bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 118: EGFL6, a potential novel ligand of EGFR, play roles in Nasopharyngeal cacinoma metastasis through establishing invasive and long-distant metastatic niche by paracrine and autocrine
Authors: Chen Jinna , Jiang Chen , Yang Jing , Yu Ya-hui , Li Lei , Xiang Yang-qun , Guan Xinyuan
Published: August 2015

Distant metastasis is the leading cause of treatment failure in Nasopharyngeal carcinoma (NPC). Our study focused on the searching of potential targets for NPC metastasis treatment. cDNA microarray was applied in this screening. We compared gene expression level in metastatic NPC, non-metastatic NPC and inflammatory cases with different bioinformatic methods. EGFL6 was chosen for further study. The over-expression of EGFL6 was confirmed in NPC cell lines and 63% of the metastatic cases(n = 7/11, 3 years follow-up) by Q-PCR. EGFL6 was identified as an independent prognostic index for NPC distant metastasis survival prognostic, P = 0.023 (n = 96, QPCR). As a follicle stem cell specifically expressed secretion protein, EGFL6 showed its powerful strength in promoting cell migration and especially the formation of aggressive morphology in the matrix-gel based three-dimensional culture. With the overexpression of secreting EGFL6, CNE2 cells formed the follicle-like structure but with more aggressive leading edge, which invaded deep into the matrix-gel instead of forming single layer epithelial structure. EGFL6 overexpressed SUNE1 cells breakthrough the restriction of its regular sphere structure, and migrated for more spaces. In vivo study also showed that EGFL6 dramatically increased the tumorigenisis in subcutaneous injection assay and the growth of metastatic tumor in the mice tail vein injection experiment. Mechanism study showed that EGFL6 was a potential novel ligand of EGFR. Our resulted demonstrated that EGFL6 could bind to EGFR and caused its phosphorylation, which activated EGFR and leaded to its internalization. c-Src was subsequently phosphorylated, and the MAPK/ERK signalling cascade was activated. The EGFL6 bound cells down-regulated their expression of E-cadherin and loosed the connection with the adjacent cells, strength their F-actin and vimentin towards the direction they migrated, which indicated a transition from epithelial to mesenchymal characteristic. Further study is on going to investigate the potential of EGFL6 as a therapeutic target for NPC metastatic treatment. In conclusion, we found that EGFL6 was a potential novel ligand of EGFR, which played roles in NPC metastasis through establishing invasive and long-distant metastatic cancer niche by paracrine and autocrine.

Citation Format: Jinna Chen, Chen Jiang, Jing Yang, Ya-hui Yu, Lei Li, Yang-qun Xiang, Xinyuan Guan. EGFL6, a potential novel ligand of EGFR, play roles in Nasopharyngeal cacinoma metastasis through establishing invasive and long-distant metastatic niche by paracrine and autocrine. [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 118. doi:10.1158/1538-7445.AM2015-118
Abstract 1180: Hexokinase II plays a pivotal role in colorectal cancer cell proliferation and survival
Authors: Ho Nelson , Coomber Brenda L.
Published: August 2015

The Warburg Effect describes the widely observed metabolic phenotype of cancer cells and their heavy reliance on the glycolytic pathway for energy production regardless of oxygen tension. This is a result of alterations to metabolic signaling pathways leading to an upregulation in key glycolytic enzymes. Hexokinase II (HKII) catalyzes the first irreversible step of glycolysis and is often overexpressed in tumors. 3-bromopyruvate (3BP) has been shown to primarily target HKII, and is a promising anti-cancer compound capable of targeting critical metabolic pathways in cancer cells. Here we examine the importance of HKII to cell proliferation and survival and also whether its inhibition could provide a therapeutic strategy in human colorectal cancer (CRC). Initially, established human CRC cell lines (HCT116, Caco2, SW480, DLD-1) were screened for HKII mRNA and protein expression. Cell proliferation and survival following HKII inhibition via both siRNA and 3BP treatment was determined using crystal violet staining, flow cytometry and western blotting. Sensitivity to 3BP was correlated with HKII expression amongst the cell lines screened. We next examined the pro-survival AKT signaling pathway via western blotting and found that AKT phosphorylation was dependent on 3BP dose and was residue-specific. Immunofluorescence was then used to examine subcellular HKII localization. Following 3BP treatment, mitochondrial localization of HKII was lost. As a result of tumor vascular abnormalities, regions within a tumor are exposed to transient and/or chronic ischemia, resulting in altered oxygen and nutrient availablity. To examine the effects of glucose availability on 3BP sensitivity, media glucose was gradually reduced in a step-wise manner and HKII expression, cell proliferation and cell survival were evaluated in CRC cell lines. Cells grown under reduced or normal glucose conditions were less sensitive to 3BP exposure than cells grown under high glucose conditions, and responses correlated with changes in HKII expression. Using immunostaining, we examined the expression of HKII in both normoxic and ischemic regions in FFPE samples of human CRC. These results were correlated to tumor stage and grade, along with patient outcome. Results from this study further define the role of HKII in colorectal cancer progression and show that 3-bromopyruvate could be useful as an anti-cancer therapy against CRC tumors with high expression of HKII.

