bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1156: Widespread deficiency of ASS1 in uveal melanoma and sensitivity to pegylated arginine deiminase
Authors: Khadeir Ramsay S. , Phillips Melissa M. , Sgoo Mandeep S. , Arora Amit , Cohen Victoria , Thaung Caroline , Szlosarek Peter W. 
Published: August 2015

Abstract
Uveal melanoma, involving the iris, choroid and ciliary body, is the commonest intraocular tumor in adults. Approximately half of these patients will develop metastasis with a high mortality despite currently available systemic therapies including immune checkpoint blockade. The urea cycle enzyme argininosuccinate synthetase 1 (ASS1), responsible for arginine synthesis, is downregulated in melanoma and other cancers and these are therefore sensitive to arginine deprivation therapy. In early phase trials of the arginine depletor pegylated arginine deiminase, ADI-PEG20, uveal melanoma, in particular, was identified with potential for further therapeutic development. Here, we tested uveal melanoma cell lines for sensitivity to ADI-PEG20 and analyzed enucleated tumors for ASS1 expression to assess the extent of ASS1 deficiency.
Methods: ASS1 gene and protein expression were assessed in three uveal melanoma cell lines (OMM1, OMM2.5 and Mel270) by real-time quantitative PCR (qPCR) and western blot analysis, respectively. Sensitivity to ADI-PEG20 was performed using the cell viability MTS assay. We screened 102 enucleated choroidal and ciliary body melanomas for ASS1 protein using red chromogen for the immunohistochemistry (IHC) and selected the most positive area for scoring.
Results: The uveal melanoma cell lines expressed negligible ASS1 mRNA with a complete absence of ASS1 protein. All three ASS1 negative uveal melanoma cell lines were sensitive to ADI-PEG20 by day 6 of the MTS assay, whereas an ASS1-expressing positive control cell line was resistant. There was a convincing lack of ASS1 expression (&lt;5% staining) in the majority of uveal melanomas (75/102; 74%) and where ASS1 was present (5-30% staining) in the remainder (27/102; 26%) this was due to a mixture of melanoma cells and intratumoral macrophages, the latter being confirmed with CD68 (IHC) in the cases with the highest ASS1 expression.
Conclusion: ASS1 is absent in the tested uveal melanoma cell lines and predisposes to arginine sensitivity with ADI-PEG20 in vitro. Most primary uveal melanomas have a marked deficiency of ASS1, representing a good target for exploring arginine deprivation further in the clinic, either alone or in combination with rationally selected agents. A trial of ADI-PEG20 combined with carboplatin and paclitaxel is planned in metastatic malignant melanoma with an expanded cohort in patients with uveal disease.
Citation Format: Ramsay S. Khadeir, Melissa M. Phillips, Mandeep S. Sgoo, Amit Arora, Victoria Cohen, Caroline Thaung, Peter W. Szlosarek. Widespread deficiency of ASS1 in uveal melanoma and sensitivity to pegylated arginine deiminase. [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 1156. doi:10.1158/1538-7445.AM2015-1156
Abstract 1166: ASCT2: A novel metabolic target for cancer therapy
Authors: Pore Nabendu , King Wanda , Lekstrom Kristen , Wilson Susan , Hollingsworth Robert , Tice David A. , Michelotti Emil 
Published: August 2015

Abstract
Uncontrolled proliferation of cancer cells is often fueled by the deregulation of various cellular signaling pathways. Such deregulation also frequently rewires the metabolism of cancer cells in order to meet their increased need for energy and nutrients required for growth and proliferation. In the process, tumor cells produce high levels of anabolic intermediates required for biosynthesis of macromolecules and redox homeostasis. Many of these building blocks are derived from tri-carboxylic acid cycle (TCA) intermediates that need to be replenished in a process called anapleurosis. Glutaminolysis, the process in which glutamine (Gln) is converted into TCA intermediates by glutaminase is one of the key pathways that feeds anapleurosis in cancers. Many tumor cell lines fail to grow in the absence of glutamine and are therefore addicted to this nutrient. Glutamine is a preferred substrate for ASCT2, a member of ASC family of amino acid transporters, and thus this transporter may play a role in this addiction. We screened a variety of cancer cells for their dependence on Gln and determined that a significant subset of cell lines require this important nutrient. Biochemical experiments indicated that the ASCT2 family of proteins is the main driver of Gln transport. In agreement with these findings, shRNA-mediated knock down of ASCT2 significantly inhibited 14C-Gln uptake and tumor cell proliferation. Expression of an shRNA-resistant ASCT2 gene rescued both the inhibition of cell proliferation and transport of Gln. Furthermore, stable knockdown of ASCT2 induced autophagy and significantly slowed growth in vivo of various tumor types such as colon carcinoma, prostate carcinoma, and in neuroblastoma. The above findings identify ASCT2 as an attractive target for therapeutic intervention.
