bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1059: Analysis of promoter methylation levels of COX2 gene in Turkish patients with head and neck cancer
Authors: Demokan Semra , Ozkoklesen Cansu , Yalniz Zubeyde , Enver Necati , Ulusan Murat , Dalay Nejat
Published: August 2015

Purpose: Methylation of CpG islands in the promoter regions of genes plays an important role in head and neck carcinogenesis. Overexpression of COX2 gene was recorded in various types of cancer in literature. In addition, the promoter region of the COX2 gene displayed high methylation in normal colorectal tissue and normal gastric tissue samples. On the other hand, it has recently been reported in two different gastrointestinal cancer studies, that low expression of COX2 was observed in some colorectal/gastric cancers and hypermethylation/related transcriptional silencing of COX2 gene is common in colorectal cancer. There is no study investigating the COX2 methylation status on head and neck cancer (HNC) in the literature. In our study we evaluated the COX2 gene promoter methylation in patients with HNC.

Experimental Design: Methylation of the COX2 was investigated by bisulfite modification/methylation-specific polymerase chain reaction in tumors and matched normal tissue samples from 99 Turkish patients with HNC.

Results: The promoter region of the COX2 was methylated in 53.5% and 65.6% of the primary tumors and the corresponding normal tissue samples, respectively [p = 0.082, χ2 = 3.02, OR(95%CI) = 0.602 (0.34-1.06)]. Considering the methylation levels observed in our previous studies, and published data on different cancer types, methylation levels <10% were considered unmethylated, whereas levels between 10% to 25% and 25% to 100% were classified as moderate and high methylation, respectively. Based on this information, methylation ratio was observed less than 10% in 46.5% and 34.3% of tumor and normal samples, respectively. The moderate methylation levels (10-25%) were found in 23.2% of the tumors and 7.1% of the adjacent normal tissues. High methylation levels (>25%) were 30.3% and 58.6% in the tumor and normal tissues, respectively (p = 0.00006, χ2 = 19.24). The results were similar when a subgroup of 60 patients with larynx cancer from this cohort, were analyzed separately (p = 0.0006, χ2 = 14.87).

Conclusions: Methylation may play an important role in HNC carcinogenesis. Although we found that there was no significant association between the methylation levels of tumor and adjacent normal tissues, high methylation levels of the COX2 gene were observed (>25%) in normal matched tissues when compared to the levels in HNC tumors.

Citation Format: Semra Demokan, Cansu Ozkoklesen, Zubeyde Yalniz, Necati Enver, Murat Ulusan, Nejat Dalay. Analysis of promoter methylation levels of COX2 gene in Turkish patients with head and neck 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 1059. doi:10.1158/1538-7445.AM2015-1059
Abstract 1060: Epigenome-wide DNA methylation profiling of lung tumors from asbestos-exposed patients
Authors: Kettunen Eeva M. , Hernandez-Vargas Hector , Cros Marie-Pierre , Durand Geoffroy , Le Calvez-Kelm Florence , Wolff Henrik , Salmenkivi Kaisa , Anttila Sisko L. , Herceg Zdenko , Husgafvel-Pursiainen Kirsti
Published: August 2015

Introduction and objectives.

Epigenetic modifications such as changes in DNA methylation have been shown as response to many toxic exposures. However, not much is known about the role of epigenetics in human lung carcinogenesis associated with asbestos exposure. Here, we explored the epigenome-wide DNA methylation (DNA methylome) patterns in lung tumors focused on asbestos-exposed and non-exposed patients who were mostly smokers. We sought to investigate whether methylation markers in lung cancer associate with exposure (asbestos, tobacco smoke) and clinico-pathological features.

Study design, subjects, and methods.

The DNA methylome was examined by Illumina Infinium 450K HumanMethylation technology covering more than 450 000 CpG sites. Validation experiments were done by pyrosequencing. DNA methylation was studied in lung tumors and normal lung as matched pairs obtained from 28 patients from lung surgery in Helsinki during years 1988-1996. Detailed data on the patients’ work and smoking histories, pulmonary fiber counts (14 asbestos-exposed and 14 non-exposed), and clinical data were available. As controls, normal lung specimens from patients with non-malignant lung disease were studied for genome-wide DNA methylation.

Results.

DNA methylation profiles differed in relation to sample type, tumor histology and exposure status. We identified more than 10.000 methylation variable positions (MVPs) that differed (adjusted P < 0.05) between lung tumors and matched normal lung. Differential methylation in 14 MVPs were significantly associated with asbestos exposure in lung tumor tissue whereas more than 100 MVPs were suggested as smoking-related. Differential methylation of genes such as those involved in cell stress and inflammation, cellular energy and lipid metabolism, and protein degradation processes were observed in lung tumors.

Conclusions.

Our analysis suggests that methylation profiles were globally affected in lung tumors in comparison to matched normal lung. We also found associations to asbestos exposure and tobacco smoking, suggesting a role for these exposures in modification of DNA methylome profiles.

