bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 905: Localization of several potential biomarkers in various types of cancer
Authors: Alegre Ballantines F. , Alegre Melissa M. , Hardy Morgan S. , Robison Richard A. , O'Neill Kim L.
Published: June 2012

DNA salvage pathway enzymes are known to be upregulated both within cancer cells and in the serum of cancer patients. These enzymes include TK1, APRT, HGPRT, and dCK. TK1 has been extensively studied and is known to be a cytosolic enzyme. However, relatively few studies have investigated the localization of the other three salvage pathway enzymes in cancer cells. The purpose of this study was to determine the localization of these salvage pathway enzymes in various types of cancer cells. Cancer cells and normal lymphocytes were embedded and prepared for immunolabeling transmission electron microscopy (TEM). Raji cells, a Burkitt's lymphoma cell line known to express high levels of TK1, were used to optimize the TEM protocol. Using rabbit polyclonal antibodies, we were able to determine where the salvage pathway enzymes are localized in cancer cells. Cancer cell lines studied included Raji, Jurkat (acute T cell leukemia), HL60 (acute promyelocytic leukemia), HT29 (colorectal adenocarcinoma), SW620 (colorectal adenocarcinoma from lymph node), and H460 (large cell lung carcinoma). Normal lymphocytes (both unstimulated and stimulated with PHA) were also embedded and prepared for labeling. An antibody control, and anti-Macrophage marker, was used as an isotype control to detect non-specific binding. We observed that DNA salvage pathway enzymes were localized in distinctive parts throughout the cytoplasm, the cell membrane, and the nucleus. The expression of APRT appeared very similar to the expression of TK1 and it was visualized in approximately the same patterns. The same appeared to be true for HGPRT and dCK, but with much lower level of expression than TK1 and ARPT. In several cases, these salvage pathway enzymes appeared to localize near the nuclear pores, as well as other parts of the nuclear membrane. These enzymes also appeared dispersed throughout the cytoplasm, and in some cases formed clusters, especially near the cellular membrane, possibly indicating exocytosis routes. There was no significant difference between the various types of cancer cell lines in the localization of these enzymes Our normal lymphocyte controls show markedly lower expression, while the secondary only and isotype controls showed no staining. Further research is needed to determine the mechanisms of this localization and the role of these enzymes in tumor cell growth.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 905. doi:10.1158/1538-7445.AM2011-905
Abstract 916: BRCA1 mutations impair breast epithelial differentiation through upregulation of the transcriptional repressor Slug
Authors: Proia Theresa A. , Keller Patricia , Gupta Piyush , Klebba Ina , Jones Ainsley , Sedic Maja , Gilmore Hannah , Tung Nadine , Naber Stephen , Schnitt Stuart , Lander Eric , Kuperwasser Charlotte
Published: June 2012

Tumor histopathology is a strong predictor of patient mortality, although the molecular and cellular factors that are responsible for this phenotypic diversity remain poorly understood. Women with inherited mutations in the BRCA1 gene have increased risk for the development of breast cancer, but also exhibit a specific predisposition for the development of aggressive basal-like breast cancers. Here we study the interplay between inherited mutations in BRCA1 and tumor differentiation by examining the regulation of progenitor cell fate in disease-free breast tissues from BRCA1 mutation carriers. We demonstrate for the first time that cell populations derived from patients harboring mutations in BRCA1 (BRCA1mut/+) give rise to tumors with increased basal differentiation, relative to cells obtained from BRCA1+/+ patients. Molecular analysis of disease-free breast tissues from BRCA1mut/+ patients revealed significant defects in epithelial progenitor cells that are present prior to cancer incidence. Moreover, we discovered that the transcriptional repressor Slug is an important functional regulator of human breast progenitor cell lineage commitment and differentiation and that it is aberrantly expressed in BRCA1mut/+ tissues and cells prior to neoplastic transformation. In addition, Slug expression is necessary for the increased basal-like phenotypes prior to and following neoplastic transformation. These findings demonstrate that the genetic background of patient populations, in addition to affecting incidence rates, significantly impacts progenitor cell fate commitment and therefore, tumor phenotype.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 916. doi:10.1158/1538-7445.AM2011-916
Abstract 939: Mechanistic basis of tamoxifen-associated development of endocrine resistance in breast cancer
Authors: Bergamaschi Anna , Katzenellenbogen Benita
Published: June 2012

