bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 494: Frequent NRG1 genomic rearrangements in invasive mucinous adenocarcinoma from caucasian patients
Authors: Trombetta Domenico , Rossi Giulio , Sparaneo Angelo , Fabrizio Federico P. , Manzorra Maria C. , Maiello Evaristo , Fazio Vito M. , Graziano Paolo , Muscarella Lucia A.
Published: July 2017

Invasive Mucinous Adenocarcinoma (IMA) accounts for 2-5% of lung adenocarcinomas and it is associated with an unfavorable clinical course, mainly due to lack of effective treatments. Current knowledge of the molecular alterations involved in IMAs is limited. Recently, the NRG1 genomic rearrangement was identified as a subtype-specific molecular feature of Asiatic IMA cohorts since it acts as a strong inductor of the aberrant tyrosine kinase activity of ErbB2/ErbB3 heterodimers through PI3K–AKT and MAPK cellular cascades.

In light of these premises we explored the occurrence and frequency of NRG1 fusions in a cohort of 90 Formalin Fixed Paraffin Embedded (FFPE) lung adenocarcinoma from Caucasian patients (35 non-IMAs and 55 IMAs) by performing FISH analysis to study the NRG1 genomic region (β-III isoform, chr 8p12). In total, 16 out of 55 (29%) IMAs showed NRG1 rearrangements, whereas in non-mucinous lung adenocarcinoma group it was found with a frequency of 3% (1/35). The functional effect of the genomic rearrangement was confirmed by RT-PCR and sequencing in three cases with available RNA, where NRG1-CD74 fusion transcripts were identified. An aberrant expression of pErbB3 was also observed in these three NRG1 rearranged cases by performing immunohistochemistry analysis, thus confirming the ErbB3 cascade activation.

Our results strongly confirm NRG1 rearrangements as potentially treatable oncogenic driver alterations associated with a definite lung adenocarcinoma subtype in Caucasian population and support a clear molecular rationale to novel therapeutic opportunity for these aggressive tumors.

Note: This abstract was not presented at the meeting.

Citation Format: Domenico Trombetta, Giulio Rossi, Angelo Sparaneo, Federico P. Fabrizio, Maria C. Manzorra, Evaristo Maiello, Vito M. Fazio, Paolo Graziano, Lucia A. Muscarella. Frequent NRG1 genomic rearrangements in invasive mucinous adenocarcinoma from caucasian patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 494. doi:10.1158/1538-7445.AM2017-494
Abstract 4944: Modeling tumor dormancy by using EMT lineage tracing under chemotherapy
Authors: Lopez Jay , Bednarczyk Robert , Altorki Nasser , Mittal Vivek , Gao Dingcheng
Published: July 2017

Tumor dormancy and recurrence after initial effective treatment arose as one of most challenging questions in cancer research. Up to now, there is still no established animal model of tumor dormancy, which significantly hurdles our exploration in this field. In an effort to trace the phenotypic changes of metastatic tumor cells in vivo, we found that the dormant tumor cells were derived through a mechanism of epithelial to mesenchymal transition (EMT). We established an EMT lineage tracing model in triple transgenic mice (Tri-MMTV) carrying Fsp1-cre, Rosa26-RFP-GFP and MMTV-PyMT alleles. Tumor cells from these mice are able to switch their fluorescent marker from RFP to GFP due to the specific activation of CRE recombinase during the EMT process. Using this EMT lineage tracing model, we confirmed that within a predominantly epithelial primary tumor, a small portion of tumor cells undergo EMT. Strikingly, lung metastases were mainly derived from non-EMT tumor cells maintaining their epithelial phenotype. However, under chemotherapy condition, EMT cells significantly contributed to recurrent lung metastasis. The EMT tumor cells survived the chemotherapy due to reduced proliferation and apoptotic tolerance, which are common characters of dormant tumor cells. More interestingly, the GFP+ EMT tumor cells reversed back to epithelial phenotype through mesenchymal to epithelial transition (MET) and formed recurrent metastatic lesions in the lung. These results suggest that our EMT lineage tracing model may provide a unique tool to study tumor dormancy and recurrence. The EMT process may represent a major mechanism for tumor dormancy under chemotherapy condition, while MET is a driving mechanism for tumor recurrence.

Citation Format: Jay Lopez, Robert Bednarczyk, Nasser Altorki, Vivek Mittal, Dingcheng Gao. Modeling tumor dormancy by using EMT lineage tracing under chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4944. doi:10.1158/1538-7445.AM2017-4944
Abstract 4945: Axl-hi DTCs in the bone marrow of a genetically engineered mouse model of prostate cancer exhibit decreased proliferation
Authors: Axelrod Haley D. , Valkenburg Kenneth C. , Simons Brian W. , Pienta Kenneth J.
Published: July 2017

The majority of prostate cancer (PCa) deaths are attributed to bone metastases, which may not arise until years after the primary tumor has been removed. Disseminated tumor cells (DTCs) have been shown to already be present in the bone marrow of patients at the time of prostatectomy, and it is thought that they undergo a period of dormancy, allowing them to remain undetected for years before manifesting into clinically detectable metastases. It is not known what allows PCa DTCs to undergo and persist in this dormant state, but it is likely that factors in the bone marrow niche play an essential role. Previously our group has shown that one of these niche factors, Gas6, can regulate growth of PCa cells. The growth restraining effects of Gas6 on PCa cells is likely mediated through the tyrosine kinase receptor Axl, whose expression was found to be increased on dormant DTCs compared to proliferating metastases in a xenograft mouse model. Here, we utilized the TRAMP model, a genetically engineered mouse model of spontaneous PCa progression, to compare the frequency of Axl-hi and Axl-low bone marrow DTCs that are proliferating versus non-proliferating. Further, we also compared Axl expression and proliferation in matched primary tumors. To investigate the functional significance of Gas6/Axl signaling in mediating PCa dormancy, we have generated Axl knockout PCa cells to test the requirement of Axl in maintaining dormancy, and Axl overexpressing PCa cells to test the sufficiency of Axl in mediating dormancy. Determining the role of Axl and any other regulatory mechanisms of PCa DTC dormancy will be crucial in efforts to prevent lethal and incurable metastasis.

