bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-042: MCPIP1 suppresses breast tumor progression by targeting anti-apoptosis pathway
Authors: Liu Jianguo , Lu Wenbao , Ning Huan , Peng Hui , Wang Qinghong , Hou Rong
Published: August 2015

The ability to evade apoptosis is a hallmark of cancer and also plays a significant role in cancer resistance to conventional therapy. While recent progress has broadened our understanding of the apoptosis-evasion mechanisms by cancer cells, how apoptosis resistance develops in cancer cells through posttranscriptional mechanisms, especially by the newly discovered RNA-binding protein monocyte chemotactic protein induced protein 1 (MCPIP1), remains unknown. Here, we report that MCPIP1 expression is impaired in breast tumors and breast tumor cell lines, with the severest impairment in highly metastatic tumors. Ectopic expression of MCPIP1 causes apoptosis of breast tumor cells through selectively suppression of anti-apoptotic gene transcripts, including Bcl2L1, Bcl2A1, RelB, Birc3 and Bcl3. This suppression is medicated through a physical interaction between the PIN domain of MCPIP1 and the 3′UTRs of anti-apoptotic transcripts, resulting in mRNA degradation and tumor cell apoptosis. In difference from the RNA-binding protein tristetraprolin which binds to the ARE in the 3′UTR of target genes for mRNA decay, MCPIP1 specially recognizes a stem-loop structure in the 3′UTR of anti-apoptotic genes for binding and mRNA decay. Furthermore, induction of MCPIP not only ameliorates breast tumor formation but also completely shrinks the established tumors within six days. Lung metastasis is also significantly reduced by MCPIP1 induction. The tumor suppressive effect of MCPIP1 acts through activation of apoptosis. Importantly, by analysis of the excised breast tumors of 251 patients, we found that low MCPIP1 levels in tumors are strongly associated with poor survival of patients over 13 years of follow up. Taken together, we demonstrate that MCPIP1 is a novel potent tumor suppressor which induces tumor apoptosis through tipping the balance between pro-apoptotic and anti-apoptotic genes via selectively targeting the mRNAs of anti-apoptotic genes for degradation. MCPIP1 can serve as a new therapeutic target for treatment of breast cancer and other cancers as well.

Citation Format: Jianguo Liu, Wenbao Lu, Huan Ning, Hui Peng, Qinghong Wang, Rong Hou. MCPIP1 suppresses breast tumor progression by targeting anti-apoptosis pathway. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-042. doi:10.1158/1538-7445.AM2015-LB-042
Abstract LB-045: Detection of keratin fusions in oral squamous cell carcinoma
Authors: Sheu Jim Jinn-Chyuan
Published: August 2015

Keratin cytoskeleton proteins form intermediate filaments in epithelial cells to regulate cell shape, mobility, membrane trafficking and cellular signaling. Although keratin-6 (K6) and -14 (K14) are highly expressed in certain squamous cell carcinomas and have been suggested as tumor markers, molecular mechanisms of how keratins contribute to cancer development still remain elusive. Here, we demonstrated novel K6-K14 chimeras in oral squamous cell carcinomas (OSCCs) by pair-ended transcriptome sequencing and subsequent validation by fluorescence in situ hybridization and junction site mapping. Two unique fusion types (type-1 and type-2) were identified with a total of 23 in-frame fusion variants verified in OSCCs. Clinical screening confirmed high detection rate of K6-K14 fusions in tumor samples: 33% for type-1 and 25% for type-2. Notably, K6-K14 fusions could be only detected in tumor lesions at late carcinoma stage, but not the ones at early stages, suggesting potential benefits of K6-K14 fusions in promoting aggressive tumors. Functional domain analyses revealed a potent role involved in EMT and metastasis.

Citation Format: Jim Jinn-Chyuan Sheu. Detection of keratin fusions in oral squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-045. doi:10.1158/1538-7445.AM2015-LB-045
Abstract LB-060: A phosphoproteomic comparison of BRAF(V600E) and MKK1/2 inhibition in melanoma
Authors: Stuart Scott , Ahn Natalie , Houel Stephane , Old William
Published: August 2015

Inhibitors of oncogenic B-RAF(V600E) and MKK1/2 have yielded remarkable responses in B-RAF(V600E)-positive melanoma patients. However, the efficacy of these inhibitors is limited by the inevitable onset of resistance. Despite the fact that these inhibitors target the same pathway, combination treatment with B-RAF(V600E) and MKK1/2 inhibitors has been shown to improve both response rates and progression-free survival in B-RAF(V600E) melanoma patients. To provide insight into the molecular nature of the combinatorial response, we used quantitative mass spectrometry to characterize the inhibitor-dependent phosphoproteome of human melanoma cells treated with the B-RAF(V600E) inhibitor PLX4032 (vemurafenib) or the MKK1/2 inhibitor AZD6244 (selumetinib). In three replicate experiments, we quantified changes at a total of 23,986 phosphosites on 4,722 proteins. This included 1,317 phosphosites that reproducibly decreased in response to at least one inhibitor. Phosphosites that responded to both inhibitors grouped into networks that included the nuclear pore complex, growth factor signaling, and transcriptional regulators. While the majority of phosphosites were responsive to both inhibitors, we identified 16 sites that decreased only in response to PLX4032, suggesting rare instances where oncogenic B-RAF signaling occurs in an MKK1/2-independent manner. Only two phosphosites were identified that appeared to be uniquely responsive to AZD6244. When cells were treated with the combination of AZD6244 and PLX4032 at subsaturating concentrations (30 nM), responses at nearly all phosphosites were additive. We conclude that AZD6244 does not substantially widen the range of phosphosites inhibited by PLX4032 and that the benefit of the drug combination is best explained by their additive effects on suppressing ERK1/2 signaling. Comparison of our results to another recent ERK1/2 phosphoproteomics study revealed a surprising degree of variability in the sensitivity of phosphosites to MKK1/2 inhibitors in human cell lines, revealing unexpected cell specificity in the molecular responses to pathway activation.