Many estrogen receptor-positive breast cancers respond well initially to endocrine therapies, but often develop resistance during treatment with SERMs such as tamoxifen. We have reported that the 14-3-3 family member and conserved protein, 14-3-3ζ, is up-regulated by tamoxifen and that high expression correlated with an early time to disease recurrence. However, the mechanism by which tamoxifen up-regulates 14-3-3ζ and may promote the development of endocrine resistance is not known. Our findings reveal that the tamoxifen up-regulation of 14-3-3ζ results from its ability to rapidly down-regulate a microRNA that specifically targets 14-3-3ζ. The levels of 14-3-3ζ and this microRNA were always inversely correlated, with 14-3-3ζ being elevated and the microRNA being at a low down-regulated level in tamoxifen-resistant breast cancer cells. Of note, down-regulation of the microRNA was selectively elicited by tamoxifen but not by other SERMs such as raloxifene or by the estrogen receptor down-regulator ICI182,780 (Fulvestrant). Reducing the cellular level of 14-3-3ζ by either antagomiR blockade of the tamoxifen suppression of the microRNA or by elevation of the intracellular level of the microRNA by over-expression resulted in decreased cell proliferation and colony formation, increased apoptosis, and very importantly, restoration of the growth inhibitory effectiveness of SERMs in endocrine-resistant breast cancer cells. Restoration of responsiveness to endocrine therapy was also accompanied by markedly reduced activation of HER2, EGFR, and MAPK signaling, key components in endocrine resistance. Thus, we identify tamoxifen down-regulation of a microRNA, and consequent elevation of the key survival factor 14-3-3ζ, as a mechanistic basis of tamoxifen-associated development of endocrine resistance. These findings suggest that therapeutic approaches that increase expression of this microRNA should be considered to down-regulate 14-3-3ζ and enhance the effectiveness of endocrine therapies. Furthermore, the observed differential effects of the two SERMs, tamoxifen and raloxifene, in regulation of this microRNA and 14-3-3ζ, may assist in understanding differences in the activities of these SERMs, as seen in the STAR breast cancer prevention trial and in other clinical trials. (Supported by a grant from The Breast Cancer Foundation to BSK and a postdoctoral fellowship from the Department of Defense (W81XWH-09-1-0398) to AB.)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 939. doi:10.1158/1538-7445.AM2011-939
Abstract 940: AR overexpression confers resistance to an aromatase inhibitor in ERα-positive breast cancer cells
Authors: Rechoum Yassine , Iacopetta Domenico , Barone Ines , Ando’ Sebastiano , Morales Stephanie , Weigel Nancy L. , Fuqua Suzanne A W
Published: June 2012

Background: Aromatase inhibitors (AIs) have emerged as the therapy of choice for the treatment of estrogen receptor alpha (ERα)-positive breast cancer. However, many patients develop resistance to AI treatment. Although the involvement of the ERα in AI resistance is well established, the role of the androgen receptor (AR) is not known. It has been estimated that about 60%-70% of ERα-positive breast cancer co-express the AR, and we have previously shown a role for AR-overexpression in tamoxifen resistance in ERα-positive MCF-7 breast cancer cells. Thus we hypothesized that AR overexpression might similarly be involved in resistance to the AI anastrazole (Anas).

Materials and Methods: Stable transfection of MCF-7 cells was performed to generate cell lines that express the aromatase gene (MCF-7 BK Arom) and then co-transfected with an AR expression vector (MCF-7 AR Arom). Aromatase and AR expression levels were evaluated by western blot analysis. Proliferation was tested using anchorage independent soft agar assays and MTT in the presence of the androgen substrate androstenedione (AD), or AD plus Anas. ERα and AR transcriptional activities were tested with ERE-luciferase reporter assays.

Results: Several clones expressing aromatase alone or aromatase plus AR were generated. MCF-7 aromatase clones overexpressing AR were resistant to the growth inhibitory effects of Anas when stimulated with the androgen AD. As expected AD treatment stimulated ERα transcriptional activity, but Anas was unable to block AD-stimulated activity in AR Arom-overexpressing cells. In addition, the growth of several of the AR Arom-overexpressing cells was stimulated with treatment of Anas alone. Resistance was not associated with activation of known mechanisms of resistance, such as HER2, or Akt activation. Inhibitors of various signaling and receptor growth pathways are currently being tested for their effects on blocking Anas resistance.

Conclusion: Using a model of ERα-positive breast cancer cells expressing endogenous aromatase and AR, we have demonstrated that AR overexpression confers resistance to the AI Anas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 940. doi:10.1158/1538-7445.AM2011-940
Abstract 946: Interaction between smoking and obesity and the risk of developing breast cancer among postmenopausal women: The Women's Health Initiative Observational Study
Authors: Luo Juhua , Horn Kimberly , Ockene Judith K. , Simon Michael S. , Stefanick Marcia L. , Tong Elisa , Margolis Karen L.
Published: June 2012

Background: Recent studies suggest that smoking increases breast cancer risk, and obesity is an established risk factor for postmenopausal breast cancer. Since there is a complex relation between smoking, weight and fat distribution, we hypothesized that the effect of smoking on breast cancer risk may be modified by obesity among postmenopausal women.

Methods: 76,628 women with no previous history of cancer aged 50-79 enrolled in the Women's Health Initiative Observational Study were recruited at 40 centers across the United States from 1993 to 1998, and were followed up through 2009. Cox proportional hazards regression models estimated hazard ratios (HRs) for invasive breast cancer risk associated with smoking, stratified by obesity status, and adjusting for other breast cancer risk factors. Interactions between obesity status and different metrics of smoking were tested by entering multiplicative interaction terms into the model.