Citation Format: Haley D. Axelrod, Kenneth C. Valkenburg, Brian W. Simons, Kenneth J. Pienta. Axl-hi DTCs in the bone marrow of a genetically engineered mouse model of prostate cancer exhibit decreased proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4945. doi:10.1158/1538-7445.AM2017-4945
Abstract 4947: Her2 inhibition and dormant cell metabolism
Authors: Fox Douglas B. , Alvarez James V.
Published: July 2017

Breast cancer is the most diagnosed cancer in women in the United States, and despite improved prognosis resulting from targeted therapies, tumors commonly re-emerge upon development of therapeutic resistance. In order to overcome this, it is critical to explore the cellular pathways that change in tumors following treatment. While many mechanisms of resistance to targeted therapies have been identified, the metabolic changes that occur following treatment have not been well defined. We believe that these changes may offer a general therapeutic target. Using a doxycycline-inducible Her2 mouse model of breast cancer, we are exploring the molecular and cellular consequences Her2 inhibition. Using in vitro mammosphere cultures derived from these mice, we showed that Her2 loss quickly downregulates ERK and Akt signaling. There is a corresponding decrease in proliferation, and apoptosis is induced in 25-50% of cells. However, a population of cells survives Her2 withdrawal and remains dormant for upwards of one month. We are using these models to study how metabolic pathways are rewired following Her2 inhibition, and we believe that the metabolic pathways adapted upon Her2 inhibition may represent targetable vulnerabilities.

Note: This abstract was not presented at the meeting.

Citation Format: Douglas B. Fox, James V. Alvarez. Her2 inhibition and dormant cell metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4947. doi:10.1158/1538-7445.AM2017-4947
Abstract 495: Somatic copy number variants detection using the NEBNext Direct target enrichment method
Authors: Patel Kruti M. , Bowman Sarah K. , Henig Noa , Emerman Amy B. , Barry Andrew , Elfe Charles , Adams Scott , Russello Salvatore , Davis Ted , Hendrickson Cynthia L.
Published: July 2017

Variations in copy number are the most common type of DNA structural variations. Many of these alterations are associated with disease or indicate disease susceptibility. Detection of copy number variants (CNVs) for clinical applications requires efficient, fast and cost effective methods.

Here we describe the use of the NEBNext Direct® hybridization-based target enrichment method to identify somatic CNVs with high sensitivity. This approach begins with target enrichment followed by enzymatic digestion of off-target sequences and ligation of adapters that contain unique molecular identifiers (UMIs). The UMIs enhance the identification of duplicate reads and further increase the final number of on-target reads used for variant detection.

We used a cell line known to contain a deletion in the CDKN2A gene and spiked DNA isolated from the cell line into a HapMap DNA sample that contains full diploid copies of CDKN2A. We were able to detect the gene deletion as a somatic CNV in a dose dependent manner with high sensitivity. Thus, we demonstrate that the NEBNext Direct approach is an efficient technique to detect somatic CNVs of high and low frequencies.

Citation Format: Kruti M. Patel, Sarah K. Bowman, Noa Henig, Amy B. Emerman, Andrew Barry, Charles Elfe, Scott Adams, Salvatore Russello, Ted Davis, Cynthia L. Hendrickson. Somatic copy number variants detection using the NEBNext Direct target enrichment method [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 495. doi:10.1158/1538-7445.AM2017-495
Abstract 4956: Transcriptome-wide association study identifies new prostate cancer susceptibility genes in the OncoArray data
Authors: Mancuso Nicholas , Zheng Wei , Penney Kathryn ,   The PRACTICAL Consortium, Kote-Jarai Zsofia , Haiman Christopher , Gayther Simon , Freedman Matthew , Pasaniuc Bogdan
Published: July 2017

Genome-wide association studies (GWAS) have identified over 150 genomic regions harboring risk variants for prostate cancer which explain one third of all familial risk. However, with some notable exceptions, the causal variants and target susceptibility genes at these risk loci have yet to be identified. Recent work has shown a strong overlap between loci associated with gene expression levels (eQTLs) in prostate tissue and GWAS loci, which suggests that the causal mechanism at a significant proportion of risk loci includes causal alleles that regulate expression levels of nearby susceptibility genes. While overlapping eQTLs with GWAS is a powerful method to prioritize susceptibility genes, it is often the case that multiple eQTLs co-localize at the GWAS risk region (due to linkage disequilibrium (LD) and correlations across transcript levels). This prohibits the identification of the true susceptibility gene as opposed to spurious co-localization at the same locus.

