bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4866: The atypical kinase SgK223 is a novel mediator of cell invasion in pancreatic cancer
Authors: Tactacan Carole M. , Humphrey Emily S. , Biankin Andrew V. , Daly Roger J.
Published: August 2012

Pancreatic cancer still remains one of the most aggressive and lethal of human cancers, with a lack of effective treatments contributing to its poor prognosis and high mortality. Perturbations in tyrosine kinase signaling are characteristic of many human cancers. In order to detect aberrant protein tyrosine phosphorylation events in pancreatic cancer, and to subclassify pancreatic cancer cell lines based on their tyrosine phosphorylation patterns, tryptic digests from a wide panel of pancreatic cancer cell lines were subjected to anti-phosphotyrosine immunoprecipitation, then analysed by liquid chromatography coupled with tandem mass spectrometry (MS/MS). Proteins were ranked according to differences in median phosphorylation levels across the cell line panel, and those that exhibited significantly variable phosphorylation levels were selected as candidates for further evaluation as biomarkers and therapeutic targets. One candidate identified by this approach was SgK223, a 175 kDa atypical kinase with substitutions in the DFG motif of its kinase domain. Since this is one of the conserved motifs critical for full catalytic activity, SgK223 may be catalytically inactive. Western blotting revealed that SgK223 protein expression varied across the panel, with a subset of pancreatic cancer lines exhibiting overexpression relative to normal human pancreatic duct epithelial (HPDE) cells. To further interrogate the role of SgK223 in pancreatic cancer, SgK223 was overexpressed in HPDE cells. This resulted in an elongated cell morphology and increased cellular migration and invasion in transwell assays, with no effect on cellular proliferation or Erk and Akt activity. MS/MS analysis determined that SgK223 was phosphorylated on tyrosine residues 159 and 413. Since the former is a candidate Stat3 binding site, we characterised Stat3 signalling in this model. SgK223 overexpression led to enhanced Stat3 tyrosine phosphorylation and transcriptional activity. These data identify a role for SgK223 as a mediator of cell invasion in pancreatic cancer, and support the use of MS-based phosphoproteomic profiling as an effective discovery tool for cancer-associated signaling proteins.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4866. doi:1538-7445.AM2012-4866
Abstract 4873: Comprehensive analysis of 160 whole-genome sequences reveals striking telomere alteration patterns in 9 pediatric cancers
Authors: Parker Matthew D. , Wu Gang , Chen Xiang , Rusch Michael , Bahrami Armita , Ding Li , Mardis Elaine , Mullighan Charles , Gilbertson Richard , Dyer Michael A. , Wilson Richard K. , Downing James , Zhang Jinghui
Published: August 2012

Although telomere shortening has long been recognized as a feature of cancer genomes, a comprehensive characterization of telomere alteration in pediatric cancer has not yet been performed. As part of the St. Jude Children's Research Hospital-Washington University Pediatric Cancer Genome Project (PCGP), we are performing whole genome sequence analysis on 600 pediatric cancers and matched germ line samples. This database will allow us to carry out a systematic investigation of telomere alteration across a broad range of pediatric cancers. To characterize the relative level of telomere length within a tumor, we have developed an approach that utilizes the WGS data and identifies all sequencing reads containing the telomeric repeat (TTAGGG)4. This read count is then normalized for genome-wide coverage and compared to the result from the matched germline sample to define the relative level of telomere amplification or loss in the tumor. To date we have analyzed 160 tumor/normal pairs collected from 9 distinct pediatric cancers types (Early T Progenitor Acute Lymphoblastic Leukemia (ALL), Infant ALL, Hypo-diploid ALL, Medulloblastoma, Retinoblastoma, Neuroblastoma, Osteosarcoma, Rhabdomyosarcoma, and Adrenocortical Carcinoma). Our analysis revealed normal telomere length or minimal loss in Early T Progenitor Acute Lymphoblastic Leukemia (ALL), Hypo-Diploid ALL, Infant-ALL, Medulloblastoma, Retinoblastoma, and Rhabdomyosarcoma. By contrast a subset of three distinct tumor types (Neurobalstoma, Oteosarcoma, and Adrenocortical Carcinoma) were characterized by marked increases in the number of telomere reads in the tumor consistent with telomere lengthening. These latter findings were validated in neuroblastoma by quantitative polymerase chain reaction (13/14) and fluorescence in situ hybridization (7/7). The presence of long telomeres was statistically associated with an increase in the number of somatic structural variations in tumor, with this association most evident in osteosarcoma. These data suggest that some pediatric cancers are associated with marked abnormalities in telomere maintenance leading to expansion in the telomere repeats. Defining the specific mutational processes that are responsible for these telomere defects and expanding the dataset to all 600 cancers in the project should help to define the mechanisms through which these alterations contribute to the transformed phenotypes.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4873. doi:1538-7445.AM2012-4873
Abstract 4878: The fallopian tube is the origin of high-grade serous ovarian carcinomas in a mouse model
Authors: Kim Jaeyeon , Coffey Donna M. , Creighton Chad J. , Yu Zhifeng , Hawkins Shannon M. , Matzuk Martin M.
Published: August 2012