Results: 3,378 incident cases of invasive breast were identified. A significant association between smoking and breast cancer risk was noted in non-obese women, but not in obese women defined by BMI > 30 (p for interaction=0.047). A significantly higher breast cancer risk was observed in non-obese women with long duration of smoking, but not in obese women (p for interaction = 0.03). Similar results were obtained when obesity status was defined by waist circumference > 88 cm.

Conclusion: Our study suggests the effect of smoking on breast cancer risk was modified by obesity among post-menopausal women. The modification effect did not differ by general vs. abdominal obesity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 946. doi:10.1158/1538-7445.AM2011-946
Abstract 949: PathSeq: A comprehensive computational tool for pathogen discovery by deep sequencing of human cancer tissues
Authors: Ojesina Akinyemi I. , Kostic Aleksandar , Pedamallu Chandra Sekhar , Jung Joonil , Duke Fujiko , Getz Gad , Meyerson Matthew
Published: June 2012

BACKGROUND: It is thought that pathogens cause a significant fraction of human cancers. However, many of these pathogens are unknown. Our project is based on the premise that if a cancer is caused by a microbial infection, the cancer tissue should contain both human and microbial DNA/RNA. High throughput sequencing, followed by computational subtraction of human reads should then yield non-human candidate sequences for further validation.

METHODS: We have developed an integrated pathogen discovery process to address this need. cDNA libraries are generated from tumor tissues and subjected to high-throughput Illumina sequencing to generate 30-60 million sequence reads per sample. Quality filtered reads are analyzed using our automated pipeline, PathSeq, comprising several subtraction steps: i) aligning to human sequence databases; ii) aligning to other vertebrate sequence databases; iii) filtering for low-complexity reads; iv) aligning using BLAST to genome databases; and v) de novo assembly and searching against microbial databases.

RESULTS: We have generated and analyzed both transcriptome and whole genome sequencing data across several cancers, and have identified microbial sequences in both frozen and formalin-fixed paraffin-embedded (FFPE) tissues. The details will be presented during the meeting.

CONCLUSION: The PathSeq software package is implemented in a cloud-computing environment and is available for public use. It therefore has the potential to make pathogen discovery accessible to any researcher with access to human deep sequencing data.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 949. doi:10.1158/1538-7445.AM2011-949
Abstract 95: Increased hypomethylation of LINE-1 and Alu in human colorectal cancer metastasis
Authors: Hur Keun , Balaguer Francesc , Takahashi Masanobu , Nagasaka Takeshi , Koike Junichi , Hemmi Hiromichi , Koi Minoru , Boland Clement Richard , Goel Ajay
Published: June 2012

Background: Global hypomethylation of cytosines within CpG dinucleotides is one of the distinguishing features of the neoplastic cells in human cancers. More specifically, hypomethylation of evolutionarily conserved repetitive elements (Alu and LINE-1) is associated with increased chromosomal instability in colorectal cancer (CRC). Recent data indicates that transcription start sites of certain proto-oncogenes are located within these repeat elements, and increased hypomethylation of these regions may induce the expression of illegitimate oncogenic transcripts. Primary CRCs demonstrate frequent global Alu and LINE-1 hypomethylation; however, it is unclear whether hypomethylation of these repeat sequences may be associated with a metastatic phenotype Aim: This study was aimed to determine the role of increased hypomethylation of Alu and LINE-1 sequences in CRC metastasis development. Materials and Methods: We analyzed a panel of CRC cells with different metastatic potential, as well as tissues from 50 CRC patients with matched primary colon cancer and corresponding liver metastasis tissues. Alu and LINE-1 methylation levels were determined by quantitative bisulfite pyrosequencing. Results: Lower levels of Alu and LINE-1 methylation were observed in CRC cell lines that came from metastatic foci. When we analyzed Alu and LINE-1 methylation levels in clinical specimens, the levels of Alu methylation in liver metastatis were significantly lower compared to the matched primary CRC tissues (77.2%±8.3 and 80.9%±10.7, respectively; P<0.01). Similarly, the levels of LINE-1 methylation in metastasized liver foci was significantly lower compared to the corresponding matched primary CRC (61.2%±9.7 vs 65.8%±7.0 (P<0.01). The relative demethylation level was higher in LINE-1 (4.6%) than Alu (3.7%) sequences. In further support of our results, methylation analysis of surrounding normal liver tissue showed higher methylation levels for Alu (82.2%±4.7) and LINE1 (71.3%±8.3) compared with both primary CRC and liver metastasis. Conclusion: Our results provide evidence that increased Alu and LINE-1 hypomethylation is a novel feature of liver metastasis from CRC. We speculate that hypomethylation of these repeat elements may inadvertently permit activation of previously silenced proto-oncogenes, which may facilitate a more aggressive malignant phenotype in these advanced stage cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 95. doi:10.1158/1538-7445.AM2011-95
Abstract 973: Targeting cancer stem cells by a novel anti-frizzled antibody inhibits pancreatic tumor growth and induces differentiation
Authors: Yen Wan-Ching , Fischer Marcus , Lewicki John , Gurney Austin , Hoey Timothy
Published: June 2012

