increase in HCC and the lack of optimal detection methods that lead to early diagnosis and treatment. It is hoped that early diagnosis may improve the prognosis of this almost uniformly fatal disease. There are substantial issues with false/negatives and false/positives and better, more specific and sensitive detection methods are urgently needed. For this reason, we aimed to design a novel detection method that is based on phase-sensitive x-ray imaging of gold nanoparticles, conjugated with HCC specific antibodies. Our laboratory has previously established various liver cancer specific antibodies by screening antigens that were uniquely present in the FOCUS hepatocellular carcinoma cell line. In the current study we used the SF25 antibody that is known to cross-react with a 125 kDa cell surface antigen. 10 nm gold nanoparticles were coated with polyacrylic acid (PAA) and poly(allylamine hydrochloride) (PAH), followed by conjugation with the SF25 antibody. The specificity of our antibody was confirmed in vitro by Western-blotting and immunoflurescence using FOCUS and NIH/3T3 cells (negative control). The gold labeling did not interfere with the immunofluorescent detection of SF25 antigen. The cellular localization of the SF25 protein was further confirmed by transmission electron microscopy. A labeling density of 10^4 gold particles per HCC cell was achieved. Given the sensitivity of the phase contrast imaging modality, this labeling density was also sufficient to enhance noticeably the density of subcutaneously raised HCC xenografts in vivo relative to healthy tissue. 10^7 cells were injected in the flanks of athymic nude mice. 1 week after inoculation the tumors were in vivo labeled by gold nanoparticle-conjugated SF25 antibodies. The gold content of these tumors were further quantified by x-ray fluorescence (XRF), which revealed gold fluorescence lines in the x-ray spectrum. These findings suggest that this imaging technique holds high in vivo potential for early detection of HCC. We envision that besides tumor detection, our x-ray imaging modality using nanoparticle-immunolabels will be useful for observing the delivery of drugs attached to or enclosed in nanoparticles.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4343.
Abstract 4344: Virus-templated magnetic nanowires for tumor-targeted imaging
Authors: Ghosh Debadyuti , Lee Youjin , Kelly Kimberly , Belcher Angela
Published: February 2011

In an effort towards early tumor detection, various diagnostic probes, such as tumor marker-specific fluorescent and magnetic nanoparticles, have been developed. Nanoparticles detected using magnetic resonance (MR) imaging is an attractive approach due to its non-invasiveness. Current work has focused on single functionalized spherical nanoparticle systems, one example being cross-linked iron oxide nanoparticles (CLIO). However, these ‘shaped’ particles can be cleared by the reticuloendothelial system upon intravenous injection due to opsonization. Recent work suggests that longer filamentous shaped structures can persist almost 10 times longer in circulation in vivo compared to spherical particles. For clinical diagnostics, it would be desirable to engineer filamentous shaped imaging agents that allow for longer circulation and better homing towards the tumor before immune clearance. M13 filamentous bacteriophage can potentially allow for longer circulation of the imaging agents. Recent work indicates that the virus can circulate in vivo for at least 24 hours compared to the 5-6 hour circulation of various spherical particles (unpublished data).

Using the M13 virus as a scaffold, we can uniquely combine multiple nanoparticles with engineered cell-targeting peptide ligands for tumor-targeted imaging. Exploiting the multiple coat proteins on M13 amenable for peptide display, we have genetically engineered peptides that bind iron oxide nanoparticles (γ-Fe2O3 NPs) and that target secreted protein, acidic and rich in cysteine (SPARC), a protein overexpressed in metastatic prostate and breast cancers. We have been able to assemble monocrystalline, monodisperse γ-Fe2O3 NPs along the virus coat and demonstrate enhanced MR contrast properties, compared to commercially available CLIO. We have investigated specific targeting against prostate cancer in vitro and in vivo. There is a decrease in transverse relaxation times (‘dark contrast’) using targeted nanowires compared to negative control and is specific towards SPARC positive C4-2B cell line compared to DU145 control. SPARC-targeted nanowires were injected intravenously in LNCaP and C4-2B and control DU145 xenograft tumors. MR images indicate dark image contrast in SPARC expressing tumors, compared to control. Histology suggests iron accumulation in the stroma and capsule of SPARC-positive tumors compared to control, suggesting tumor targeting in vivo. These virus-templated probes may have potential as long circulating, targeted non-invasive imaging agents for the early detection of tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4344.
Abstract 4355: The C19MC miRNA polycistron are frequent targets of gene amplification in aggressive primitive neuroectodermal brain tumors and encode oncogenic miRNAs that inhibit normal neural stem cell differentiation
Authors: Li Meihua , Lee Kyle , Lu Yuntao , Clarke Ian , Shih David , Meter Tim Van , Zhou Limei , Picard Daniel , Modena Piergiorgio , Pomeroy Scott , Lau Ching C. , Taylor Micheal D. , Bouffet Eric , Rutka James T. , Gajjar Amar , Dirks Peter B. , Hawkins Cynthia E. , Huang Annie
Published: February 2011