Ovarian cancer is a lethal disease primarily because it is often not detected until it spreads beyond the female reproductive tract. Early detection is thus the key to successful intervention in ovarian cancer. Yet it is not known how this cancer arises and metastasizes. In the last decade, new evidence has challenged the dogma that the ovary is the main source of these cancers. The fallopian tube has been proposed instead as the primary origin of high-grade serous ovarian cancer _ the subtype causing 70% of ovarian cancer deaths. To understand the origin and early progression of this serous cancer, we have generated double knockout (DKO) mice by conditionally disabling in the reproductive tract two critical genes _ Dicer, an essential gene for microRNA synthesis, and Pten, a tumor suppressor that negatively regulates the PI3K pathway. These DKO mice develop high-grade serous carcinomas that arise from the fallopian tube. These high-grade serous cancers spread to engulf the ovary and then extensively metastasize throughout the abdominal cavity, causing ascites and killing 100% of the mice by 13 months. This is the first mouse model demonstrating that the fallopian tube is capable of initiating and developing high-grade serous carcinomas with similar clinical manifestations shown in the human serous ovarian carcinomas. Intriguingly, analyzing these DKO tumors at early time points also reveals that these epithelial cancers begin in the stroma of the fallopian tube, suggesting that the cancers arise through a mesenchymal-to-epithelial transition (MET) _ a novel mechanism of carcinoma initiation. This study thus presents a new paradigm for the origin and initiation of deadly high-grade serous ovarian cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4878. doi:1538-7445.AM2012-4878
Abstract 4879: Distinct roles of p53 and p19ARF in MYC-dependent tumor oncogene addiction
Authors: Adam Stacey J. , Yetil Alper , Gevaert Olivier , Jojic Vladimir , Gentles Andrew , Felsher Dean W.
Published: August 2012

Acute T-cell lymphoblastic leukemia (T-ALL) is a pediatric malignancy in which the MYC oncogene is frequently overexpressed. Although, T-ALL responds to standard therapies, in 20% of cases, treatment fails to induce sustained remission, resulting in reduced patient survival. Inhibition or restoration of the mutant gene products that drive tumorigenesis can reverse the aberrant cell growth and result in elimination of tumor cells through the phenomenon of oncogene addiction. In order to recapitulate tumor regression and recurrence, we have developed conditional mouse models of MYC-dependent T-ALL, thereby allowing for the investigation of therapeutic resistance. Recently, we have shown oncogene addiction in our MYC-driven murine model of T-ALL occurs through both tumor cell-intrinsic mechanisms, such as cellular senescence and apoptosis, and tumor cell-extrinsic, host-dependent mechanisms, including inhibition of angiogenesis, immune system-dependent tumor clearance, and autocrine/paracrine survival signaling. We now present evidence that loss of either p53 or p19ARF facilitates tumor recurrence through distinct mechanisms. p53 utilizes host-dependent mechanisms by allowing tumors to maintain angiogenesis, while p19ARF employs tumor-cell intrinsic mechanisms to circumvent senescence upon oncogene inactivation in vivo. To further interrogate the mechanisms that underlie p53- and p19ARF-dependent tumor recurrence, we performed gene expression analysis on MYC wild-type, MYC/p53-/-, and MYC/p19-/- tumors before and after MYC inactivation. Utilizing novel computational techniques to compare gene expression from our T-ALL cells to gene expression of normal hematopoietic differentiation from the Immunologic Genome Project, we have delineated the regulatory pathways underlying the effects of tumor suppressor loss in human MYC-driven lymphoma cells in the presence of targeted MYC-inactivation. We have also utilized expression analysis to establish gene signatures from unique to our MYC/p53-/- and MYC/p19-/- murine T-ALL models and shown them to be prognostic for specific human T-ALL subtypes, as well as patient relapse-free survival. Overall, we have utilized whole transcriptomic analysis to further define the underlying cell signaling by which loss of p53 and p19 facilitate tumor recurrence and demonstrated that loss of these tumor suppressors can predict outcome in human patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4879. doi:1538-7445.AM2012-4879
Abstract 488: Investigating the molecular mechanisms of tumor cell invasion
Authors: Clancy James , Sedgwick Alanna , Method Michael , Chari Vandhana , D'Souza-Schorey Crislyn
Published: August 2012