Clinical management of pancreatic cancer over the past years has not been improved and this disease remains the fourth most common cause of cancer-related death. It has been suggested that cancer stem cells drive tumor growth and progression and are resistant to many current therapies. The WNT/beta-catenin pathway, which signals through the Frizzled (FZD) receptor family and co-receptors, plays an important role in regulating cell fate, stem cell self-renewal and maintenance. We have recently demonstrated that inhibition of WNT/beta-catenin pathway by an anti-FZD antibody 18R5 decreased tumorigenicity and induced differentiation in solid tumors. The present study evaluated the anti-tumor effect of OMP-18R5 in a panel of pancreatic tumors. In vivo studies using primary pancreatic xenograft tumor models showed that OMP-18R5 was efficacious against both high and low grade pancreatic tumors. Histologic and gene expression analyses indicated that the 18R5-mediated anti-tumor effect was associated with inhibition of WNT target genes while inducing of mucin expression and tumor cell differentiation. Furthermore, inclusion of OMP-18R5 delayed pancreatic tumor recurrence following termination of gemcitabine. The delay in tumor recurrence by OMP-18R5 treatment was associated with a decrease in cancer stem cell frequency. The combination of OMP-18R5 and gemcitabine further decreased cancer stem cell frequency compared to the single agents. Our findings provide a rationale to target cancer stem cells through interference with WNT/beta-catenin pathway as a therapeutic approach in pancreatic cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 973. doi:10.1158/1538-7445.AM2011-973
Abstract 981: Study of altered metabolism due to anoikis resistance in ovarian cancer
Authors: Caneba Christine A. , Bellance Nadège , Karedath Thasni , Nagrath Deepak
Published: June 2012

Cancer cells have recently been shown to be resistant to anoikis, a form of cell death due to detachment, thus decreasing responsiveness to therapy. Catecholamines, antioxidants, and oncogenes have been shown to rescue metabolic defects caused during cell detachment. Thus, there is a strong motivation to study metabolic alterations associated with anoikis resistance in cancer. Despite efforts to understand the link between anoikis and cancer metabolism, extensive metabolic analysis of cancer cells is lacking. Tissue engineering of cancer cells to create three-dimensional cell environments can also be used as a model system to study cancer metabolism. We postulate that anoikis can be regulated by metabolism in tissue engineered cultures of ovarian cancer (OC) cells. Our findings using quantification of metabolites by conducting Ultra Performance Liquid Chromatography and metabolic assays pertaining to central carbon and nitrogen metabolism provided clues as to which pathways relevant to glycolysis, the pentose phosphate pathway, the TCA and urea cycles, lipid cycle, and amino acid and nucleotide metabolisms, may be altered by anoxia in cancer cells, resulting in identification of dominant factors which regulate OC metabolism. Amino acid supplementation significantly increased the TCA cycle flux at the level of citrate synthase and the fatty acid-derived acetyl-CoA to CO2. The information we have gained elucidates the critical role of metabolism in anoikis resistance in OCC in tissue engineered cultures.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 981. doi:10.1158/1538-7445.AM2011-981
Abstract 982: Transgenic expression of NSAID-activated gene-1 (NAG-1) protects mice from high fat diet-induced obesity
Authors: Kim Jong-Sik , Chrysovergis Kaliopi , Kosak Justin , Kissling Grace , Eling Thomas
Published: June 2012

Previously, we generated transgenic mice which over-express human NAG-1/GDF15 gene. These mice are resistant to the development of colorectal cancer and have reduced responses to inflammatory stimuli. In the present study, we observed that NAG-1 transgenic mice (NAG-1 Tg) are smaller and leaner than their wild-type counterparts and have less abdominal fat despite comparable food intake. Interestingly, the transgenic mice have lower circulating levels of the inflammatory adipokine, leptin, and lower expression in abdominal fat, the major source of leptin. Placed on a high fat diet (60% fat), body weight gain in NAG-1 Tg mice is very small or negligible compared to wild-type mice. Analysis of the metabolic activity showed that NAG-1 Tg mice on the high fat diet have higher energy expenditure than WT mice. In addition, global gene expression profiling analysis showed that expression of several genes involved in lipid metabolism were significantly down-regulated in the liver of NAG-1 Tg mice. Real-time PCR analysis confirmed decreased expression of genes such as Cidea, Cidec, Mogat1, CD36, and Apoa4, while the expression of SIRT-1 and phosphorylated SIRT-1 was not altered in the NAG-1 Tg mice. Taken together, our data indicate increased energy expenditure and decreased expression of lipid metabolism genes have pivotal roles for the lower observed abdominal fat levels. Furthermore, lower leptin levels, a critical mediator of intestinal inflammation, found in NAG-1 transgenic mice, may contribute to lower intestinal tumor growth and reduced inflammatory responses reported for the NAG-1 Tg mice.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 982. doi:10.1158/1538-7445.AM2011-982
Abstract LB-101: Y-box binding protein-1 (YB-1) inhibition triggers differentiation of normal and cancer stem cells from the brain
Authors: Fotovati Abbas , Abu-Ali Sam , Wang Pei-Shan , Deleyrolle Loic , Lee Cathy , Tricott Joanna , Chen James , Franciosi Sonia , Nakamura Yas , Sugita Yasuo , Uchiumi Takeshi , Kuwano Michihiko , Leavitt Blair R. , Singh Sheila , Jury Alexa , Jones Chris , Wakimoto Hiroaki , Reynolds Brent A. , Pallen Catherine J. , Dunn Sandra E.
Published: June 2012