We recently leveraged gene expression imputation to perform transcriptome-wide association studies (TWAS) as a principled approach to measure the strength of association between gene expression and disease status. Here, we use imputed expression to identify new susceptibility genes for prostate cancer in the OncoArray GWAS data. We integrate gene expression data from more than 44 tissues across ~4,000 individuals with GWAS of prostate cancer from the OncoArray in ~140,000 individuals. Our approach identified 118 susceptibility genes for prostate cancer that reside in 90 independent loci across the genome. Of these, we report 7 genes located more than 0.5 Megabases away from any previously reported GWAS loci for prostate cancer, thus providing new risk loci. Second, we use TWAS to investigate genes previously reported as susceptibility genes for prostate cancer through overlaps of eQTL and GWAS. We find 36 (out of 86 previously reported genes) to be significant in TWAS. Overall, our findings highlight the power of integrating gene expression data with GWAS and provide testable hypotheses for future functional validation of prostate cancer risk.

Citation Format: Nicholas Mancuso, Wei Zheng, Kathryn Penney, The PRACTICAL Consortium, Zsofia Kote-Jarai, Christopher Haiman, Simon Gayther, Matthew Freedman, Bogdan Pasaniuc. Transcriptome-wide association study identifies new prostate cancer susceptibility genes in the OncoArray data [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4956. doi:10.1158/1538-7445.AM2017-4956
Abstract 4969: Impaired PARP1 DNA repair defines chemosensitivity in IDH1 mutant cell
Authors: Lu Yanxin , Liu Yang , Su Yu-Ting , Bautista Wendy , Gilbert Mark R. , Wu Jing , Yang Chunzhang
Published: July 2017

INTRODUCTION: Mutations in isocitrate dehydrogenase (IDH1/2) are the most prevalent genetic abnormalities in lower grade gliomas. The presence of IDH mutations in glioma are prognostic for better clinical outcomes with longer patient survival, and greater sensitivity to chemotherapy. In the present study, we explore the molecular mechanisms that determine the chemosensitivity in IDH1-mutated glioma cells, and seek a potential therapeutic strategy by targeting DNA repair pathway in IDH1-mutated cells.

METHODS: We established IDH1-mutated cell lines by introducing pathogenic IDH1 mutations into glioma cells via lentivirus. We confirmed the metabolic deficiency and enhanced chemosensitivity in cells expressing IDH1 mutant enzyme. Further, we measured the intracellular level of nicotinamide adenine dinucleotide (NAD+), Poly (ADP-ribose) polymerase (PARP)-associated DNA repair and DNA damage level in these cells when treated with temozolomide (TMZ). Moreover, we evaluated a PARP inhibitor Olaparib and its synergic effect on TMZ-associated cytotoxicity.

RESULTS: Our results show that the IDH1-mutated cells are more vulnerable to chemotherapy. TMZ treatment resulted in over 20-fold increase of cell death in IDH1-mutated cells compared with their wild type counterpart. IDH1-mutated cells exhibited an over 1.3-fold increase in DNA damage and over 1.42-fold increase in cellular apoptosis under TMZ treatment. Accordingly, IDH1-mutated cells produced 83.8% less poly (ADP-ribose) polymer (pADPR), an important substrate for PARP-associated DNA repair, during TMZ treatment; suggesting their incompetence to maintain genomic integrity due to decreased availability of NAD+. Targeting the PARP-associated DNA repair pathway using Olaparib remarkably potentiated TMZ-induced cytotoxic effects by 2.16 fold in IDH1 mutated cells.

CONCLUSION: Our findings demonstrate that metabolic defects in IDH1-mutated cells affect PARP-associated DNA repair pathway via NAD+ depletion, and therefore prompt the sensitivity to chemotherapies. Targeting PARP-associated DNA repair pathway may represent a novel therapeutic avenue for IDH1-mutated gliomas.

Citation Format: Yanxin Lu, Yang Liu, Yu-Ting Su, Wendy Bautista, Mark R. Gilbert, Jing Wu, Chunzhang Yang. Impaired PARP1 DNA repair defines chemosensitivity in IDH1 mutant cell [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4969. doi:10.1158/1538-7445.AM2017-4969
Abstract 4975: A small molecule pan Id protein antagonist shows strong antitumor activity
Authors: Wojnarowicz Paulina M. , Desai Bina , Chin Yvette , Lee Sang Bae , Garcia-Cao Marta , Ouerfelli Ouathek , Yang Guangli , Xu Sijia , Goldgur Yehuda , Miller Meredith A. , Chaudhary Jaideep , Garland William A. , Albanese Steven K. , Soni Rajesh , Philip John , Norton Larry , Rosen Neal , Hendrickson Ronald C. , Zhou Xi Kathy , Iavarone Antonio , Dannenberg Andrew J. , Chodera John D. , Pavletich Nikola , Lasorella Anna , Benezra Robert
Published: July 2017