Increased MAPK signaling, small GTPase activation, cytoskeletal rearrangements and the directed targeting of proteases to sites of extracellular matrix (ECM) degradation, all accompany the process of tumor cell invasion. We have shown that nucleotide cycling on ARF6, a Ras-related small GTP-binding protein, regulates the release of protease-loaded, plasma membrane-derived microvesicles from tumor cells into the microenvironment to promote ECM degradation. These ‘invasive’ microvesicles can be isolated from peripheral body fluids and thereby, represent a source of disease and tissue specific markers. They are distinct from invadopodia, which also mediate cell invasion, rather they appear to be linked to amoeboid motility of tumor cells. While pre-invasive tumor cells shed microvesicles, the amount of shed microvesicles increases with invasiveness. We suggest that the release of protease-loaded microvesicles potentially serves as a mechanism to bring about matrix degradation and also deposit paracrine information at distal locations, creating paths of “least resistance” as tumor cells traverse distances and invade through surrounding tissue. Invadopodia, on the other hand, facilitate pericellular proteolysis of the ECM at the cell's invasive front and appear to be linked to mesenchymal type of tumor cell motility. Rho GTPase signaling in part governs whether tumor cells produce invadopodia or adopt the amoeboid type movement and release microvesicles. Moreover, the specific targeting of distinct cargo to each of these sites enables the biogenesis of each invasive structure. Understanding the interplay between these two invasive cell programs will provide new and important insights into the progression toward pathophysiological states.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 488. doi:1538-7445.AM2012-488
Abstract 4880: Disruption of STAT3 signaling promotes K-Ras induced lung tumorigenesis
Authors: Grabner Beatrice , Schramek Daniel , Mueller Kristina M. , Zwick Ralf Harun , Penninger Josef , Poli Valeria , Moriggl Richard , Sibilia Maria , Popper Helmut , Eferl Robert , Casanova Emilio
Published: August 2012

Lung cancer related and unrelated to smoking is still leading cause of cancer deaths worldwide with an overall survival rate of 15%. Several genetic alterations have been associated with lung cancer: loss of tumor suppressor genes such as p53, INK4a, LKB1 and mutations/amplifications in several oncogenes like K-Ras, EGFR, or c-Myc. Most frequent smoking-related mutations impair GTP hydrolysis in K-Ras, an oncogene downstream of the EGFR pathway, causing persistent cell growth and proliferation in 20-30% of lung adenocarcinomas. Another important downstream effector of EGFR signaling is the signal transducer and activator of transcription (STAT)-3. STAT-3 regulates important pathways in tumorigenesis, through upregulation of genes encoding apoptosis inhibitors (Bcl-XL, Bcl-2, Mcl-1, survivin). In patient samples and NSCLC cell lines nuclear, phosphorylated STAT3 is enhanced and correlates with subsequent suppression of apoptosis of NSCLC tumors. However, the role of STAT-3 in lung cancer in vivo has not yet been established. In order to investigate the role of STAT-3 in lung tumors, we have established a genetic mouse model that allows inducing K-RasG12D-dependent lung tumors and simultaneously genetically ablating STAT-3. Survival analysis of this model showed a significant advantage of K-RasG12D male mice harbouring STAT-3 compared to K-RasG12D mice lacking one or both alleles of Stat-3, indicating a hapoloinsufficient tumor suppressor role in oncogenic K-RasG12D tumor formation. Furthermore, animals with deleted STAT-3 and activated K-RasG12D have a significant increase in tumor burden and develop more adenomas and adenocarcinomas than age-matched animals, harbouring only oncogenic K-RasG12D. This data suggest that disruption of STAT-3 signaling promotes tumorigenesis in K-Ras induced tumors. We are currently investigating the molecular and cellular mechanisms responsible for this observation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4880. doi:1538-7445.AM2012-4880
Abstract 4882: Downregulation of core component of miRNA machinery, Tudor-SN, impedes NSCLC resistance to chemotherapy
Authors: Akbar Nadeem S. , Surova Olga , Zhivotovsky Boris
Published: August 2012

Lung cancer (LC) is among the most common tumors liable for worldwide highest mortality rate. It has a poor prognosis and symptoms related to disease occur at an advanced stage where therapy response becomes less effective. Resistance to radio- and chemotherapy of all tumors in general and LC, in particular, is a complex phenomenon. Evasion of cell death is one of the key hallmarks of both tumorigenesis and resistance to treatment. Differential expression of microRNAs (miRNAs or miRs), a class of small non-coding RNAs, 19-25 nucleotides in length, and proteins involved in miRNAs maturation (Drosha, Exportin-5, Dicer1, PACT, Tudor-SN, Argonaute-2, and FXR1) have been linked to carcinogenesis and therapy resistance. Nevertheless, comprehensive information is needed to better understand their function in tumor formation and resistance/sensitization to therapy. Therefore, the aim of this study was to investigate the role of miRNA machinery in chemoresistance of a selected panel of non-small cell lung carcinoma (NSCLC) cell lines (U1810, H661 and A549) resistant to treatment. It was revealed that knockdown of Drosha, Dicer-1 and Ago-2 was not sufficient to sensitize them to subsequent treatment with either cisplatin, 5-FU, etoposide or camptothecin (CPT), while silencing of Staphylococcal nuclease domain containing 1(SND1/p100/TSN), a key component of RISC complex, led to increased sensitivity of NSCLC cells to the DNA-damaging agents. Besides its function as a component of the multiprotein complex involved in miRNA functioning, TSN is known to act as a transcriptional activator and oncogene in many cancers. Additionally, it is cleaved during apoptosis, losing its pro-carcinogenic function. Our results show that these NSCLC cells with TSN-knocked down exhibited much stronger response to treatment with CPT and cisplatin compared to wild-type cells, as monitored by enhanced cleavage of PARP, increase in percentage of subG1 cells and potentiation of caspase-3-like activity. Overall, obtained data suggest that this nuclease can play an important role in the resistance of NSCLC cells to chemotherapy and can be used as a potential target to increase sensitivity of lung tumors to this type of treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4882. doi:1538-7445.AM2012-4882
Abstract 4892: EBV infectivity determines sensitivity to bortezomib in hematopoietic malignancy cells
Authors: Kim Areumnuri , Lee Jung-Eun , Park Sunhoo , Lee Seung-Sook
Published: August 2012

