bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-227: New SRC inhibitors induce p27-mediated apoptosis in mesothelioma cell lines
Authors: Indovina Paola , Giorgi Francesca , Rizzo Valeria , Khadang Baharak , Schenone Silvia , Mattioli Eliseo , Tomei Valentina , Dimarzo Domenico , Forte Iris M. , D'Urso Vittorio , Botta Maurizio , Giordano Antonio , Pentimalli Francesca
Published: June 2012

Malignant mesothelioma (MM) is a highly aggressive tumor of the serous membranes for which there is currently no specific curative modality. Recent data suggest that hyperactivation of the tyrosine kinase SRC has a key role in MM development and therefore this kinase represents an important molecular target for MM therapy. We tested new pyrazolo-[3,4-d]-pyrimidine SRC inhibitors on a panel of MM cell lines expressing the active form of SRC. These SRC inhibitors exerted a significant proapoptotic effect on MM cells without affecting the normal mesothelial cell line MET-5A, supporting a possible use of these SRC inhibitors for a safe treatment of MM. We also showed that SRC inhibitor-induced apoptosis occurred concomitantly with an increase in the nuclear stability of the cyclin-dependent kinase inhibitor p27. This finding is remarkable considering that loss of nuclear p27 expression is a well-established adverse prognostic factor in MM and p27 nuclear localization is crucial for its tumor suppressive function. Consistently, SRC inhibition seems to promote the increase in p27 nuclear level also by inactivating the AKT kinase and downregulating cyclin D1, which would otherwise delay p27 nuclear import and provoke its cytoplasmic accumulation. To determine whether p27 stabilization has a direct role in apoptosis induced by SRC inhibition, we stably silenced the CDKN1B gene, encoding p27, in MSTO-211H and REN mesothelioma cells by transduction with lentiviral vectors expressing short hairpin RNAs against the CDKN1B transcript. Strikingly, p27 silencing was able to suppress the apoptosis induced by these SRC inhibitors in both MM cell lines, suggesting that p27 has a crucial proapoptotic role in MM cells treated with SRC inhibitors. Our findings reveal a new mechanism, dependent on p27 nuclear stabilization, by which SRC inhibition can induce apoptosis in MM cells and provide a new rationale for the use of SRC inhibitors in MM therapy.

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-227. doi:10.1158/1538-7445.AM2011-LB-227
Abstract LB-234: Aptamer-prodrugs for targeted cancer therapy
Authors: Levy Matthew
Published: June 2012

Many current cancer therapy drugs are severely hindered in efficiency due to issues of specificity and targeting. We aim to improve the efficacy of these drugs by linking or incorporating them directly to non-immunogenic targeting molecules called aptamers. These aptamers would guide drugs to tumor sites thereby limiting off-target effects and toxicity.

As initial targets, we have developed aptamer-prodrugs directed against the cancer markers prostate membrane specific antigen (PSMA) and human transferrin receptor (hTfR). These constructs are capable of binding and internalizing specifically into target cells, but not into non-target cells in tissue culture. We are currently testing the cancer-specific toxicity of several FDA-approved cancer drugs delivered to cells via these aptamers. Additionally, we are developing approaches to directly identify tumor homing RNAs. These molecules will similarly be adapted for drug delivery.

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-234. doi:10.1158/1538-7445.AM2011-LB-234
Abstract LB-239: Genetic approaches for next generation of breast cancer tailored therapies
Authors: Silva Jose , Rodriguez Ruth
Published: June 2012

Cancer therapy has radically changed during the last decade. Novel therapies based on the specific molecular changes that drive tumorigenesis in every patient are emerging as low toxicity and more efficient alternatives to classical treatments. However, even these ideal tailored therapies fail to provide a long-term cure and can only delay the progression of the disease.

An alternative promising approach is the use of genetic synthetic lethal interactions. These occur when two genetic alterations that are individually innocuous appear in the same cell causing growth inhibition. This concept can be exploited to identify genes that, when inhibited, exclusively reduce the viability of tumor cells that carry a preexisting genetic lesion. Although synthetic lethality has always been proposed as an attractive anticancer approach with proven success, identification of these genetic interactions has remained elusive mainly because of the lack of proper genetic tools. However, RNA interference (RNAi) technology has emerged as a very powerful approach to attenuate the expression of any chosen gene. Thus, we envision using RNAi to identify genes that, when attenuated, exclusively reduce the viability of tumor cells carrying specific genetic lesions without affecting normal ones.

During the last years, we have pioneered the development of RNAi based genetic tools for studies in mammalian cells. Thus, we have generated a highly efficient RNAi library that allows us to block any gene of interest in the human genome. Additionally, we have developed a microarray-based analytical platform that, when combined with our RNAi library, greatly facilitates genome-wide RNAi studies. This technology represents a unique opportunity to identify synthetic lethal effects with major cancer alterations. In this project we have started to apply our state-of-the-art technology to uncover synthetic lethal interaction with the major breast cancer genes (ErbB2, c-Myc, Cyclin-D1 and RB).