Citation Format: Eeva M. Kettunen, Hector Hernandez-Vargas, Marie-Pierre Cros, Geoffroy Durand, Florence Le Calvez-Kelm, Henrik Wolff, Kaisa Salmenkivi, Sisko L. Anttila, Zdenko Herceg, Kirsti Husgafvel-Pursiainen. Epigenome-wide DNA methylation profiling of lung tumors from asbestos-exposed patients. [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 1060. doi:10.1158/1538-7445.AM2015-1060
Abstract 1064: RASSF10 suppresses colorectal cancer growth by activating p53 signaling and sensitizes colorectal cancer cell to docetaxel
Authors: Guo Jing , Yang Yage , Yang Yunsheng , Linghu Enqiang , Zhan Qimin , Brock Malcolm V. , Herman James G. , Zhang Bingyong , Guo Mingzhou
Published: August 2015

RASSF10 has previously been reported to be frequently methylated in a number of malignancies. To understand the importance of RASSF10 inactivation in colorectal carcinogenesis, eight colorectal cancer cell lines, 89 cases of primary colorectal cancer and 5 cases of normal colorectal mucosa were examined. Methylation specific PCR, western blot, siRNA, gene expression array and xenograft mice were employed. The expression of RASSF10 was was regulated by promoter regional methylation in colorectal cancer cells. RASSF10 was methylated in 60.7% (54/89) of primary colorectal cancers and was positively associated with tumor stage (p<0.05) and metastasis (p<0.05). Restoration of RASSF10 led to inhibition of colorectal cancer cell proliferation in vitro and in vivo and increased apoptosis. Gene expression arrays discovered RASSF10 inhibition of MDM2 expression as a mediator of these effects, which was confirmed with RT- PCR and western blot. RASSF10 was shown to activate P53 signaling in RKO and HCT116 cells after UV exposure, and sensitized these cells to docetaxel. In conclusion, our study demonstrates RASSF10 is frequently methylated in human colorectal cancer leading to loss of expression. RASSF10 normally suppresses human colorectal cancer growth by activating P53 signaling in colorectal cancer, and restored expression sensitizes colorectal cancer to docetaxel.

Citation Format: Jing Guo, Yage Yang, Yunsheng Yang, Enqiang Linghu, Qimin Zhan, Malcolm V. Brock, James G. Herman, Bingyong Zhang, Mingzhou Guo. RASSF10 suppresses colorectal cancer growth by activating p53 signaling and sensitizes colorectal cancer cell to docetaxel. [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 1064. doi:10.1158/1538-7445.AM2015-1064
Abstract 1068: Correlation of DNA methylation pattern between peripheral blood cell and normal breast tissue
Authors: Guo Xingyi , Shu Xiao-Ou , Li Chun , Long Jirong , Li Bingshan , Gao Yu-Tang , Zheng Wei , Cai Qiuyin
Published: August 2015

Aberrant DNA methylation in peripheral blood cells (PBCs) may be a potential noninvasive biomarker for breast cancer risk. Whether methylations at CpG sites in PBCs can serve as proxies in normal breast tissues are unknown. We evaluated the correlation of DNA methylation between PBC DNA and breast cancer adjacent normal tissue using data and samples from the Shanghai Breast Cancer Study. Genome-wide DNA methylation profiles in PBCs and matched tumor adjacent normal tissues from 31 breast cancer patients were assayed using Illumina HumanMethylation450 BeadChip, which includes >485,000 CpG sites and covers 99% of RefSeq genes with multiple probes per gene. After quality control filtering, a total of 432,513 CpG sites were retained for analysis. We evaluated the association of methylation for each CpG site between DNA samples for PBCs and normal breast tissue using Spearman's rank correlation (r). The overall median correlation (r) is 0.35. A total of 99,928 (23.1%) and 18,290 (4.2%) of CpG sites had a high correlation between PBC DNA and normal breast tissue DNA with r > 0.50 and r > 0.75, respectively. Interestingly, we found that the correlation was negatively associated with both methylation levels (mean) and inter-person variability (standard deviation) in normal breast tissues (ρ = -0.14 and -0.19; P < 2.2 x10-16 for both). In 926 previously reported methylation quantitative trait loci, the correlations between PBCs and normal breast tissue were significantly higher (median r = 0.42) than the remaining loci (median r = 0.34) (Wilcoxon test, P < 2.2 x10-16), suggesting that methylation variations controlled by genetic variations exhibited a robust correlation between PBC and normal breast tissue DNA. In summary, our results suggest that the methylation status of CpG sites with large inter-person variations or genetically-controlled variations in PBC DNA correlate well with those in normal breast tissue. This supports the conduct of a genome-wide methylation study for breast cancer using PBC DNA.

Citation Format: Xingyi Guo, Xiao-Ou Shu, Chun Li, Jirong Long, Bingshan Li, Yu-Tang Gao, Wei Zheng, Qiuyin Cai. Correlation of DNA methylation pattern between peripheral blood cell and normal breast tissue. [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 1068. doi:10.1158/1538-7445.AM2015-1068
Abstract 1102: Integrated genomic analysis of clear-cell ovarian cancer identifies PRKCI as a therapeutic target
Authors: Tsang Tsun Yee , Mohapatra Gayatry , Itamochi Hiroaki , Mok Samuel C. , Birrer Michael J.
Published: August 2015

Clear-cell ovarian cancer (CCOC) is the third most common subtype of ovarian cancer. CCOC is more resistant to standard chemotherapy and has a poorer prognosis than serous and endometrioid histotypes. Through a comprehensive genomic approach, genes that are responsible for the aggressive behavior of CCOC were identified and their mechanism explored.