The Y-box-binding protein-1 (YB-1) is up-regulated in many human malignancies including glioblastoma (GBM). It is also essential for normal brain development, suggesting that YB-1 is part of a neural stem cell (NSC) network. Here we show that YB-1 was highly expressed in the subventricular zone (SVZ) of mouse fetal brain tissues but not in terminally differentiated primary astrocytes. Conversely, YB-1 knock-out mice had reduced Sox-2, nestin and musashi expression in the SVZ. While primary murine neurospheres were rich in YB-1, its expression was lost during glial differentiation. Likewise, YB-1, Sox-2, mushashi, Bmi-1 and nestin are coordinately expressed in SF188 cells and 9/9 GBM patient-derived primary CSCs. Silencing YB-1 with small interfering RNA attenuated the expression of these NSC markers, reduced neurosphere growth and triggered differentiation via coordinate loss of GSK3-β. Further, differentiation of CSCs with 1% serum or bone morphogenetic protein-4 (BMP-4) suppressed YB-1 protein expression. Likewise, YB-1 expression was lost during differentiation of normal human NSCs. Consistent with these observations, YB-1 was preferentially expressed in highly undifferentiated primary gliomas based on the analysis of WHO grade 1-IV tumors (n=49 cases). YB-1 was also co-expressed with Bmi-1 (Spearmans 0.80, p>0.001) and Sox-2 (Spearmans 0.66, p>0.001) based on the analysis of 282 cases of high-grade gliomas. These CSC markers were also highly expressed in 10/15 (67%) of GBM patients that subsequently relapsed. In conclusion, YB-1 is a key feature of stem cells where it functions to suppress differentiation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-101. doi:10.1158/1538-7445.AM2011-LB-101
Abstract LB-110: Bioinformatic discovery of repositioned drugs to target breast tumor initiating cells
Authors: Dave Bhuvanesh , Zhao Hong , Vahdat Linda T. , Chang Jenny C. , Wong Stephen TC
Published: June 2012

Background: We have previously identified a tumorigenic gene signature based on profile features in common in CD44+/CD24−/low cells vs. all other tumor cell subpopulations(13–15), and in cancer-derived mammospheres vs. bulk tumor tumor initiating cells (TICs) (CD44hi/CD24−/low). A novel method to expedite drug development is to reposition FDA-approved known drugs for any medical indication as anti-cancer therapy. By using bioinformatic approaches which combines protein-protein interactions, signaling pathways and drug information on 6000 drugs, we mapped these known drugs to critical pathways identified in our tumorigenic signature in order to target breast tumor initiating cells. Results: This bioinformatic approach identified 10 drugs which were then tested in vitro and in vivo for ability to inhibit tumor initiating cells. These in silico results were first confirmed by in vitro experiments by evaluating the effects of these repositioned drugs on mammosphere forming efficiency. In two “stem cell like” cell lines, SUM159 and BT549 treated with 10nM & 1μM of chloroquine, a dramatic reduction in MSFE was noted after a single treatment dose. Next, we performed limiting dilution transplantation assays, whereupon we treated SUM159 cells with 1μM chlorquine overnight and then transplanted the next day 200,000 cells/mouse (single sided). We observed a reduction in tumor initiation rate with only 1/12 xenografts growing within 10 weeks with chloroquine treatment vs 9/12 in control vehicle treated group. Conclusion: Bioinformatic approaches can be used to identify repositioned drugs against breast tumor initiating cells. This novel approach will allow the rapid translation of repositioned drugs that target breast tumor initiating cells into clinical trials.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-110. doi:10.1158/1538-7445.AM2011-LB-110
Abstract LB-114: Molecular and lineage analysis of glioblastoma stem cells identifies clinically relevant models of glioblatoma
Authors: Fu Jun , Koul Dimpy , Yao Jun , Wang Shuzhen , Gumin Joy , Shen Ruijun , Vaillant Brian , Colman Howard , Lang Frederick F. , Aldape Kenneth D. , Yung W.K
Published: June 2012