The Id family of helix-loop-helix (HLH) proteins, Id1, Id2, Id3 and Id4, play a critical role in inhibiting differentiation during mammalian embryogenesis. They function in part by sequestering ubiquitously expressed E protein bHLH transcription factors via direct protein-protein interactions. Various Id proteins are re-expressed in adults in a number of pathologic states including cancer and diseases of the vasculature, where their activity has been shown to be essential for disease progression. The present study describes the solving of the Id1-E47 dimer crystal structure and subsequent development and characterization of a small molecule antagonist of the Id protein family, AGX51. AGX51 was identified in an in silico screen for compounds that could bind a hydrophobic crevice adjacent to the loop region of Id1, highly conserved in the Id family. AGX51 inhibits the endogenous Id1-E protein interaction leading to the degradation of Id1 via ubiquitin-mediated proteolysis. The stability of all four members of the Id family are antagonized by AGX51 leading to a G0-G1 arrest and profound inhibition of viability with no acquired resistance observed in multiple cell lines after continuous exposure to the compound. Administration of AGX51 is well tolerated in mice and phenocopies genetic loss of Id expression analyses: suppression of breast cancer metastases to the lung associated with a reduced mesenchymal-to-epithelial transition, perturbation of the vasculature within the primary tumor, and growth regression of paclitaxel resistant breast tumors in combination with paclitaxel therapy. These studies identify a novel, first-in-class compound capable of antagonizing the activity of a protein family formerly considered undruggable and point to the possible utility of AGX51 in the management of multiple disease processes in patients.

Citation Format: Paulina M. Wojnarowicz, Bina Desai, Yvette Chin, Sang Bae Lee, Marta Garcia-Cao, Ouathek Ouerfelli, Guangli Yang, Sijia Xu, Yehuda Goldgur, Meredith A. Miller, Jaideep Chaudhary, William A. Garland, Steven K. Albanese, Rajesh Soni, John Philip, Larry Norton, Neal Rosen, Ronald C. Hendrickson, Xi Kathy Zhou, Antonio Iavarone, Andrew J. Dannenberg, John D. Chodera, Nikola Pavletich, Anna Lasorella, Robert Benezra. A small molecule pan Id protein antagonist shows strong antitumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4975. doi:10.1158/1538-7445.AM2017-4975
Abstract 498: Attenuation of polycyclic aromatic hydrocarbon (PAH)-mediated pulmonary carcinogenesis in mice by omega-3-fatty acids
Authors: Moorthy Bhagavatula , Jiang Weiwu , Wang Lihua , Kondraganti Sudha R. , Zhou Guodong
Published: July 2017

3-Methylcholanthrene (MC) and benzo[a]pyrene (BP) are potent polycyclic aromatic hydrocarbons (PAHs) carcinogens. PAHs are present in cigarette smoke, diesel exhausts, and charcoal broiled meats, etc. Cytochrome P450 (CYP) 1A/1B1 enzymes play key roles in the activation of PAHs to carcinogenic metabolites, which initiate carcinogenesis by binding covalently to DNA, and the adducts, if not repaired, could lead to tumorigenesis. In this study we tested the hypothesis that pre-treatment of mice with omega-3-fatty acids, i.e. [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) will lead to attenuation of PAH-mediated pulmonary DNA adduct formation and pulmonary tumorigenesis. Twelve week old male and female A/J mice received EPA (60 mg/kg) and DHA (40 mg/kg) from day 1 to day 24. Control mice were treated with vehicle corn oil. On day 3, mice were treated with BP (40 µmol/kg) or 3-methylcholanthrene (MC, 40 µmol/kg) by i.p. In the short-term experiment (DNA adduct studies), 3-5 mice from each group were terminated at day 10 (7 days after BP or MC treatment). EPA/DHA significantly suppressed formation of BP-DNA and MC-DNA adducts in lung and liver of both male and female mice. In the long-term experiment (tumor studies), 8 mice for each group continued to receive EPA/DHA twice per week till end of experiment (16 weeks). Pulmonary tumor incidence and multiplicity was significantly suppressed in mice given EPA+DHA, compared to those given the PAHs, BP or MC alone. These studies suggest that the omega 3-fatty acids could be developed as novel candidates for the prevention of PAH-mediated lung cancers in humans.

Citation Format: Bhagavatula Moorthy, Weiwu Jiang, Lihua Wang, Sudha R. Kondraganti, Guodong Zhou. Attenuation of polycyclic aromatic hydrocarbon (PAH)-mediated pulmonary carcinogenesis in mice by omega-3-fatty acids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 498. doi:10.1158/1538-7445.AM2017-498
Abstract 4983: T cells expressing chimeric PD1 receptors that contain a Dap10 costimulatory domain are a potential treatment for multiple types of cancer
Authors: Deal Kelsey , Nylen Emily , Barber Amorette E.
Published: July 2017

Adoptive transfer of tumor-reactive T cells is a promising anti-tumor therapy for many cancers. To enhance tumor recognition by T cells, chimeric antigen receptors (CAR) consisting of signaling domains fused to receptors that recognize tumor antigens can be created and expressed in T cells. One receptor that is a prospective target for a new chimeric antigen receptor is PD1 because the ligands for the PD1 receptor are expressed on many cancer types. Therefore we developed a murine chimeric PD1 receptor (chPD1) consisting of the PD1 receptor extracellular ligand recognition domain and the activation domain of CD3 zeta. In addition, current chimeric antigen receptor therapies utilize various costimulatory domains to enhance anti-tumor efficacy. Therefore, we also compared the inclusion of CD28, Dap10, 41BB, GITR, ICOS, or OX40 costimulatory domains in our chPD1 receptor to determine which costimulatory domain induced optimal anti-tumor immunity. To determine if this novel CAR could potentially target a wide variety of tumors, the anti-tumor efficacy of chPD1 T cells against murine lymphoma, melanoma, kidney, pancreatic, liver, and colon cancer cell lines was measured. Of the ten cell lines tested, all expressed PD1 ligands on their cell surface, making them potential targets for chPD1 T cells. Regardless of the costimulatory domain in the CAR, all of the chPD1 T cells induced similar levels of T cell proliferation and tumor cell lysis. However, differences were observed in the cytokine secretion profiles depending on which costimulatory receptor was included in the CAR. While most of the chPD1 T cell receptor combinations secreted both pro-inflammatory (IFNγ, TNFα, IL-2, GM-CSF, IL-17, and IL-21) and anti-inflammatory cytokines (IL-10 and IL-5) as determined by ELISA and LegendPlex analysis, chPD1 T cells containing a Dap10 costimulatory domain secreted high levels of proinflammatory cytokines, but did not secrete a significant amount of anti-inflammatory cytokines. Therefore, adoptive transfer of chPD1 T cells could be a novel therapeutic strategy to treat multiple types of cancer and inclusion of the Dap10 costimulatory domain in chimeric antigen receptors may induce a preferential cytokine profile for anti-tumor therapies.