Epstein-Barr virus (EBV) is closely associated with several human malignancies where it expresses limited subsets of latent proteins. Of the latent proteins, latent membrane protein 1 (LMP1) is a potent transforming protein that constitutively induces multiple cell signaling pathways. C-terminal signaling domain of LMP1 (CTAR2) is known to engage the c-Jun N-terminal kinase (JNK) and NF-κB pathways, which contributes to EBV-associated oncogenesis. Bortezomib, proteasome inhibitor, blocks degradation of IκBα, thereby blocking not only NF-κB activation but also related cytokine production and the survival advantage for patients. However, to date, no study has examined that EBV infectivity is correlated with efficacy of bortezomib in the hematopoietic malignancies cells. Here, we used EBV-positive cell lines (Hank-1, Jijoye, Daudi and Granta519), EBV-negative cells (NK-92, Ramos, Jurkat and Rec1) and stable EBV-transfected cells (Ramos/EBV, Jurkat/EBV and Rec1/EBV) to evaluate the bortezomib sensitivity, highlighting the role of NF-κB. In the present study, we investigated that treatment with bortezomib significantly induced apoptosis and growth inhibition through blocking nuclear NF-κB signaling pathway in EBV-positive cells than EBV-negative cells. Thus, this data suggest that LMP1-induced NF-κB plays a critical role of survival and growth in EBV-positive cells. Additionally, treatment with bortezomib may provide a therapeutic advantage for patients with EBV-positive cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4892. doi:1538-7445.AM2012-4892
Abstract 4893: XIAP downregulation accompanies inhibition of melanoma xenograft growth by mebendazole
Authors: Doudican Nicole A. , Byron Sara , Pollock Pamela , Orlow Seth J.
Published: August 2012

Background: Melanoma's intrinsic resistance to therapy has been attributed to modulation of cellular survival pathways including apoptosis. We originally reported that mebendazole (MBZ), which acts as a microtubule-disrupting agent, is a potent inducer of apoptosis in melanoma cells in vitro via a Bcl-2 dependent mechanism (Molecular Cancer Research, 2008). Here, we show that MBZ is also able to effectively modulate another key anti-apoptotic factor, XIAP, to promote melanoma apoptosis both in vitro and in vivo. Methodology: Safety and efficacy of mebendazole was assessed using a human melanoma xenograft model established from M-14 cells. The effect of MBZ on XIAP expression and induction of apoptotic pathways was evaluated by immunoblotting and co-immunoprecipitation techniques along with densitometric quantification. The growth inhibitory effects of MBZ were determined in a panel of melanoma cell lines with the sulphorhodamine (SRB) assay. siRNA techniques were used to reduce expression of XIAP. Results: Oral MBZ is as effective as the current standard of care temozolomide (TMZ) in reducing melanoma growth in vivo, with no notable toxicities observed. Inhibition of melanoma growth in vivo is accompanied by MBZ specific reduced expression of XIAP and cleavage of caspase 9. In response to MBZ treatment, sensitive cell lines display reduced levels of XIAP expression whereas resistant cell lines do not. Moreover, down-regulation of XIAP expression by siRNA in the MBZ-resistant melanoma cell line UACC1097 was accompanied by a reduction in the IC50 for MBZ from >10 μM to 3.7 μM. Exposure of melanoma cells to MBZ promotes the interaction of SMAC/DIABLO with XIAP, thereby alleviating inhibition of apoptosis by XIAP. Conclusions: In addition to demonstrating efficacy and safety in vivo, our preclinical studies of the promising anti-melanoma agent mebendazole provide insight into characterization of an apoptotic promoting mechanism of action.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4893. doi:1538-7445.AM2012-4893
Abstract 4894: Effect of lysosome destabilization on response to ceramide in prostate cancer cells over-expressing acid ceramidase
Authors: Turner Lorianne S. , Dungee Stephen , Pezzimenti Frank , Weatherford Margot
Published: August 2012