These functional studies have already revealed that Stat-3 is synthetic lethal with activation of ErbB2. Thus, attenuating the activation levels of Stat-3 using small molecules inhibitors or RNAi silencing differentially reduced the viability of cells transformed with an ErbB2 oncogene. Mechanistically, we have linked this effect to the activation of an autocrine loop in which ErbB2 transformed cells secrete interleukin-6 (IL6) and upregulate its bona fide receptor IL6R. This activates the canonical JAK/STAT3 pathway increasing their tolerance to oncogene-induced stress.

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-239. doi:10.1158/1538-7445.AM2011-LB-239
Abstract LB-24: Molecular subtypes of pancreatic adenocarcinoma with different biological characteristics and therapeutical responses
Authors: Sadanandam Anguraj , Collisson Eric A. , Olson Peter , Gibb William J. , Truitt Morgan , Olshen Adam , Tempero Margaret A. , Spellman Paul T. , Hanahan Douglas , Gray Joe W.
Published: June 2012

Pancreatic ductal adenocarcinoma (PDAC) is an invariably lethal disease. Due to its late clinical presentation, surgical cure is attempted in only a minority, and resected patients usually recur quickly with incurable, metastatic disease. These attributes may reflect the variable and often disappointing responses seen when deploying the standard treatment, gemicitabine alone or in combination with other chemotherapeutic agents in unselected PDAC populations. Studies in other solid tumors have shown that heterogeneity in therapeutic responses can be anticipated by molecular differences between tumors, and targeting drugs specific to tumor subtypes in which they are predicted to be selectively effective can indeed improve treatment. Seeking to extend this new paradigm of personalized medicine to PDAC, we performed an integrative analysis of transcriptional profiles of human primary PDAC tumors (n = 143) and cell lines (n = 35). We have defined 62 gene (PDAssigner) signature that classifies the human PDAC tumors into three subtypes (classical, QM-PDAC and exocrine-like tumors) and present evidence that two (classical and QM-PDAC) of these three are present in human and mouse PDAC cell lines. Interestingly, we found that PDAC subtype classification is an independent predictor of overall survival, and patients with classical PDAC subtype tumors have significantly better survival than those with QM-PDA tumors. In addition, the expression of GATA6 (a transcriptional factor involved in the embryonic pancreas development) and KRAS (mutated in majority of PDACs) are functionally associated with classical PDAC subtype relative to QM-PDAC subtype. Intriguingly, treatment of PDAC cell lines with gemcitabine or erlotinib shows significantly differential and opposing responses between classical and QM-PDAC subtypes. Overall, we describe here a broadly integrative approach to PDAC subtype discovery and analysis that identifies gene expression signature with prognostic significance in primary patient samples and couples them with biological information and subtype specific drug responses.

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-24. doi:10.1158/1538-7445.AM2011-LB-24
Abstract LB-245: Loss of function of the TGFβRI receptor leads to the spontaneously regressing squamous carcinoma condition, multiple self-healing squamous epithelioma (Ferguson-Smith disease)
Authors: Goudie David R. , D'Alessandro Mariella , Merriman Barry , Lee Hane , Szeverényi Ildiko , Avery Stuart , O'Connor Brian D. , Nelson Stanley F. , Coats Stephanie E. , Stewart Arlene A. , Christie Lesley , Pichert Gabriella , Friedel Jean , Hayes Ian , Burrows Nigel , Whittaker Sean , Gerdes Anne-Marie , Broesby-Olsen Sigurd , Ferguson-Smith Malcolm A. , Verma Chandra , Lunny Declan P. , Reversade Bruno , Lane E. Birgitte
Published: June 2012

A re-examination has been carried out of the region on chromosome 9 containing the locus responsible for Ferguson-Smith disease, or multiple self-healing squamous epithelioma (MSSE/FSD); this is a rare autosomal dominant inherited condition first identified in the west of Scotland, that presents with multiple squamous cell skin carcinomas which grow, invade locally and then spontaneously regress.

Approach: A 4Mb locus on chromosome 9 was earlier identified by genetic mapping in a cluster of families. In this study a wider region encompassing 24Mb around this earlier identified locus was examined using high-throughput sequencing with exon capture, followed by Sanger sequencing.

Result: This effort identified mutations in the TGFBR1 gene in 18 out of 22 families diagnosed as affected by MSSE/FSD. These include 11 different mutations. The tumours occur in sun-exposed areas of the skin, and loss-of-heterozygosity in tumours is frequently seen. The sequence variants disturb the function of the TGFβRI receptor such that although heterozygous carriers are asymptomatic during development, loss of the second (wild-type) allele ablates the receptor function and leads to local cancer susceptibility.