Citation Format: Scott Stuart, Natalie Ahn, Stephane Houel, William Old. A phosphoproteomic comparison of BRAF(V600E) and MKK1/2 inhibition in melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-060. doi:10.1158/1538-7445.AM2015-LB-060
Abstract LB-063: PTEN function is controlled by recruitment to cytoplasmic vesicles
Authors: Naguib Adam , Bencze Gylua , Cho Hyejin , Zheng Wu , Tocilj Ante , Elkayam Elad , Faehnle Christopher R , Jaber Nadia , Pratt Christopher , Chen Muhan , Zong Wei-Xing , Marks Michael S , Joshua-Tor Leemor , Pappin Darryl J , Trotman Lloyd C.
Published: August 2015

PTEN is thought to function at the plasma membrane where receptor tyrosine kinases activate PI 3-Kinases. Yet the majority of PTEN is located throughout the cytoplasm so that only a fraction of PTEN could be actively suppressing PI 3-K signaling at any time. Here we show that cytoplasmic PTEN is distributed along microtubules, tethered to vesicles via interaction with phosphatidylinositol 3- phosphate (PI(3)P), the signature lipid of endosomes. We demonstrate that the C2 domain of PTEN specifically binds PI(3)P via the CBR3-loop. Mutations that render the CBR3-loop incapable of PI(3)P binding abrogate PTEN function in cells but not in vitro. The loss-of-function in cells is rescued by fusion of the canonical PI(3)P vesicle targeting domain, FYVE, to CBR3-loop mutant PTEN, demonstrating the functional relevance of PTEN activity on endosomal membranes. These findings introduce an entirely unexpected site of action of the PTEN tumor suppressor. Furthermore, they introduce the concept of PI 3-K signal activation over the vast surface of the plasma membrane that is contrasted by PTEN-mediated signal termination on the discretely sized and much smaller surfaces of endocytic vesicles. Implications of these results for cancer signaling and growth control will be discussed.

Note: This abstract was not presented at the meeting.

Citation Format: Adam Naguib, Gylua Bencze, Hyejin Cho, Wu Zheng, Ante Tocilj, Elad Elkayam, Christopher R Faehnle, Nadia Jaber, Christopher Pratt, Muhan Chen, Wei-Xing Zong, Michael S Marks, Leemor Joshua-Tor, Darryl J Pappin, Lloyd C. Trotman. PTEN function is controlled by recruitment to cytoplasmic vesicles. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-063. doi:10.1158/1538-7445.AM2015-LB-063
Abstract LB-065: Mutational and functional analysis of the tumor suppressor PTPRD in human melanoma
Authors: Walia Vijay , Prickett Todd , Kim Jung-Sik , Gartner Jared J. , Lin Jimmy C. , Rosenberg Steven A. , Elble Randolph C. , Solomon David A. , Waldman Todd , Samuels Yardena
Published: August 2015

Protein tyrosine phosphatases (PTPs) tightly regulate tyrosine phosphorylation essential for cell growth, adhesion, migration, and survival. We performed a mutational analysis of the PTP gene family in cutaneous metastatic melanoma and identified 23 phosphatase genes harboring somatic mutations. Among these, receptor-type tyrosine-protein phosphatase delta (PTPRD) is one of the most highly mutated genes, harboring 17 somatic mutations in 79 samples, a prevalence of 21.5%. Functional evaluation of six PTPRD mutations show enhanced anchorage-dependent and anchorage-independent growth. Interestingly, melanoma cells expressing mutant PTPRD are significantly more migratory than cells expressing wild-type PTPRD or vector alone, indicating a novel gain-of-function associated with mutant PTPRD. To understand the molecular mechanism of PTPRD, we searched for its binding partners by converting the active PTPRD enzyme into a ‘‘substrate trap’’ form. Using mass spectrometry and co-immunoprecipitation, we report desmoplakin, a desmosomal protein that is implicated in cell-cell adhesion, as a novel PTPRD substrate. Further analysis showed reduced phosphatase activity of mutant PTPRD against desmoplakin. Thus our study has established a novel link between PTPRD and desmoplakin and identified a phosphatase implicated in desmosome formation, which is disrupted in melanoma. As both Met and EGFR signaling have been shown to be involved in desmoplakin phosphorylation and their respective inhibitors, SU11274 and Gefinitib reduce its phosphorylation; melanoma cells harboring PTPRD mutations may be selectively sensitive to these two inhibitors. Moreover, because PTPRD is also mutated in glioblastomas and adenocarcinoma of the colon and lung, our data might be applicable to a number of human cancers.

Note: This abstract was not presented at the meeting.

