bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5047: Role of estrogen receptors alpha and beta in the balance between proliferation and surveillance
Authors: Jerry D. Joseph , Dunphy Karen A. , Roberts Amy L. , Brown Margarita
Published: August 2015

Estrogens have paradoxical effects in both promoting and preventing breast cancer. The proliferative actions of estrogens promote the expansion of both normal mammary epithelium and breast cancer. But estrogen also activates p53-mediated surveillance and apoptotic pathways to eliminate cells with potential oncogenic mutations. This is exemplified by tumor regression in response to high dose estrogen-treatment in postmenopausal breast cancer. Estrogens mediate their effects through the activation of two estrogen receptor subtypes: Estrogen Receptor alpha (ERα)and Estrogen Receptor beta (ERβ). Our objective is to examine the contribution of these receptors in mediating surveillance as opposed to proliferation by comparing selective estrogen receptor agonists with 17β-estradiol (E2) for induction of proliferation and surveillance in three model systems: (1) in vivo mouse model, (2) in vitro MCF7-tet-off-ERβ model, and (3) an ex-vivo human mammary explant model. Selective activation of ERβ with the agonist diarylpropionitrile (DPN) in vivo enhances p53-mediated apoptosis in the mouse mammary epithelium without stimulating proliferation. In addition, radiation-induced apoptosis is significantly reduced in mice lacking ERβ (βERKO). E2 or the ERα selective agonist pyrazole triol (PPT) induced the expression of estrogen response genes including progesterone receptor and amphiregulin in all three models. DPN-mediated activation of ERβ failed to induce the expression of these genes. The ERβ agonist DPN selectively induced the expression of genes that repress proliferation including TGFβ and inhibitors of canonical WNT signaling, WNT5a and AXIN2. DPN was also more potent in stimulating EGR1, a modulator of p53 activity, and CEBPd, a pro-apoptotic gene. Conclusions: The ability of DPN and ERβ to potentiate surveillance pathways while limiting proliferation suggests that ERβ agonists may provide a new approach for chemoprevention of breast cancer.

Citation Format: D. Joseph Jerry, Karen A. Dunphy, Amy L. Roberts, Margarita Brown. Role of estrogen receptors alpha and beta in the balance between proliferation and surveillance. [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 5047. doi:10.1158/1538-7445.AM2015-5047
Abstract 5054: Discerning the PARP-dependent AR cistrome/transcriptome in prostate cancer
Authors: Schiewer Matthew J. , Han Sumin , Evans Joseph , Augello Michael A. , Berman-Booty Lisa , Parsons Theodore , Birbe Ruth , Dicker Adam P. , Kelly William Kevin , Gomella Leonard G. , Feng Felix , Knudsen Karen E.
Published: August 2015

Poly (ADP-ribose) polymerase 1 (PARP-1) is an abundant nuclear enzyme that modifies substrates by poly (ADP-ribose)-ylation. Although PARP-1 has a number of well-described roles in the response to and repair of DNA damage (especially as associated with base excision repair), significant studies have demonstrated that PARP-1 functions in transcriptional regulation in multiple contexts. In the context of prostatic adenocarcinoma (PCa), our group recently discovered that PARP-1 enzymatic activity is a critical effector of androgen receptor (AR) function, and is recruited to regulatory sites of select AR target genes. Pharmacological inhibition of PARP-1 enzymatic activity results in diminished AR and PARP-1 residency at AR target gene regulatory loci, reduced AR target gene expression, and reduced AR-driven, PCa-associated phenotypes, including castrate-resistant PCa (CRPC) AR function, tumor cell growth, and transition to CRPC. Accordingly, to gain further mechanistic insight in to the PARP-1-dependent AR cistrome/transcriptome, unbiased genome-wide analyses were undertaken in both hormone therapy-sensitive PCa and CRPC model systems. Data to be discussed provide essential insight into the mechanisms by which PARP-1 modulates gene regulation and AR function, but also identifies new and unexpected functions of PARP-1 in human malignancies.

Citation Format: Matthew J. Schiewer, Sumin Han, Joseph Evans, Michael A. Augello, Lisa Berman-Booty, Theodore Parsons, Ruth Birbe, Adam P. Dicker, William Kevin Kelly, Leonard G. Gomella, Felix Feng, Karen E. Knudsen. Discerning the PARP-dependent AR cistrome/transcriptome in prostate 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 5054. doi:10.1158/1538-7445.AM2015-5054
Abstract 5061: Astrocytes promote medulloblastoma tumorigenesis via sonic hedgehog secretion
Authors: Yuelling Larra Walling , Du Fang , Lee Eric , Muradimova Renata , Li Peng , Yang Zeng-jie
Published: August 2015

Tumor development is a complex process that involves interactions between tumor cells and the surrounding cells (the microenvironment). However, in medulloblastoma (MB), the most common malignant pediatric brain tumor, the contribution of the tumor microenvironment in tumorigenesis still remains elusive. Using MB mouse models, we have recently found that astrocytes represent the major component of the MB microenvironment. Astrocytes significantly enhance MB cell proliferation in vitro and genetic ablation of astrocytes dramatically prevents MB cell proliferation and inhibits MB growth in tumor-bearing mice. These results indicate the critical role of astrocytes during MB development. Our studies have further revealed that astrocytes stimulate proliferation of MB cells by secretion of sonic hedgehog (Shh), a mitogen required for neuronal proliferation during normal development. It is well established that Shh triggers canonical hedgehog signaling via activation of the Gli1 transcription factor. Interestingly, astrocyte-derived Shh stimulates MB cell proliferation independent of Gli1 activation, suggesting that astrocytes promote MB tumorigenesis through a novel Shh signaling pathway. Together, our studies shed light on the important function of the tumor microenvironment in MB initiation and progression, and pave the road to develop therapeutic approaches to treat MB by targeting Shh secretion in astrocytes.