Note: This abstract was not presented at the meeting.
Citation Format: Nabendu Pore, Wanda King, Kristen Lekstrom, Susan Wilson, Robert Hollingsworth, David A. Tice, Emil Michelotti. ASCT2: A novel metabolic target for cancer therapy. [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 1166. doi:10.1158/1538-7445.AM2015-1166
Abstract 1173: Extracellular ATP is internalized through not only macropinocytosis but also other endocytic process and promotes growth of human lung cancer cells with Ras mutations
Authors: Qian Yanrong , Wang Xuan , Li Yunsheng , Cao Yanyang , Wu Shiyong , Chen Xiaozhuo 
Published: August 2015

Abstract
Within a tumor, extracellular ATP (exATP) concentrations are in the range of several hundred micromolars or higher, 103-104 times higher than those in normal tissues1. We recently showed that extracellular ATP, within the intratumoral concentrations, was internalized by Ras-mutated (Rasmut) A549 human lung cancer cells through macropinocytosis, elevated intracellular ATP levels and rescued cancer cells under various stresses2. However, macropinocytosis3 alone could not account for all the elevated intracellular ATP increase. Here, we show that other endocytic processes, in addition to macropinocytosis, also contributed to the internalization of exATP in A549 and H1299 human lung cancer cells. Cell viability assays, intracellular ATP luminescence measurement assays, fluorescent microscopy were used in this study. First, high-molecular-weight (HMW) dextran uptake assay indicated that A549 and H1299, both Rasmut cancer cells, exhibited a phenotype of macropinocytosis. The colocalization of the red fluorescent HMW dextran and green nonhydrolyzable ATP analog inside the cells indicated that extracellular ATP was internalized by macropinocytosis. In contrast, significantly fewer macropinosomes were found in NL-20 noncancerous lung cells. In addition, the colocalization of low-molecular-weight (LMW) dextran, an endocytic tracer, and ATP analog indicated the internalization of exATP through non-macropinocytic-endocytosis in both lung cancer cell lines. Interestingly, when both red HMW dextran and green LMW dextran were applied to cancer cells, not only colocalization, but also some green-only endosomes were observed, strongly suggesting that both endocytic processes were responsible for exATP internalization. Collectively, these data indicated for the first time that other endocytic processes in addition to macropinocytosis contributed to the internalization of exATP in human lung cancer cells with Rasmut. This finding may significantly enhance our understanding of energy hemostasis within cancer cells and the Warburg effect, which in turn facilitates the development of anticancer therapeutics targeting the endocytic processes and Ras mutations as well as novel anticancer strategies.