Citation Format: Vijay Walia, Todd Prickett, Jung-Sik Kim, Jared J. Gartner, Jimmy C. Lin, Steven A. Rosenberg, Randolph C. Elble, David A. Solomon, Todd Waldman, Yardena Samuels. Mutational and functional analysis of the tumor suppressor PTPRD in human melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-065. doi:10.1158/1538-7445.AM2015-LB-065
Abstract LB-078: RNAi and CRISPR/Cas9-based in vivo models for drug discovery
Authors: Premsrirut Prem K. , Fellmann Christof
Published: August 2015

Genetically engineered mouse models (GEMMs) are a powerful platform that enable the study of disease initiation and maintenance, the microenvironment and the responsiveness of disease to known or novel therapeutics; however, the long lead times and high costs required to develop, intercross and maintain models with various disease predisposing gene combinations have limited their practical utility in the drug discovery process. RNA interference (RNAi), a mechanism that controls gene expression, is a rapid and cost-effective alternative to gene deletion that can be exploited experimentally to reversibly silence nearly any gene target not only in vitro but also in live mice. By using our “Sensor assay” to biologically identify short hairpin RNAs (shRNAs) that induce potent gene suppression in combination with a new miRNA scaffold, miR-E, we have engineered a reliable system for in vivo gene suppression. Furthermore, by utilizing tetracycline-regulated miR-E based shRNAs with high efficiency ES cell targeting, we have developed a fast, scalable pipeline for the production of shRNA transgenic mice with reversible gene silencing. Recently, with the advent of new genome editing techniques, such as CRISPR/Cas9 technology, we are able to introduce additional sensitizing lesions to induce disease pathogenesis. In synergy with RNAi technology, complex multi-allelic ESC based GEMMs can be generated without extensive intercrossing. Using this combination of CRISPR/Cas9 and RNAi technologies, we are able to not only model disease pathogenesis, but also mimic drug therapy in mice, giving us unprecedented capabilities to perform preclinical studies in vivo. Here, we demonstrate that RNAi in combination with CRISPR/Cas9 genome editing enables us to recapitulate the phenotypes of knockout mice and further explore potential therapeutic approaches within the same model. Using our robust system, we have created a a cost-effective and scalable platform for the production of complex GEMMs with RNAi silencing of nearly any gene - mice with enormous predictive power that will shape our development of better tolerated therapies.

Citation Format: Prem K. Premsrirut, Christof Fellmann. RNAi and CRISPR/Cas9-based in vivo models for drug discovery. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-078. doi:10.1158/1538-7445.AM2015-LB-078
Abstract LB-079: Specific epigenetic reader role for cyclin D1
Authors: Di Sante Gabriele , Casimiro Mathew Craig , Wang Chenguang , Yu Zuoren , Crosariol Marco , Vadlamudi Ratna K. , Mann Monica , Tompa Peter , Tantos Agnes , Pestell Richard G.
Published: August 2015

Amplification of the CCND1 gene occurs in approximately 30% of human breast cancer and is sufficient when overexpressed for the induction of mammary tumorigenesis. A DNA-associated form of cyclin D1 governs gene expression and chromosomal instability. Herein, the mechanisms governing gene activation by cyclin D1 were defined. Cyclin D1 was recruited to activate gene regulatory regions associated with enrichment of p300, HP1α and reduced HDAC3 and SUV39H1. The recruitment of cyclin D1 into local chromatin was dissociable from its kinase function and required an intrinsically disordered carboxyl-terminus flanked by a glutamine-rich motif. The cyclin D1 epigenetic interaction motif bound acetylated or methylated H3 on specific residues (H3K36me2, H3K9me3). Cyclin D1 bound to the Top2A gene promoter induced Top2A transcription, abundance and sensitivity to Top2A inhibitors. The direct recognition of an epigenetic code by a motif within cyclin D1 and the induction of Top2A may facilitate communication of genome wide expression changes during cell-cycle progression and tumorigenesis.

Citation Format: Gabriele Di Sante, Mathew Craig Casimiro, Chenguang Wang, Zuoren Yu, Marco Crosariol, Ratna K. Vadlamudi, Monica Mann, Peter Tompa, Agnes Tantos, Richard G. Pestell. Specific epigenetic reader role for cyclin D1. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-079. doi:10.1158/1538-7445.AM2015-LB-079
Abstract LB-093: Activation of the FGFR1 signaling pathway by the epstein-barr virus-encoded LMP1 promotes aerobic glycolysis and transformation of human nasopharyngeal epithelial cells
Authors: Lo Kwok Fung , Dawson Christopher W , Young Lawrence S , Lo Kwok Wai
Published: August 2015

Undifferentiated nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) latent infection. The EBV-encoded latent membrane protein 1 (LMP1) oncogene is believed to be important in NPC pathogenesis by virtue of its ability to activate multiple cell signaling pathways to induce proliferation, transformation, angiogenesis and invasiveness as well as modulation of energy metabolism. In this study, we report that LMP1 increases cell uptake of glucose and glutamine, enhances LDHA activity and lactate production, but reduces pyruvate kinase activity and pyruvate concentration. LMP1 also increases the phosphorylation of PKM2, LDHA and FGFR1 as well as expression of PDHK1, FGFR1, c-Myc and HIF-1α regardless of oxygen availability. This suggests that LMP1 promotes aerobic glycolysis. In addition to FGFR1, LMP1 also upregulates FGF2, the FGFR1 ligand, setting up a constitutive activation loop of FGFR1 signaling to promote aerobic glycolysis. FGFR1 inhibitors also abolish LMP1-mediated cellular transformation (proliferation and anchorage-independent growth) as well as cell migration and invasion in nasopharyngeal epithelial cells. Immunohistochemical staining revealed that a high level of phosphorylated FGFR1 is common in primary NPC specimens, and that this correlated with the expression of LMP1. Inhibition of FGFR1 activity in NPC cells results in the suppression of cell proliferation and anchorage-independent growth. Our current findings demonstrate that LMP1-mediated FGFR1 activation contributes to growth and transformation of epithelial cells, thereby implicating FGF2/FGFR1 signaling activation in the EBV-driven pathogenesis of NPC.