Citation Format: Kelsey Deal, Emily Nylen, Amorette E. Barber. T cells expressing chimeric PD1 receptors that contain a Dap10 costimulatory domain are a potential treatment for multiple types of cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4983. doi:10.1158/1538-7445.AM2017-4983
Abstract 4984: BNip3 suppresses hepatocellular carcinoma (HCC) growth by limiting lipogenesis
Authors: Macleod Kay F.
Published: July 2017

BNip3 is a mitochondrial protein that promotes the turnover of mitochondria at the autophagolysosome when nutrient supplies are low. BNip3-null livers exhibit lipid accumulation and develop a phenotype mimicking non-alcoholic steatohepatitis, a known precursor for development of hepatocellular carcinoma (HCC). Additionally, BNip3 is silenced in human HCC and other malignancies and this loss often correlates with more aggressive tumors and worse outcomes. However, the functional significance of BNIP3 loss for growth and progression of HCC has not been determined. We utilized the diethylnitrosamine (DEN)-induced mouse model of HCC to determine how loss of BNip3 affected HCC development in the mouse. Wild type and BNip3-null mice were treated with DEN, and tumor burden (size and number) was assessed at 6, 8, and 10 months of age. We also generated primary HCC cell lines from the tumors arising in BNip3-null mice for in vitro analysis of tumor cell growth and metabolism. We observed that BNip3-null mice had reduced tumor latency and enhanced tumor growth rate in the liver following DEN treatment compared to wild type mice consistent with BNip3 functioning as a tumor suppressor of HCC. Interestingly, tumors arising in BNip3-null mice accumulated increased lipid and qPCR analysis of primary tumors and cell lines revealed increased expression of lipogenesis genes compared to wild type. Treatment with a novel fatty acid synthase inhibitor or re-expression of BNip3 in the BNip3-null HCC cell lines reduced tumor cell growth and lipogenesis, and promoted oxidative metabolism. These results indicate that BNip3 acts as a tumor suppressor in HCC by limiting de novo lipogenesis and suggest that fatty acid synthase inhibitors could be effective therapeutically against BNIP3 deficient HCC in patients.

Citation Format: Kay F. Macleod. BNip3 suppresses hepatocellular carcinoma (HCC) growth by limiting lipogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4984. doi:10.1158/1538-7445.AM2017-4984
Abstract 4996: The m6A hallmark of cancer: RNA demethylase ALKBH5 maintains tumorigenicity of glioblastoma stem-like cells by sustaining FOXM1 expression and cell proliferation
Authors: Zhang Sicong , Zhou Aidong , Bogler Oliver , Majumder Sadhan , Huang Suyun
Published: July 2017

N6-methyladenosine (m6A) is the most prevalent internal modification on mRNA, but its functions in human diseases are poorly understood. The dynamic and reversible m6A modification installed and erased by N6-methyltransferases and demethylases regulates cell fate and gene expression. We show that the m6A demethylase ALKBH5 is highly expressed in patient-derived glioblastoma stem-like cells (GSCs) and informs poor survival of patients with glioblastoma. Silencing ALKBH5 suppresses the proliferation of GSCs in vitro and in vivo. Results of integrated transcriptome and m6A-seq analyses reveal a global change of gene expression enriched in cell cycle and altered expression of select ALKBH5 targets. Among these targets, Ingenuity’s upstream regulator analysis identified FOXM1, an essential transcription factor for GSC proliferation, as a key mediator responsible for the disrupted proliferation program. Using multiple molecular and biochemical approaches, we demonstrate that ALKBH5 binds to and demethylates FOXM1 nascent transcripts. This promotes the interaction of FOXM1 pre-mRNA with HuR, thereby maintaining FOXM1 expression. Further, a long noncoding RNA antisense to the FOXM1 (FOXM1-AS) interacts with ALKBH5 as well as FOXM1 pre-mRNA and promotes their interaction. Depleting ALKBH5 and FOXM1-AS abolishes GSC tumorigenesis through the FOXM1 axis. The vulnerability of GSCs to disruptions in ALKBH5-dependent gene expression suggests that m6A has a central role in tumor development and provides a rationale for therapeutically targeting epitranscriptomic modulators in patients with glioblastoma.