Citation Format: Nelson Ho, Brenda L. Coomber. Hexokinase II plays a pivotal role in colorectal cancer cell proliferation and survival. [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 1180. doi:10.1158/1538-7445.AM2015-1180
Abstract 1183: Metabolic characterization of follicular lymphoma transformation
Authors: Poore Brad , Ortega-Molina Ana , Nguyen Christopher , Zhao Liang , Blackwell Anne , Hartung Thomas , Wendel Hans-Guido , Le Anne
Published: August 2015

Follicular lymphoma (FL), a form of non-Hodgkin lymphoma, is the second most common form of B-cell lymphoma and remains incurable in the majority of cases despite recent advances in therapy. Following an indolent phase, 50% of patients suffer disease transformation to an aggressive form of lymphoma (transformed FL; tFL). This dramatic switch in disease behavior typically culminates in rapid deterioration and patient demise. Accordingly, much effort has been focused on understanding the genetics of transformation and has resulted in the identification of key genetic lesions (e.g. MYC activation, loss of p53, cell cycle controls, activation of NFKB (TNFAIp3/A20)). However, exactly how tumor metabolism, which is altered by these genetic lesions, contributes to disease aggressiveness is not known and therefore the metabolic changes that occur upon FL transformation are poorly understood. We have developed a murine model of FL transformation that recapitulates key genetic and pathological aspects of human FL (Oricchio et al, 2011). This model allows us to study the genetics and metabolism of FL transformation. Specifically, we will systematically define the metabolic profiles of genetically defined murine lymphomas that represent different stages of transformation and cross-compare metabolic changes to primary patient samples. This ensures focus on clinically relevant changes and provides metabolic annotation of distinct tumor genotypes. This study builds on the complementary strengths of the Le lab (Johns Hopkins) in cancer metabolism and the Wendel lab (MSKCC) in modeling FL genetics. Our study shows that MYC transformed FL exhibits a distinct metabolic profile as compared to indolent follicular lymphoma or normal spleen. The most altered pathways examined thus far are glycolysis and amino acid metabolism. We believe that the transformed lymphoma is more reliant upon glycolysis and may be exhibiting aerobic glycolysis, also known as the Warburg Effect. This is substantiated from previous experiments in which a Burkitt lymphoma line, also overexpressing MYC, was found to have altered glycolytic intermediates levels. We next plan to examine the metabolic profile of other transformed follicular lymphoma models of known genetic backgrounds. We will also cross validate the transformed mouse models with follicular lymphoma patient samples of known genetic backgrounds to identify potential metabolic markers.

Citation Format: Brad Poore, Ana Ortega-Molina, Christopher Nguyen, Liang Zhao, Anne Blackwell, Thomas Hartung, Hans-Guido Wendel, Anne Le. Metabolic characterization of follicular lymphoma transformation. [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 1183. doi:10.1158/1538-7445.AM2015-1183
Abstract 1194: O-GlcNAcylation regulates breast cancer lipid metabolism via sterol regulatory element binding protein 1
Authors: Sodi Valerie L. , Bacigalupa Zachary , Ferrer Christina , Reginato Mauricio
Published: August 2015

The Warburg hypothesis states that cancer cells display altered metabolic features to support their rapid growth and biosynthetic demands including increased glycolytic flux to synthesize necessary building blocks required by growing cells. Increased glucose uptake feeds not only glycolysis but other glucose dependent pathways as well, such as the Hexosamine Biosynthetic Pathway (HBP). HBP diverts fructose-6-phosphate from glycolysis to produce UDP-GlcNAc, the amino sugar donor to O-GlcNAc Transferase (OGT). Analagous to phosphorylation, O-GlcNAcylation can alter protein function and stability and itself is altered in several disease states. Our lab has demonstrated that OGT and O-GlcNAcylation are elevated in breast cancer and that expression of this enzyme is critical for various cancer phenotypes such as avoidance of ER stress and apoptosis, supporting invasion and metastasis and more recently promotion of Warburg effect. Here we demonstrate that OGT and O-GlcNAc are important for lipid metabolism in cancer cells through regulation of transcription factor SREBP-1 and its targets. Metabolic profiling revealed that OGT depletion in MDA-MB-231 cells decreased various lipids metabolites measured, including long-chain fatty acids, lysolipids and essential fatty acids. OGT suppression results in a decrease in SREBP-1 protein and mRNA and reduction of its transcriptional targets, enzymes involved in lipid synthesis, in both breast cancer cells and highly lipogenic normal tissue, the mammary fat pad. Over-expression of SREBP-1 blocks apoptosis induced by OGT suppression in 2D and 3D culture. Overall, we show that OGT and O-GlcNAc play a role in yet another process critical to cancer cell survival, lipid metabolism.