Citation Format: Kwok Fung Lo, Christopher W Dawson, Lawrence S Young, Kwok Wai Lo. Activation of the FGFR1 signaling pathway by the epstein-barr virus-encoded LMP1 promotes aerobic glycolysis and transformation of human nasopharyngeal epithelial cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-093. doi:10.1158/1538-7445.AM2015-LB-093
Abstract LB-100: Development of novel selective tumor-associated carbonic anhydrase inhibitors as promising anticancer agents
Authors: Alafeefy Ahmed Mahmoud , Atia Sabry , Ahmad Sheikh , Zoheir Khairy , Ashour Abdelkader , Kumar Ashok
Published: August 2015

The molecular complexity of cancers and therapy-related side effects often limit efficacy of numerous anti-tumor therapies, and warrant development of new drugs that are specific for certain molecular targets while minimizing the off-target effects. We previously have synthesized a series of benzene-sulfonamides incorporating cyanoacrylamide moieties (tyrphostine analogues), and investigated such new compounds as inhibitors of the metalloenzyme carbonic anhydrase (CA). Specifically, we determined the inhibitory activity of such novel compounds against the cytosolic, house-keeping human (h) isoforms hCA I and II, as well as the transmembrane, tumor-associated ones CA IX and XII. Four compounds, namely CS2, CS6, CS8 and CS13, were very potent CA IX/XII inhibitors whereas they were much less effective as inhibitors of CA I and II. To determine whether these selective tumor-associated CA inhibitors exert antitumor activity, we examined their antiproliferative activity against the human medulloblastoma Daoy cell line, human hepatoma HepG2 cell line and the human epithelial cervical cancer Hela cell line. Compounds CS6 and CS13 showed significant antiproliferative activity against the three cancer cell lines. Daoy was the most sensitive cell line, and compound CS6 was the most potent one. Remarkably, compound CS6 was more potent against Daoy cells than the multi-targeted kinase inhibitor of BCR-ABL and SRC family kinases, dasatinib, since the former exerted smaller IC50 than that exerted by the latter (4.14 versus 7.28 μg/mL). In addition, flow cytometric Annexin-V/propidium iodide assay results showed that cell death induced by compounds CS6 is mediated, at least in part, by apoptosis. Moreover, CS6 significantly inhibited tyrosine kinase activity in Daoy cells, compared to DMSO-treated (control) cells. Taken together, these data indicate that compound CS6 is a novel multiple cancer pathways inhibitor, and warrants further investigation of its antitumor activity in medulloblastoma and other brain tumors. Currently, compounds CS6 and CS13 are being tested for their inhibitory activity against dihydrofolate reductase and thymidylate synthase.

Citation Format: Ahmed Mahmoud Alafeefy, Sabry Atia, Sheikh Ahmad, Khairy Zoheir, Abdelkader Ashour, Ashok Kumar. Development of novel selective tumor-associated carbonic anhydrase inhibitors as promising anticancer agents. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-100. doi:10.1158/1538-7445.AM2015-LB-100
Abstract LB-107: Targeting ATR using a novel ATR inhibitor AZD6738 in human gastric cancer cells
Authors: Min Ahrum , Im Seock-Ah , Jang Hyemin , Kim Seongyeong , Lee Miso , Kim Jungeun , Lee Kyung-Hun , Han Sae-Won , Kim Tae-Young , Oh Do-Youn , Kim Tae-You , Kim Woo-Ho , Bang Yung-Jue
Published: August 2015

Introduction: The DNA repair system is critical for maintaining genomic integrity. In particular, the homologous recombination (HR) repair pathway, on that repairs DNA double-strand breaks (DSBs), is directly associated with cancer development. Many cancer cells could contain mutations in genes involved in the HR pathway including BRCA1/2, ATM, ATR, and RAD51. ATR can be activated by various types of DNA damage and it initiates DNA damage-induces signaling cascade. As a result, ATR pathway components are considered promising therapeutic targets because ATR inhibition is likely to have greater deleterious effect on cancer cells.

Materials and Methods: The antiproliferative activity of AZD6738 was examined in vitro using a cytotoxic assay, cell cycle analysis, and western blotting. To figure out the action mechanism of AZD6738 in gastric cancer cells, the expression of proteins which participate in DNA repair were investigated. The accumulation of DNA damage was also assessed with a DNA comet assay. These in vitro data were validated in vivo using a human gastric cancer xenograft model.