Acid ceramidase (AC) over-expression has been observed in prostate cancer cell lines and primary tumors, and contributes to resistance to chemotherapy and radiation. The consequence of AC over-expression is the ability to convert ceramide, which is often produced as a pro-apoptotic response to stress, to sphingosine, which can then be converted to the pro-survival molecule sphingosine-1-phosphate. In addition to the ability to metabolize ceramide produced in response to stress, prostate cancer cell lines over-expressing AC also have increased lysosomal density and increased levels of autophagy. Autophagy is a cellular mechanism for recycling proteins and organelles which can be used as a survival mechanism in response to stress. Therefore, in addition to the increased capacity to metabolize ceramide produced in response to insult, the increased basal level of autophagy results in cells that have a heightened resistance to cellular stress. Preliminary results suggest that prostate cancer cell lines over-expressing AC have increased expression of lysosomal-stabilizing proteins, which highlights lysosome stability as a potential therapeutic target for cancer therapy. We have evaluated the effect of chloroquine, an FDA-approved drug that localizes to lysosomes, on the response of these cells to ceramide treatment. Pre-treatment with chloroquine increased the sensitivity of the cells to ceramide treatment, possibly due to AC disruption. These studies suggest that chloroquine may increase the efficacy of treatments that induce ceramide.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4894. doi:1538-7445.AM2012-4894
Abstract 4895: Caveolin-1 modulates docetaxel activity by inducing p53 expression in breast cancer.
Authors: Park Joo Hee , Kang Jin Ho , Jo Uk Hyun , Gil Eun Young , Park Jong Kuk , Lee Eun Sook , Kim Yeul Hong , Kim In Sun , Park Kyong Hwa
Published: August 2012

Caveolin-1 is reported to be down-regulated in breast cancers compared with normal mammary tissue. More recent data showed that high caveolin-1 expression is more associated with basaloid cancers than ER and/or PR or HER-2 expressing cancers. Investigatirs have reported that Caveolin-1 promoted resistance to chemotherapy-induced apoptosis in Ewing's sarcoma cells. However, the biologic relevance of caveolin-1 in breast cancer remains unclear. Thus, the aim of this study is to investigate its potential biologic relevance of Caveolin-1 to cell survival after docetaxel chemotherapy, one of the most important drug in breast cancer treatment. In this current study, we first showed that Caveolin-1 protein expression was suppressed in the ER(+) human breast cancer cell lines (MCF-7, T47D, and ZR75-1), but not in triple negative cancer cells (MDA-MB-231 and HS578T) and one of the HER-2 type cell (HCC1954) using Western blot analysis. Better cytotoxic effect of docetaxel was observed in the caveolin-1-expressing triple negative cells and HER-2 type cell than the other caveolin-1-deficient HER-2 type and luminal type of cancer cells. Next, caveolin-1 gene was reintroduced into caveolin-1 deficient luminal type breast cancer cells (MCF-7 and ZR75-1) to investigate its potential modulatory effect on docetaxel-induced cytotoxicity. The cell proliferation and MTT assay showed that the overexpressed caveolin-1 had further modulated docetaxel-induced anti-proliferative and cytotoxic effect in the luminal type cells. The anti-proliferative effect of docetaxel in the caveolin-1 gene over-expressed breast cancer cell lines was accompanied by decreasing cyclin D1 expression and inducing cyclin B1 accumulation, then resulting in cell cycle arrest at G2/M phase in the FACS analysis. In addition, re-introduction of caveolin-1 further increased docetaxel-induced cell death by synergistically inducing p53 expression and subsequent induction of p21, then finally apoptosis of breast cancer cells. These results were verified in the mouse model using SCID mice implated with either Caveolin-1-MCF-7 cells or control MCF-7 cells. When each group of tumor-bearing mice were treated by docetacel, mice with Caveolin-1-MCF-7 tumors showed a signiflcantly smaller tumors than those of control group. These results suggest that caveolin-1 may have a modulating factor for docetaxel activity by inducing p53 expression in breast cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4895. doi:1538-7445.AM2012-4895
Abstract 4901: Impact of the TGF-β1 isoform on p53 signalling in ovarian cancer cell lines in response to cisplatin
Authors: Baribeau Sébastien , Chaudhry Parvesh , Asselin Éric
Published: August 2012