Citation Format: Valerie L. Sodi, Zachary Bacigalupa, Christina Ferrer, Mauricio Reginato. O-GlcNAcylation regulates breast cancer lipid metabolism via sterol regulatory element binding protein 1. [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 1194. doi:10.1158/1538-7445.AM2015-1194
Abstract 1208: Glutamine modulates cellular NAD+/NADH homeostasis thereby regulating cancer metastasis, drug sensitivity in cancer cells
Authors: Yang Lifeng , Achreja Abhinav , Moss Tyler , Baddour Joelle , Stilles Katherine , Chiba Lisa , Kim Sun Hye , Morse Josh , Marini Juan , Sood Anil K. , Ram Prahlad T. , Nagrath Deepak
Published: August 2015

Glutamine can play a critical role in cellular growth in multiple cancers. Glutamine-addicted cancer cells are dependent on glutamine for viability, and their metabolism is reprogrammed for glutamine utilization through the tricarboxylic acid (TCA) cycle. Recently, we uncovered a missing link between cancer invasiveness and glutamine dependence. Using isotope tracer and bioenergetic analysis, we found that low-invasive ovarian cancer (OVCA) cells are glutamine independent, whereas high-invasive OVCA cells are markedly glutamine dependent. Consistent with our findings, OVCA patients’ microarray data suggest that glutaminolysis correlates with poor survival. Notably, the ratio of gene expression associated with glutamine anabolism versus catabolism has emerged as a novel biomarker for patient prognosis. Significantly, we found that glutamine regulates the cellular NAD+/NADH homeostasis, which mediates cancer metastasis and progression. On the other hand, the overexpression of NAD+ biosynthesis pathway enhances glutamine's entry into TCA cycle for cancer metastasis, as well as chemo-drug resistance. Our findings suggest that a combined approach of targeting high-invasive OVCA cells by blocking glutamine's entry into the TCA cycle, along with targeting NAD+ biosynthesis pathway may lead to potential therapeutic approaches for treating OVCAs. Our insights will present a unique opportunity for overcoming the drug resistance limitation in clinical trials in ovarian cancers.

Citation Format: Lifeng Yang, Abhinav Achreja, Tyler Moss, Joelle Baddour, Katherine Stilles, Lisa Chiba, Sun Hye Kim, Josh Morse, Juan Marini, Anil K. Sood, Prahlad T. Ram, Deepak Nagrath. Glutamine modulates cellular NAD+/NADH homeostasis thereby regulating cancer metastasis, drug sensitivity in 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 1208. doi:10.1158/1538-7445.AM2015-1208
Abstract 1238: Effects of MLH1 on prostate cancer cell function
Authors: Fukuhara Shinichiro , Chang Inik , Mitsui Yozo , Yamamura Soichiro , Chiyomaru Takeshi , Majid Shahana , Saini Sharanjot , Hirata Hiroshi , Deng Guoren , Gill Ankurpreet , Wong Darryn K. , Shiina Hiroaki , Nonomura Norio , Dahiya Rajvir , Tanaka Yuichiro
Published: August 2015

Mismatch repair (MMR) enzymes have been shown to be deficient in prostate cancer. MMR can influence the regulation of tumor development in various cancers but their role on prostate cancer has not been investigated. The aim of the present study was to determine the functional effects of the mutL-homolog 1 (MLH1) gene on growth of prostate cancer cells. The DU145 prostate cancer cell line has been previously established as MLH1-deficient and thus, this cell line was utilized to determine effects of MLH1 by gene expression. Lack of MLH1 expression was confirmed by Western blotting in DU145 cells whereas levels were high in normal prostatic PWR-1E and RWPE-1 cells. Stably expressing MLH1 in DU145 resulted in decreased cell proliferation, migration and invasion properties. Lack of cell growth using athymic nude mice model also indicated a tumor suppressive effect by MLH1. Interestingly, MLH1 caused an increase in apoptosis along with phosphorylated c-Abl, and treatment with MLH1 siRNAs countered this effect. Furthermore, inhibition of c-Abl with imatinib (STI571) also abrogated the effect on apoptosis caused by MLH1. These results demonstrate MLH1 protects against prostate cancer development by inducing c-Abl-mediated apoptosis.

Citation Format: Shinichiro Fukuhara, Inik Chang, Yozo Mitsui, Soichiro Yamamura, Takeshi Chiyomaru, Shahana Majid, Sharanjot Saini, Hiroshi Hirata, Guoren Deng, Ankurpreet Gill, Darryn K. Wong, Hiroaki Shiina, Norio Nonomura, Rajvir Dahiya, Yuichiro Tanaka. Effects of MLH1 on prostate cancer cell 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 1238. doi:10.1158/1538-7445.AM2015-1238
Abstract 1244: Hyperthermia and chemotherapy mediated effects on tumor cell proliferation and heat shock protein expression in human colon cancer
Authors: Grimmig Tanja , Thumm Rebeca , Moench Romana , Moll Eva M. , Germer Christoph T. , Waaga-Gasser Ana Maria , Gasser Martin
Published: August 2015

In patients with peritoneal carcinomatosis (PC) of gastrointestinal cancer hyperthermic intraperitoneal chemotherapy (HIPEC) represents a promising treatment option integrated into multimodal concepts. Heat shock proteins (HSP) play a major role in cellular stress response conferring increased resistance in tumor cells. Therefore we analyzed HSP expression profiles in tumor cells exposed to hyperthermic and chemotherapeutic stress. To mimic HIPEC-like conditions HT29 colon cancer cells were exposed to varying hyperthermic conditions for 60 min with additional 5-fluorouracil (5-FU) treatment. HSP expression was analyzed 30 min, 24 h, 48 h and 72 h after treatment using Western Blot and RT-qPCR. Untreated cells cultivated at 37°C served as controls. Additionally, effects on tumor cell proliferation were determined 24 h, 48 h and 72 h after treatment by MTS-assay. Hyperthermia caused temperature dependent upregulation of HSP27, HSP70, HSP72, and HSP90 gene and protein expression that was further increased by additional cytotoxic 5-FU treatment. 5-FU initiated progressive rise in HSP gene expression up to 72 h after 1 h exposure at normothermia as well as under hyperthermia. After isolated hyperthermia tumor cell proliferation was recovered at 72 h. Antiproliferative effects of 5-FU could not be enhanced by further increased hyperthermia. Antiproliferative effects of hyperthermia induced during HIPEC therapy seem to be negatively influenced by highly conserved HSP mechanisms. Our findings suggest that HSP27, HSP70/72, and HSP90 are significantly involved in hyperthermia and chemotoxicity mediated cell stress repair mechanisms. While initial increase in HSP expression can counteract cytotoxic effects during HIPEC therapy long-term elevated expression levels may cause lasting resistance to cellular stress.