The Cancer Genome Atlas project described a robust gene expression-based molecular classification of GBM. However, the functional and biological significance of the molecular subclasses are being determined. In this study, we hypothesize that Glioma Stem Cells (GSCs) isolated from individual patient tumor samples will recapitulate the molecular characteristics of tumor samples and provide a relevant model for functional analysis of the molecular subclasses. Thus we conducted a comprehensive analysis of 26 GSC lines with expression array, RPPA, and a series of neural lineage markers. Analysis of the expression data classified the 26 GSC lines into four subtypes (Classical, Proneural 1, Proneural 2 and Mesenchymal,) closely similar to the TCGA subclasses with a distinct profile for each subtype (c-Myc, Cyclin D2 for Classical; Olig2, NKX2–2, Notch-1, Notch-3 for Proneural 2; BMP4, DCX, p16INK4a, ID2 for Proneural 1; CD44, CAV1, TGFBR2 for Mesenchymal). Further analysis showed that GSC subtypes exhibit divergent patterns of signaling pathway activation. The major pathways activated in 4 subtypes were Notch pathway in Proneural 2, Wnt/β-Catenin in Proneural 2 and Classical, while FGF/VEGF and TGF-β in Mesenchymal. In vitro treatment with SB 431542, a TGF-βR inhibitor, showed that Mesenchymal subtype is more sensitive than other subtypes. More importantly, lineage analysis of GSCs subtypes show that Proneural and Classical GSCs differentially express lineage markers for neural stem/progenitor cells and were responsive to differentiating agent retinoic acid. In addition, GSC subtypes exhibit distinct biological behaviors in self-renewal capacity, proliferation, invasiveness, angiogenic potential, response to growth factor stimulus, and differentiation in vitro and in vivo with Classical subtype being more proliferative and Mesenchymal subtype being more angiogenic and invasive.

In conclusion, our comprehensive analysis showed that GSCs reflect patient tumor subclass and these subtypes showed distinct regulatory pathway activation, lineage profile and biological behaviors. Thus GSC is biologically and molecularly a more relevant model system for preclinical studies of therapeutic intervention and to expand our molecular understanding of human GBM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-114. doi:10.1158/1538-7445.AM2011-LB-114
Abstract LB-119: A 3′UTR KRAS-variant and triple negative breast cancer
Authors: Paranjape Trupti , Weidhaas Joanne B.
Published: June 2012

Background: We previously identified a functional variant in a let-7 microRNA complementary site in the 3′UTR of the KRAS oncogene (rs61764370) associated with cancer. Here we investigate the association of this variant with breast cancer and breast cancer tumor biology.

Methods: We genotyped subjects from three breast cancer cohorts and controls (n=2323), and additionally evaluated the association of the KRAS-variant with genome wide mRNA and specific microRNA expression in triple negative breast cancer (TNBC) patients.

Findings: The KRAS-variant is significantly associated with ER/PR negative breast cancer risk in premenopausal women by case control analysis (p = 0.015). A breast cancer cohort with complete receptor status shows the association of the KRAS-variant specifically with TNBC (p = 0.044), and a case control analysis indicates a significant increased risk of TNBC in KRAS-variant positive premenopausal women (OR = 2.31, CI = 1.26–4.22, p<0.007, n = 361). Gene expression analysis of TNBC tumors with and without the KRAS-variant indicates that KRAS-variant positive tumors have significantly altered gene expression, and are enriched for the luminal progenitor and BRCA1 deficiency signatures. MicroRNA analysis indicates lower levels of let-7 microRNA species.

Interpretation: These findings support the hypothesis that the KRAS-variant may be a genetic marker for the development of triple negative breast cancer in premenopausal women. Furthermore, tumors harboring the KRAS-variant appear to have altered gene and microRNA expression that can distinguish them from other triple negative breast cancers. Thus, the variant may help molecularly and biologically stratify patients with triple negative breast tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-119. doi:10.1158/1538-7445.AM2011-LB-119
Abstract LB-120: Oncogenic property of FOXP1 isoform3 in diffuse large B-cell lymphoma.
Authors: Kim Saerom , Kim Soyeon , Kim Eunkyung , Kim Tae Min , Heo Dae Seog
Published: June 2012

Introduction. FOXP1 forkhead transcription factor is one of the markers of activated B-cell-like (ABC) subgroup of diffuse large B-cell lymphoma (DLBCL). High level expression of FOXP1 has been reported to have a poor prognosis and nine different truncated isoforms of N-terminally truncated FOXP1 were found apart from full length FOXP1. However, the biologic roles of isoforms are not fully investigated. In this study, oncogenic effect of FOXP1 smaller isoform3 (FOXP1.3) was evaluated and complementary regulation between FOXP1 and FOXP1.3 was investigated.

Methods. Various B-cell lymphoma cell lines (BJAB, OCI-Ly-19, SU-DHL-6, U2932, U2940 and Daudi) were used to evaluate FOXP1 isoforms by immunoblotting and RT-PCR. Two different cell lines, U2932 (ABC-DLBCL) and U2940 (primary mediastinal B-cell lymphoma) cells were exposed to FOXP1-specific siRNA and transfected with FOXP1.3 plasmid tagged with flag for up to 48 hr, respectively. After silencing and over-expression of FOXP1, cell proliferation was measured by colorimetric technique. Therapeutic effects were also confirmed by the treatment of monoclonal anti-CD20 antibody, rituximab at a dose of 10 μg/106 cells for 3 days.