Note: This abstract was not presented at the meeting.

Citation Format: Larra Walling Yuelling, Fang Du, Eric Lee, Renata Muradimova, Peng Li, Zeng-jie Yang. Astrocytes promote medulloblastoma tumorigenesis via sonic hedgehog secretion. [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 5061. doi:10.1158/1538-7445.AM2015-5061
Abstract 5068: Treatment with regorafenib inhibits the tumor-promoting effect of bone marrow-derived mesenchymal stem cells in an orthotopic nude mice model of colon cancer
Authors: Shinagawa Kei , Kitadai Yasuhiko , Yuge Ryo , Onoyama Mieko , Tanaka Shinji , Yasui Wataru , Chayama Kazuaki
Published: August 2015

Bone marrow-derived mesenchymal stem cells (MSCs) have been reported to migrate to tumor stroma as well as injured tissue. We reported that, in an orthotopic nude mice model of colon cancer, MSCs travel to tumor stroma and differentiate into carcinoma-associated fibroblasts (CAFs), and then, they promote growth and metastasis of colon cancer. We also found that CAFs express platelet-derived growth factor receptor-beta (PDGFR-β), at a high level and that imatinib therapy targeting PDGFR in CAFs combined with administration of a cytotoxic drug significantly inhibits growth and metastasis of human colon cancer. A novel oral multi-kinase inhibitor, regorafenib not only inhibits oncogenic receptor tyrosine kinases such as c-KIT, RET, and B-RAF, but also inhibits stromal cells which express VEGFR1-3, TIE2, PDGFR-β, and fibroblast growth factor receptor 1 (FGFR1). These cell surface receptor tyrosine kinases are known to be involved in tumor neovascularization, vessel stabilization, lymphatic vessel formation as well as activation of stroma. We examined whether the effect of MSCs on tumor growth and metastasis was inhibited by regorafenib. KM12SM human colon cancer cells alone or KM12SM cells mixed with MSCs in a 1:2 ratio were transplanted into the cecal wall of nude mice. Orthotopic transplantation of KM12SM cells + MSCs, in comparison to transplantation of KM12SM cells alone, resulted in tumors of greater weight and volume, and higher rate of lymphatic metastasis. Co-injection of MSCs with tumor cells promoted tumor growth and metastasis of colon cancer by enhancing angiogenesis, lymphangiogenesis, and tumor cell proliferation and by inhibiting tumor cell apoptosis. When CRC tumor + MSCs bearing animals were treated with regorafenib (by oral gavage once daily at 10 mg/kg for 35 days), primary tumor size or the number of lymph node metastases were significantly decreased compared to those treated with vehicle, and reached to the level with no significant difference from KM12SM tumor cells alone. Our data suggest that targeting tumor microenvironmental signaling pathways by regorafenib influences the interaction between bone marrow-derived MSCs and tumor cells and, hence, inhibits the progressive growth of colon cancer.

Citation Format: Kei Shinagawa, Yasuhiko Kitadai, Ryo Yuge, Mieko Onoyama, Shinji Tanaka, Wataru Yasui, Kazuaki Chayama. Treatment with regorafenib inhibits the tumor-promoting effect of bone marrow-derived mesenchymal stem cells in an orthotopic nude mice model of 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 5068. doi:10.1158/1538-7445.AM2015-5068
Abstract 507: Ionizing radiation regulates mutant p53-mediated cancer cell invasiveness through targeting cyclin D1
Authors: Lee Shin-Hee , Craigmile Phillip , Wu Shiyong
Published: August 2015

Ionizing radiation (IR) is widely used as a main treatment for solid tumors, however, its potential influence and its role in the invasion and metastasis of cancer still remain unknown. In this study, we found that IR showed an inhibitory effect on the invasion of mutant p53 expressing cancer cells through targeting cyclin D1, which has been known as implicated in invasion and metastasis. Our data showed that gamma-irradiation (5 Gy) decreased trans-well migration of mutant p53 expressing cancer cells. It has been reported that following exposure to IR cyclin D1 is rapidly degraded via the ubiquitin pathway. We showed that IR-induced cyclin D1 degradation is restored after 24 hr in H1299 p53 negative cells. In contrast, cyclin D1 depletion was not recovered in H1299 mutant p53 cells, suggesting its inhibiting effect on cyclin D1 regulation. In addition, the levels of matrix metalloproteinase 9 were decreased in mutant p53 expressing cancer cells, indicating the reduction of cell migration and invasion. These data indicate that IR suppresses the restoration of cyclin D1 via the mutant p53, thus inhibiting the invasion of cancer cells expressing mutant p53.

Citation Format: Shin-Hee Lee, Phillip Craigmile, Shiyong Wu. Ionizing radiation regulates mutant p53-mediated cancer cell invasiveness through targeting cyclin D1. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 507. doi:10.1158/1538-7445.AM2015-507
Abstract 5077: Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of pro-metastatic TAMs
Authors: Rabe Daniel C. , Frankenberger Casey , Bainer Russell , Sankarasharma Devipriya , Chada Kiran , Krausz Thomas , Gilad Yoav , Becker Lev , Rosner Marsha R.
Published: August 2015

Triple-negative breast cancer (TNBC) patients have the highest risk of recurrence and metastasis. Because they cannot be treated with targeted therapies, and many do not respond to chemotherapy, they represent a clinically underserved group. While physiological inhibitors of metastasis (metastasis suppressors) play key roles in regulating tumor growth, invasion and metastasis, their role in regulating the tumor microenvironment and immune system is unknown. We hypothesized that the metastasis suppressor Raf Kinase Inhibitory Protein (RKIP) regulates stromal cells, which then affect tumor invasiveness.