Conclusions: The nature of the mutations sets the mechanism apart from that involved in Marfan syndrome-related disorders, in which developmental defects in vasculature are also caused by mutations in this gene. The involvement of TGFβ receptors in this condition is intriguing as TGFβ pathway effects are known to be biphasic and opposing at different stages of cancer development.

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-245. doi:10.1158/1538-7445.AM2011-LB-245
Abstract LB-246: Recurrent inactivating mutations in SPOP define a molecular subset of prostate cancer
Authors: Barbieri Christopher E. , Demichelis Francesca , Grasso Catherine , Vuong Terry , MacDonald Theresa , Boysen Gunther , Banerjee Samprit , Kitabayashi Naoki , Berger Michael F. , Tewari Ashutosh K. , Garraway Levi A. , Chinnaiyan Arul M. , Rubin Mark A.
Published: June 2012

Considerable evidence exists that prostate cancer is driven by cardinal genetic alterations that activate oncogenes and inactivate tumor suppressors. Recently, recurrent fusions involving members of the ETS transcription factor family have been implicated in the majority of prostate cancer. In addition, several studies have shown that prostate cancers can be classified by genome-wide analysis of somatic copy-number aberration, or transcriptome-wide analysis of gene expression profiles. These discoveries raise the possibility that prostate cancer may soon transition from a poorly understood, clinically heterogeneous disease to a collection of homogenous subtypes identifiable by molecular criteria. However, the limited number of known driver alterations in prostate cancer currently limits this effort.

Here, we report the presence of recurrent mutations in human prostate cancer in SPOP, the substrate-recognition component of an E3-ubiquitin ligase. Recurrent missense mutations in SPOP were discovered by whole genome DNA sequencing (DNA-seq) and whole transcription RNA sequencing (RNA-seq). SPOP mutations were found in approximately 10% of prostate cancers in multiple independent patient cohorts. All mutations were heterozygous, and were found exclusively in the structurally-defined substrate-binding cleft of SPOP. Structural analysis suggests that these mutations inactivate SPOP function by disrupting SPOP-substrate interaction, and loss of SPOP function in prostate cell lines resulted in increased invasion. Prostate cancers harboring SPOP mutations displayed characteristic somatic genomic aberrations. However, all tumors with SPOP mutations lacked both ERG rearrangement and deletion of PTEN, two of the most common genetic alterations in human prostate cancer. We conclude from these results that recurrent mutations in SPOP define a distinct molecular subclass of prostate cancer.

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-246. doi:10.1158/1538-7445.AM2011-LB-246
Abstract LB-256: S6K1 mediates glycolysis and apoptosis resistance in Pten deficient cells
Authors: Tandon Preeti , Gallo Catherine A. , Khatri Shikha , Plas David R.
Published: June 2012

Pten loss and subsequent Akt activation promotes cell survival in human cancer cells through activation of glycolytic metabolism and repression of pro-apoptotic factors. Because sustained glycolysis is required for Akt dependent apoptosis resistance, we investigated the downstream signaling components that mediate Akt dependent increases in glycolysis in Pten-deficient cells. Loss of the ribosomal protein S6K1 in Pten-deficient cells prevented Akt-induced glycolysis and triggered Bax translocation and commitment to apoptosis.

Inactivation of S6K1 was associated with decreased expression of the pro-glycolytic HIF1α transcription factor. Restoring HIF1α expression was sufficient to restore both glycolysis and cell survival in S6K1-deficient cells. Conversely, inhibiting HIF1α expression in Pten deficient cells resulted in decreased glycolysis and cell survival, mimicking the loss of S6K1. In vivo, S6K1 deficiency delayed the development of lethal disease in the Pten fl/fl Mx-1 Cre+ model of leukemia. Thus, together the data suggest that S6K1 is a useful target for counteracting the metabolic program that supports apoptosis resistance in Pten-deficient 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 LB-256. doi:10.1158/1538-7445.AM2011-LB-256
Abstract LB-268: Tumor classification and prediction using the WG-DASL HT Assay in archived sectioned FFPE (AS-FFPE) material
Authors: April Craig , Hoshida Yujin , Fan Jian-Bing
Published: June 2012