1. Pellegatti, et al. (2008). PLoS ONE 3, e2599.
2. Qian, et al. (2014). Cancer Letters 351, 242-251.
3. Commisso, et al. (2013). Nature 497, 633-637.
Citation Format: Yanrong Qian, Xuan Wang, Yunsheng Li, Yanyang Cao, Shiyong Wu, Xiaozhuo Chen. Extracellular ATP is internalized through not only macropinocytosis but also other endocytic process and promotes growth of human lung cancer cells with Ras mutations. [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 1173. doi:10.1158/1538-7445.AM2015-1173
Abstract 1176: The effect of resveratrol combined with dichloroacetate (DCA) on breast cancer cell lines and MCF-10a noncancerous cells
Authors: Piepenbrink Sarah , Sisler Dan , Feirer Russ 
Published: August 2015

Abstract
Resveratrol, (3,5,49-trihydroxy-trans-stilbene), was first reported to act as a chemo-preventative anticancer compound in mice by Jang et al. in 1997 and has been shown to induce apoptosis and reduce both cell viability and mitotic index in many cancer cell lines. Earlier work in our lab found that it affects glucose utilization by decreasing glucose uptake by MCF-7 cells. The present study examined combinations of resveratrol with DCA, a compound that affects mitochondrial metabolism (reversing the Warburg Effect). A goal of this study was to determine if DCA might sensitize cancer cells to other chemotherapeutic compounds that affect glucose metabolism, such as resveratrol. Glucose uptake and lactate production by treated cells were measured, and Western blots were used to estimate levels of several proteins, including cleaved PARP and p21. Both resveratrol and DCA were found to reduce cell viability of treated breast cancer cell lines. Resveratrol, but not DCA, was found to induce caspase-3,7, a measure of apoptosis. This suggests that resveratrol and DCA may affect viability via different mechanisms. More importantly, a synergistic effect of these compounds on cell viability was observed, where DCA was found to enhance the anti-proliferative effect of resveratrol.
Citation Format: Sarah Piepenbrink, Dan Sisler, Russ Feirer. The effect of resveratrol combined with dichloroacetate (DCA) on breast cancer cell lines and MCF-10a noncancerous 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 1176. doi:10.1158/1538-7445.AM2015-1176
Abstract 1191: The RNA binding protein, HuR, regulates pancreatic cancer cell metabolism
Authors: Blanco Fernando F. , Zarei Mahsa , Brody Jonathan R. , Boros Laszlo G. , Winter Jordan M. 
Published: August 2015

Abstract
Introduction: Few proteins have been found to be master-regulators of pancreatic ductal adenocarcinoma (PDA) cell metabolism (e.g., LKB1, KRAS). We recently demonstrated that the regulatory RNA binding protein, HuR, binds to numerous metabolic mRNA transcripts and regulates their expression. Additionally, HuR silencing with small interfering RNAs(siRNAs) inhibited growth of PDA cells in vitro under glucose deprivation. Herein, we manipulated HuR expression levels in PDA cells and performed isotope tracer fate association studies to better understand HuR's role in metabolic reprogramming.
Methods: We used 13C-labeled nutrients to map carbon flux in BxPC3 pancreatic cancer cells that were either transiently transfected with siRNA oligos against HuR (siHuR) or scrambled control (siCTRL). Cells were incubated with standard DMEM or mild glucose deprivation (5 mM glucose) for 48 hours, and media were supplemented with [1,2-13C2]-D-glucose or [U-13C5]-L-glutamine tracers for the final 24 hours. A total of 24 samples were snap frozen and prepared for GC-MS isotopomer analysis (3 replicates X 2 different siRNA oligos X 2 isotope tracers X 2 glucose concentrations). Transfection experiments were validated for reduced HuR expression (&gt;70% reduction) and reduced protein expression of at least one metabolic and established HuR target (e.g., IDH1) by immunoblot.
Results: HuR silencing directly impaired fatty acid (Table, line 1-3), ribose (line 5) and glycogen synthesis (line 6). Reductive carboxylation of glutamine-derived isocitrate was impaired and futile carbon exchange fluxes were prevalent (not shown).
Conclusions: HuR enhances metabolic efficiency in PDA cells by directly regulating multiple metabolic pathways. Ongoing microarray studies will highlight which metabolic transcripts are post-transcriptionally regulated by HuR, resulting in the observed phenotype.