Using species-specific RNAseq we determined that expression of RKIP in tumors markedly reduces the number and metastatic potential of infiltrating TAMs. While TAMs isolated from TNBC xenografts drive in vitro invasion, RKIP+ derived TAMs did not drive invasion and had decreased secretion of pro-metastatic factors including SLPI, OPN, MMP-12, Galectin-3, VEGF-A, VEGF-D, TNFR2, and PGRN. We determined that RKIP regulates TAM recruitment by blocking HMGA2, which activates CCL5 expression. CCL5 rescued TAM infiltration as well as tumor intravasation. We additionally showed that factors decreased in RKIP-derived TAMs were restored in CCL5-derived TAMs. Finally, we demonstrated the TAM secreted factor PGRN is both necessary and sufficient for TAM driven invasiveness.

To determine the clinical utility of these TAM genes we combined their expression with RKIP signaling in the tumor to create a signature that strikingly separates TNBC patients based on outcome. Our results demonstrate for the first time that metastasis suppressors can regulate the microenvironment, regulating invasion through TAMs. Our results also suggest TNBC patients with decreased RKIP activity and increased TAM infiltration may respond to therapies targeting CCL5 or PGRN.

Citation Format: Daniel C. Rabe, Casey Frankenberger, Russell Bainer, Devipriya Sankarasharma, Kiran Chada, Thomas Krausz, Yoav Gilad, Lev Becker, Marsha R. Rosner. Metastasis suppressors regulate the tumor microenvironment by blocking recruitment of pro-metastatic TAMs. [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 5077. doi:10.1158/1538-7445.AM2015-5077
Abstract 5090: Targeting metastatic prostate cancer with polyisoprenylated cysteinyl amides
Authors: Poku Rosemary Aniwaa , Nkembo Augustine , Salako Olufisayo , Amissah Felix , Flores-Rozas Hernan , Mazu Tryphon , Lamango Nazarius S.
Published: August 2015

Background: Metastatic castration-resistant prostate cancer (mCRPC) poses a major clinical management challenge due to lack of effective therapies. Monomeric G- proteins of the Ras superfamily such as Rho, Rac and Cdc42 are critical mediators in prostate cancer progression and metastasis, due to their effect on F-actin organization in cell migration. These proteins are polyisoprenylated and subject to regulation by polyisoprenylated methylated protein methyl esterase (PMPMEase). We hypothesized that metabolism of monomeric G-proteins by PMPMEase regulates growth, survival and differentiation as well as cell migration and invasion through its effects on F-actin assembly.

Methods: The effects of polyisoprenylated cysteinyl amides (PCAIs), NSL-RD-036, NSL-BA-040, NSL-BA-055 and NSL-BA-056 on the viability and proliferation of prostate cancer cell lines were investigated using the MTS assay. Docetaxel and paclitaxel were used as positive controls. Metastatic PC -3 cell migration and invasion in the presence of NSL-RD-036 were determined using the scratch and matrigel invasion assays. The effect of NSL-RD-040 on F-actin organization in TagRFP F-actin marker-transfected PC 3 cells was also investigated.

Results: The PCAIs were cytotoxic to all prostate cancer cell lines (PC-3, DU 145, LNCaP and 22Rv1). In all the cell lines, NSL-BA-040 showed the highest activity (EC50 4.3 - 5.0 μM) followed by NSL-RD-036 (EC50 2.0 - 9.2 μM), NSL-BA-056 (EC50 4.8 - 7.5 μM) and NSL-BA-055 (EC50 2.9 - 11.2 μM) while docetaxel and paclitaxel were not as effective (EC50 >100 μM). Metastatic PC-3 cell proliferation was inhibited in a concentration-dependent manner by NSL-RD-036 and at 2 μM PC-3 cell proliferation was halted. Exposure of PC-3 cells to NSL-BA-040 induced apoptosis and disrupted F-actin cytoskeleton organization in TagRFP F-actin marker transfected metastatic PC-3 cells. NSL-RD-036 also significantly inhibited PC-3 cell migration and invasion through matrigel.

Conclusions: Polyisoprenylated small molecules suppress migration and invasion as well as disrupt F-actin organization of metastatic PC-3 cells. Polyisoprenylated small molecules could serve as a new class of therapeutic agents in metastatic castration resistant prostate cancer.

Citation Format: Rosemary Aniwaa Poku, Augustine Nkembo, Olufisayo Salako, Felix Amissah, Hernan Flores-Rozas, Tryphon Mazu, Nazarius S. Lamango. Targeting metastatic prostate cancer with polyisoprenylated cysteinyl amides. [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 5090. doi:10.1158/1538-7445.AM2015-5090
Abstract 5093: Pre-clinical assessment of a novel anti-invasion nanoparticle therapeutic in combination with bevacizumab for the treatment of glioblastoma
Authors: Murray David W. , O'Halloran Philip , Jarzabek Monika , MacCarthy Brian , Sarkaria Jann N. , Schiffelers Raymond M. , Symons Marc , Byrne Annette T.
Published: August 2015