Formalin-fixed archival tissues represent an invaluable resource for cancer research, since they are widely available and afford correlations of historical clinical data with gene expression signatures thereby facilitating better disease classification and prediction. While FFPE tissue is commonly available in block form, it is also standard practice to archive sectioned slices (AS-FFPE), often at room temperature, which further degrades genetic material due to oxidation. Because of these limitations, gene expression studies using FFPE material are usually performed on material derived from freshly cut blocks and not AS-FFPE samples. Previous mRNA data generated on freshly cut FFPE blocks for two independent liver cancer sample sets yielded gene expression signatures which classified hepatocellular carcinoma (HCC) samples into three subclasses (Cancer Res 2009, 69: 7385) and cirrhotic liver (CL) samples into two (good and poor survival) groups (N Engl J Med 2008, 359:1995). Here, using the WG-DASL HT assay (29K probes), we report on our efforts to use RNA derived from 5-year old AS-FFPE samples that were obtained from a subset of the previously assayed liver cancer sample sets, to generate clinically informative gene expression profiles. With a passing quality control filter of >80% probes detected (p < 0.01) we were able to obtain good quality data for 64/83 (77%) and 37/48 (77%) of the HCC and CL samples, respectively. On average, for the two sample sets, the sample reproducibility across all 29K probe intensities was R2 ∼ 0.85. We next performed prediction analysis using a nearest template prediction method and compared the results with that originally predicted for each of the two sample set. With a confidence threshold of p < 0.05, 38/64 (59%) of the passing HCC samples yielded a prediction with an accuracy of 95% and an error rate of 5%. At the same confidence threshold (p < 0.05), 13/37 (35%) of the passing LC samples yielded a prediction with an accuracy of 69% and an error rate of 31%. Together our results suggest that, despite degradative events such as oxidation and hydrolysis that further fragment archived FFPE sections, gene expression signatures derived from AS-FFPE samples can accurately classify disease states and provide clinically relevant prognoses.

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-268. doi:10.1158/1538-7445.AM2011-LB-268
Abstract LB-279: Cancer cDNA resequencing with an exon-capture system
Authors: Ueno Toshihide , Yamashita Yoshihiro , Soda Manabu , Mano Hiroyuki
Published: June 2012

While cancer is a genetic- and/or epigenetic-disorder, “driver” mutations in the cancer genome/epigenome are yet to be revealed for many cancer subtypes. A whole-genome resequencing should provide us with important information on this issue, but resequencing of multiple samples is still a demanding task. A recent introduction of the exon-capture systems has significantly facilitated the comprehensive resequencing of exonic regions that only occupy ∼1.5% of the human genome. However, such exon resequencing of cancer genome likely fails to identify fusion genes, since gene fusion usually takes place at introns. To efficiently discover gene fusions in addition to point mutations and indels, we here tried to resequence cDNAs of a given gene set by using a custom SureSelect system (Agilent Technologies). First we confirmed, by using the SureSelect X chromosome-purification kit, that capturing efficiency of cDNA is no worse than that of genomic DNA. Then we constructed a custom SureSelect system to capture cDNAs of cancer-related genes (n = 913 corresponding to ∼3.77 Mbp). Such cDNA capture system was then applied to a total of five cell lines of chronic myeloid leukemia. Deep sequencing of the purified cDNA fragments with Illumina Genome Analyzer IIx yielded the nucleotide information for an average of 54 million reads (= ∼4.1 Gbp) per sample. While BCR is not included in our custom SureSelect system, we could successfully isolate 38∼50 reads in each cell line encompassing the fusion points of the BCR-ABL1 cDNA, confirming the ability to detect gene fusions by our cDNA-capture system. A comparison of the read numbers in our data to the expression level defined by DNA microarray analyses has revealed a high concordance between the two data sets (Pearson's correlation coefficient = 0.73, P <2.2 × 10–16). Computational analyses of the read data that passed our quality filtering revealed a total of 199 non-synonymous point mutations on 155 independent genes. Further, we discovered a total of 15 (3 in-frame) independent insertions and 19 (6 in-frame) deletions. Among such mutation profiles, we could readily confirm the G-to-C substitution corresponding to the G266R amino acid change of TP53, one C insertion at nt position 604 of TP53, and one three-base deletion (nt = 894∼896) of TP53. These data confirm that a coupling of a sequence-based cDNA capture system to a next generation sequencer is a feasible approach to discover point mutations and fusions of target genes in the cancer genome.

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-279. doi:10.1158/1538-7445.AM2011-LB-279
Abstract LB-73: Patient/Public Involvement in Cancer Research in the United Kingdom
Authors: Haswell Thomas
Published: June 2012

Academic cancer research in the UK is structured around key organizations. The National Cancer Research Institute (NCRI) is a ‘virtual institute’ that brings together government and charitable funders to set priorities and co-ordinate funding of cancer research. NCRI Clinical Studies Groups (CSGs), which provide the site-specific leadership to develop studies, will be adopted into the national portfolio of cancer studies as part of the National Institute for Health Research (NIHR) if the funding is available. The NIHR National Cancer Research Network leads the delivery of research through research networks throughout the UK. Related groups and initiatives facilitate or carry out specific tasks in research development, management and monitoring.

Patients have input at all levels and their voice has, throughout the history of NCRI & NCRN, been considered critically important in developing research. The key principles from researchers and clinicians include working together with consumers as partners in the research effort, involving consumers in developing strategy as well as specific initiatives and studies, listening to the consumer voice on research needs and the experience of participating in research, and learning from experience to develop and increase the impact of the consumer role in cancer research.