Embryonal brain tumors which include medulloblastoma and primitive neuroectodermal brain tumors (CNS-PNET) comprise the largest group of malignant pediatric brain tumors and account for substantial cancer related morbidity and mortality in childhood. Unlike medulloblastoma, a common, cerebellar PNET, few CNS-PNET arising in extracerebellar locations have been characterized. Lack of insight into the molecular pathogenesis of CNS-PNET is a major obstacle towards development of much-needed disease-specific models and treatments for these devastating tumors. In this study, we performed high-resolution DNA copy number analysis on a substantial collection of primary CNS-PNET obtained through an international collaborative group, and discovered a frequent amplicon in 25% (11/46) of CNS-PNET which span 34 protein coding genes and two miRNA clusters, C19MC and miR-371-373, on chr19q13.41. Detailed mapping studies revealed C19MC, which encode 54 primate-specific miRNAs, as the specific target of gene amplification resulting in striking tumor-specific overexpression of a sub-set of miRNAs, including miR-520 g and miR- 517c. Stable expression of miR-520 g and miR-517c promoted in vitro and in vivo oncogenicity and conferred cell survival in tumor cell lines. Strikingly expression of both miR-520g and 517c promoted growth and inhibited differentiation of untransformed normal human neural stem cells. Notably, clinicopathologic analyses revealed that C19MC amplification identifies a distinct group of CNS-PNET with similar gene expression profiles, characteristic histology, and much poorer survival. Our aggregate findings which point to C19MC as an important, new oncogenic locus in a human cancer, have significant implications for the diagnosis and clinical management of embryonal brain tumors in children.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4355.
Abstract 4366: Chronic inflammation in benign prostate tissue is related to the presence of high grade prostate cancer
Authors: Gurel Bora , Lucia Marshall S. , Platz Elizabeth A. , De Marzo Angelo M.
Published: February 2011

Background: Chronic inflammation may be crucial for the etiology of prostatic adenocarcinoma (CaP). If inflammation is part of the pathogenesis of this disease then it might be expected that prostates with adenocarcinoma would harbor more inflammation than prostates without adenocarcinoma.

Design: Cases (biopsy detected and centrally reviewed) and age frequency-matched controls, defined as negative for adenocarcinoma on an end-of-study biopsy, were selected using a nested case-control design from among participants in placebo arm of the Prostate Cancer Prevention Trial (PCPT). The PCPT (n= 18,000 men) determined whether finasteride, a 5-alpha reductase inhibitor, could reduce the period prevalence of adenocarcinoma over 7 years. All men were screened annually by PSA and DRE, and all men not diagnosed with adenocarcinoma during the study were offered an end-of-study biopsy. Cases consisted of 191 men, and controls were from 209 men. Microscope slides (1- 5 core biopsies for each man) were digitized and evaluated online after masking of adenocarcinoma and random benign areas to ensure blinding of the pathologist to case/control status. Inflammation was assessed using a modified National Institutes of Health (NIH) grading system and data were analyzed using logistic regression.

Result: Men who had at least one biopsy core positive for chronic inflammation (CI) (majority was chronic) had 1.79 (95% CI 1.06-3.04) times the risk of prostate cancer compared with no cores positive. The association was stronger for higher-grade (Gleason score 7-10; OR=2.41, 95% CI 1.17-4.95) disease than for lower-grade (Gleason score 6; OR=1.45, 95% CI 0.79-2.68) disease. Risk of prostate cancer (p-trend=0.05) and higher-grade disease (p-trend=0.02) increased with increasing percent of cores positive.

Conclusion: The presence of any chronic inflammation in benign prostate tissue was positively and statistically significantly associated with adenocarcinoma, especially higher grade lesions (Gleason score 7-10). Additional studies to further examine a potential role for inflammation as a cofactor in overall and high-grade prostate cancer should help determine whether chronic inflammation present in benign tissue is a reaction to the presence of cancer, or, is related to the pathogenesis of prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4366.
Abstract 4377: Pulmonary inflammation and lung tumorigenesis in mice
Authors: Keohavong Phouthone , Kahkonen Beth , Kinchington Edwina , Yin Jinling , Jin Jide , Siegfried Jill M. , Di Peter
Published: February 2011