Glioblastoma (GBM), a highly invasive primary brain tumour, remains an incurable disease (1). Angiogenesis, the formation of new blood vessels, is a defining feature of GBM (2). Targeting GBM angiogenesis with Bevacizumab (Bev) is associated with improved progression free survival, but may also significantly enhance local tumour invasion (3). RhoGTPases and their activators, guanine nucleotide exchange factors (GEFs), play central roles in the invasive process (4). Herein, we sought to identify and target GEFs of importance in meditating GBM invasion with a view to improving Bev response. We report a novel strategy by which GBM tumours invade and proliferate via overexpression of the GEF beta-PIX which was shown to be increased at the invasive edge in 74% of GBM tumours assessed (n = 19) compared with tumour core (5). We have further shown that siRNA-mediated knockdown of beta-PIX in GBM patient-derived xenograft cell cultures and cell lines resulted in decreased cell invasion in 3D, cell proliferation and survival assays in vitro. Furthermore, we have uncovered a role for beta-PIX expression in endothelial cell function, as knockdown of beta-PIX inhibits HUVEC cell migration in vitro. To interrogate in vivo effects, we established an imagable orthotopic model of invasive GBM in mice, by stereotactically implanting GBM cells stably overexpressing firefly luciferase (U87R-GFP-luc2). beta-PIX-(human and mouse) specific siRNA or scrambled control siRNA (2 × 10 μg i.c.) were delivered to tumours using an alphaVbeta3 integrin targeting-(RGD peptide conjugated)-nanoparticle (InVivoPlex Aparna Bio Corp, Rockville, MD). Animals were treated with- or without- Bev (6 × 10mg/kg i.p. over 12 days). Initial data has shown that animals treated with beta-PIX siRNA nanoparticles in combination with Bev had an improved median survival of 100 days compared with Bev- alone treated mice (median: 88 days). Our data may support the future clinical use of a beta-PIX-targeting nanoparticle therapeutic, to improve Bev outcomes in GBM.

1. Kohler BA et al J Natl Cancer Inst. 2011; 103, 714-736

2. Jain RK et al Nat Rev Neurosci. 2007; 8(8):610-22

3. Norden AD et al Neurology 2008; 70: 779-787

4. Murray D et al Brit J Can 2014; 110(5):1307-15

5. Hoelzinger DB et al Neoplasia 2005; 7(1): 7-16

Citation Format: David W. Murray, Philip O'Halloran, Monika Jarzabek, Brian MacCarthy, Jann N. Sarkaria, Raymond M. Schiffelers, Marc Symons, Annette T. Byrne. Pre-clinical assessment of a novel anti-invasion nanoparticle therapeutic in combination with bevacizumab for the treatment of glioblastoma. [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 5093. doi:10.1158/1538-7445.AM2015-5093
Abstract 5101: The control of migration and invasion processes in colorectal adenocarcinoma is modulated by prion protein and its ligand STI1/HOP
Authors: Lacerda Tonielli S. , Dias Marcos Vinicius S. , Giudice Fernanda S. , Teixeira Bianca Luise , Martins Vilma Regina
Published: August 2015

The colorectal cancer is one of the most common types of cancer in the world. Previous results from our group and others revealed the Cellular Prion Protein (PrPC) as a possible therapeutic target in glioblastomas and ovarian tumors. Its activity depends on the interaction with the secreted form of the Stress Inducible Protein 1 (STI1), also known as HSP70/90 Heat Shock Organizing Protein (HOP). In the present work, we aimed to understand the mechanism by which PrPC-STI1/HOP complex can influence the aggressiveness of colorectal tumor cell lines. Cell migration and invasion assays were performed using recombinant STI1/HOP as a chemical attractant in boyden chambers coated with matrigel. The results showed that when stimulated with recombinant STI1/HOP, cells exhibited higher migration and invasion potentials than non-stimulated cells or those that were stimulated with STI1/HOP deletion mutant for the PrPC binding domain (STI1Δ230-245). Moreover, migration and invasion mediated by STI1/HOP were blocked by a STI1/HOP peptide (230-245), which mimics STI1/HOP binding site to PrPC, as well as by a neutralizing anti-PrPC antibody. To confirm the importance of PrPC-STI1/HOP complex in tumor progression and metastasis we generated a stable PrPC-knockdown colorectal adenocarcinoma cell line (WIDr). These cells showed a decreased invasion upon recombinant STI1/HOP stimulus, suggesting an important role of PrPC-STI1/HOP complex in the invasion process. In addition, as ERK signaling pathway has been related to invasion, we evaluated the ERK1/2 phosphorylation pattern in WIDr wild-type cells and their PrPC knockdown (KD) counterpart. Cells where PrPC was impaired showed a reduction in ERK1/2 phosphorylation when compared to those expressing the former protein. Experiments are under way to evaluate if these lower ERK1/2 levels are associated with decreased migration in PrPC-KD cells. In conclusion, our findings pointed that the disruption of PrPC-STI1/HOP complex could be a therapeutic target in colorectal adenocarcinoma.

Supported by São Paulo Research Foundation (FAPESP)

Citation Format: Tonielli S. Lacerda, Marcos Vinicius S. Dias, Fernanda S. Giudice, Bianca Luise Teixeira, Vilma Regina Martins. The control of migration and invasion processes in colorectal adenocarcinoma is modulated by prion protein and its ligand STI1/HOP. [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 5101. doi:10.1158/1538-7445.AM2015-5101
Abstract 5103: Loss of p27 upregulates MnSOD in a STAT3-dependent manner, disrupts intracellular redox activity and enhances cell migration
Authors: An Jing , Zhang Dongyun , Huang Chuanshu
Published: August 2015