Genome-wide DNA copy number alterations were measured in 13 CCOC cell lines using high-resolution oligonucleotide array comparative genomic hybridization (Agilent 105k Human Genome CGH Microarray). Genomic identification of significant targets in cancer (GISTIC) analysis identified 16 amplicons containing 391 genes. Integrating whole genome expression data from human CCOC tumor specimens and normal ovarian surface epithelium specimen revealed 45 amplified genes showed mRNA overexpression in CCOC tumor specimens. Among the 45 genes, protein kinase C iota (PRKCI) was amplified in 9/13 CCOC cell lines and was overexpressed (6.7 fold) in CCOC tumor specimens. Cell proliferation, migration/invasion and tumorigenicity were suppressed by knockdown of PRKCI in PRKCI-overexpressing cells (KOC-7c and OVISE) and were enhanced by overexpression of PRKCI in cells with low endogenous levels of PRKCI (ES2 and TOV21G). Targeted inhibition of PRKCI with sodium aurothiomalate (ATM) suppressed cell growth, cell migration/invasion and tumorigenicity in CCOC cells. Western blot analysis revealed that PRKCI oncogenic function was mediated through MEK/ERK and PI3K/Akt signaling pathways. Thus, PKRCI can be considered as a potential novel CCOC-specific target; not only it inhibits malignant behavior of CCOC cells, but also induces the two major molecular pathways regulating cisplatin resistance. The results from the present study indicate that our comprehensive genomic analysis of CCOC allows identification of therapeutic targets responsible for the aggressive behavior specific of this ovarian cancer histotype and thus improve its therapeutic outcome.

Citation Format: Tsun Yee Tsang, Gayatry Mohapatra, Hiroaki Itamochi, Samuel C. Mok, Michael J. Birrer. Integrated genomic analysis of clear-cell ovarian cancer identifies PRKCI as a therapeutic target. [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 1102. doi:10.1158/1538-7445.AM2015-1102
Abstract 1109: In vivo loss of function screening reveals carbonic anhydrase IX (CAIX) as a key modulator of tumor initiating potential in primary pancreatic tumors
Authors: Pore Nabendu , Jalla Sanjoo , Higgs Brandon , Liu Roger , Tice David A. , Hollingsworrth Robert , Michelotti Emil , Sorio Claudio , Scarpa Aldo
Published: August 2015

Re-programming of energy metabolism is one of the emerging hallmarks of cancer. Upregulation of energy metabolism pathways fuels cell growth and division, a key characteristic of neoplastic disease, and can lead to dependency on specific metabolic pathways. Thus targeting energy metabolism pathways might offer the opportunity for novel therapeutics. Here we describe the application of a novel in vivo screening approach for the identification of genes involved in cancer metabolism using a patient derived pancreatic xenograft model. Lenti-viruses expressing shRNAs targeting twelve different cell surface protein transporters were separately transduced into the primary pancreatic tumor cells. Transduced cells were pooled and implanted into mice. Tumors were harvested at different times and the frequency of each shRNA was determined as a measure of which ones prevented tumor growth. Several targets including CAIX, MCT4, and xCT were identified in these studies and shown to be required for tumor initiation and growth. Interestingly, CAIX was overexpressed in the tumor initiating cell population. CAIX expression alone correlated with a highly tumorigenic subpopulation of cells. Furthermore, CAIX expression was essential for tumor initiation since shRNA knockdown eliminated the ability of cells to grow in vivo. To the best of our knowledge, this is the first parallel in vivo assessment of multiple novel oncology target genes using a patient derived pancreatic tumor model.

Citation Format: Nabendu Pore, Sanjoo Jalla, Brandon Higgs, Roger Liu, David A. Tice, Robert Hollingsworrth, Emil Michelotti, Claudio Sorio, Aldo Scarpa. In vivo loss of function screening reveals carbonic anhydrase IX (CAIX) as a key modulator of tumor initiating potential in primary pancreatic tumors. [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 1109. doi:10.1158/1538-7445.AM2015-1109
Abstract 1112: Loss-of-function genetic screening with shRNA and CRISPR libraries
Authors: Tedesco Donato , Makhanov Mikhail , Baron Sylvain , Suchkov Dmitry , Chenchik Alex
Published: August 2015

Genome-wide loss-of-function screens provide a direct approach to identify the genes regulating biological responses and find new therapeutic targets. While RNAi screens have proven an effective tool for these screens, CRISPR/CAS9 provides an alternative approach to implement these screens. To complement our established shRNA screening platform, we have developed pooled format genome-wide modular sgRNA libraries for cost-effective functional CRISPR knockout screens. Pooled sgRNA and shRNA libraries were then run to identify lethal interactions in isogenic PDX-derived cell line pairs.