Chronic inflammation has been suggested to be associated with an increased risk of human cancer, including lung cancer, the leading cause of cancer death in the United States. However, the mechanisms of lung tumorigenesis associated with chronic lung inflammation still remain poorly understood. The purpose of this study is to get insight into the molecular mechanisms by which bacterial endotoxin-elicited chronic lung inflammation increases carcinogen-induced lung tumorigenesis. Groups of FBV/N mice were treated weekly for a 15-week period with lipopolysaccharide (LPS), a major pro-inflammatory glycolipid component of the gram-negative bacterial cell wall, with or without a co-treatment of 4-(methyl-nitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), a major component of tobacco smoke and a potent lung carcinogen, during the first four weeks. Analysis of bronchoalveolar lavage fluid (BALF) at one day, one week, and fifteen weeks after LPS-treatment showed a significant increase in pro-inflammatory responses, including both in numbers of macrophages and inflammatory mediators in the mice treated with LPS alone and in those treated with LPS+NNK, compared with the mice treated with NNK alone or those treated with vehicles. These data were confirmed by pathological analysis and the presence of inflammatory cells and lung tissue injury from the groups of mice treated LPS or LPS+NNK, compared with those treated with NNK or vehicles. At week 15, the averaged number of lung tumors per mouse was 5.56 (100% tumor incidence; tumor numbers between 2-9) in mice treated with LPS+NNK and was significantly higher than 0.79 tumor per mouse (67% tumor incidence; tumor numbers between 0-2) in the mice treated with NNK alone (p<0.0001). No lung tumors were observed in the mice treated with LPS or those treated with vehicles alone. Furthermore, a higher proportion of lung tumors from mice treated with LPS+NNK harbored mutations, an GGT to GAT transition, in codon 12 of the K-ras oncogene, compared with the mice treated with NNK alone (76.7% versus 44.4%, p<0.05). Our data show that LPS-elicited chronic lung inflammation increases the risk of NNK-induced lung tumorigenesis in FBV/N mice, and suggest that such an increase occurs mostly through K-ras gene activation pathways.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4377.
Abstract 4378: Aflatoxin B1 inhibits LPS-induced TNF-alpha production in RAW 264.7 cells
Authors: Traore Kassim , Singhal Rohit , Rivera Rachel , Ganey Patricia E. , Roth Robert A.
Published: February 2011

Aflatoxin B1 (AFB1), a potent hepatocarcinogen, is known to impair specific and nonspecific immune responses. Recent studies suggested that AFB1 affects macrophage functions. Macrophages play an important role in a host defense against tumors and bacteria. In addition, some macrophage products, including tumor necrosis alpha (TNF-alpha), can be cytotoxic. In the present study, we investigated the effect of aflatoxin B1 (AFB1) on LPS-induced TNF-alpha production by a mouse macrophage cell line, RAW 264.7 cells. Cells were pretreated with increasing concentrations of AFB1 for 2 hours followed by stimulation with lipopolysaccharide (LPS) for 6 h. The concentration of TNF-alpha released in the culture medium was assessed by enzyme-linked immunosorbent assay (ELISA). AFB1 at 1, 10, 50 or 100 µM reduced the production of TNF-alpha induced by LPS. Compared to vehicle control, there was a greater reduction of TNF-alpha production with increased concentration of AFB1 pretreatment and LPS stimulation. AFB1 at 100 µM decreased the synthesis of both TNF-alpha mRNA and protein in RAW 264.7 cells. To explore the mechanism of AFB1 activation by RAW 264.7 cells, we examined the expression of CYP3A4 and CYP3A11, two isoforms of cytochrome p450 known to activate AFB1. Our data indicated that CYP3A11 but not CYP3A4 was significantly expressed in RAW 264.7 cells. These results suggest that AFB1 pretreatment suppresses LPS-induced TNF production in RAW 264.7 cells. (Supported by NIH grant R01ES04139.)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4378.
Abstract 4381: Biochemical and histopathological evaluation of mice exposed to functionalized single-walled carbon nanotube
Authors: Patlolla Anita K. , McGinnis Britney , Tchouwou Paul
Published: February 2011

Single walled carbon nanotubes (SWCNTs) with their unique physicochemical properties, have many potential new applications in medicine and industry such as sensors, implants or delivery systems. The biomedical application of single-walled carbon nanotubes requires a fundamental understanding of their fate and toxicological profile after administration. However, the toxicity of SWCNT is barely known when they are introduced into the blood circulation, which is especially vital for their biomedical applications. The aim of this study was to conduct biochemical analysis to determine the effect of purified/functionalized single-walled carbon nanotube (SWCNT) on the induction of reactive oxygen species (ROS), activities of specific liver enzymes such as aminotransferases (GOT/GPT), alkaline phosphatases (ALP), concentration of lipid hydro peroxide (LPO) and histopathology of liver, which may be useful as biomarkers of hepatotoxicity and oxidative stress. Three groups of five male mice each weighing approximately 30 + 2 g were injected intraperitoneally once a day for five days with doses of 0.25, 0.5, 0.75 mg/kg BW of functionalized SWCNT. A control group was also made of 5 mice. At the end of the experiment, samples were collected following standard protocols. Exposure to functionalized SWCNT was found to show an increase in the induction of ROS, activities of serum amino-transferases (GOT/GPT), alkaline phosphatases (ALP) and concentration of lipid hydro peroxide compared to control. Histopathological evaluation of liver showed a statistically significant effect in the liver tissue (hepatic fibrosis) compared to controls. The results demonstrate that purified functionalized SWCNT was able to induce hepatotoxicity and oxidative stress. Our result does not imply that CNTs should be banned from use but more in vivo studies with histopathological characterization should be designed in biological application.

Keywords: Single walled carbon nanotube, reactive oxygen species, lipid hydroperoxide, serum aminotransferases, alkaline phosphatases, Swiss-Webster mice, histopathology, hepatotoxicity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4381.