Citation Format: Sicong Zhang, Aidong Zhou, Oliver Bogler, Sadhan Majumder, Suyun Huang. The m6A hallmark of cancer: RNA demethylase ALKBH5 maintains tumorigenicity of glioblastoma stem-like cells by sustaining FOXM1 expression and cell proliferation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4996. doi:10.1158/1538-7445.AM2017-4996
Abstract 4997: Specialized microRNP and translation mechanisms in quiescent cancer cells
Authors: Bukhari Syed I. , Truesdell Samuel S. , Lee Sooncheol , Kollu Swapna , Classon Anthony , Boukhali Myriam , Jain Esha , Mortensen Richard D. , Yanagiya Akiko , Sadreyev Ruslan , Haas Wilhelm , Vasudevan Shobha
Published: July 2017

Quiescence (G0) represents an assortment of reversible, cell cycle-arrested states that are resistant to unfavorable conditions and associated with cancer persistence. G0 involves regulated gene expression with selective mRNA expression and decreased canonical translation. Low mTOR activity in G0 activates the cap complex inhibitor, eIF4EBP, and impairs canonical translation. The alternative translation mechanisms in G0 remain to be uncovered. Our data show that microRNAs, regulatory, non-coding RNAs that target distinct mRNAs to alter gene expression, can associate with alternative complexes and translation factors to regulate specific mRNA translation in G0. One subset of transcripts expressed in G0 includes specific mRNAs recruited by an FXR1a-associated microRNP (microRNA-protein complex) for translation activation in G0 mammalian cells. MicroRNPs predominantly mediate repression and downregulation; however, FXR1a-microRNP lacks conventional microRNP repressors, and instead, contains a specific RNA binding protein isoform, FXR1a. FXR1a promotes translation and is overexpressed and associated with poor prognosis in several cancers. Our data reveal that microRNA-mediated activation requires target mRNAs with unadenylated/ shortened poly(A) tails to avoid the roles of PABP in enhancing microRNA-mediated downregulation and in canonical translation that is impaired in G0. Instead of canonical translation factors that are inhibited by eIF4EBP in G0, we find alternative translation factors—a non-canonical 5’cap binding factor and an eIF4G homolog that interacts with the ribosome—are recruited by the 3’-UTR binding FXR1a-microRNP, and promote specific mRNA translation. Our data show that G0 leukemic cells are chemoresistant and their translation profile is similar to surviving leukemic cells that are isolated after clinical therapy. We find expression of critical cytokines and immune regulators in G0. Significantly, inhibiting these immune regulators in resistant G0 cancer cells reduces their survival and chemoresistance. These data reveal a specialized translation mechanism in G0 cancer cells that promotes specific mRNA translation in these conditions of reduced canonical translation, and is important for chemoresistance.

Citation Format: Syed I. Bukhari, Samuel S. Truesdell, Sooncheol Lee, Swapna Kollu, Anthony Classon, Myriam Boukhali, Esha Jain, Richard D. Mortensen, Akiko Yanagiya, Ruslan Sadreyev, Wilhelm Haas, Shobha Vasudevan. Specialized microRNP and translation mechanisms in quiescent cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4997. doi:10.1158/1538-7445.AM2017-4997
Abstract 5: The effects of SIRT1 inhibitors nicotinamide and Ex-527 on lymphoma cells
Authors: Guardi Manuela , Pistoni Mariaelena , Frazzi Raffaele
Published: July 2017

SIRT1 is a well-known lysine-deacetylase, having both histone and non-histone proteins as molecular targets. SIRT1 may function as a tumor promoter as well as a tumor suppressor in a context-dependent manner. We previously demonstrated that the treatment with resveratrol at concentrations able to induce apoptosis leads to SIRT1 down-regulation in lymphoma cells. Here we look for SIRT1 inhibition in order to investigate the effects on proliferation potential, apoptosis induction and targets modulation at a molecular level. The aim is to study whether SIRT1 inhibition affects cell cycle and proliferation capability of lymphoma cells. Experimental procedures. Diffuse large-B cell lymphoma derived cell line Toledo; human lymphoblastoid cell line GGB #7; SIRT1 inhibitors: nicotinamide (NAM) and Ex-527; cell cycle analysis; caspase-3 activity fluorimetric assay; genotoxicity assay gamma-H2AX; fluorescence-activated cell sorting intracellular staining for acetylated-H4K16 histone. New data. We found that the calculated IC50s for SIRT1 inhibition is 50mM for NAM and 343μM for Ex-527. The treatment with either NAM or Ex-527 leads to cell cycle arrest in both Toledo and GGB#7 cells, although in a different fashion. Namely, NAM causes an S-phase accumulation of Toledo while it leads GGB #7 to G0/G1 phase arrest with a concomitant decrease in S-phase already after 10mM. In both cell lines NAM 50mM induces apoptosis as demonstrated by caspase-3 activation and sub-G1 peak appearance in the cell cycle profiles. Ex-527 causes an accumulation in the S phase of Toledo cells and a decrease of G2/M in GGB#7 cells. No induction of apoptosis at the IC50 concentration was observed in both cell lines. Genotoxicity of the above mentioned treatments was investigated through the quantitation of gamma-H2AX histone released by treated cells. No genotoxic effects have been observed upon the treatments with these two inhibitors even at the concentration where NAM induces apoptosis. In order to correlate the observed changes with SIRT1 inhibition, we studied the acetylated H4K16 histone, a direct target of SIRT1 deacetylation. Our preliminary data indicate that NAM treatment increases the percentage of acetylated H4K16. Conclusions. Lymphoma and lymphoblastoid cells are affected by SIRT1 inhibition. NAM and Ex-527 cause cell cycle arrest and growth inhibition. Only NAM 50mM induces apoptosis without genotoxic effects. Overall, our data suggest the direct involvement of SIRT1 during the observed cell cycle arrest and growth inhibition mediated by these inhibitors.