Citation Format: Donato Tedesco, Mikhail Makhanov, Sylvain Baron, Dmitry Suchkov, Alex Chenchik. Loss-of-function genetic screening with shRNA and CRISPR libraries. [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 1112. doi:10.1158/1538-7445.AM2015-1112
Abstract 1116: Oncogene signatures identify novel therapeutic targets and combinatorial strategies in breast cancer
Authors: Guest Stephen , Kratche Zachary , Irish Jonathan , Bollig-Fischer Aliccia , Garrett-Mayer Elizabeth , Ethier Stephen
Published: August 2015

During the course of tumorigenesis, cancer cells acquire a large number of genetic and epigenetic alterations. A subset of these alterations results in the generation of driver oncogenes that play critical roles in initiating and maintaining the transformed phenotype. We hypothesize that most solid tumors are simultaneously driven by multiple driver oncogenes that together form an oncogene network and that durable therapies for solid tumors will need to target multiple oncogenes. Identifying multiple driver oncogenes from among the large number of mutated/amplified genes present in most solid tumors is a nontrivial task that will require novel approaches. In this work, we have combined genome-wide, RNAi-based dropout screens with copy number, expression and exome sequencing analysis to identify the full complement of driver oncogenes that function in a panel of breast cancer cell lines. The panel of cell lines used for this study is the SUM panel of breast cancer cells which contains 10 cell lines and includes representatives of HER2 positive, ER positive, and triple negative breast cancer subtypes. For each line we have identified multiple activated driver oncogenes that when combined define a complete oncogene signature for the cell line. All of the oncogene signatures contain both well-characterized oncogenes that are known to play a role in breast cancer as well as novel driver genes that do not have a well-characterized role in breast cancer. Subsequent work has confirmed the role of several of the novel driver oncogenes including the epigenetic modifier KAT6A and the apoptotic regulator BCL2L1. Additionally, we show that the cell line oncogene signatures can be used to successfully predict sensitivity of individual cell lines to small molecule inhibitors. Predictions of sensitivity to inhibitors were confirmed through the integration of oncogene signatures with published data from large-scale drug screens across numerous cancer cell lines. Finally, we demonstrate the utility of oncogene signatures through their use in the design of novel therapeutic strategies that effectively reduce cancer cell viability.

Citation Format: Stephen Guest, Zachary Kratche, Jonathan Irish, Aliccia Bollig-Fischer, Elizabeth Garrett-Mayer, Stephen Ethier. Oncogene signatures identify novel therapeutic targets and combinatorial strategies in 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 1116. doi:10.1158/1538-7445.AM2015-1116
Abstract 1121: Analysis of gene expression changes as a function of PBRM1, BAP1, and SETD2 mutation status clear cell renal cell carcinoma in TCGA tumors
Authors: Abbosh Philip H. , Ibragimova Ilsiya , Slifker Michael , Cairns Paul
Published: August 2015

In addition to VHL, the most commonly mutated clear cell renal cell carcinoma (ccRCC)genes are the chromatin modifiers PBRM1, BAP1, and SETD2. Mutations in these genes predict loss-of-function and presumably exert cancer-related functions through changes in chromatin context and gene expression. Mining publicly available data from The Cancer Genome Anatomy (TCGA) allowed us to correlate mutation status and gene expression profiles, potentially suggesting roles for these mutations in ccRCC. Gene set enrichment analysis (GSEA)reveals that specific signaling and metabolic changes are common for each tumor mutation and may reveal the biologic mechanism of tumor-associated mutations. Work is underway to functionally validate the effect of loss-of-function ccRCC mutations in epigenetic modifiers.

Citation Format: Philip H. Abbosh, Ilsiya Ibragimova, Michael Slifker, Paul Cairns. Analysis of gene expression changes as a function of PBRM1, BAP1, and SETD2 mutation status clear cell renal cell carcinoma in TCGA tumors. [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 1121. doi:10.1158/1538-7445.AM2015-1121
Abstract 1132: Gluconeogenesis, lipogenesis, and HBV replication are commonly regulated by PGC-1α-dependent pathway
Authors: Hsu Wei-Hsiang , Jhuang Hong-Jhih , Huang Chi-Ying
Published: August 2015

Peroxisome proliferator-activated receptor-γ coactivator 1 (PGC-1α), a major metabolic regulator of gluconeogenesis and lipogenesis, is known to be strongly induced to coactivate HBV gene expression in the liver of fasting mice. In this study, we found that the combination of 8-Br-cAMP and glucocorticoids showed the synergistic induction of PGC-1α and its downstream gene expression, including the expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). Moreover, HBV corepromoter activity was synergistically enhanced by the combination of 8-Br-cAMP and glucocorticoid treatment. Graptopetalum paraguayense (GP), a herbal medicine, is commonly used in Taiwan to treat liver disorders. Here, we found that a partially purified fraction of GP (named HH-F3) dose dependently suppressed 8-Br-cAMP/glucocorticoid-induced G6Pase, PEPCKand PGC-1α expression as well as suppressed HBV core promoter activity. Additionally, HH-F3 blocked HBV core promoter activity via the inhibition of PGC-1α expression. The ectopic expression of PGC-1α effectively reversed the HH-F3-mediated inhibition of HBV core promoter activity.HH-F3-reduced HBV surface antigen expression, HBV mRNA production, core protein level, and HBV replication were drastically rescued by ectopically expressed PGC-1α. In addition, HH-F3 could also inhibit fatty acid synthase (FASN) expression as well as decrease lipid accumulation by the down-regulation of PGC-1α in human hepatocarcinoma cell lines. In conclusion, HH-F3 could inhibit HBV replication, gluconeogenesis, and lipogenesis through the down-regulation of PGC-1α. Our study indicates that targeting PGC-1α may be a novel therapeutic strategy for HBV infection. Together, HH-F3mighthave potential use for the treatment of chronic hepatitis B patients with associated metabolic syndrome.