Note: This abstract was not presented at the meeting.

Citation Format: Tanja Grimmig, Rebeca Thumm, Romana Moench, Eva M. Moll, Christoph T. Germer, Ana Maria Waaga-Gasser, Martin Gasser. Hyperthermia and chemotherapy mediated effects on tumor cell proliferation and heat shock protein expression in human colon 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 1244. doi:10.1158/1538-7445.AM2015-1244
Abstract 1246: c-Myc is critical for apoptosis in 4-hyroxynonenal-treated colorectal cancer cells
Authors: Wales Christina TK , Gristock Rachel , So Nadine , Jacobs Aaron T.
Published: August 2015

The transcription factor c-myc has an important role in the control of cell proliferation, differentiation and apoptosis. The dysregulation of c-myc activity is a feature of many cancers. Although it enhances proliferation, the overexpression of c-myc also sensitizes cells to a variety of pro-apoptotic stimuli. 4-hydroxynonenal (HNE) is a reactive lipid that is generated as a consequence of oxidative stress, and is found to be elevated in many solid lesions. HNE is known to promote apoptosis in various cancer cell types, including colorectal cancer cells. We therefore decided to investigate whether c-myc has a role in HNE-induced apoptosis in this setting.

We began by investigating the effect of HNE on c-myc expression and function. Treatment of colorectal cancer cell lines RKO and HCT-116 with HNE caused a time- and concentration-dependent nuclear accumulation of c-myc protein. The increase in nuclear c-myc levels was not accompanied by an increase in either c-myc mRNA or total cellular levels, leading us to speculate that enhanced nuclear import or sequestration are involved. To evaluate whether c-myc activity was also increased in response to HNE, we used a luciferase reporter construct bearing a conserved c-myc binding element. These data reveal that in addition to causing its nuclear accumulation, HNE also enhances c-myc transcriptional activity.

To examine the consequence of c-myc activation and explore its role in HNE-induced apoptosis, we silenced c-myc expression using 3 different siRNA sequences in both the RKO and HCT-116 cell lines. Silencing c-myc expression caused a significant attenuation of apoptosis in HNE-treated cells, as evidenced by a reduction in caspase 3 cleavage, PARP cleavage, and caspase 3 activity assays. To investigate the reason behind this effect, we examined known pathways for HNE-induced apoptosis. In accordance with published data, we find that HNE promotes apoptosis through the ASK1-JNK pathway, and that apoptosis can be blocked with an ASK1-specific inhibitor. Furthermore, our data show for the first time that silencing c-myc expression leads to a profound reduction in the phosphorylation and activity of JNK, which we propose explains the reduction in apoptosis in c-myc deficient cells.

Since c-myc is a protein of interest and potential target for colorectal therapy, the consequence of its inhibition on cancer cell viability and cell death pathways is critical to understand. Together, our work reveals a novel pathway for c-myc mediated apoptosis and highlights its importance in HNE-treated cancer cells.

Citation Format: Christina TK Wales, Rachel Gristock, Nadine So, Aaron T. Jacobs. c-Myc is critical for apoptosis in 4-hyroxynonenal-treated colorectal 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 1246. doi:10.1158/1538-7445.AM2015-1246
Abstract 1249: MLN4924, a protein neddylation inhibitor, induces apoptosis via endoplasmic reticulum (ER)-stress in human cervical cancer
Authors: Kuo Kuan-Lin , Pu Yeong-Shiau , Ho I-LIN , Hsu Chen-Hsun , Hsieh Ju-Ton , Lin Wei-Chou , Chou Chien-Tso , Huang Kuo-How
Published: August 2015