The NCRI Consumer Liaison Group brings together patient and caregiver members to support research development at all levels from the NCRI Board through CSGs to membership of individual Trial and Study Management groups. Impact has been captured in many narratives from researchers, clinicians and patients. Working together in a robust partnership is a particular strength of UK Cancer Research and forms the ideal platform to truly achieve research intended for patient betterment. This is recognized in the recent White Paper: ‘Equity and excellence: Liberating the NHS’. The organization's first decade of patient and public involvement is captured in the NCRI report: Patient, Carer & Public Involvement in Cancer Research.

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-73. doi:10.1158/1538-7445.AM2011-LB-73
Abstract LB-74: NECCS- The Voice of Cancer Survivorship
Authors: Jeames Sanford
Published: June 2012

The disease of cancer extends its impact far beyond the clutches it holds over those diagnosed with cancer. The latest statistics from the American Cancer Society (ACS) estimate that over 500,000 Americans will be diagnosed with cancer in 2011, and these figures do not take into account the thousands of individuals under the age of 18 who are also diagnosed with cancer. A diagnosis of cancer not only affects patients, but also family members, caregivers, employers_all components of life.

The New England Coalition of Cancer Survivorship (NECCS) is an organization dedicated to advocating for the wider audience of those affected by cancer. The mission of NECCS is to educate and provide resources about issues related to cancer and cancer survivorship. Other significant aspects of NECCS's mission are to advocate on behalf of those impacted by cancer, and to empower cancer survivors, family members, friends and caregivers by creating strong communities, providing an information network, and providing access to resources, programs and events.

To achieve and reach its main goal of acting as the voice to the concerns of cancer survivorship, NECCS has initiated a variety of programs and activities to inform the public of its resources. NECCS is a collaborative partner with many organizations to better facilitate its effectiveness and outreach. NECCS board members serve on the survivorship workgroup of the Massachusetts Comp Cancer Coalition, the Leukemia/Lymphoma Society of New England and the New England Division of the American Cancer Society. NECCS programs include the Speakers' Bureau and Caregiver Program, which provides NECCS members to various community groups to share their experiences with cancer. NECCS provides printed materials through in the form of tip sheets, which highlight cancer survivors, caregivers and advocates, as well as providing information about the latest research. The NECCS website has links to state, regional and national organizations that address the concerns of cancer survivorship. A recent online campaign resulted in over 100 new members joining NECCS via its Facebook and Twitter accounts. NECCS also participated in the Boston Health Fair and was featured at a recent Boston Red Sox baseball game for its contributions to the Greater Boston area and surrounding communities.

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-74. doi:10.1158/1538-7445.AM2011-LB-74
Abstract SY16-02: microRNA regulation of the tumor angiogenic switch
Authors: Cheresh David A. , Anand Sud
Published: June 2012

Endothelial cells (EC) in the adult mammal are among the least proliferative cell types, with about 1 in 10,000 cells entering the cell cycle at any given time. Such a degree of quiescence is rapidly reversed in response to growth factors during pathological neovascularization, particularly during tumorigenesis. This robust proliferative switch of the quiescent endothelium is a complex process governed by intricate checks and balances. Recently, small 22-nt RNAs termed microRNAs (miR) have been identified as important regulators of several physiological processes including angiogenesis. To identify microRNAs that activate might regulate the tumor angiogenic switch, we profiled miRs in both human umbilical vein endothelial cells (HUVECs) treated with angiogenic growth factors VEGF or FGF and in a human embryonic stem (hES) cell vasculogenesis model in which hES cell derived embryoid bodies form well-defined, endothelial networks. We show here that microRNA miR-132 represents an angiogenic switch by targeting p120RasGAP in quiescent endothelium inducing neovascularization. miR-132 was highly expressed in the endothelium of human tumors and hemangiomas yet was undetectable in normal endothelium. Ectopic expression of miR-132 in endothelial cells increased their proliferation and tube-forming capacity while intraocular injection of anti-miR-132 blocked postnatal retinal vascular development in mice. Among its likely targets, miR-132 only impacted p120RasGAP expression, identified in normal but not tumor endothelium. Accordingly, endothelial expression of miR-132 suppressed p120RasGAP levels and increased Ras activity while a miR-resistant version of p120RasGAP reversed the miR-132-induced vascular response. Importantly, anti-miR-132 failed to inhibit angiogenesis in mice with an inducible deletion of p120RasGAP. Finally, vascular-targeted nanoparticle delivery miof anti-miR-132 restored p120RasGAP in the tumor endothelium, where it suppressed angiogenesis and inhibited breast cancer in mice. Therefore, miR-132 acts as an angiogenic switch by suppressing endothelial p120RasGAP expression leading to Ras activation and the induction of neovascularization, whereas the application of anti-miR-132 prevents this effect by maintaining vessels in the resting state.