Citation Format: Wei-Hsiang Hsu, Hong-Jhih Jhuang, Chi-Ying Huang. Gluconeogenesis, lipogenesis, and HBV replication are commonly regulated by PGC-1α-dependent 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 1132. doi:10.1158/1538-7445.AM2015-1132
Abstract 1134: N-Myc promotes glutamine anaplerosis and aggressive tumor progression through direct GLS2 activation
Authors: Xiao Daibiao , Ren Ping , Su Hexiu , Yue Ming , Xiu Ruijuan , Gan Lei , Liu Hudan , Qing Guoliang
Published: August 2015

Elevated glutamine metabolism is an essential feature for malignant transformation. Glutaminase-catalyzed deamidation of glutamine to glutamate is a key step in both glutaminolysis and synthesis of ROS-scavenging glutathione. Two predominant human isozymes of glutaminase, kidney-type GLS1 (also called GLS) and liver-type GLS2, are involved in regulation of glutaminolysis. It has been shown the Myc family member, c-Myc, specifically potentiates elevated expression of GLS1 and promotes the downstream utilization of glutamine carbon in anaplerosis in liver cancer, whereas p53 tumor suppressor specifically activates GLS2 to support cellular defense against oxidative stress, suggesting GLS1 promoted tumorigenesis whereas GLS2 may inhibited it. However, whether cancer cells of different origins use a common or unique signal pathways to regulate glutamine metabolism remains largely unexplored. Using MYCN-amplified neuroblastoma as a model system, we identified GLS2 expression dramatically increased while that of GLS1 substantially decreased in the tumorigenic process of N-Myc transformed neuroblastoma. GLS2 depletion profoundly inhibited glutaminolysis concomitant with a substantial decrease in cell proliferation and viability in vitro and inhibition of tumorigenesis in vivo. Mechanistically, N-Myc, but not p53, selectively activates GLS2 transcription by direct binding to a conserved Myc-binding site within GLS2 promoter. In support of this notion, we found significant elevation of GLS2 expression concomitant with considerable GLS1 down-regulation in primary tumors obtained from MYCN-amplified neuroblastoma patients (invariably with poor prognosis) in comparison with those from MYCN non-amplified patients. In aggregate, these studies suggest that the metabolic regulation of c-Myc induced liver tumors differs from that of N-Myc induced neuroblastoma tumors which is likely to depend on both the genotype and the tissues of origin and have implications regarding the design of selective therapies targeting tumor metabolism.

Citation Format: Daibiao Xiao, Ping Ren, Hexiu Su, Ming Yue, Ruijuan Xiu, Lei Gan, Hudan Liu, Guoliang Qing. N-Myc promotes glutamine anaplerosis and aggressive tumor progression through direct GLS2 activation. [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 1134. doi:10.1158/1538-7445.AM2015-1134
Abstract 1139: Tumor-associated fibroblasts facilitate head and neck cancer metabolism
Authors: Kumar Dhruv , Kasturi Partha , Houten Bennett Van , Thomas Sufi
Published: August 2015

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy affecting 40,000 cases in the USA annually, associated with poor prognosis and significant morbidity. HNSCC tumors are dysplastic with up to 80% fibroblasts. We reported that tumor associated fibroblasts (TAFs) facilitate HNSCC progression. However, the molecular mechanisms that facilitate TAF-mediated tumor growth and metastasis remain unknown. Unlike normal cells, malignant cells often display increased glycolysis, even in the presence of oxygen; a phenomenon known as the Warburg effect. As a consequence, there is an increase in lactic acid (LA) production. It has been reported that HNSCC tumors have high LA levels that correlate with reduced survival. The mechanisms whereby HNSCC tumors survive in highly acidic conditions remain unknown. We reported that activation of the receptor tyrosine kinase, c-Met, by TAF-secreted hepatocyte growth factor (HGF) contributes to HNSCC progression. The role of TAFs-secreted HGF in HNSCC metabolism remains unknown. In addition, we were unable to detect HGF secretion by HNSCC indicating paracrine activation of c-Met. In nasopharyngeal carcinoma, c-Met inhibition down regulates the TP53-induced glycolysis and apoptosis regulator (TIGAR) and NADPH production. We hypothesized that TAF-secreted HGF regulates HNSCC glycolysis via c-Met. Further, HNSCC cells regulate metabolism in TAFs. We found that PF2341066, a c-Met inhibitor significantly decreased glycolysis (p = 0.0023) and hexokinase-II levels in HNSCC cells. These data demonstrate that c-Met regulate glycolysis in HNSCC through modulation of hexokinase-II. In admixed cultures, HNSCC and TAFs demonstrate higher expression of the bi-directional lactate transporter monocarboxylate transporter 1 (MCT-1). Our data demonstrate that TAFs have a higher capacity to proliferate than HNSCC in the presence of LA. Others have reported that NFκB increases MCT-1 levels in tumor associated stroma under high LA conditions. In ongoing studies, we will determine the role of HNSCC in regulating MCT-1 levels in TAFs. Further, the role of c-Met in regulating expression of MCT-1 in HNSCC will be elucidated. Based on the cumulative data we conclude that TAF-secreted HGF regulates HNSCC metabolism and TAFs utilize LA as a carbon source making the microenvironment more conducive to tumor progression.