Citation Format: Manuela Guardi, Mariaelena Pistoni, Raffaele Frazzi. The effects of SIRT1 inhibitors nicotinamide and Ex-527 on lymphoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5. doi:10.1158/1538-7445.AM2017-5
Abstract 5003: Serum parathyroid hormone and risks of colorectal adenoma, adenoma recurrence and colorectal cancer, results from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial
Authors: Zhu Xiangzhu , Shrubsole Martha J. , Giovannucci Edward , Edwards Todd L. , Dai Qi
Published: July 2017

Background: Serum parathyroid hormone (PTH) may be related to risk of incident colorectal cancer. However, no study has prospectively examined whether serum PTH is differentially related to risks of different stages of colorectal carcinogenesis (incident adenoma and metachronous adenoma). Further, it is unclear if PTH is associated with risk of incident colorectal neoplasia in individuals receiving endoscopic screenings. To address these important scientific inquiries, we have conducted three nested case-control studies within the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial.

Methods: The PLCO is a large, multicenter, population-based randomized trial designed to determine the effects of screening on cancer-related mortality with a median of 12.5 years of follow up. We evaluated the associations between serum PTH and the risks of incident colorectal adenoma (755 cases and 514 controls), metachronous adenoma (755 cases and 755 controls) and incident colorectal cancer (755 cases and 514 controls) within PLCO participants aged 55 to 74 years. Odds ratios (OR) and 95% confidence intervals (95%CIs) were estimated using unconditional logistic regression models after adjusting for potential confounding factors.

Results: Compared to low serum PTH (<30 ng/L), higher concentrations of serum PTH were associated with significantly reduced risk of incident colorectal cancer with the ORs (95% CIs) being 0.65(0.48-0.88) and 0.52(0.35-0.76) for PTH ≥30 ng/L and PTH≥65 ng/L (p for trend, 0.001). The inverse associations appeared significant for both women and men. However, overall, serum PTH was not related to risk of incident adenoma and metachronous adenoma.

Conclusion: In conclusion, compared to the lowest PTH levels, higher serum PTH were related to reduced risks of incident colorectal cancer among an US population who received endoscopy, but not incident colorectal adenoma and metachronous adenoma.

Citation Format: Xiangzhu Zhu, Martha J. Shrubsole, Edward Giovannucci, Todd L. Edwards, Qi Dai. Serum parathyroid hormone and risks of colorectal adenoma, adenoma recurrence and colorectal cancer, results from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5003. doi:10.1158/1538-7445.AM2017-5003
Abstract 501: Tyrosyl-DNA phosphodiesterase I cellular function dependent on its N-terminal residues
Authors: Cuya Selma M. , Waardenburg Robert C.A.M. Van
Published: July 2017

Tyrosyl-DNA phosphodiesterase I (Tdp1) is a highly conserved eukaryotic DNA repair enzyme that catalyzes the resolution of 3’ and 5’ phospho-DNA adducts. Tdp1 has been implicated in the repair of DNA topoisomerase I (Top1)-DNA covalent complexes reversibly stabilized by FDA approved camptothecins (CPTs) derivatives topotecan and irinotecan. Tdp1 activity relies on two catalytic histidines that function as a nucleophile and an acid-base residue. A mutation of the acid-base His to Arg (H493R) in human Tdp1 is associated with the rare recessive ataxia SCAN1. We defined alternative substitution of either catalytic histidine that induce cytotoxicity, reduce catalytic activity and enhances the requisite Tdp1-DNA covalent adduct lifetime in the cell. The phenotypes of the catalytic mutants provide excellent tools to study Tdp1 cellular function. Biochemical studies revealed that Tdp1 catalysis in vitro is independent of the N-terminal domain. Among Tdp1 proteins, the N-terminal domain is poorly conserved in sequence and size (79aa for yeast and 148aa for human Tdp1). Conversely, the N-terminal domain regulates the in vitro activity of these Tdp1 mutants. Additionally, we investigated the role of the N-terminal domain for Tdp1 activity in the yeast and human cell models. Expression of N-terminal truncated proteins showed similar cellular distribution as the full-length proteins. However, these N-terminal truncated Tdp1 mutants did not display the toxicity that was observed with the full-length Tdp1 mutant proteins. Our data suggests that the N-terminal domain is required to resolve protein-DNA covalent complexes, such as Top1. Indeed, preliminary results suggest that this domain is also critical to process Top2-DNA covalent complexes, but only in the presences of etoposide. We are currently investigating other protein-DNA adducts that are resolved by Tdp1. These results suggests that the N-terminal domain is a critical determinate of Tdp1 cellular function. However, further studies are necessary to ensure that these constructs are properly distributed and retain their catalytic activity. Additionally, the N-terminal domain of human Tdp1 is post-translational modified, while our preliminary results suggest that this domain is important for protein-protein interaction and Tdp1 recruitment to its substrates. Understanding Tdp1 substrate and protein-interactions are important in the development of Tdp1 as therapeutic target. This work is in part supported by the ADDA, UAB Cancer Comprehensive Center (P30CA013148), ACS-IRG-60-001-53, DOD OCRP (W81XWH-15-1-0198).