Cell migration is a dynamic process that is central to a variety of physiological functions as well as disease pathogenesis. The modulation of cell migration by p27 (officially known as CDKN1B) has been reported, but the exact mechanism(s) whereby p27 interacts with downstream effectors that control cell migration have not been elucidated. By systematically comparing p27+/+ mouse embryonic fibroblasts (MEFs) with genetically ablated p272/2 MEFs using wound-healing, transwell and time-lapse microscopic analyses, we provide direct evidence that p27 inhibits both directional and random cell migration. Identical results were obtained with normal and cancer epithelial cells using complementary knockdown and overexpression approaches. Additional studies revealed that overexpression of manganese superoxide dismutase (MnSOD, officially known as SOD2) and reduced intracellular oxidation played a key role in increased cell migration in p27-deficient cells. Furthermore, we identified signal transducer and activator of transcription 3 (STAT3) as the transcription factor responsible for p27-regulated MnSOD expression, which was further mediated by ERK- and ATF1-dependent transactivation of the cAMP response element (CRE) within the Stat3 promoter. Collectively, our data strongly indicate that p27 plays a crucial negative role in cell migration by inhibiting MnSOD expression in a STAT3-dependent manner.

Citation Format: Jing An, Dongyun Zhang, Chuanshu Huang. Loss of p27 upregulates MnSOD in a STAT3-dependent manner, disrupts intracellular redox activity and enhances cell migration. [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 5103. doi:10.1158/1538-7445.AM2015-5103
Abstract 5105: The imprinted tumor suppressor gene NDN inhibits cell motility in ovarian cancer by reactivating FAK and RhoA
Authors: Yang Hailing , Das Partha , Mao Weiqun , Marquez Rebecca T. , Lu Zhen , Bast Robert C.
Published: August 2015

Ovarian cancers exhibit a distinctive pattern of metastasis over the surface of the peritoneum. The ability of tumor cells to migrate and invade is a prerequisite for metastasis and cancer progression. Imprinted tumor suppressor genes are of particular interest in that only a single allele is expressed and function can be lost in a single event. Here we report that an imprinted tumor suppressor gene, NDN, can suppress ovarian cancer cell migration and inhibit cell motility. NDN is a maternally imprinted gene consistently expressed in normal ovarian epithelium, but dramatically downregulated in the majority of ovarian cancers. Little or no NDN expression could be detected by immunohistochemistry in 73% of 351 epithelial ovarian cancers. NDN was also downregulated in 10 ovarian cancer cell lines with total loss in 6 of 10. Re-expression of NDN in SKOv3ip cells significantly inhibited cell migration and invasion by wound healing and Boyden Chamber assays. NDN re-expression disrupted actin stress fiber formation and prevented focal adhesion kinase (FAK) and paxillin assembly at the focal adhesion site by fluorescence microscopy. NDN re-expression reduced FAKY397 autophosphorylation by 50% and reduced SrcY416 phosphorylation by 25%. NDN re-expression also blocked RhoA signaling pathway by decreasing levels of active GTP-RhoA. Our results indicate that NDN deactivates FAK-RhoA signaling pathway in ovarian cancer cells, leading to disruption in stress fiber and focal adhesion formation, and thus suppresses cancer cell motility.

Citation Format: Hailing Yang, Partha Das, Weiqun Mao, Rebecca T. Marquez, Zhen Lu, Robert C. Bast. The imprinted tumor suppressor gene NDN inhibits cell motility in ovarian cancer by reactivating FAK and RhoA. [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 5105. doi:10.1158/1538-7445.AM2015-5105
Abstract 511: Rictor/mTORC2 drives formation, progression and therapeutic resistance of HER2-amplified breast cancers
Authors: Morrison Meghan M. , Jones Bayley , Sanchez Violeta , Estrada Monica V. , Hicks Donna , Williams Michelle , Brantley-Sieders Dana , Cook Rebecca
Published: August 2015

The phosphatidyl inositol-3-kinase (PI3K)/Akt signaling pathway is aberrantly activated in nearly 60% of breast cancers, through HER2 amplification, PIK3CA mutation, PTEN inactivation, and other alterations. The mTOR complexes mTORC1 and mTORC2 operate as activators (mTORC2) or effectors (mTORC1) of Akt. We found that mRNA upregulation in the mTORC2 cofactors RICTOR and MAPKAP1 correlated with poor survival in breast cancer patients, while upregulation in the mTORC1 cofactor RPTOR did not. Genomic gains of RICTOR and MAPKAP1 occurred more frequently in breast cancers with PI3K pathway alterations than genomic RPTOR gains. Importantly, Rictor protein levels were increased in invasive over non-invasive breast tumors, while Raptor levels were not. RICTOR gene ablation in a transgenic mouse model of HER2-amplified breast cancer delayed tumorigenesis and decreased lung metastasis, Akt-S473 phosphorylation, cell growth and survival. In human HER2-amplified breast cancer cells, Rictor loss, but not Raptor loss, decreased Akt-S473 phosphorylation, reducing cell survival and motility/invasion. Interestingly, Rictor/mTORC2 loss or treatment with a dual mTORC1/2 inhibitor improved lapatinib-induced cell killing in parental and lapatinib-resistant tumor cells to a greater extent than mTORC1 inhibition. Akt re-activation rescued cell survival, but not motility/invasion, in Rictor-depleted cells. However, Rictor loss caused accumulation of the Rac inhibitor RhoGDI2, thus impairing Rac1-dependent invasion. We conclude that HER2-amplified breast cancers use Rictor/mTORC2 to drive Akt-mediated cell survival and Rac1-mediated cellular invasion. These studies support additional studies into mTORC2-specific inhibitors.