Keywords : HNSCC, TAFs, HGF, Glycolysis, OXPHOS

Citation Format: Dhruv Kumar, Partha Kasturi, Bennett Van Houten, Sufi Thomas. Tumor-associated fibroblasts facilitate head and neck cancer 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 1139. doi:10.1158/1538-7445.AM2015-1139
Abstract 1170: TTP inhibits insulin receptor signals in cancer cell
Authors: Yoon Ji Eun , TRAM VO MAI , Yoon Nal Ae , Back Jin Ho , Min Young Joo , Cho Wha Ja
Published: August 2015

Insulin receptors (IRs) belong to the large class of tyrosine kinase receptors and are activated by insulin, IGF-I, IGF-II and. The binding of ligands to the IR initiates a cascade of events leading to activation of signal transduction pathways, mainly PI3K and AKT pathways, and induce glucose uptake and cell proliferation. IR signaling pathway has been reported to be deregulated in cancer cells resulting in a range of clinical manifestations including cancer. It has been shown that the presence of IR was required for transformation induced by many oncogenes and over-expression or constitutive activation of IR gave rise to transformed phenotypes. Here, we report an unexpected role of a tumor suppressor tristetraprolin (TTP) in inhibiting IR. TTP bound to the AU-rich element (ARE) within the mRNA 3′UTRs of IR, enhanced the decay of their mRNAs and inhibited the metabolism of cancer cells. The ectopic expression of IR without their 3′UTRs blocked the inhibitory effects of TTP on the Warburg effect cancer. Our data propose a new model whereby the TTP down-regulates IR and plays an important role as a negative regulator of both the energy metabolism and proliferation of cancer cells.

Citation Format: Ji Eun Yoon, VO MAI TRAM, Nal Ae Yoon, Jin Ho Back, Young Joo Min, Wha Ja Cho. TTP inhibits insulin receptor signals in cancer cell. [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 1170. doi:10.1158/1538-7445.AM2015-1170
Abstract 1175: Curcumin may have anticancer effect by normalizing cancer metabolic pathway
Authors: Takeyama Hideaki , Hayashi Hiromitsu , Kaida Takayoshi , Arima Kota , Taki Katsunobu , Higashi Takaaki , Okabe Hirohisa , Nitta Hidetoshi , Hashimoto Daisuke , Chikamoto Akira , Beppu Toru , Baba Hideo
Published: August 2015

Background: Cancer metabolism is a new and exciting field of biology that provides a fundamentally different approach to treating cancer. The characteristic of cancer metabolism is Warburg effect formation that is the glucose metabolism in the glycolytic pathway in aerobic environments. Specific high expression of PKM2 (Pyruvate kinase type M2) is indispensable to the Warburg effect formation. Curcumin is an ingredient of Termeric, and has a variety of bioactivity with less toxicity. Recently, an anti-cancer effect of Curcumin attracts attention, and various studies are conducted to investigate the bio-mechanisms as an anti-cancer agent. While Curcumin has been reported to provide an anti-cancer effect by suppressing NF-κB-COX pathway and/or the oxidative stress, its effect on cancer metabolism still remains unclear. Here, we investigated the mechanism of anti-cancer effects derived by Curcumin by focusing on cancer metabolism.

Method: The anti-cancer effect of Curcumin was examined by growth-assay in HCC cell lines (HepG2 and HLF). To further assess the biological mechanism of Curcumin on cancer cells, the changes in cancer metabolic pathways such as pyruvate kinase type M2 (PKM2), glucose transporter1 (Glut1), glucose-6-phosphate dehydrogenase deficiency (G6PD), and Transketolase (TKT).

Result: In growth assay, Curcumin treatment significantly suppressed cell growth of HepG2 cell. For the cancer metabolic pathways, Curcumin treatment induced a shift into PKM1 from PKM2 expression represented by decreased PKM2/1 ratio by real time PCR in HepG2 and HLF cells. Indeed, Glut1 and G6PD expressions were also suppressed by Curcumin treatment, whereas TKT expression was increased in HepG2 cell.

Conclusion: Curcumin displayed anti-proliferative effects on HCC cell lines, and its anti-cancer effects may be due to normalize the cancer metabolic pathway represented by a shift into PKM1 from PKM2 expression.

Citation Format: Hideaki Takeyama, Hiromitsu Hayashi, Takayoshi Kaida, Kota Arima, Katsunobu Taki, Takaaki Higashi, Hirohisa Okabe, Hidetoshi Nitta, Daisuke Hashimoto, Akira Chikamoto, Toru Beppu, Hideo Baba. Curcumin may have anticancer effect by normalizing cancer metabolic 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 1175. doi:10.1158/1538-7445.AM2015-1175
Abstract 1178: Loss of PHLPP expression promotes glycolysis in colon cancer cells
Authors: Xiong Xiaopeng , Wen Yang-an , Gao Tianyan
Published: August 2015