Cervical cancer is the second most common cancer among the women worldwide. The treatment of the cervical cancer includes the surgery, chemotherapy, external and intracavitary radiotherapy adjusted to the different cancer stage. Despite these treatments, a certain proportion of women still die of the cancer due to recurrent or chemoresistent disease. The toxicity and side effect of these therapies are substantial. Therefore, it is important to develop new drugs or combination treatments to improve patient survival and minimize side effect of the therapy. MLN4924 is an inhibitor of NEDD8 activating enzyme (NAE), has been reported to elicit anti-tumor response in various malignancies. In this study, we aim to investigate the anti-tumor effect of MLN4924 on human cervical cancer and underlying mechanism in vitro and in vivo. We used two different grade human bladder cervical cell lines: ME-180 and HeLa. After exposing to MLN4924, the cell viability and apoptosis were measured by MTT and flow cytometry with annexin V-FITC labeling. The efficacy of cell proliferation was determined by BrdU incorporation assay. The cell cycle regulators, cell death-related molecules, and ER stress-related proteins were examined by Western blotting. We also use Nu/Nu xenograft mice model to clarify the effect of MLN4924 on tumor growth in vivo. We demonstrated that MLN4924 effectively induces dose-dependent cytotoxicity, apoptosis and anti-tumor phenomenon in cervical cancer cells. MLN4924 also activate cleaved-Bid, phospho-histone H2A.X, caspases and PARP, decresed phospho-Bcl2, and cause cell cycle arrest. Furthermore, MLN4924 possessed the ability to activate ER stress-related moleculors caspase-4, and CCAAT/enhancer binding protein homologous protein (CHOP), which were involved in UC cell apoptosis, and other stress responses (JNK and c-Jun activations). Moreover, we confirmed MLN4924 inhibited tumor growth and induced ER-stress in a cervical cancer xenograft mice model. Taken together, we demonstrated that MLN4924 induces cytotoxicity and cell cycle retardation, as well as activation of ER stress responses in human cervical cancer. The anti-tumor effect of MLN4924 provides a novel implication in clinical treatment of cervical cancer.

Citation Format: Kuan-Lin Kuo, Yeong-Shiau Pu, I-LIN Ho, Chen-Hsun Hsu, Ju-Ton Hsieh, Wei-Chou Lin, Chien-Tso Chou, Kuo-How Huang. MLN4924, a protein neddylation inhibitor, induces apoptosis via endoplasmic reticulum (ER)-stress in human cervical 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 1249. doi:10.1158/1538-7445.AM2015-1249
Abstract 1250: Role of mitochondria elongation in p53-induced cellular senescence
Authors: Kim Young Yeon , Jee Hye Jin , Jeong Na Young , Yun Jeanho
Published: August 2015

Various stresses such as oncogene activation, oxidative stress, and activation of tumor suppressors induce cellular senescence in both normal and cancer cells. This phenomenon, termed premature senescence or accelerated senescence, acts as an important barrier against tumorigenesis and is also considered to be a potential mechanism for controlling human cancers. Although mitochondria has been implicated in cancer, but the exact role of mitochondria in premature senescence has not been fully determined. Here, we studied how morphological and functional change in mitochondria involves in the onset of p53-induced premature senescence. Upon p53 expression in p53-defective cancer cells, extensive elongation of mitochondria network and functional defects in mitochondria were detected. Antioxidant NAC treatment indicates that mitochondria elongation induces increase the level of ROS, which is an important mediator for cellular senescence. Our results suggest that morphology change and subsequent dysfunction of mitochondria play a critical role in p53-induced premature senescence.

Citation Format: Young Yeon Kim, Hye Jin Jee, Na Young Jeong, Jeanho Yun. Role of mitochondria elongation in p53-induced cellular senescence. [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 1250. doi:10.1158/1538-7445.AM2015-1250
Abstract 1258: The unfolded protein response may contribute to racial disparity in endocrine responsiveness in breast cancer
Authors: Eltayeb Ahreej E. , Demas Diane M. , Clarke Robert , Shajahan-Haq Ayesha N.
Published: August 2015

About 70% of all breast cancers are estrogen receptor alpha positive (ER+) and depend on estrogen to grow and proliferate. Anti-hormone therapy such as antiestrogens (e.g., Tamoxifen; TAM) are often used to treat ER+ breast tumors but the cancer cells can develop resistance to these drugs (endocrine resistance). Unfortunately, ∼50% percent of all antiestrogen treated tumors eventually develop endocrine resistance, and therefore, there is an urgent need to find ways to treat this incurable disease. Nonetheless, little is known about the causes of endocrine resistance, and even less is known about the racial disparities that exist for antiestrogen responsiveness among ER+ breast cancer cases. Clinical investigations into ER+ breast cancer cases with similarly treated tumors showed that progression-free survival (PFS) and overall survival (OS) in African-American (AA) women were worse than in European-American (EA) women. The underlying causes of these racial differences within ER+ breast cancers is unknown. One cellular adaptive mechanism that allow endocrine resistant cells to survive antiestrogen treatment is a called the unfolded protein response (UPR) that is initiated within the endoplasmic reticulum caused by a stress stimulus. Cellular stress induced by antiestrogens can trigger the UPR leading to induce a pro-survival response by inhibiting cell death (by apoptosis) and promoting cell survival (by autophagy). Gene expression analysis for ER+ tumors of AA patients show up-regulation of UPR genes such as glucose-regulated protein 78, GRP78 (also known as HSP5A or BiP), activation transcription factor-6 (ATF6) and spliced X-box-protein-1 (XBP1s). Moreover, ER+ breast cancer cell lines derived from tumors of AA patients show increased levels of GRP78, ATF6 and XBP1 compared with cells derived from EA patients. The ER+ breast cancer cell lines derived from tumors of AA patients also show reduced sensitivity to Tamoxifen compared with cells derived from EA patients. Through our study, we will determine how up-regulation of the UPR contribute to the differences noted in anti-hormone therapy in treatment of ER+ breast cancer in AA versus EA women. Therefore, targeting critical pro-survival signaling molecules of the UPR can inhibit endocrine resistance and reduce growth of ER+ breast cancer cells more efficiently and avoid unsuccessful treatment in AA breast cancer patients.