Transforming growth factor β is a pleiotropic cytokine which inhibits cell growth, induces cellular differentiation, and can lead to cellular apoptosis under certain conditions. TGF-β is also involved in epithelial-mesenchymal transition (EMT), a phenomenon by which cells acquire a dedifferentiated phenotype and gain motility and invasive properties. In the present study, we investigated the impact of TGF-β1 on p53 mediated cellular signalling in ovarian cancer cell lines in response to cisplatin. Four cell lines with different p53 status: A2780 (wild-type p53), A2780CP (derived from A2780, resistant to cisplatin, one p53 allele mutated V172F and one p53 allele wild-type), OVCAR-3 (p53 mutated R248Q) and SKOV-3 (p53 negative) were used in the present study. Cells were co-treated with TGF-β1 (10ng/mL) and cisplatin (10μM) for 24 hours and protein levels were analysed by western blotting. Our results show that TGF-β1 inhibits cisplatin-induced apoptosis in SKOV-3 cells as demonstrated by reduced PARP cleavage and caspase-3 activation. However, the inhibition of cisplatin-induced apoptosis was not observed in cells with wild type or mutated p53. Co-treatment of TGF-β1 and cisplatin decreased the levels of phosphorylated/active Akt compared to cisplatin alone, suggesting that TGF-β1 promotes cisplatin-induced apoptosis in A2780 cells in part through p53. In addition, Mdm2 was cleaved in response to cisplatin treatment only in p53 wild-type expressing A2780 cells. The levels of the caspase inhibitor XIAP were also decreased in A2780 cells when treated with cisplatin. Together, these results suggest that TGF-β1 promotes apoptosis when used in combination with cisplatin in p53 wild-type ovarian cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4901. doi:1538-7445.AM2012-4901
Abstract 4973: Telomerase-specific replication-selective oncolytic viruses for adenoid cystic carcinoma cell lines
Authors: Sato Daisuke , kurihara Yuji , Kondo Seiji , shirota Tatsuo , Urata Yasuo , Fujiwara Toshiyoshi , Shintani Satoru
Published: August 2012

There is no effective treatment of adenoid cystic carcinoma (ACC) in oral region, which low sensitivity of chemotherapy and radiation therapy. We previously showed that telomerase-specific replication-competent adenovirus (Telomelysin, OBP-301), in which the human telomerase reverse transcriptase (hTERT) promoter controls the adenoviral E1 gene expression, induces a selective antitumor effect in oral squamous cell carcinoma (OSCC) cells in vitro and in vivo orthotopic graft model. We conducted to evaluate the effectiveness of OBP301 against ACC. First, we could confirm that the expression of hTERT in two types of ACC cell lines (ACC2, ACCM) by Western blotting. Then, we examined the antitumor effect of OBP301 in human ACC cells in vitro. OBP-301 infection induced cell death in human ACC cells in a dose-dependent manner. We also examined the expression levels of coxsackievirus and adenovirus receptor (CAR) on the cell surface of each type of cell by flow cytometric analysis. Apparent amounts of CAR expression were detected on human ACC cells. Relative hTERT mRNA expression in ACC was analyzed by real-time RT-PCR, which showed high expression time dependent. In addition, OBP-401 is a genetically engineered adenovirus that expresses GFP by inserting the GFP gene under the control of the cytomegalovirus promoter at the deleted E3 region of OBP-301. Human ACC cells expressed bright GFP fluorescence as early as 12 h after OBP-401 infection. The fluorescence intensity gradually increased in a dose-dependent manner, followed by rapid cell death due to the cytopathic effect of OBP-401, as evidenced by floating, highly light-refractile cells under phase-contrast photomicrographs. In conclusion, our data clearly indicate that telomerase-specific oncolytic adenoviruses have a significant therapeutic potential against human ACC in vitro. These results suggested that treatment of OBP-301 and OBP-401 are possible to improvement of QOL of oral cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4973. doi:1538-7445.AM2012-4973
Abstract 4974: Metformin has an anti-cancer effect by repressing TWIST/N-cadherin signaling
Authors: Ge Rongbin , Wang Zongwei , Olumi Aria
Published: August 2012

Introduction and Objective Metformin, one of the most commonly used medications for treatment of type 2 diabetes, has emerged as a potential anticancer agent. The molecular mechanisms associated with the anti-cancer effect of metformin are poorly understood. We demonstrate, for the first time, that metformin inhibits prostate cancer proliferation through suppression of TWIST/N-cadherin signaling pathway. Methods RTαPCR, Western blot, immunofluorescence assays and confocal microscopy were applied to evaluate protein expression level. MTS assay and FACS analysis were applied to determine cellular proliferation. N-cadherin expression vectors were transfected into PC3 prostate cancer cells to establish stable cells with over-expression of N-cadherin. Metformin-resistant prostate cancer cells were established by exposure to higher concentrations (10mM) of metformin over 4 weeks. Results Treatment with metformin (5mM) inhibited proliferation in three different types of cancer cells (PC3-prostate cancer cells; T24-bladder cancer cells and 786-O- kidney cancer cells). Metformin treatment suppressed expression of N-cadherin in all cell types. Similar findings were observed by confocal microscopy. Expression of E-cadherin was not affected by metformin. Metformin-mediated repression of N-cadherin was dose and time- dependent in prostate cancer cells. PC3 prostate cancer cells with stable over-expression of N-cadherin became resistant to metformin-mediated inhibition. Stable PC3 prostate cancer cells after selection for metformin became resistant to metformin-mediated inhibition, and the metformin-resistant cancer cells had slightly higher baseline level of N-cadherin. In addition, in the metformin-resistant cells, N-cadherin levels were unchanged after treatment with metformin. The expression of AKT and AP-1, the downstream molecules of N-cadherin, closely correlated with expression of N-cadherin after treatment with metformin. Moreover, we also found that metformin inhibited expression of TWIST-1, a transcriptional activator of N-cadherin. Similar findings were observed by confocal microscopy. Conclusions We demonstrate that Metformin's anti-cancer therapeutic effect may be mediated through repression of the TWIST/N-cadherin signaling pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4974. doi:1538-7445.AM2012-4974
Abstract 4976: Telomerase-specific replication-selective virotherapy combined with radiation therapy for oral squamous cell carcinoma cells
Authors: Kurihara Yuji , Sato Daisuke , Shirota Tatsuo , Kondo Seiji , Kataoka Masafumi , Urata Yasuo , Fujiwara Toshiyoshi , Shintani Satoru
Published: August 2012