Increased glycolysis is considered as one of the most important metabolic alterations adapted by cancer cells in order to generate high levels of glycolytic intermediates to support proliferation. PHLPP belongs to a novel family of Ser/Thr protein phosphatases. Our previous studies have shown that PHLPP serves as a tumor suppressor to inhibit cell proliferation, promote apoptosis and increase therapeutic sensitivity in colon cancer cells. Here, we further examined the role of PHLPP in regulating metabolic pathways in colon cancer. Our results showed that the rate of glucose consumption and lactate production was significantly increased in PHLPP knockdown colon cancer cells and in PHLPP knockout MEF cells. Metabolic analysis using Seahorse XF96 analyzer revealed that decreased PHLPP expression resulted in an increase in the extracellular acidification rate (ECAR) suggesting enhanced glycolysis. To determine the underlying molecular mechanism, we found that the Akt-mediated phosphorylation of HK2 was elevated in PHLPP knockdown colon cancer cells and the amount of mitochondria-associated hexokinase 2 (HK2) was increased. This is consistent with previous finding that Akt-mediated phosphorylation of HK2 increases its activity by promoting mitochondria translocation. Furthermore, PHLPP, Akt and HK2 were found in the same mitochondria fraction and PHLPP co-immunoprecipitated with HK2 in colon cancer cells. As HK2 is the key enzyme that determines the direction and magnitude of glucose flux, our studies identified PHLPP as a novel regulator of glucose metabolism by controlling Akt-mediated regulation of HK2 activity.

Note: This abstract was not presented at the meeting.

Citation Format: Xiaopeng Xiong, Yang-an Wen, Tianyan Gao. Loss of PHLPP expression promotes glycolysis in colon 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 1178. doi:10.1158/1538-7445.AM2015-1178
Abstract 1185: Regulation of neutral amino acid transporters gene expression profile in non-small cell lung cancer
Authors: Massion Pierre P. , Senosain Maria , Hassanein Mohamed , Ji Xiangming , Qian Jun , hoeksema Megan
Published: August 2015

INTRODUCTION: In a recent study, we showed that SLC1A5, a key glutamine (Gln) transporter, regulates tumor growth and survival in NSCLC. Here we sought to characterize the expression of other Gln transporters in lung cancer and to test whether the inhibition of SLC1A5 activity induced a change in expression of other amino acid transporters in NSCLC.

METHODS: Neutral amino acid transporters reported in the cancer literature were evaluated in publically available lung cancer gene expression datasets. Among those, SLC38A1, SLC1A4, SLC1A5, SLC7A5, SLC7A11, SLC7A8 were selected for the in vitro validation. The expression of these genes was evaluated in two lung squamous carcinoma cell lines (HCC15, H226) and one adenocarcinoma cell line (A549) by RT-PCR and then quantified by qPCR, using SYBR® Green Supermix protocol. The expression of the same genes was assessed in response to transient SLC1A5 knockdown in HCC15 and A549 cell lines by qPCR.

RESULTS: Amino acid transporters SLC38A1, SLC1A5, SLC7A5 and SLC7A11 are expressed in NSCLCs, a finding that was confirmed in the three cell lines studied. SLC1A4 was found to have the lowest expression and SLC7A8 no expression in any of cell lines. In response to SLC1A5 transient knockdown in A549, SLC38A1, SLC1A4 and SLC7A5 were significantly up-regulated (p<0.02); in contrast, in HCC15, SLC38A1, SLC1A4 and SLC7A5 were significantly down-regulated (p<0.02) and SLC7A11 was up-regulated (p<0.13).

CONCLUSION: Our results show that SLC38A1, SLC1A5, SLC7A5 and SLC7A11 have the highest level of gene expression in NSCLC. We identified a possible compensatory mechanism to satisfy Gln transport and cellular function upon SLC1A5 silencing involving different transporters in a cell-specific manner. Compensatory mechanisms in response to SLC1A5 knockdown deserve further investigation as it may have implications in strategies aiming at inhibiting its activity. Further expression, localization and functional studies will follow to better understand changes occurring in lung cancer progression.

Key words: Non-small cell lung cancer, SLC1A5, expression, amino acid, transporters

Citation Format: Pierre P. Massion, Maria Senosain, Mohamed Hassanein, Xiangming Ji, Jun Qian, Megan hoeksema. Regulation of neutral amino acid transporters gene expression profile in non-small cell lung 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 1185. doi:10.1158/1538-7445.AM2015-1185
Abstract 1217: Determining the impact of CRPC-specific p53 mutation on therapeutic response and prostate tumor progression
Authors: Dean Jeffry L. , Jones Jennifer K. , Goodwin Jonathan F. , Knudsen Karen E.
Published: August 2015

Prostatic adenocarcinoma (PCa) is the most frequently diagnosed non-cutaneous malignancy and second leading cause of cancer death in men in the US. Although organ-confined disease is manageable, treatment options for disseminated PCa are limited. First-line therapy for metastatic PCa targets the androgen receptor (AR) via androgen deprivation therapy (ADT); however, tumors often recur, displaying reactivation of AR signaling despite continued therapeutic targeting. There is currently no durable treatment for this advanced disease stage, termed castrate-resistant PCa (CRPC). While most localized PCa express wild-type p53, recent high-profile, genome-wide studies identified increased TP53 gene mutation rates in advanced disease (specifically CRPC). Using these data, we noted that the patient-derived, CRPC-specific p53 mutations observed are relatively unique to prostate cancer. These mutations occur in “hotspot” clusters altered in other tumor types, but represent distinct amino acid changes seemingly unique to prostate cancer. While the underlying consequences of these CRPC-specific p53 mutations are unknown, it was hypothesized that their presence in the DNA-binding domain of p53 protein may represent “gain-of-function” (GOF) alterations that direct the transcription factor to alternative, pro-tumorigenic gene targets. Our preliminary findings strongly support this contention and reveal that these p53 mutations are major drivers of CRPC phenotypes. Specifically, our findings demonstrate that mutant p53: 1. Selectively alter p53 activity, based on analyses of PCa-relevant p53 target genes; 2. Compromise DNA damage response; 3. Alter AR signaling and response to AR-directed therapeutics; and 4. Promote transition to castration-resistance. These data are further supported by recent longitudinal studies of patient progression, wherein the R248Q mutation was found to be a key genetic alteration identifying lethal disease. While future investigation will be directed to better understand the specific contribution of individual DDR mutations, it is clear that deregulation of DNA damage repair and response pathways is likely to underlie increased genomic instability that is observed among advanced prostate cancers.