Citation Format: Meghan M. Morrison, Bayley Jones, Violeta Sanchez, Monica V. Estrada, Donna Hicks, Michelle Williams, Dana Brantley-Sieders, Rebecca Cook. Rictor/mTORC2 drives formation, progression and therapeutic resistance of HER2-amplified breast cancers. [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 511. doi:10.1158/1538-7445.AM2015-511
Abstract 5115: An orthotopic lung tumor model for image-guided microirradiation in rats
Authors: Zhang Zhang , Wodzak Michelle , Belzile Olivier , Zhou Heling , Mason Ralph , Brekken Rolf , Chopra Rajiv , Story Michael D. , Timmerman Robert , Saha Debabrata
Published: August 2015

Introduction:

Studies have confirmed that a new lung cancer treatment called stereotactic body radiation therapy (SBRT) can cure certain patients with early stage tumors situated peripherally in their lungs, using a non-invasive, outpatient procedure. While nearly curative for peripheral lung tumors, SBRT also may present life-threatening toxicity for patients with centrally located lung tumors. Moreover, large, hypoxic tumors are at a further risk of radiotherapy failure with SBRT. The efficacy of SBRT application can be improved through the addition of agents designed to sensitize the tumor and/or protect normal tissue. To investigate and validate the response to SBRT, alone or in combination with radiomodulating compounds, it is necessary to develop a tumor model for image-guided high-dose irradiation of rodent tumors and normal tissues in a manner that closely mimics delivery of SBRT in humans. Therefore, the purpose of this study was to develop a rat orthotopic lung tumor model with a solitary intrapulmonary nodule to study the effects of high-dose radiation.

Methods:

Adult female athymic nude rats were anesthetized, intubated and then placed on a ventilator (Inspira, Harvard Apparatus, Holliston, MA) prior to surgery. A small incision (1.0 cm) was made between ribs 5 and 6 on the right side. The right lung was captured using a forceps, clamped with a carotid clamp and H460-luc/A549-luc NSCLC cells (one million cells and matrigel in 20 μl) were then injected into the right lung. The tumor growth was monitored by in vivo bioluminescent imaging (BLI) weekly. Other imaging modalities, including microCT, CBCT, and MRI, were also performed. At the end of study, the rats were sacrificed and lungs were harvested to confirm tumor location and size.

Results:

We achieved 100% survival from this surgical orthotopic implantation procedure. We also achieved >90% success in generating solitary lung tumors in the rats, whereas percutaneous orthotopic injection of tumor cells/chunks in our previous model met only 50 to 60% success in producing solitary tumors.

Conclusion:

This study presents a successful solitary lung tumor model in rodents which provides investigators a useful model to apply conformal radiation treatment, using a sophisticated treatment planning system and significantly preventing normal tissue damage.

Citation Format: Zhang Zhang, Michelle Wodzak, Olivier Belzile, Heling Zhou, Ralph Mason, Rolf Brekken, Rajiv Chopra, Michael D. Story, Robert Timmerman, Debabrata Saha. An orthotopic lung tumor model for image-guided microirradiation in rats. [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 5115. doi:10.1158/1538-7445.AM2015-5115
Abstract 5116: Detection of pancreatic cancer using acidic pH targeted probes detected using multispectral optoacoustic tomography
Authors: Zeiderman Matthew , Khanal Anil , Kimbrough Charles W. , Gomez Jorge , Grizzle William E. , McMasters Kelly M. , McNally Lacey R.
Published: August 2015

Introduction: The use of theranostic nanoparticles for simultaneous tumor imaging and drug delivery is of great research interest. The tumor extracellular environment is significantly more acidic than physiologic pH, often in the range of pH 6.0-6.8. Exploitation the acidic extracellular tumor environment is a promising method of tumor localization with pH sensitive probes and targets. Further, the use of multispectral optoacoustic tomography (MSOT) allows in vivo 3D tumor imaging via gold nanoparticles or near-infrared dyes conjugated to a targeting molecule. Gemzar is used for first-line treatment of pancreatic adenocarcinoma, a malignancy with less than 5% survival at 5 years. We have created chitosan-capped mesoporous silica gold nanorods (C-MS-GNRs) to serve as pH sensitive theranostic nanoparticles for in vivo tumor imaging and targeted drug delivery.

Methods: The chemical nature of all particles were characterized by electron microscopy, UV-Vis, and zeta-potential. Acidic pH specific Gemzar release was measured from C-MS-GNRs by UV-Vis. Cell viability assays on S2VP10 pancreatic adenocarcinoma cells with G-C-MS-GNR and Gemzar alone were performed at pH 6.5 and 7.4. S2VP10 cells were treated in pH 6.5 or 7.4 media with C-MS-GNR loaded with Indocyanin green (ICG) to demonstrate pH-sensitive cell targeting. ICG uptake was read on an Odyssey imaging system.

Results: Particle characterization demonstrated appropriate chemical composition. A drug release assay of G-C-MS-GNR demonstrated 1/10 as much drug release at pH7.4 compared to in pH 6.4 or 6.0 media. Cell viability assays demonstrated enhanced cytotoxicity with Gemzar loaded C-MS-GNR at pH 6.5 and 7.4 compared to Gemzar alone. In vitro treatment of S2VP10 cells with C-MS-ICG in pH 6.5 media demonstrated 8X greater ICG delivery by C-MS-ICG than observed at pH 7.4.

Conclusions: C-MS-GNR provides an efficacious means of targeting the acidic tumor environment for in vivo tumor imaging and drug delivery. C-MS-GNRs may be a suitable vehicle for tumor-targeted, pH-sensitive drug delivery to this currently untreatable tumor.