Replication-selective tumor-specific viruses present a novel approach for treating neoplastic disease. These vectors are designed to induce virus-mediated lysis of tumor cells after selective viral propagation within the tumor. Telomerase activation is considered to be a critical step in carcinogenesis, and its activity is closely correlated with human telomerase reverse transcriptase (hTERT) expression. We previously, investigated the antitumor effect of the hTERT-specific replication-competent adenovirus (Telomelysin: OBP-301) on oral squamous cell carcinoma (OSCC) cells in vitro and in vivo orthotopic graft model. OBP-301 replicated efficiently and induced more over 50% cell killing in a panel of human OSCC cell lines, but not in normal human fibroblasts, which were lacking telomerase activity. In orthotopic graft model, intratumoral injection of OBP-301 resulted in a significant inhibition of tumor growth and prolongation of survival. Moreover, OBP-301 in use has limited potency when administered alone; however, combination therapy using these agents and conventional anticancer agents, such as radiation exhibits encouraging levels of efficacy. Here, we describe the mechanistic basis for synergy of irradiation and OBP-301. This combination therapy was more effective compared with OBP-301 alone in OSCC cells. These results illustrate the potential of combining oncolytic virotherapy and ionizing radiation as a promising strategy in the management of human oral cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4976. doi:1538-7445.AM2012-4976
Abstract 4979: Co-operative role for Notch and fibroblast growth factor FGF2 signaling pathways in maintaining malignant phenotype of neuroblastoma: Potential targets for neuroblastoma growth inhibition.
Authors: Wesley Umadevi V. , Wesley Cedric S. , Dempsey Robert J.
Published: August 2012

Neuroblastoma, an extracraniel tumor of childhood generally progresses to therapy resistant metastatic tumor. Increased expression and activities of mitogenic FGF and the Notch signaling have been extensively correlated with highly malignant behavior and poor prognosis of many cancers including neuroblastoma, making FGF2-Notch3 as rational targets for therapeutic intervention. We have previously shown that a cell surface protease called dipeptydyl peptidase IV (DPPIV) induces apoptotic cell death of neuroblastoma cells thereby inhibiting their tumorigenic potential. In this study, we further examined if tumor suppressor activity of DPPIV is linked to decreased FGF2 and notch signaling pathways. We utilized Affymetrix microarray gene expression analysis, RNA interference and pharmacological inhibitor approaches, western blot and immunofluorescence analysis in these studies. Our results show that either endogenous up-regulation of DPPIV or exogenous treatment of DPPIV leads to decreased FGF2 and Notch3 levels. Furthermore, inhibition of FGF2 expression using FGF2-targeted small interfering RNA decreased the levels of Notch3 and matrix metalloproteinases leading to down regulation of p-Akt, an important survival factor for tumor cells. Blocking of Notch3 function either through a pharmacological inhibitor gamma secretase, or through shRNA also resulted in decreased p-Akt levels, and increased p21/waf1 and cleaved caspase 3 that are apoptosis inducers. Decreased levels of FG2 and Notch3 were associated with induction of differentiation, apoptosis and growth inhibition of neuroblastoma cells (SK-N-AS). In summary, our studies suggest a cooperative role for FGF2 and Notch3 signaling pathways in maintaining tumor phenotype and blocking of these pathways can lead to neuroblastoma tumor cell death. Thus these studies identify FGF2-Nothch 3 signaling pathways as potential targets for inhibiting growth and survival of neuroblastoma cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4979. doi:1538-7445.AM2012-4979
Abstract 4980: Age dependent carcinogenic susceptibility of rat liver is related to potential of gap junctional intercellular communication
Authors: Naiki-Ito Aya , Asamoto Makoto , Takahashi Satoru , Shirai Tomoyuki
Published: August 2012