Results. Differential patterns of expression of FOXP1 isoforms were detected in various DLBCL cell lines on both protein and mRNA levels. U2940 cells exhibited high level of endogenous FOXP1.3 compared with other cell lines. The suppression of FOXP1 by siRNA led to the over-expression of FOXP1.3 in DLBCL cell lines. Up-regulation of FOXP1.3 showed approx. 2.5 folds increase of cell proliferation by colorimetric assay. This was due to induction of survival pathways involving NF-κB and NFAT2 transcriptional factors, which are nuclear transcriptional factors that represent major neoplastic events in DLBCL. Activation of FOXP1.3 was also observed after exposure to rituximab. Rituximab suppressed FOXP1 and dramatically increased expression levels of FOXP1.3 simultaneously in a time-dependent manner.

Conclusion. A novel oncogenic property of FOXP1.3 and its complementary regulation with FOXP1 in DLBCL cell lines was observed. These data also suggest a possible mechanism of resistance to rituximab treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-120. doi:10.1158/1538-7445.AM2011-LB-120
Abstract LB-121: Polymorphic variants in PPARGC1A and PCMTD1 associate with earlier age of onset in ER-negative breast cancer
Authors: Terlizzi Joseph P. , Vazquez Alexei , Mehta Madhura Sreenath , Hirshfield Kim
Published: June 2012

Background:

Breast cancer is the most frequent cancer and leading cause of cancer death among women worldwide. As <10% of breast cancers are due to mutations in BRCA1 and BRCA2, other perturbations such as single nucleotide polymorphisms (SNPs) may be genetic contributors. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) enhances estrogen receptor (ER) and estrogen related receptor gamma (ERRγ) activity by acting as a coactivator. ERRγ has been demonstrated to regulate vascular endothelial growth factor mRNA expression in both ER-positive and ER-negative breast cancer cell lines, indicating that it may accelerate angiogenesis and metastasis. PCMTD1 encodes protein-L-isoaspartate O-methyltransferase domain-containing protein 1, a S-adenosylmethionine-dependent methyltransferase whose biological relevance is largely unknown to present. SNPs in PPARGC1A have been correlated with metabolic diseases, but within the three studies evaluating cancer phenotypes for this gene, only Thr612Met (76873 C→T) revealed a significant association with familial breast cancers.

Experimental Procedure:

SNPs in PPARGC1A and PCMTD1 were selected using a bioinformatics approach based on SNP associations with drug response in NCI-60 cell lines and evidence of selection bias for haplotype frequencies. Allelic discrimination assays were performed on genomic DNA isolated from whole blood from over 900 Caucasian breast cancer patients with ductal carcinomas. Clinical information was linked to genotypes to search for genotype-phenotype correlations, and statistical analyses were carried out.

Results:

Analysis of PPARGC1A rs4619879 revealed a mean age of diagnosis of ER-negative cases for CC and AA carriers at 50.1 and 43.8 years, respectively (p=0.019). The difference was less striking in ER-positive ductal carcinomas, with only a 2.7year earlier onset for AA carriers (p=0.013). For PCMTD1 rs9298462, the mean age at diagnosis of ER-negative cases for CC carriers was 41.2, compared to 48.8 for the TT carriers (p=0.004). No significant difference was seen in ER-positive ductal carcinomas (p=0.15).

Conclusions:

Our results indicate that polymorphisms in PPARGC1A and PCMTD1, two transcriptional regulators, may play a role in age at diagnosis in breast cancer, particularly ER-negative ductal carcinomas. We are performing functional studies to further evaluate these findings and to elucidate the molecular mechanisms underlying these observations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-121. doi:10.1158/1538-7445.AM2011-LB-121
Abstract LB-126: Negative regulation of the Hippo pathway by the E3 ubiquitin ligase ITCH promotes tumorigenicity
Authors: Salah Zaidoun , Melino Gerry , Aqeilan Rami
Published: June 2012

The Hippo tumor suppressor pathway regulates cellular proliferation and survival, thus has profound effects on normal cell fate and tumorigenesis. WW domain-containing proteins regulate diverse biological processes through interaction with proline-tyrosine (PPxY) containing targets. Here, we showed that the E3 ligase ITCH regulates stability of LATS1, a key components of the Hippo pathway through protein-protein interaction of the PPxY motifs of LATS1 and the WW domains of ITCH by showing both endogenous and exogenous LATS1 and ITCH co-immunoprecipitation and that a double mutation in LATS1 PPxY motifs abrogates ITCH-LATS1 interaction. Wild type, but not mutant, ITCH catalyzed ubiquitination of LATS1 and stimulated its proteosomal degradation. Activation of the Hippo pathway, either by overexpressing MST2 or culturing cells at high density, induced ITCH and subsequent degradation of LATS1. Modulation of LATS1 levels via ITCH overexpression or Knockdown was associated with status of YAP phosphorylation, its subcellular localization and subsequently its transcription co-activation function. While ITCH knockdown induced epithelial-mesenchymal transition (EMT) phenotypes and tumorigenicity, ITCH overexpression induced these phenotypes. These findings provide evidence of a novel functional link between ITCH and Hippo pathway, underscoring a critical role for this association in tumorogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-126. doi:10.1158/1538-7445.AM2011-LB-126
Abstract LB-132: Protein interactome between PTEN and cancer-associated mutant demonstrated the regulatory pathway of migration through its novel interactors
Authors: Goh Mei Xian , Gunaratne Jayantha , Swa Lee Foon , Sanford Emma M. , Lee Fen Yee , Hogue Kelly A. , Blackstock Walter , Okumura Koichi
Published: June 2012