Results: Human gastric cancer cell lines showed heterogeneous response to AZD6738. In AZD6738 sensitive cells, ATR inhibition leads to the accumulation of unrepaired DSBs due to dysfunctional RAD51 foci formation along with increased caspase 3-dependent cell death and S phase cell cycle arrest. Compared with sensitive cells, the activation of ATM-chk2 signaling pathway under the ATR inhibition was observed in the AZD6738 insensitive cells. It suggests that the activation of ATM-chk2 signal leads to attenuation of AZD6738 sensitivity. Furthermore, AZD6738 significantly suppressed tumor growth with increased apoptosis in vivo.

Conclusion: We evaluated the anti-tumor activity of AZD6738 in gastric cancer in vitro and in vivo model. This is the first study to show that AZD6738 interferes with RAD51-mediated homologous recombination, as well as promotes cell death by inducing S cell cycle arrest and apoptosis in gastric cancer cells. Our findings can help to promote novel treatment strategies using AZD6738 in gastric cancer.

Citation Format: Ahrum Min, Seock-Ah Im, Hyemin Jang, Seongyeong Kim, Miso Lee, Jungeun Kim, Kyung-Hun Lee, Sae-Won Han, Tae-Young Kim, Do-Youn Oh, Tae-You Kim, Woo-Ho Kim, Yung-Jue Bang. Targeting ATR using a novel ATR inhibitor AZD6738 in human gastric cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-107. doi:10.1158/1538-7445.AM2015-LB-107
Abstract LB-132: Adult lineage-restricted CNS progenitors specify distinct glioblastoma subtypes
Authors: Alcantara Llaguno Sheila R. , Wang Zilai , Sun Daochun , Chen Jian , Xu Jing , Kim Euiseok , Hatanpaa Kimmo , Raisanen Jack , Burns Dennis , Johnson Jane , Parada Luis F.
Published: August 2015

A central question in glioblastoma multiforme (GBM) research is the hierarchy of tumor-initiating cells, and its contribution to the malignant phenotype and genomic make-up of GBM. We examine the potential of adult lineage restricted central nervous system (CNS) progenitors to form malignant gliomas. We show that targeting of Nf1,p53 and Pten mutations in adult CNS progenitors but not stem cells gives rise to fully penetrant GBM. We identify two phenotypically and molecularly distinct GBM subtypes that arise from different adult progenitor lineages. Using multiple inducible cre transgenic lines, we demonstrate that murine GBMs are molecularly separable based on the cell of origin. The oligodendrocyte progenitor cell-derived murine tumors have parallels with a subset of human high-grade gliomas with oligodendrocytic component, tumors that have been ascribed better prognosis compared to classic malignant astrocytomas. These studies indicate that two independent sources of GBM-initiating adult progenitors are susceptible to identical mutations and point to the cell of origin as a major determinant of GBM subtype.

Citation Format: Sheila R. Alcantara Llaguno, Zilai Wang, Daochun Sun, Jian Chen, Jing Xu, Euiseok Kim, Kimmo Hatanpaa, Jack Raisanen, Dennis Burns, Jane Johnson, Luis F. Parada. Adult lineage-restricted CNS progenitors specify distinct glioblastoma subtypes. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-132. doi:10.1158/1538-7445.AM2015-LB-132
Abstract LB-161: Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells
Authors: Ju Young Seok , Tubio Jose , Mifsud William , Fu Beiyuan ,   ICGC Prostate Cancer, Bone Cancer, Breast Cancer Working Groups, Yang Fengtang , Campbell Peter , Stratton Michael
Published: August 2015

Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm and the mitochondrial double membrane. Despite these physical barriers we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements and the features of the fusion fragments indicate that non-homologous end joining and/or replication-dependent DNA double strand break repair are the dominant mechanism involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells.

Citation Format: Young Seok Ju, Jose Tubio, William Mifsud, Beiyuan Fu, ICGC Prostate Cancer, Bone Cancer, Breast Cancer Working Groups, Fengtang Yang, Peter Campbell, Michael Stratton. Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-161. doi:10.1158/1538-7445.AM2015-LB-161
Abstract LB-164: Ran Binding Protein 9 (RanBP9) is a novel mediator of cellular DNA damage response in lung cancer cells
Authors: Palmieri Dario , Scarpa Mario , Tessari Anna , Uka Rexhep , Amari Foued , Lee Cindy , Richmond Timothy , Sheetz Tyler , Parvin Jeffrey , Ludwig Thomas , Croce Carlo M. , Coppola Vincenzo
Published: August 2015

Currently, most of the anti-neoplastic treatments for lung cancer patients are based on DNA-damaging cytotoxic therapies such as platinum-containing compounds and radiotherapy. Therefore, a better understanding of the molecular mechanisms involved in the cellular response to genotoxic stresses is required in order to improve the clinical management of lung cancer.

Ran Binding Protein 9 (RanBP9, also known as RanBP-M) is a ubiquitous and evolutionary conserved scaffold protein that shuttles between the nucleus and the cytoplasm, and interacts with many major players in tumor biology. However, its biological functions are not well studied and still debated.

Here, we show that RanBP9 interacts with and is phosphorylated by ATM, one of the apical activators of the DNA damage response (DDR) following DNA Double-Strand Breaks (DSBs). Following ATM-dependent phosphorylation, RanBP9 rapidly accumulates into the nucleus of lung cancer cells. By using three different lung cancer cell lines (A549, H460, and H1299), we found that stable silencing of RanBP9 (ShRanBP9) significantly affects the DDR. In fact, stable ShRanBP9 clones display a delayed and/or reduced activation of key components of the cellular response to Ionizing Radiation (IR), including ATM, Chk2, H2AX-γ and p53. Accordingly, abrogation of RanBP9 expression significantly affected Homology-Directed repair of damaged DNA. On the other hand, stable silencing of RanBP9 results in increased IR-induced senescence and apoptosis.