Citation Format: Ahreej E. Eltayeb, Diane M. Demas, Robert Clarke, Ayesha N. Shajahan-Haq. The unfolded protein response may contribute to racial disparity in endocrine responsiveness 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 1258. doi:10.1158/1538-7445.AM2015-1258
Abstract 1266: Autophagy-mediated degradation of nuclear envelope proteins during oncogene-induced senescence
Authors: Lenain Christelle , Gusyatiner Olga , Douma Sirith , Peeper Daniel S.
Published: August 2015

Cellular senescence is a stable form of cell cycle arrest triggered by a variety of damages and stresses including oncogene expression (oncogene-induced senescence or OIS). We and others previously demonstrated that OIS occurs in human benign lesions, acting as a potent tumor suppressor mechanism preventing cancer progression. Numerous phenotypic changes occur during OIS both in the cytoplasm and in the nucleus. These include the activation of autophagy, a catabolic process operating in the cytoplasm, and downregulation of lamin B1, a component of the nuclear lamina. However, it is unknown whether these changes relate to each other. We discovered that cells entering BRAFV600E- or H-RASV12-induced senescence downregulate not only lamin B1 but also lamin A, as well as several other nuclear envelope (NE) proteins. This depletion was associated with an altered NE morphology. We further found that the global loss of NE proteins is a consequence of their degradation by the autophagy machinery. This occurs concomitantly with autophagy induction and increased lysosomal content and activity. Our study reveals for the first time to our knowledge, a connection between autophagy and the disruption of nuclear envelope integrity during OIS.

Note: This abstract was not presented at the meeting.

Citation Format: Christelle Lenain, Olga Gusyatiner, Sirith Douma, Daniel S. Peeper. Autophagy-mediated degradation of nuclear envelope proteins during oncogene-induced senescence. [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 1266. doi:10.1158/1538-7445.AM2015-1266
Abstract 1267: The senescence-associated secretory phenotype requires the histone variant macroH2A1 and is antagonized by ATM in a novel ER stress response
Authors: Chen Hongshan , Ruiz Penelope D. , McKimpson Wendy , Novikov Leonid , Kitsis Richard N. , Gamble Matthew J.
Published: August 2015

Oncogene induced senescence (OIS) is an important tumor suppressive mechanism typified by permanent proliferative arrest, a persistent DNA damage response and the senescent-associated secretory phenotype (SASP). MacroH2A1, a histone variant that plays tumor suppressive roles in a several cancer types is upregulated during OIS. Our ChIP-seq data demonstrate that SASP genes are found in macroH2A1-containing chromatin. Additionally, we found that macroH2A1 is a critical positive regulator of both the transcriptional upregulation of SASP genes and the persistent ATM activation seen during senescence. SASP factors participate in a positive feedback loop to maintain senescence through autocrine signaling and can also induce paracrine senescence in bystander cells. Strikingly, we find that cells depleted of macroH2A1 are immune to paracrine senescence triggered by SASP factors, indicating that macroH2A1 is a critical regulator of SASP positive feedback. Additionally, ectopic expression of macroH2A1.1, the macroH2A1 splice variant that is typically lost in cancer cells, is sufficient to trigger senescence in normal cells complete with a robust SASP response and persistent activation of ATM.

Due to the increased expression of secreted factors, endoplasmic reticulum (ER) stress is a feature of OIS. ER stress has been shown to lead to the generation of reactive oxygen species which can cause DNA damage and ATM activation. We determined that ER stress, as assayed by the activation of the unfolded protein response, is reduced during OIS in cells depleted of macroH2A1. Furthermore, activated ATM participates in a novel negative feedback loop reducing SASP expression in response to ER stress by triggering the removal of macroH2A1 from SASP genes. Overall, our results demonstrate that SASP gene expression is regulated by the combined actions of a positive feedback loop that requires macroH2A1 and a negative feedback loop where ER stress leads to ATM activation critical for the removal of macroH2A1 from SASP genes and consequently their repression.

Citation Format: Hongshan Chen, Penelope D. Ruiz, Wendy McKimpson, Leonid Novikov, Richard N. Kitsis, Matthew J. Gamble. The senescence-associated secretory phenotype requires the histone variant macroH2A1 and is antagonized by ATM in a novel ER stress response. [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 1267. doi:10.1158/1538-7445.AM2015-1267
Abstract 1285: Production of interleukin-17 is increased in patients with gastrointestinal cancer and correlates with immune suppression involving MDSC, nutritional impairment, and poor prognosis
Authors: Shibata Masahiko , Gonda Kenji , Nakajima Takahiro , Ohki Shinji , Nakamura Izumi , Shimura Tatsuo , Kono Koji , Takenoshita Seiichi
Published: August 2015