Mutation of the PTEN tumor suppressor protein frequently occurs in a variety of human cancers. PTEN is a phosphatase that negatively regulates the phosphatidyl-inositol-3-kinase (PI3K) pathway, and regulates cell proliferation, apoptosis, and cell motility. Though the tumor suppressive function involves PTEN's lipid phosphatase-dependent and -independent activities, the mechanism leading to the phosphatase-independent function of PTEN is poorly understood. Some PTEN mutants have lipid phosphatase activity but fail to suppress cell growth. Here we use a cancer associated mutant, G20E, to gain insight into the phosphatase-independent function of PTEN by investigating protein-protein interactions using mass spectrometry (MS)-based stable isotope labeling by amino acids in cell culture (SILAC). A strategy named parallel affinity purification (PAP) and SILAC has been developed to prioritize interactors and to compare the interactions between wild-type and G20E PTEN. Clustering of the prioritized interactors acquired by the PAP-SILAC approach are mainly involved in cell migration and apoptosis pathways, suggesting deregulation of the pathways could be involved in the tumorigenesis derived by the PTEN mutant. We further demonstrate that the one of wild-type specific interactor is required for the regulatory function of wild-type PTEN in cell migration. Furthermore, the other wild type specific interactor affects cell growth. These finding contribute to a better understanding of the mechanisms of PTEN's functions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-132. doi:10.1158/1538-7445.AM2011-LB-132
Abstract LB-150: Influence of CD103-E-cadherin interaction in stimulatory versus cytotoxic immune synapse formed between CTL and specific tumor cell
Authors: Franciszkiewicz Katarzyna , Floc'h Audrey Le , Boutet Marie , Mami-Chouaib Fathia
Published: June 2012

We have previously reported that interaction of integrin αE(CD103)β7, often expressed by tumor-infiltrating lymphocytes (TIL), with E-cadherin on epithelial tumor cells is required for polarized exocytosis of cytotoxic granules resulting in target cell lysis. Our results also indicated that binding of CD103 on tumor-specific cytotoxic T lymphocytes (CTL) to a recombinant E-cadherin-Fc molecule is sufficient to induce polarization of cytolytic granules in a phospholipase Cγ-dependent pathway, whereas degranulation also requires co-engagement of the T-cell receptor (TCR). In the present study, we compared the ultrastructure of the immune synapses formed between CD103+ or CD103- CTL and specific lung cancer cells, and analyzed the involvement of adhesion/costimulatory molecules in the activation of cytotoxicity versus stimulatory functions. Our results indicated that stimulatory and lytic synapses display differential activation threshold and intercellular molecular requirements.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-150. doi:10.1158/1538-7445.AM2011-LB-150
Abstract LB-154: Anti-tumor effect of dendritic cell-based immunotherapy in the patients with advanced breast cancer.
Authors: Akiyama Shinichiro , Yasuda Hiroyasu , Abe Hiroyuki
Published: June 2012

Background and objective: Tumor-specific cytotoxic T lymphocytes (CTLs) can be activated in vivo by dendritic cell (DC)-based vaccination. However, clinical responses to the immunotherapy with DC vaccination have only been observed in a minority of patients with solid cancer. In the current study, the clinical efficacy of the DC vaccine pulsed with the peptide derived from breast cancer-associated antigens has been evaluated in the patients with advanced, inoperable breast cancer.

Patients and Methods: 21patients with advanced, inoperable breast cancer refractory to standard treatment were entered the study. DCs which were generated from CD14+ monocytes from leukapheresis by 6-day cultivation with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-4, were matured by OK-432, a streptococcal agent, and were pulsed with the pancreatic cancer-associated antigens, such as WT1, MUC1. These DCs (1 × 107) were intradermally administered more than 5 times at 14-day intervals.

Results: Of the 21 patients, complete response (CR) was observed in 0 (0%), partial response (PR) in 2 (9.6%), stable disease (SD) in 7 (33.3%), progressive disease (PD) in 12 (57.1%). Response rate was 9.6%. Tumor control rate was 42.9%. Mean survival time after DC therapy was 514days. Severe side effects of more than grade 3 which were assessed in accordance with NCI-Common Toxicity Criteria v.2.0, were not observed.

Conclusions: It was strongly suggested that the DC vaccination pulsed with cancer associated-peptides was safety and effective in the patients with the inoperable breast cancer refractory to standard treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-154. doi:10.1158/1538-7445.AM2011-LB-154