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 SY16-02. doi:10.1158/1538-7445.AM2011-SY16-02
Abstract SY17-03: Inferring cell death networks from biochemical data
Authors: Sorger Peter K. , Spencer Sabrina , Gaudet Suzanne , Aldridge Bree , Flusberg Deborah , Bachman John , Sims Josh
Published: June 2012

The responses of cells to extracellular ligands results in a series of complex spatiotemporal changes in protein levels and state that vary considerably from one cell to the next. I will discuss our attempts to understand the biochemical mechanisms underlying these phenomena with a focus on TRAIL and Fas ligand in human tumor cells. These molecules are prototypical inducers of receptor-mediated (extrinsic) apoptosis and TRAIL is a first-in-class investigational therapeutic. I will discuss the development and application of computational methods for constructing, managing, calibrating and validating detailed kinetic models of core apoptotic process. With these methods we aim to go beyond the informal pictorial models that currently dominating molecular biology and create probabilistic mathematical constructs that assign rigorous “degrees of belief” to specific biochemical hypothesis given prior knowledge and a specific set of empirical data.

I will discuss why some TRAIL-treated human cells die within ∼40 min, some only after 12 hr and yet others live indefinitely. We have explored three explanations for these differences: (i) genetic or epigenetic variation (ii) the involvement of one or more biochemical processes subject to stochastic fluctuation (iii) transient but deterministic differences in cell state. I will illustrate how all three interact on different time scales to determine those aspects of cellular physiology that are highly invariant and those that are variable and I will present a modeling framework for understanding the impact of specific protein factors in cell-to-cell variability. A key conclusion from this work is that variability in the responses of cells to drugs is inherent to the stochastic operation of the biochemical pathways that anti-cancer drugs target. Fractional killing is one inevitable consequence.

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 SY17-03. doi:10.1158/1538-7445.AM2011-SY17-03
Abstract SY19-02: Role of the Tim-3 and PD-1 pathways in T cell exhaustion and antitumor immunity
Authors: Anderson Ana C.
Published: June 2012

The immune response plays an important role in fighting cancer; however, mechanisms of immune suppression in tumor-bearing hosts hinder productive antitumor immunity. T cell dysfunction or exhaustion is one such mechanism. PD-1 has been identified as a marker of dysfunctional or exhausted T cells in chronic disease states and blockade of PD-1/PD-1L interactions has been shown to partially restore T cell function. Recently, Tim-3 has also been identified as a marker of exhausted T cells. We have found that Tim-3 is expressed on both CD4+ and CD8+ tumor-infiltrating lymphocytes (TILs) in mice bearing solid tumors (4T1, CT26, and B16). All CD8+ Tim-3+ TILs co-express PD-1 and Tim-3+PD-1+ TILs represent a predominant fraction of the CD8+ T cells infiltrating tumors. CD8+Tim-3+PD-1+ TILs exhibit the most severe exhausted phenotype as defined by failure to proliferate, produce IL-2, TNFα and IFNγ. We have further found that combined immunotherapeutic targeting of the Tim-3 and PD-1 pathways is more effective in controlling tumor growth than targeting either pathway alone. Indeed, 50% of the mice receiving combination immunotherapy exhibited complete tumor regression. We have examined whether combined targeting of Tim-3 and PD-1 restores effector function to TILs and have found that culture of TILs in vitro in the presence of anti-Tim-3 plus anti-PD-L1 antibodies augments IFNγ production. In addition, T cells isolated from the tumor-draining lymph nodes of mice treated in vivo with anti-Tim-3 and anti-PD-L1 antibodies exhibit restored tumor antigen-specific T cell responses compared to those isolated from mice treated with control immunoglobulins. Collectively, our data support that combined targeting of the Tim-3 and PD-1 signaling pathways is highly effective in restoring antitumor immunity.

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 SY19-02. doi:10.1158/1538-7445.AM2011-SY19-02
Abstract SY23-01: Early endosomes: Platforms for the induction of oncogenic phenotypes
Authors: D'Souza-Schorey Crislyn
Published: June 2012

Oncogenic signaling markedly impacts the adhesive and migratory potential of tumor cells. Many of the resulting cellular changes are elicited by coordinated alterations in endosomal membrane trafficking. Although long regarded as a means for cells to internalize nutrients and cell surface molecules, emerging evidence suggests that the endosomal circuitry is also an essential platform for signal transduction and a conduit for the transport of cellular machinery, including adhesion proteins and signaling molecules, appropriate compartmentalization of which appears to be essential for eliciting changes that accompany disease progression. The disruption of epithelial glandular architecture and the acquisition of aggressive invasive phenotypes, two hallmarks of tumor progression, exemplify the above paradigm. Our efforts are directed at elucidating and defining the role of ARF6-coupled endocytic pathways in the acquisition of migratory/invasive phenotypes. Recent work using three-dimensional basement membrane cultures of renal and mammary epithelial cells reveals that the formation of signaling endosomes during glandular cyst morphogenesis, serve as platforms for hyperactive receptor signaling leading to the disruption of epithelial cysts and generation of certain tumorigenic phenotypes. We are also investigating the structural and molecular changes at the invasive front of tumor cells. Our recent studies, and others, have shown that selective sorting of specific cargo such as the membrane-type proteases along early endocytic recycling pathways, is tightly coupled to the biogenesis and function of invasive structures such as invadopodia and microvesicles. Invadopodia are actin-rich protrusions that form at the adherent cell surface and mediate pericellular proteolysis. Microvesicles, generated by the outward budding and fission of the plasma membrane, facilitate the horizontal transfer of bioactive molecules and are now thought to have vital roles in tumor invasion and metastasis, inflammation and stem-cell expansion. Since endosomes confer spatial and temporal dimensions to oncogenic signaling, understanding the interplay between endocytic trafficking and the activation of invasive cell programs could provide new and important insights into the progression toward pathophysiological states.