Although a causal relationship between inflammation and innate immunity of cancer is more widely accepted today, many of the precise cellular mechanisms mediating this relationship remain unclear. Th17 cells, which produce the proinflammatory cytokine IL-17, have been recognized as one of the key factors in regulation of inflammatory bowel disease and rheumatoid arthritis. IL-17 also has recently been reported to play an important role in induction of MDSC (myeloid-derived suppressor cells). This study demonstrated that, in patients with gastric and colorectal cancers, IL-17 production was correlated with MDSC level and with markers for nutritional impairment, immune suppression and chronic inflammation. IL-17 was significantly higher in patients with gastrointestinal cancer than in normal volunteers. In addition, IL-17 levels were significantly correlated with neutrophil counts and the neutrophil/lymphocyte ratio, and significantly inversely correlated with cell mediated immune response indicators (lymphocyte PHA-blastogenesis and IL-12 induction) and patients’ nutritional status (prealbumin levels). These patients were separated into two groups with the production of IL-17 and the overall survival of the patients with higher production of IL-17 was significantly worse than those with lower production of it. These results suggest that, in human gastrointestinal cancers, chronic inflammation involving IL-17 may be an important mechanism for disease progression through enhancement of induction of MDSC resulting immune suppression, or cachexia. The production of IL-17 was also demonstrated as one of the effective prognostic indicators in these patients. Controlling activation of Th17 cells may prove to be a valuable strategy for treatment of patients with gastrointestinal cancer. Further studies are warranted to explore this possibility.

Citation Format: Masahiko Shibata, Kenji Gonda, Takahiro Nakajima, Shinji Ohki, Izumi Nakamura, Tatsuo Shimura, Koji Kono, Seiichi Takenoshita. Production of interleukin-17 is increased in patients with gastrointestinal cancer and correlates with immune suppression involving MDSC, nutritional impairment, and poor prognosis. [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 1285. doi:10.1158/1538-7445.AM2015-1285
Abstract 1342: A new approach to cancer therapy based on dynamic anchor-mediated activation of tumor-specific T cells
Authors: Mao Chih-Ping , Hung Chien-Fu , Wu TC
Published: August 2015

Although it has been shown that T cells can play a key role in the control of tumor progression, tumor-specific T cells almost universally suffer from a poor capacity to recognize tumor antigen due to intricate mechanisms of central and peripheral immune tolerance. It has become clear that in order for immune-based cancer therapy to be successful, the major obstacle of immune tolerance to tumor self-antigen must be overcome. Here we report a strategy to accomplish this by engineering molecular events at the interface between antigen peptide-MHC (pMHC) and TCR. In particular, our approach is based on fusion of pMHC to the protein annexin V (ANXA5), which behaves as a ‘dynamic anchor’. The dynamic anchor, in a synchronized and synergistic manner, couples the early onset of TCR signaling by cognate pMHC with a boost in pMHC-TCR affinity, with serial pMHC binding, and with extensive TCR crosslinking. In our system, the dynamic anchor is linked to pMHC and strongly attaches to the plasma membrane of cognate T cells upon (and only upon) the early onset of TCR signaling. This anchor in turn exerts a mechanical force that stabilizes interactions at the pMHC-TCR interface. Furthermore, once the dynamic anchor attaches to these T cells, it facilitates repeated, serial pMHC binding and quickly arranges into uniform 2D matrices, thereby prompting TCR crosslinking. We found that fusion of ANXA5 to pMHC augments activation of cognate T cells by several orders of magnitude (>1,000-fold), bypasses the need for costimulation, and breaks tolerance against a model self-antigen in vivo. Our study opens the door to a new class of vaccination that can raise a robust immune response against low affinity tumor self-antigen.

Citation Format: Chih-Ping Mao, Chien-Fu Hung, TC Wu. A new approach to cancer therapy based on dynamic anchor-mediated activation of tumor-specific T 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 1342. doi:10.1158/1538-7445.AM2015-1342
Abstract 1347: Genomic stress in antigen experienced T-lymphocytes
Authors: Patel Shashank , Sukumar Madhusudhanan , Palmer Douglas , Roychoudhari Rahul , Roy Rabindra , Nussenzweig Andre , Restifo Nicholas
Published: August 2015

DNA damage response and repair (DDR) pathways are central to biological processes like hematopoietic stem cell maintenance, lymphocyte development and adaptive response to inflammation and cancer. However, the role of DDR in antigen experienced T-lymphocytes remains unclear.

We studied the dynamics of DDR response during CD8+ T cell proliferation and differentiation. We found that DDR gene transcripts and gamma-H2AX, a marker for DDR pathway activation, are significantly up-regulated in CD8+ T cells expanded in-vitro and in-vivo. Next we aimed to determine the consequence of the activation of DDR pathways. Based on flow cytometry measurements of gamma-H2AX phosphorylation levels, we categorized CD8+ T cells into gamma-H2AXLo and gamma-H2AXHi cells. gamma-H2AXLo CD8+ T cells actively proliferate and produce cytokines, while gamma-H2AXHi CD8+ T cells lose their ability to produce cytokines, and undergo apoptosis.

To define whether oxidative stress or replicative stress incurred in CD8+ T cell triggers this activation of DDR, we acutely treated cells with chemical agents and studied functional differences. These studies revealed that oxidative stress may be responsible for the inhibition of cytokine production and increase in cell death. Using Pmel transgenic p53-/- mouse model, we show that by deleting p53, a major signal modulator of DDR, the loss of cytokine production and cell death due to oxidative stress is reverted in CD8+ T cells. Currently, we are exploring the chemical and gene modification methods to manage oxidative stress in CD8+ T cells to improve T-cell based adoptive cell transfer therapies for cancer.