In summary, here we present evidence that RanBP9 is a novel mediator of the cellular DDR, whose recruitment into the nucleus upon IR is dependent on ATM kinase activity. In turn, nuclear RanBP9 participates to the efficient activation of cellular DDR. On the contrary, its absence hampers the repair of damaged DNA following DSBs, resulting in enhanced lung cancer sensitivity to genotoxic stresses.

Taken together, our findings suggest that targeting RanBP9 might represent a new potential approach to increase sensitivity of lung cancer cells to genotoxic anti-neoplastic treatments.

Citation Format: Dario Palmieri, Mario Scarpa, Anna Tessari, Rexhep Uka, Foued Amari, Cindy Lee, Timothy Richmond, Tyler Sheetz, Jeffrey Parvin, Thomas Ludwig, Carlo M. Croce, Vincenzo Coppola. Ran Binding Protein 9 (RanBP9) is a novel mediator of cellular DNA damage response in lung cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-164. doi:10.1158/1538-7445.AM2015-LB-164
Abstract LB-167: The role of Sirt1 in tumorigenesis
Authors: Ren Natalie Shunxiang
Published: August 2015

SIRT1 is a highly conserved NAD+-dependent protein deacetylase. Homologs of SIRT1 in lower model organisms are able to delay the aging process in response to nutrients. Although the SIRT1 protein deacetylase activities have been shown to regulate numerous transcription factors and co-factors (eg. PCG-1, p53), modulate cellular metabolism and promote cell survival and stress resistance, the role of SIRT1 in cancer metabolism, growth and survival is still highly controversial. Colorectal cancer is one of the most common malignancies in the world. However, there are few studies revealing the clinical relevance of the expression of SIRT1 and related markers in colorectal cancer with human tissue. Although recent studies have revealed that SIRT1 plays an important role in colorectal tumorigenesis, the exact role of SIRT1 in colorectal tumorigenesis is still controversial. Thus far, our data demonstrates that knocking out SIRT1 induces the acetylation of p53 and alters cellular metabolism. Deletion of SIRT1 in MEFs decreases glutamine uptake and increases cell death by trigging apoptosis pathways. As a result, SIRT1 KO MEFs fails to induce tumors in a xenograft model in nude mice. We have recently generated a mouse colon cancer model on SIRT1 intestine knockout mouse strains (SIRT1 iKO) and discovered that SIRT1 iKO mice display a reduced rate of tumorigenesis. To further confirm the role of SIRT1 on colon cancer, we propose to analyze the association of SIRT1 expression and the prognosis in colorectal cancer.

Citation Format: Natalie Shunxiang Ren. The role of Sirt1 in tumorigenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-167. doi:10.1158/1538-7445.AM2015-LB-167
Abstract LB-176: Identification of mutations in histone modification genes in Hodgkin lymphoma
Authors: Liang Winnie S. , Salhia Bodour , Helland Adrienne , Sekar Shobana , Garrido-Laguna Ignacio , Fanale Michelle , Oki Yasuhiro , Westin Jason R. , Davis R. Eric , Meric-Bernstam Funda , Janku Filip
Published: August 2015

Background: Understanding genetic aberrations in cancer has led to discoveries of new targets for cancer therapies. The genomic landscape of Hodgkin lymphoma (HL) has not been fully described.

Methods: We performed targeted next generation sequencing (NGS) on 13 archival tumor samples from patients with relapsed/refractory HL treated in the phase I clinical trial with the mTOR inhibitor sirolimus and the HDAC inhibitor vorinostat using the Foundation One NGS panel (Foundation One, Foundation Medicine, MA). Subsequently, we performed whole exome and RNA sequencing on pre- and post-treatment tumor biopsies from 3 patients treated in the same study.

Results: In archival samples from 13 HL patients tested using the Foundation One panel, a total of 21 gene aberrations across 13 genes were detected; 12 (92%) tumor samples had mutations in genes involved in immune response, apoptosis, and cell proliferation pathways (SOCS1, PIM1, MCL1, BRCA1, TP53, TNFAIP3, B2M, XPO1, BCL6) and 7 (54%) samples had mutations in DNA repair pathway genes (TP53, BRCA1, ATM, PIM1). In addition, whole exome and RNA sequencing of pre- and post-treatment tumor and germline (peripheral blood mononuclear cells) samples from HL patients treated with sirolimus and vorinostat (complete response, n = 1; stable disease for 3 months, n = 1; progression, n = 1) identified missense point mutations in key histone modification genes not included in the Foundation One panel, including HDAC8 (histone deacetylase 8), JMJD1C (jumonji domain containing 1C), and KDM2A (lysine-specific demethylase 2A) in the patient who progressed on therapy. This same patient additionally had a B2M missense mutation (M1R) affecting the same residue as the B2M event (M1I) identified in the archival cohort. Furthermore, there was a trend towards increased burden of molecular aberrations (median, 67 aberrations) in pre- and post- tumor samples of the patient who progressed compared to the other 2 patients (median, 6 aberrations), who did not progress.