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 SY23-01. doi:10.1158/1538-7445.AM2011-SY23-01
Abstract SY25-01: Functional genomics, transformation, and resistance
Authors: Hahn William C.
Published: June 2012

Recent advances in genomics now make it possible to consider enumerating all of the genetic lesions in specific cancers. While these approaches will yield critical information regarding the identify, number, and types of alterations found in human tumors, a complementary approach to decipher the molecular basis of malignant transformation depends upon the application of genome scale tools to annotate the function of genes involved in cancer initiation and progression. Over the past several years, we have developed genome scale RNAi libraries and open reading frame expression libraries that permit a systematic evaluation of genes involved in cancer initiation and maintenance. Using these libraries, we have now performed screens in a panel of human cancer cell lines to systematically identify cancer vulnerabilities. By combining these functional approaches with information derived from mapping the structural abnormalities present in cancer genomes, we have identified several new oncogenes that contribute to cancer development. In addition, many commonly occurring and well-validated oncogenes and tumor suppressor genes remain refractory to molecularly targeted therapies. An alternative strategy for targeting such cancer drivers is to identify gene products that, when suppressed or inhibited, result in cell death only in the presence of an oncogenic allele. Through the use of systematic RNAi screens, we have identified several genes that act as synthetic lethal partners to known oncogenes. Taken together, these studies suggest that combining forward and reverse genetic approaches with information derived from the cancer genome characterization projects will yield a comprehensive list of cancer vulnerabilities and establish a general approach for the rational identification of oncogenic and co-dependent pathways in cancer.

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 SY25-01. doi:10.1158/1538-7445.AM2011-SY25-01
Abstract SY27-01: Colon commensals and cancer
Authors: Sears Cynthia L.
Published: June 2012

A clear intersection between the infectious diseases and oncology fields has emerged from our understanding that many cancers arise in the setting of chronic infection. Roughly one-third of cancers worldwide, particularly epithelial cancers, are associated with identified single microbial infections, leading to the conceptual paradigm that chronic infection with specific microbes cause these cancers independent of other components of the ambient microbial community. Among epithelial cancers, colon cancer is the second leading cancer killer of adults in the United States but specific microbial contributors have not yet been identified. Rather, we now understand that the colon is home to one of the most dense and diverse communities of bacteria in the body and that we are each remarkably unique in our bacterial makeup, reinforcing the contrasting view that the microbial contribution to colon cancer pathogenesis may lie in the composition of the colon microbiome. This talk will explore the scientific data supporting differing paradigms for how the colonic flora may contribute to colon oncogenesis. Specific, usually commensal, members of the colonic microbiome and the mechanisms by which they may initiate and/or promote colon tumors with be discussed with a particular emphasis on enterotoxigenic Bacteroides fragilis (ETBF). B. fragilis not only colonizes most humans but is the leading anaerobe in human disease. ETBF is a molecular subset of B. fragilis distinguished by secretion of a zinc-dependent metalloprotease toxin. In murine models, ETBF is a potent inducer of colonic tumors. Tumor induction by ETBF is dependent, in part, on a specific host immune response involving IL-17-producing CD3+CD4+ T cells. A framework for utilizing this knowledge to better understand the pathogenesis of colon cancer and to develop new approaches to colon cancer prevention and/or therapy will be discussed.

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 SY27-01. doi:10.1158/1538-7445.AM2011-SY27-01
Abstract A10: L1236, a Hodgkin and Reed-Sternberg cell line, stimulates monocytes in vitro to differentiate into M2-like macrophages
Authors: Lee Kim Yee , Chong Siew Meng , Lim Yaw Chyn
Published: June 2012

The microenvironment of classical Hodgkin lymphoma (cHL) is characterized by a small number of malignant Hodgkin and Reed-Sternberg (HRS) cells embedded in a background rich with infiltrating immune cells. HRS cells and the surrounding cellular infiltrates are believed to produce soluble and membrane-bound factors that are essential for the survival and proliferation of HRS cells. Steidl et al (2010) have reported that an increase in the number of tumor associated macrophages in cHL correlates with poor prognosis. However, little is known about the molecular crosstalk between macrophages and HRS cells in cHL. This study aims to examine in-vitro the influence of HRS cells on monocyte activation and differentiation.