Citation Format: Matthew Zeiderman, Anil Khanal, Charles W. Kimbrough, Jorge Gomez, William E. Grizzle, Kelly M. McMasters, Lacey R. McNally. Detection of pancreatic cancer using acidic pH targeted probes detected using multispectral optoacoustic tomography. [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 5116. doi:10.1158/1538-7445.AM2015-5116
Abstract 5117: Fluorescence-guided surgery of liver metastasis in orthotopic nude-mouse models
Authors: Murakami Takashi , Hiroshima Yukihiko , Miwa Shinji , Shuya Yano , Toneri Makoto , Yamamoto Mako , Momiyama Masashi , Chishima Takashi , Tanaka Kuniya , Bouvet Michael , Hasegawa Satoshi , Endo Itaru , Hoffman Robert M.
Published: August 2015

We report here the development of fluorescence-guided surgery of liver metastasis. HT29 human colon cancer cells expressing green fluorescent protein (GFP) were initially injected in the spleen of nude mice. Three weeks later, established liver metastases were then harvested and implanted to the left lobe of the liver in other nude mice in order to make an orthotopic liver metastasis model. Eleven mice with a single liver metastasis were randomized into BLS or FGS groups. Three weeks after the implantation, the left lobe of the liver with a single metastasis was exposed through a median abdominal incision. BLS was performed under white light. FGS was performed using a hand-held portable fluorescence imaging system (Dino-Lite). Post-surgical residual tumor fluorescence was visualized with the OV100 Small Animal Imaging System. Five mice were treated with BLS, six were treated with FGS. Residual tumor fluorescence after BLS was clearly visualized at high magnification with the OV100. In contrast, residual tumor fluorescence after FGS was not detected even at high magnification with the OV100.

Citation Format: Takashi Murakami, Yukihiko Hiroshima, Shinji Miwa, Yano Shuya, Makoto Toneri, Mako Yamamoto, Masashi Momiyama, Takashi Chishima, Kuniya Tanaka, Michael Bouvet, Satoshi Hasegawa, Itaru Endo, Robert M. Hoffman. Fluorescence-guided surgery of liver metastasis in orthotopic nude-mouse models. [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 5117. doi:10.1158/1538-7445.AM2015-5117
Abstract 5121: Study of a synthetic peptide probe for apoptosis imaging
Authors: Yang Shen , Meng Jie , Liu Huike , Wang Chuan , Yang Yanlian , Guo Hua , Liu Jian , Wang Chen , Xu Haiyan
Published: August 2015

Chemotherapy and radiotherapy can cause a great many apoptosis in the tumor mass. Thus, direct and fast observation for the therapy-induced apoptosis is important and valuable to evaluate the effectiveness of anti-tumor treatments. In this work, a peptide (named as P17) labeling apoptotic cells was designed and chemically synthesized. To validate the labeling function, different tumor cells (Jurkat, THP-1, K562, Hela and MDA-MB-231) were treated with TRAIL (the TNF-related apoptosis-inducing ligand) to induce apoptosis, followed by incubation with FITC-conjugated P17 and then co-stained with annexin v. Flow cytometry results indicate that P17 binding to the cells was markedly increased with apoptosis rates rising. Confocal microscopy observations show that only cells with annexin v staining were labeled by P17, while live cells were not. By pull-down assay and mass spectrometry, P17-binding protein was identified to be heat shock protein 60 (HSP60), a mitochondrial chaperoninm with accumulation in the cytoplasm during apoptosis. And this result is further confirmed by confocal microscopy with anti-hsp60 antibody and a native-gel-based analysis to investigate FITC-P17 binding to HSP60. To evaluate the apoptosis-binding ability of the peptide in vivo, BALB/c mice bearing 4T1 tumor were treated with cyclophosphamide (CTX) to induce apoptosis in the tumor mass, followed by intravenously injection of fluorescent P17 prior to sacrifice. The tumor was removed for ex vivo imaging immediately. It was observed that P17 accumulated in CTX-treated tumors. The tumor tissue was further stained with TUNEL assay, confirming that the fluorescent signal observed was resulted from the labeling of apoptotic cells in tumor, because of the colocalization of P17 and TUNEL. In conclusion, this study demonstrates that P17 is a promising probe for the apoptosis imaging for uses in the evaluation of cancer therapy, drug screening and monitoring the cytotoxicity of therapeutics. (This work is supported by National Key Basic Research Program of China (2011CB933504) and Key project of the Major Research Plan from National Natural Science Foundation of China (91127043).)

Citation Format: Shen Yang, Jie Meng, Huike Liu, Chuan Wang, Yanlian Yang, Hua Guo, Jian Liu, Chen Wang, Haiyan Xu. Study of a synthetic peptide probe for apoptosis imaging. [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 5121. doi:10.1158/1538-7445.AM2015-5121
Abstract 5126: Establishment of an esophageal small cell carcinoma cell line (TYUC-1)
Authors: Shimada Yutaka , Okumura Tomoyuki , Takei Yoshinori , Watanabe Kazuaki , Hirasawa Akira , Yamane Arito , Nishiyama Masahiko , Nagata Takuya , Tsukada Kazuhiro , Shimizu Kazuharu
Published: August 2015

Background: Small cell carcinoma of the esophagus is rare and its prognosis is extremely poor. However, there is currently no in vitro model of this disease.

Methods: After obtaining written informed consent, we obtained a tumor from a 56-year-old female patient with esophageal small cell carcinoma in 2009 and transplanted it into a Severe Combined Immuno Deficiency (SCID) mouse. After successful transplantation, a tumor from the back of this mouse was minced with a sharp scissors without enzymes and was cultured in Ham F12/DMDM supplemented with 5% fetal bovine serum.