Conclusion: While analysis of additional HL specimens is needed, our data suggest that testing for molecular aberrations with NGS is feasible and somatic missense mutations in HDAC8, JMJD1C, and KDM2A may be associated with lack of clinical response to sirolimus and vorinostat.

Citation Format: Winnie S. Liang, Bodour Salhia, Adrienne Helland, Shobana Sekar, Ignacio Garrido-Laguna, Michelle Fanale, Yasuhiro Oki, Jason R. Westin, R. Eric Davis, Funda Meric-Bernstam, Filip Janku. Identification of mutations in histone modification genes in Hodgkin lymphoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-176. doi:10.1158/1538-7445.AM2015-LB-176
Abstract LB-188: Epigenome-wide study in prediagnostic samples from the European Prospective Investigation into Nutrition and Cancer (EPIC-Italy) cohort: Differentially methylated microRNAs in subjects who developed breast cancer
Authors: Naccarati Alessio , Polidoro Silvia , Fiorito Giovanni , Cordero Francesca , Ferrero Giulio , Campanella Gianluca , Sacerdote Carlotta , Mattiello Amalia , Panico Salvatore , Masala Giovanna , Palli Domenico , Agnoli Claudia , Krogh Vittorio , Frasca Graziella , Tumino Rosario , Vineis Paolo
Published: August 2015

The crosstalk between microRNAs (miRNAs) and other epigenetic factors may lead to novel hypotheses about carcinogenesis identifying new targets for research. Since a single miRNA can regulate multiple downstream target genes, its altered expression may potentially be a very sensitive biomarker to detect early malignant transformation and improve diagnosis and prognosis. In the current study, we used a genome-wide approach to test the hypothesis that altered methylation of miRNA encoding genes may be related to dietary and lifestyle factors and may be associated with deregulated mature miRNA expression ultimately leading to cancer.

In a case-control study nested in a prospective cohort (EPIC-Italy), we analysed DNA methylation levels of miRNA encoding genes (2,191 CpG probes related to 517 genes) that are present in the Infinium Human Methylation450 BeadChip array in prediagnostic peripheral white blood cells of subjects who developed Colorectal Cancer (CRC, n = 159) and Breast Cancer (BC, n = 166) and matched subjects who remained clinically healthy. In the whole cohort, several differentially methylated miRNA genes were observed in association with age, sex, smoking habits and physical activity. Interestingly, in the case-control study, 8 differentially methylated miRNAs were identified in subjects who went on to develop BC (miR-328, miR-675, miR-1307, miR-1286, miR-1275, miR-1910, miR-24-1, and miR-548a-1; all Bonferroni-adjusted p-values < 0.05). No significant associations were found with CRC.

Assuming that altered methylation of miRNAs may be present before diagnosis, it may represent a biomarker for early detection or risk of cancer and may help to understand the cascade of events preceding tumour onset.

Citation Format: Alessio Naccarati, Silvia Polidoro, Giovanni Fiorito, Francesca Cordero, Giulio Ferrero, Gianluca Campanella, Carlotta Sacerdote, Amalia Mattiello, Salvatore Panico, Giovanna Masala, Domenico Palli, Claudia Agnoli, Vittorio Krogh, Graziella Frasca, Rosario Tumino, Paolo Vineis. Epigenome-wide study in prediagnostic samples from the European Prospective Investigation into Nutrition and Cancer (EPIC-Italy) cohort: Differentially methylated microRNAs in subjects who developed breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-188. doi:10.1158/1538-7445.AM2015-LB-188
Abstract LB-192: A single catastrophic genomic event is required for the development of osteosarcoma
Authors: Bilke Sven , Meltzer Paul
Published: August 2015

Over sixty years ago, the groundbreaking works by Nordling1, Armitage and Doll2 found a deep connection between the age dependent incidence rates of cancer with elementary mutational processes in cancer. However, their method to estimate the number of driver mutations from the characteristic increase of adult cancer risk with patient age implicitly assumes tissue homeostasis. It can therefore not be used for developmental cancers emerging from growing tissues.

Osteosarcoma (OS), a bone cancer most frequently occurring during adolescence, is one prominent example. Here we combine a model of bone growth and maintenance with somatic mutation theory. Based on age dependent stature3` and morphometric data, we find that our model accurately reproduces epidemiological OS incidence rates4`. We conclude that the OS risk can be explained by the cell cycle rate in the osteoblast lineage. Other risk factors, such as endocrine and paracrine signaling have only a weak, if any, impact. The strict association with the cell cycle rate, as opposed to wall clock time, suggests that environmental factors play no dominant role either. In other words, with few exceptions such as genetic syndromes or unusually strong environmental factors such as radiation in cancer treatment, the OS risk is dominated by pure chance.

We find that the OS incidence rate is strictly proportional to the age dependent cell cycle rate. This result implies that there is only a single rate limiting factor in the etiology of the disease. This result is a remarkable as it suggests that the disease is not necessarily initiated within a stem cell because the Hayflick limit set by telomere shortening can not suppress single-hit-malignancies.

Our results are not only important for a better understanding of the disease and the design of future sequencing efforts. But they also inform development of treatment strategies to reduce the mortality caused by this still deadly disease.

1. Nordling, C. O. C. A New Theory on the Cancer-inducing Mechanism. Br. J. Cancer 7, 68¨C72 (1953).

2. Armitage, P. & Doll, R. The age distribution of cancer and a multi-stage theory of carcinogenesis. Br. J. Cancer VIII, 1¨C12 (1954).