Citation Format: Shashank Patel, Madhusudhanan Sukumar, Douglas Palmer, Rahul Roychoudhari, Rabindra Roy, Andre Nussenzweig, Nicholas Restifo. Genomic stress in antigen experienced T-lymphocytes. [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 1347. doi:10.1158/1538-7445.AM2015-1347
Abstract 135: Associations between VEGF polymorphisms and clinical outcome in breast cancer
Authors: Furriol Jessica , Puntervoll Hanne E. , Knutsvik Gøril , Mannelqvist Monica , Aziz Sura , Wik Elisabeth , Akslen Lars A.
Published: August 2015

Introduction

Vascular Endothelial Growth Factor (VEGF) is a key regulator of angiogenesis and is involved in the development and progression of solid tumors. Recent advances in sequencing technologies have allowed the identification of genetic variants associated with development and progression of different diseases including breast cancer. Despite evidence suggesting that these genetic variants can be used for improved risk stratification, results are not conclusive. In this work we have evaluated the relationship between 8 VEGF SNPs (single nucleotide polymorphisms) and survival as well as clinico-pathologic characteristics in breast cancer.

Material and Methods

In this study 8 VEGF SNPs (rs3025039, rs69947, rs833070, rs2010963, rs3025010, rs25468, rs3025035 and rs833068) were selected. DNA was extracted from non-tumor FFPE-samples from a series of 367 breast cancer patients from a Norwegian population. Associations between SNPs and categorical variables were analyzed by chi-square and Fisher exact tests. We used logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). Survival was calculated by the Kaplan-Meier method (log-rank test).

Results

Our results showed that for a subset of patients, rs3025035 CT and TT were associated with relapse (p = 0.044; OR 3.07, 95%CI 1.08-8.76). Accordingly the rs3025035 CC genotype was related to longer time to recurrence after surgery (p = 0.10). Interestingly, in patients with histologic grade 3, a trend between CC and improved survival was also found in rs3025035 (p = 0.10), whereas the CC genotype in rs3025039 was associated with worse prognosis in this group (p = 0.037). Finally, the haplotype rs3025035T-rs3025039C was associated with relapse (p = 0.015; OR 3.72, 95% CI 1.31-10.62).

Conclusions

We report for the first time an association of the rs3025035 CC genotype with disease relapse and suggest that it could be a prognostic marker in breast cancer. Independent studies are needed to confirm our result.

Citation Format: Jessica Furriol, Hanne E. Puntervoll, Gøril Knutsvik, Monica Mannelqvist, Sura Aziz, Elisabeth Wik, Lars A. Akslen. Associations between VEGF polymorphisms and clinical outcome 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 135. doi:10.1158/1538-7445.AM2015-135
Abstract 1384: CRLX101, an investigational camptothecin-containing nanoparticle-drug conjugate, reverses the HIF-1α-mediated increase in cancer stem cells caused by bevacizumab in a preclinical model of triple-negative breast cancer
Authors: Conley Sarah J. , Baker Trenton L. , Burnet Joseph P. , Thiesen Rebecca L. , Lazarus Douglas , Peters Christian G. , Clouthier Shawn G. , Eliasof Scott , Wicha Max S.
Published: August 2015

Antiangiogenic agents are designed to impede the development of new tumor blood vessels, thereby starving tumors of oxygen and nutrients to ultimately block tumor growth. Despite advances made in developing antiangiogenic therapies, clinical and preclinical data suggest that these drugs have limited efficacy in breast cancer patients. Tumors inevitably develop resistance to antiangiogenic agents and patients frequently fail to demonstrate significantly better overall survival. Acquired resistance to antiangiogenic agents has been attributed in part to the induction of intra-tumoral hypoxia and the concomitant stabilization of hypoxia-inducible factor 1α (HIF-1α), a transcription factor that promotes tumor angiogenesis, invasion, metastasis, and cancer stem cell (CSC) self-renewal. In this preclinical model, we demonstrate that CRLX101, an investigational nanoparticle-drug conjugate (NDC) containing the payload camptothecin (CPT), can reverse the stimulatory effects of hypoxia on the CSC population in an orthotopic triple-negative xenograft model. The payload, camptothecin, a topoisomerase 1 inhibitor, inhibits HIF-1α protein accumulation at concentrations below those that were cytotoxic to tumor cells, and inhibits hypoxia-mediated CSC induction at these low concentrations in vitro. In an orthotopic triple-negative breast cancer model, CRLX101 is synergistic with bevacizumab. Tumor reimplantation experiments confirm that the combination therapy effectively targets both the bulk tumor cell and CSC populations. Results generated from these preclinical studies support the clinical research of combining antiangiogenic agents with CRLX101 to increase patient survival. CRLX101 is currently in phase 2 clinical trials in combination with bevacizumab in both recurrent ovarian cancer and metastatic renal cell carcinoma.

Citation Format: Sarah J. Conley, Trenton L. Baker, Joseph P. Burnet, Rebecca L. Thiesen, Douglas Lazarus, Christian G. Peters, Shawn G. Clouthier, Scott Eliasof, Max S. Wicha. CRLX101, an investigational camptothecin-containing nanoparticle-drug conjugate, reverses the HIF-1α-mediated increase in cancer stem cells caused by bevacizumab in a preclinical model of triple-negative 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 1384. doi:10.1158/1538-7445.AM2015-1384