Results: Culture cells grew as adherent cells during the initial culture phase and gradually grew as floating aggregated cells. We carefully maintained these floating cells and transferred them without enzymes. These cells could passage to another flask with a split ratio of 1/10. We named these cells “TYUC-1”, and passaged them more than 85 times. The population doubling-time of TYUC-1 was approximately 30 hours. The G-band karyotype confirmed that these cells had a human origin. These cells could be transplanted to SCID mice with the same histological features of primary esophageal small cell carcinoma, and were shown to express TrkA, NGF, NSE, FGFRL1, p53, CD56, ALDH1A1, and CD44, but not CD133. A cDNA array also revealed that 9 genes were overexpressed while the expression of 33 genes was significantly lower than that in 28 esophageal squamous cell carcinoma (ESCC) cell lines. Whole exome sequencing revealed that TYUC-1 had TP53, PIK3CA, KMT2D, CACNA1H, NCOR1 and HRAS mutations. Furthermore, TYUC-1 had mutations in 128 genes, whereas 28 ESCC cell lines had no mutations in these genes.

Conclusions: We newly established TYUC-1 cells that exhibited neuroendocrine characteristics and expressed several stem cell-related molecules. These cells may be useful for understanding the characteristics of esophageal small cell carcinoma.

Citation Format: Yutaka Shimada, Tomoyuki Okumura, Yoshinori Takei, Kazuaki Watanabe, Akira Hirasawa, Arito Yamane, Masahiko Nishiyama, Takuya Nagata, Kazuhiro Tsukada, Kazuharu Shimizu. Establishment of an esophageal small cell carcinoma cell line (TYUC-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 5126. doi:10.1158/1538-7445.AM2015-5126
Abstract 5137: IQGAP1, an ERK1/2 MAPK scaffold, is an oncogenic target in canine melanoma
Authors: Zehnder Ashley , Lee Becky , Neela Poornima , Khavari Paul
Published: August 2015

BACKGROUND: Human cutaneous melanoma is primarily driven by activating mutations in Braf (60%) or Nras (20%). However, human oral melanoma harbors these mutations much less frequently. Similarly, canine oral mucosal melanomas have not been found to have activating Braf or Nras mutations. This makes them an ideal model to study alternative means of ERK1/2 MAPK pathway activation as these tumors are still reliant on MAPK signaling. We have previously studied IQGAP1 as a tumor specific ERK1/2 MAPK scaffold and shown that it is required for cancer progression. METHODS: In this study, we utilized canine oral melanoma cell lines obtained from the University of California-Davis. We examined the expression and localization of IQGAP1, a signaling scaffold that regulates oncogenic ERK1/2 MAPK signaling in human cancer, and validate it as an oncogenic target in the canine melanoma model. Using a CRISPR/Cas9 knockout of IQGAP1, we examined effects on downstream pathway activation. Additionally, we assayed proliferation of these cell lines when treated with a peptide that blocks the interaction between IQGAP1 and ERK1/2.

RESULTS: We observed that canine IQGAP1 is expressed and localizes to a similar extent in human and canine melanoma by qPCR, Western blot and immunofluorescence. Deletion of IQGAP1 from two canine oral melanoma cell lines using CRISPR-Cas9 genome editing reduces MAPK pathway activation, similar to effects seen in human BrafV600E cell lines. Additionally, we demonstrated reduced proliferation when these cells are treated with the WW blocking peptide in-vitro. We are currently investigating the expression and localization of IQGAP1 in primary canine oral melanoma compared to normal oral mucosa.

CONCLUSION: Building on the above findings to explore alternative MAPK signaling in melanoma using the canine melanoma model may yield novel therapeutic strategies and novel means to target canine and human tumors that are resistant to current Braf and MEK targeted therapies.

Citation Format: Ashley Zehnder, Becky Lee, Poornima Neela, Paul Khavari. IQGAP1, an ERK1/2 MAPK scaffold, is an oncogenic target in canine 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 5137. doi:10.1158/1538-7445.AM2015-5137
Abstract 5145: Y-27632 inhibits Myc-induced apoptosis and cooperates with Myc to immortalize human keratinocytes
Authors: Dakic Aleksandra , Divito Kyle , Fang Shuang , Palechor-Ceron Nancy , Simic Vera , Choudhury Sujata , Yu Songtao , Simbulan-Rosenthal Cynthia M. , Rosenthal Dean , Schlegel Richard , Liu Xuefeng
Published: August 2015

The high-risk HPV E6 and E7 genes are sufficient to immortalize human foreskin keratinocytes (HFKs) through activation of telomerase and inactivation of the RB/p16 pathway, respectively. Our previous work has shown that Myc (via induction of hTERT) may substitute for E6 and immortalize HFKs when combined with HPV E7. When expressed alone, however, Myc induced p53 expression and apoptosis. In the current study we found that Myc, in combination with the ROCK inhibitor (Y-27632), led immortalization of human foreskin keratinocytes. Our data confirmed that Myc induced apoptosis and blebbing of human keratinocytes when cultured in serum free synthetic medium (KGM) and that Y-27632 rapidly inhibits this process. Thus, our data demonstrate that Myc is capable of independently immortalizing HFKs when apoptosis pathways are blocked.

Citation Format: Aleksandra Dakic, Kyle Divito, Shuang Fang, Nancy Palechor-Ceron, Vera Simic, Sujata Choudhury, Songtao Yu, Cynthia M. Simbulan-Rosenthal, Dean Rosenthal, Richard Schlegel, Xuefeng Liu. Y-27632 inhibits Myc-induced apoptosis and cooperates with Myc to immortalize human keratinocytes. [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 5145. doi:10.1158/1538-7445.AM2015-5145