3. CDC Height Data. at

4. Cancer incidence in five continents, vol. I to VIII. CancerBase No. 7. (Lyon: IARC). at

Citation Format: Sven Bilke, Paul Meltzer. A single catastrophic genomic event is required for the development of osteosarcoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-192. doi:10.1158/1538-7445.AM2015-LB-192
Abstract LB-195: Supporting cancer epidemiology research through cohort registration: NCI's cancer epidemiology cohort descriptive database
Authors: Lane Crystal , Kennedy Amy , Brotzman Michelle , Miller Amy , Lai Gabriel , Khoury Muin , Seminara Daniela
Published: August 2015

Carefully designed observational studies have recognized value and efficiency in determining associations between exposures and outcomes and thereby evaluating health care. In particular, longitudinal cohorts have served as an essential research infrastructure for studies producing a wealth of information on disease etiology and prevention. The onset of the ‘omics age has compelled many funding agencies to foster collaborations across existing large cohorts, to design studies large enough to address the dynamic and interactive nature of the factors underlying common diseases.

There is currently an ongoing discussion in the scientific community of whether or not observational studies should be registered, and if so what the scientific and practical benefits of the implementation would be. Cohorts are the backbone of observational studies, and making their descriptive data rapidly available to the scientific community through a centralized descriptive database is the first step necessary to increase transparency, scientific quality and collaboration.

We have created the Cancer Epidemiology Descriptive Cohort Database (CEDCD) to assist the research community in identifying and accessing population resources, with the intention of maximizing the efficiency and effectiveness of existing cohorts and targeting areas of needs when establishing new ones. This public database includes many details, including cohort profiles and investigator contact information, study design and eligibility criteria, enrollment numbers broken down by race/ethnicity/gender, number and types of biospecimens and cancer diagnoses, policies, protocols and questionnaires, publications and funded research projects, and links to the cohort websites and related resources. The initial phase of this database will include cohorts focusing on cancer as their primary outcome, specifically those funded by NCI's EGRP and members of NCI's Cohort Consortium that have more than 10,000 subjects enrolled (healthy individuals or cancer survivors).

The CEDCD is serving as a model for a parallel world-wide cohort registration project. The creation of a querable web-based tools for direct population of this descriptive database, which will provide a valuable resource for the scientific community in the planning and design of large, cooperative observational studies is in progress.

Citation Format: Crystal Lane, Amy Kennedy, Michelle Brotzman, Amy Miller, Gabriel Lai, Muin Khoury, Daniela Seminara. Supporting cancer epidemiology research through cohort registration: NCI's cancer epidemiology cohort descriptive database. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-195. doi:10.1158/1538-7445.AM2015-LB-195
Abstract LB-197: Circulating rare cells enable highly efficient cancer detection
Authors: Obermayr Eva , Maritschnegg Elisabeth , Speiser Paul , Singer Christian , Schuster Eva M. , Danzinger Sabine , Pecha Nina , Zeillinger Robert
Published: August 2015

Objectives of the study

We intended to develop a protocol combining a novel micro-fluidic enrichment technology and RT-qPCR for the molecular analysis of CTCs. Recently we identified CTC-specific mRNA markers allowing CTC detection in 29% of breast cancer patients and in 24.5% of ovarian cancer patients at diagnosis. However, the detection of cancer cells was hampered by the large number of contaminating leukocytes. The necessary use of cut-off values for positivity reduced the specificity of the down-stream PCR assay. By improving the purity of cancer cells and PCR analysis we sought to increase both sensitivity and specificity of the diagnostic procedure.

Methodology

For reducing the blood sample volume (up to 20ml) density gradient centrifugation was used when needed. The samples were passed through a micro-fluidic disposable cassette, which captures tumor cells based on their less deformable nature and larger size compared to blood cells. Lysis of the captured cells was done directly in the cassette and total RNA was extracted. After a cDNA pre-amplification step gene expression levels of leukocyte-specific and CTC-related markers were measured using RT-qPCR. The efficiency of the combined protocol was assessed in blood samples taken from patients with primary and recurrent malignant diseases.

Results

7 out of 13 pre-selected RNA markers were not detectable in blood samples from 11 healthy volunteers. In cancer patients we observed measurable gene expression of at least one out of these 7 RNA markers. 5 out of 5 breast cancer (primary disease: N = 1; metastatic: N = 4), 9 out of 10 primary and 4 out of 8 relapsed ovarian cancer patients were classified correctly by the test. The most striking finding is the detection rate of 90% for primary ovarian cancer at a specificity of 100%.

Conclusions

The enrichment of rare cells from blood samples using micro-fluidics results in a highly pure cell population. This enables the application of extremely sensitive methods, like RT-qPCR to specifically detect rare events. By combining a novel micro-fluidic cell enrichment and molecular analysis we have taken a major step forward, which allows the implementation of ′liquid biopsies′ in cancer detection studies and as a companion diagnostic in clinical trials.

Citation Format: Eva Obermayr, Elisabeth Maritschnegg, Paul Speiser, Christian Singer, Eva M. Schuster, Sabine Danzinger, Nina Pecha, Robert Zeillinger. Circulating rare cells enable highly efficient cancer detection. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-197. doi:10.1158/1538-7445.AM2015-LB-197