Citation Format: Jeffry L. Dean, Jennifer K. Jones, Jonathan F. Goodwin, Karen E. Knudsen. Determining the impact of CRPC-specific p53 mutation on therapeutic response and prostate tumor progression. [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 1217. doi:10.1158/1538-7445.AM2015-1217
Abstract 1234: Impact of cancer-associated mutations on MDM2 function
Authors: Chauhan Krishna M. , Martinez Luis A.
Published: August 2015

MDM2 is an E3 ubiquitin ligase that functions as a negative regulator of the tumor suppressor p53. MDM2 can promote the ubiquitination and proteasomal degradation through 26S proteasome. In addition to p53, MDM2 can ubiquitinate and promote the degradation of other proteins including SLUG, PCNA, and TERT. Although MDM2 has a well accepted role as an oncogene in human cancer, it also exhibits the ability to suppress the SLUG-driven epithelial mesenchymal transition (EMT) that is a key component of the metastasis process. The fact that MDM2 is required to suppress the SLUG-driven epithelial mesenchymal transition (EMT) led us to speculate that mutations in the MDM2 gene might impair the proteasomal degradation of key regulatory proteins that control biological events and thereby contribute to tumorogenesis. Here, we studied twenty-one somatic point mutants in MDM2 that occur in human cancer. We find that seven of these MDM2 mutants have lost the capacity to degrade p53. Of these mutants, three have lost the capacity to polyubiquitinate and two do not interact with p53. Additionally, we found that two of the mutants exhibit enhanced ability to degrade p53. We also assessed whether these mutants impacted the ability of mdm2 to degrade SLUG. Although previous studies have shown that MDM2 needs to form a trimeric complex with p53 and SLUG in order for degradation of the latter, we find that MDM2 efficiently degraded SLUG in the absence of p53. Furthermore, MDM2 mutants that do not interact with p53 still retain the ability to degrade SLUG. Our study indicates that mutations in MDM2 can yield mutant proteins that exhibit distinct capacities to degrade its substrates. Further, in vitro and in vivo studies will address the impact of these mutations on the oncogenic properties of MDM2.

Citation Format: Krishna M. Chauhan, Luis A. Martinez. Impact of cancer-associated mutations on MDM2 function. [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 1234. doi:10.1158/1538-7445.AM2015-1234
Abstract 1239: CDKN2B loss promotes progression from benign melanocytic nevus to melanoma
Authors: McNeal Andrew , Liu Kevin , Nakhate Vihang , Natale Christopher , Capell Brian , Dentchev Tzvete , Berger Shelley , Herlyn Meenhard , Seykora John , Ridky Todd W.
Published: August 2015

The CDKN2A locus on chromosome 9p21 encodes two tumor suppressors: the cyclin dependent kinase inhibitor p16INK4a and the MDM2 regulator p14ARF. Homozygous deletion of this locus is among the most common genetic events in human cancer across tissues, with the resultant selective advantage to cancer cells generally attributed to the loss of CDKN2A proteins, which help maintain functional Rb and p53. However, in greater than 90% of cancer tissues harboring CDKN2A deletion, the adjacent CDKN2B gene encoding the p15 cyclin dependent kinase inhibitor, is also deleted. The degree to which CDKN2B-encoded p15 loss contributes to human tumorigenesis is unclear. Here we show that CDKN2B is highly upregulated in common, benign melanocytic nevi (moles) expressing the constitutively active BRAF(V600E) oncogene. A large percentage of melanomas develop in continuity with these pre-existing nevi, suggesting that nevus melanocytes are not permanently senescent, and can serve as tumor-initiating cells upon acquisition of additional genetic changes. By examining primary melanocytes isolated directly from freshly excised benign human nevi, as well as normal primary melanocytes engineered to inducibly express BRAF(V600E), we link BRAF activation to a TGFβ-dependent p15 induction that arrests nevi in their pre-malignant state. We also use the primary nevus cells to establish a new genetically-defined, human in vivo melanoma xenograft model, which maximizes medical relevance by utilizing the naturally occurring melanoma precursor cells in a native 3-dimensional environment. With this approach, we show that p15 depletion in benign nevi promotes progression to melanoma, establishing the reversibility of nevus melanocyte growth arrest, and the functional importance of CDKN2B loss in human cancer.

Citation Format: Andrew McNeal, Kevin Liu, Vihang Nakhate, Christopher Natale, Brian Capell, Tzvete Dentchev, Shelley Berger, Meenhard Herlyn, John Seykora, Todd W. Ridky. CDKN2B loss promotes progression from benign melanocytic nevus to 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 1239. doi:10.1158/1538-7445.AM2015-1239