Freshly isolated human monocytes were co-cultured with L1236 cells, a HRS cell-line, under standard culture conditions. At the end of 8 days in culture, we examined the influence of HRS cells on monocyte survival and differentiation. In addition, we determined the activation and differentiation status of the co-cultured monocyte by assessing the cells for CD206 and IL-10 expression. The role of IL-4Rα and Macrophage colony-stimulating factor (M-CSF) receptor on HRS cell-induced monocyte differentiation was examined using antibody blocking assay. We also examined consented cHL patient samples for the presence of CD206/CD68 double positive macrophages by immunofluorescent staining.

Our data showed that L1236 cells are able to enhance the survival of monocytes in vitro. In the presence of L1236 cells, monocytes differentiated into alternatively activated, M2-like macrophages which expressed CD206 and IL-10. The observed enhanced survival, and differentiation to M2-like macrophages, was mediated by soluble factors secreted by the L1236 cells. The survival of co-cultured monocytes is enhanced by signalling through the M-CSF receptor. In contrast, the differentiation to M2-like macrophages is in part, regulated by signals generated via IL-4Rα. Finally, the presence of CD68/CD206 double positive macrophages was detected in three out of four cHL patient samples.

We conclude that HRS cells secrete soluble factors that can in vitro directly modulate monocyte survival and differentiation to a CD206+ M2 macrophage phenotype.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A10.
Abstract A12: AmotL2 linking hypoxia to invasion
Authors: Mojallal Mahdi , Zheng Yujuan , Hultin Sara , Holmgren Lars
Published: June 2012

Hypoxia has been shown to be a bad prognostic marker correlating with metastasis and poor survival. Furthermore, in response to antiangiogenic therapy hypoxic tumor cells become invasive and form metastasis. Malignant tumor cells undergo epithelial-mesenchymal transition (EMT) and become depolarized. A protein important for apicobasal polarity during tumor progression is Crumbs3 (crb3). Silencing of Crumbs3 disrupts epithelial cell polarity and possibly promotes metastasis. AmotL2, a gene regulated by hypoxia, associates to the Crb3/Pals/Patj polarity complex via its PDZ-binding motif (unpublished data).

Here we show that AmotL2 disrupts apicobasal polarity resulting in the development of an invasive phenotype.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A12.
Abstract A3: p53-dependent release of alarmin HMGB1 is a central mediator of senescent phenotypes
Authors: Davalos Albert R. , Kawahara Misako , Malhotra Gautam K. , Huang Jiahao , Ved Urvi , Rodier Francis , Beausejour Christian , Coppe Jean Philippe , Campisi Judith
Published: June 2012

Cellular senescence irreversibly arrests the proliferation of cells at risk for malignant transformation in part through activities of the transcriptional regulator and tumor suppressor p53. Cells that senesce owing to DNA damage also secrete many biologically active factors, including inflammatory cytokines such as IL-6. Some data suggest that the senescence associated secretory phenotype (SASP) creates a tumor permissive environment. However, we find that senescent cells secrete a potent bioactive molecule—High Mobility Group Box 1 (HMGB1) protein, which is unusual in having two distinct functions. Intracellularly, it binds chromatin and modulates transcription, including stimulating p53 activity. In addition, necrosis or microbial infection causes HMGB1 leakage or active secretion, respectively, whereupon it functions as an extracellular alarmin to signal tissue damage and promote tissue regeneration, stem cell recruitment and immune activation. We show that HMGB1 is largely nuclear in non-senescent human and mouse fibroblasts and epithelial cells, but is actively exported from the nucleus and secreted by senescent cells. In culture and in vivo, HMGB1 re-localization occurred prior to the appearance of other hallmarks of senescence, and depended on the function of p53, but not the upstream p53 activator ATM, which distinguished HMGB1 secretion from the SASP. Aged mice or human sera contained significantly higher levels of circulating HMGB1 compared to sera from young mice or human subjects. Disruption of HMGB1 stoichiometry, either by overexpression or depletion, induced a p53-dependent senescence growth arrest, but only HMGB1 overexpression, not HMGB1 depletion, promoted IL-6 secretion. Senescence-associated secretion required endogenous and secreted HMGB1 because deletion of endogenous HMGB1— or addition of an HMGB1 blocking antibody – attenuated IL-6 secretion. Recombinant HMGB1 protein induced IL-6 secretion in cells depleted, but not harboring, endogenous HMGB1. Depletion of endogenous HMGB1 promoted NF-κ B transcriptional activity in cells cultured with recombinant HMGB1. Our findings identify a novel biological setting (senescence), independent of necrosis or microbial infection, in which HMGB1 secretion occurs in vitro and in vivo, and link senescence-dependent HMGB1 redistribution to p53 activity and inflammatory cytokine secretion.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A3.