Altered metabolites due to HuR silencing in PDA cells ([1,2-13C2]-D-glucose tracer)PathwayMetabolitesiHuR 25mM glucosesiHuR 5 mM glucoseCorrelation1Myristate (C:14) Intracell13C enrichment70.271.01.02Myristate (C:14) intracellFNS (direct)56.060.41.03Oleate (C:18-1) IntracellIndirect synthes-m187.689.51.04Glutam extracell [C2-C5]13C-m1 (m/z198)97.497.91.05RNA-ribose Intracell [C1-C4]13C-m3(m/z242)99.399.10.9846Glucose intracell [C3-C6]Peak area, Glycog-gluc74.180.10.983
Citation Format: Fernando F. Blanco, Mahsa Zarei, Jonathan R. Brody, Laszlo G. Boros, Jordan M. Winter. The RNA binding protein, HuR, regulates pancreatic cancer cell metabolism. [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 1191. doi:10.1158/1538-7445.AM2015-1191
Abstract 1192: Glutamic acid and glutaminolysis mark aggressive tumorigenesis in head and neck squamous cell carcinoma
Authors: Banda Adam D. , Bermudez Cortes Mercedes , Kamarajan Pachiyappan , Rajendiran Thekkenlnaycke , Chinnaiyan Arul M. , Kapila Yvonne L. 
Published: August 2015

Abstract
The purpose of this study was to identify markers of aggressive tumor behavior to inform processes underlying tumor aggressivity in head and neck squamous cell carcinoma (HNSCC). To this end, metabolomic profiling and validation of biomarkers of aggressive HNSCC tumorigenesis were assessed in HNSCC human specimens and cell lines. Using LG/GC-MS, we found that glutamic acid is one of the most highly differentially elevated metabolites in HNSCC specimens. In subsequent validation studies, where we incorporated metastatic tissues, glutamic acid was further verified as differentially elevated in metastatic tissues compared to primary HNSCC and normal adjacent tissues. In addition, significantly elevated expression levels of c-Myc and glutaminase, the enzyme that regulates glutamic acid levels, were highest in metastatic tissues compared to primary HNSCC and normal tissues. Parallel changes in c-Myc and glutaminase expression in HNSCC tissues suggest a link between c-Myc regulation and glutamine metabolism. Furthermore, Western Blot analyses show similar expression patterns for c-Myc and glutaminase in oral cancer cell lines. Inhibiting glutamic acid levels by stably suppressing glutaminase expression in HNSCC cells, led to suppression of aggressive tumorigenesis in vitro, whereas enrichment with external glutamine or glutamic acid further enhanced tumorigenesis. Together, this data suggest that oncogenic levels of c-Myc may induce a transcriptional program that promotes elevated levels of glutamic acid and glutaminolysis via glutaminase to promote tumor aggressivity in head and neck cancer.
Citation Format: Adam D. Banda, Mercedes Bermudez Cortes, Pachiyappan Kamarajan, Thekkenlnaycke Rajendiran, Arul M. Chinnaiyan, Yvonne L. Kapila. Glutamic acid and glutaminolysis mark aggressive tumorigenesis in head and neck 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 1192. doi:10.1158/1538-7445.AM2015-1192
Abstract 1212: Mutant p53 stabilizes and protects the transcription factor ETS2 from proteasomal degradation by the ubiquitin ligase COP1/DET1
Authors: Carrero Zunamys I. , Kollareddy Madhusudhan , Chauhan Krishna M. , Ramakrishnan Gopalakrishnan , Martinez Luis A. 