Citation Format: Selma M. Cuya, Robert C.A.M. Van Waardenburg. Tyrosyl-DNA phosphodiesterase I cellular function dependent on its N-terminal residues [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 501. doi:10.1158/1538-7445.AM2017-501
Abstract 5021: Semaphorin signal via MICAL3 induces symmetrical cell division of cancer stem-like cells to confer aggressiveness in breast cancer
Authors: Tominaga Kana , Yano Masao , Tada Kei-ichiro , Tojo Arinobu , Gotoh Noriko
Published: July 2017

Breast cancer stem cells (BCSCs) are thought to be maintained in cancerous tissues by increased frequency of symmetric cell division at the expense of asymmetric cell divisionin the cancer tissues, although how this occurs it remain largely unknown. Here, we discovered that molecules interactinging with CasL 3 (MICAL3) contributed to tumor sphere formation in patient-derived breast cancer cells and tumor initiating activity in a patient-derived xenograft (PDX) model. Semaphorin (Sema)-stimulation induced complex formation involving MICAL3 and collapsin response mediator protein 2 (CRMP2), leading to stabilization of Numb in breast cancer cells. Neuropillin-1 (NP1), a receptor for Sema, and Numb were specifically expressed and colocalized at high levels in a BCSC-enriched population that induce tumor sphere formation. MICAL3 knockdown decreased symmetric cell division and increased asymmetric division of in NP1-high cancer stem-like cells that express high level of Numb at high levels. Thus, MICAL3/CRMP2/Numb pathway appears to play a critical role in the symmetric division of NP1-high cancer stem-like cells to expand the pool of BCSCs. Finally, we showed that breast cancer patients with higher expression levels of NP1 and Numb in cancer tissues show poor prognosis compared with those with lower expression levels of NP1 and Numb by using tissue microarray of breast cancer tissues. We provide a rationale for eradicating BCSC by blocking the symmetric division of BCSC by targeting molecules in Sema/NP1/MICAL3 pathway.

Citation Format: Kana Tominaga, Masao Yano, Kei-ichiro Tada, Arinobu Tojo, Noriko Gotoh. Semaphorin signal via MICAL3 induces symmetrical cell division of cancer stem-like cells to confer aggressiveness in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5021. doi:10.1158/1538-7445.AM2017-5021
Abstract 5024: Unmasking heterogeneity within the adult mammary stem cell compartment
Authors: Fu Nai Yang , Rios Anne , Pal Bhupinder , Law Charity , Jamieson Paul , Vaillant Francois , Smyth Gordon K. , Ritchie Matthew E. , Lindeman Geoffrey J. , Visvader Jane E.
Published: July 2017

Breast cancer is a highly heterogeneous disease at both the molecular and pathological levels. To understand this heterogeneity and ‘cells of origin’ of breast cancer, it is important to dissect the normal mammary epithelial hierarchy. Despite accumulating evidence for a mammary differentiation hierarchy, the basal compartment comprising stem cells remains poorly characterized. Through gene expression profiling of Lgr5+ versus Lgr5– basal epithelial cells, we identify a novel marker that led to the fractionation of three distinct mammary stem cell (MaSC) subsets in the adult gland. These exist in a largely quiescent state but differ in their repopulating ability, spatial localisation, and their molecular signatures. Interestingly, the dormant MaSC subset localises to the proximal region of the gland throughout life. These cells appear to originate from the embryonic mammary primordia before switching to a quiescent state post-natally but can be recruited into the cell cycle in response to hormones. Single cell gene expression analyses have also revealed unexpected complexity within the basal and luminal compartments. Moreover, analyses at different stages of development have provided insights into the earliest ‘lineage priming’ events.

Citation Format: Nai Yang Fu, Anne Rios, Bhupinder Pal, Charity Law, Paul Jamieson, Francois Vaillant, Gordon K. Smyth, Matthew E. Ritchie, Geoffrey J. Lindeman, Jane E. Visvader. Unmasking heterogeneity within the adult mammary stem cell compartment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5024. doi:10.1158/1538-7445.AM2017-5024
Abstract 5038: Comparison of the dose response of malignant peripheral nerve sheath tumor in vitro growth inhibition of 30 drugs to reported Cmax values
Authors: Reilly Karlyne M. , Tuskan Robert G. , Widemann Brigitte C.
Published: July 2017

In this study we aim to identify drugs that can be repurposed to inhibit malignant peripheral nerve sheath tumor (MPNST), a rare and deadly sarcoma associated with Neurofibromatosis type 1 (NF1). Inhibition of MPNST cell growth in vitro was tested for 30 drugs that have previously been through human clinical trials such that the maximum concentration of compound in human serum (Cmax) at the maximum tolerated dose has been determined. Drugs were compared to the chemotherapeutic doxorubicin. Six MPNST cell lines from human and mouse were tested and dose response curves were compared to Cmax for each drug.

For most compounds tested, inhibition of MPNST viability occurred at drug concentrations higher than Cmax. Doxorubicin was one of the best compounds tested. Several compounds with less specific molecular targets appear promising, however, currently available inhibitors of receptor tyrosine kinase signaling pathways required concentrations above Cmax to inhibit MPNST viability. These data suggest that difficulty in developing therapy for MPNST may be due to the requirement for high concentrations of drugs to inhibit MPNST cells.

Citation Format: Karlyne M. Reilly, Robert G. Tuskan, Brigitte C. Widemann. Comparison of the dose response of malignant peripheral nerve sheath tumor in vitro growth inhibition of 30 drugs to reported Cmax values [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5038. doi:10.1158/1538-7445.AM2017-5038