Published: August 2015

Abstract
Genetic mutations of the tumor suppressor gene TP53 contribute to a great majority of human cancers. One mechanism by which mutant TP53 (mtp53) acts is through the interaction with other transcription factors, which can either enhance or repress the transcription of their target genes. Mtp53 preferentially interacts with ETS2, an ETS transcription factor, and increases its stability. This results in an increase of the expression of ETS target genes that are associated with the transition of normal cells into tumor cells. Previous studies have shown that the ubiquitin-proteasomal pathway regulates ETS2 stability. To study the mechanism of ETS2 ubiquitin-mediated degradation, we used siRNA to knockdown ubiquitin ligases known to interact with ETS2. A significant increase in ETS2 stability was observed when the ubiquitin ligase COP1 and its binding partner DET1 were knocked down. We find that ectopically expressed COP1/DET1 leads to ETS2 ubiquitination and degradation, and that a COP1 without an intact RING domain fails to degrade ETS2. Mutation of COP1 putative binding sites in ETS2 also prevented its degradation. Given that mtp53 interacts with ETS2, we assessed mtp53's role in ETS2 stability by conducting ubiquitination assays. Our data showed that mtp53 prevents COP1/DET1 from ubiquitinating ETS2, thus preventing it from being degraded. We are currently studying the mechanism of COP1/DET1 binding to ETS2 and how mtp53 interferes with this process, thus rescuing ETS2. We surmise that mtp53 disrupts the binding of COP1/DET1 to ETS2, leading to its stabilization. Through this mechanism, mtp53 can alter the balance of ETS proteins in normal cells, which results in an increased ETS2 transcriptional program that drives cancer cells to be more invasive and metastatic.
Citation Format: Zunamys I. Carrero, Madhusudhan Kollareddy, Krishna M. Chauhan, Gopalakrishnan Ramakrishnan, Luis A. Martinez. Mutant p53 stabilizes and protects the transcription factor ETS2 from proteasomal degradation by the ubiquitin ligase COP1/DET1. [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 1212. doi:10.1158/1538-7445.AM2015-1212
Abstract 1218: A biological crosstalk between p53 and MYCN/MYC in neuroblastoma
Authors: Ikegaki Naohiko , Tang Xao 
Published: August 2015

Abstract
We previously showed that TSA (an HDAC inhibitor) and Epoxomycin (a proteasome inhibitor) as single agents and in combination significantly suppressed growth of MYCN-amplified neuroblastoma cells. However, these compounds had contrasting effects on MYCN expression. TSA down-regulated MYCN expression, but Epoxomycin and the TSA/Epoxomycin combination led to MYCN hyper-expression (defined as markedly increased expression beyond that observed in the untreated cells). The expression of p53 was also increased in MYCN-amplified cells treated with Epoxomycin or the TSA/Epoxomycin combination. In an independent study, we also found that treatment of neuroblastoma cells (MYCN-amplified or non-MYCN amplified) with 17-DMAG and S(+) Ibuprofen resulted in an increase in p53 expression and a reduction in MYCN or MYC expression. In this study, we examined (i) the pattern of gene expression induced by MYCN hyper-expression in MYCN-amplified cells, and (ii) a potential functional relationship between p53 and MYCN/MYC in neuroblastoma. Transient transfection of MYCN and TP53 into neuroblastoma cells was done by electroporation. Gene expression profiling, TaqMan real-time PCR, and Western blot assays were used to detect expression patterns of genes and proteins. It was observed that ectopic over MYCN expression in MYCN-amplified IMR5 cells resulted in growth suppression. Gene expression profiling analysis revealed that the hyper-expression of MYCN in the MYCN-transfected IMR5 cells led to an increased expression of genes involved in growth suppression and apoptosis, including EGR1, EPHA2, KLF2, PERP and SEL1L. The expression of PERP and EPHA2 was confirmed by TaqMan real-time PCR and Western blot assay, respectively. Interestingly, co-transfection of TP53 and MYCN in IMR5 cells led to high p53 expression but a reduction in MYCN expression (below the levels of endogenous MYCN). Transfection of TP53 into IMR5, SY5Y, and SKNAS reduced endogenous MYCN and MYC expression in these cells. Consistent with these observations, treatment of IMR5 and SY5Y cells with known p53-inducers, Doxorubicin and CoCl2, resulted in an increased p53 expression and a reduction of MYCN and MYC expression. Although high MYCN expression sustains growth of MYCN-amplified neuroblastoma, the hyper-expression of MYCN is deleterious to survival of these cells. In addition, augmented p53 expression may elicit a negative feedback regulation of MYCN/MYC expression in neuroblastoma.
Citation Format: Naohiko Ikegaki, Xao Tang. A biological crosstalk between p53 and MYCN/MYC in neuroblastoma. [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 1218. doi:10.1158/1538-7445.AM2015-1218