Cancer incidence rises with age, thus, it seems that advancing age is one of the most important risk factors for malignancy. Several factors have been implicated, like DNA alterations. However, there is little experimental evidence to establish the link between aging and carcinogenesis. Gap junctions have important roles in the maintenance of tissue homeostasis and the control of cell growth and differentiation. Connexins are subunits of gap junction channels, which allow intercellular exchange of small molecules, such as ions, second messengers, and cellular metabolites between contacting cells. In the liver, connexin 32 (Cx32) is a major gap junction protein. We previously demonstrated that transgenic rats carrying a dominant negative mutant of Cx32 (Cx32ΔTg) have much decreased capacity for gap junctional intercellular communication (GJIC), and increased susceptibility to diethylnitrosamine (DEN)-induced hepatocarcinogenesis as compared to littermate wild-type (wt) rats. In order to evaluate the age-dependent susceptibility to DEN-induced hepatocarcinogenesis, male Cx32ΔTg and wt rats at 10, 30 or 85 week-old (wk-old) were given a single intraperitoneal administration of DEN (40 mg/rat) and sacrificed 12 weeks later. The number and area of glutathione S-transferase placental form (GST-P)-positive preneoplastic foci were significantly increased in the liver of 10 and 30 wk-old Cx32ΔTg rats compared with age-matched wt. However, in the 85 wk-old rats, both Cx32ΔTg and wt rats had similarly large number and area of GST-P-positive foci, and the difference was not significant. In accordance with these results, the lack of a difference at 85 weeks may be supposed to the initial lower levels of Cx32 and GJIC function in older wt rats. To confirm this hypothesis, we examined alteration of GJIC function with age in the livers of wt type rats at 10, 40, 70 and 100 wk-old. Interestingly, function of hepatic GJIC was gradually reduced, and protein and mRNA expression of Cx32 were also decreased with aging in wt rats. In summary, the present study shows that GJIC function is decreased with aging in rats, and it may cause promotion of hepatocarcinogenesis in older rats. In addition, Cx32ΔTg may be a good model to study roles of gap junctions in aged liver.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4980. doi:1538-7445.AM2012-4980
Abstract 4981: NADPH oxidase is a novel target of delphinidin to inhibits UVB-induced MMP-1 expression in human dermal fibroblasts
Authors: Lim Tae-Gyu
Published: August 2012

Ultraviolet (UV) induced ROS production is considered a major cause of photoaging via abnormal expression of matrix metalloproteinase (MMP)-1 and NADPH oxidase (NOX) is a key enzyme of endogenous ROS production. Here, we investigated the anti-photoaging effect of delphidin, a major anthocyanin found in berry, beans, and red wine, and its molecular target in UVB-induced MMP-1 expression using primary cultured human dermal fibroblast. Delphinidin inhibited UVB-induced MMP-1 expression in human dermal fibroblasts. UVB-induced MKK4-JNK1/2, MKK3/6-p38, and MEK-ERK1/2 phosphorylation were suppressed by delphinidin. In addition, quantification of ROS stained with the 2′,7′-dichlorofluorescein diacetate (DCF-DA) dye showed that delphinidin significantly inhibited UVB-induced ROS production. Delphinidin significantly inhibited UVB-induced NOX activity. Interestingly, the inhibitory effect of delphinidin on UVB-induced NOX activity was stronger than apocynin, a pharmaceutical NOX inhibitor. Fractioned cell analysis results using a western blot assay showed that delphinidin strongly suppressed UVB-induced P47phox, a NOX subunit, translocation from the cytosol to the membrane. Delphinidin produced similar effects with apocynin on UVB-induced MMP-1 expression. Pull down assays showed that delphinidin directly bound to P47phox. Collectively, our results suggest that NOX is a potential target of delphinidin in the suppression of UVB-induced MMP-1 expression in human dermal fibroblasts.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4981. doi:1538-7445.AM2012-4981
Abstract 4983: Correlation telomere shortening in chronic lymphocytic leukemia cells with oxidative stress and dysregulation of shelterin proteins
Authors: Ishdorj Ganchimeg , Mai Sabine , Zang Yunli , Gibson Spencer B. , Johnston James B.
Published: August 2012

Telomeres are important in maintaining the integrity of the chromosomes. A series of shelterin proteins (TRF1, TRF2, RAP1, POT1a and b, TIPP1 and TIN2), are involved in the maintenance and synthesis of telomeres. In chronic lymphocytic leukemia (CLL), the telomeres are shorter than in normal B cells, with very short telomeres being associated with poor survival. The mechanism for this telomere shortening has been evaluated in the present study. We demonstrated in 150 CLL patients using a Q-RT-PCR assay that the median telomere length was similar in mutated IgVH (Mu-IgVH) cases as in normal B cells, but was significantly shorter in unmutated (Un-IgVH) cases. However, there was considerable variation and overlap in telomere length between the groups. In addition, telomere length was found to shorten in both IgVH mutated and unmutated groups when patients were sequentially followed over years indicating that telomere shortening was an ongoing process. When lymphocytes were stimulated and the telomeres evaluated in metaphase by Q-FISH, telomere length shortening affected all chromosomes equally. To determine if telomere shortening in CLL cells was related to increased free radical formation, we measured plasma lipid peroxidation level (Lipid Hydroperoxide (LPO) assay, Cayman) and DNA breaks (gamma H2AX). As compared to normal B cells, there was increased lipid peroxidation and DNA breaks in both mutated and unmutated CLL cells. When cells were treated with N-acetyl-L-cysteine to scavenge free radicals, there was a decrease in DNA breakage. To assess, whether these changes were associated with alterations of the shelterin complex, protein levels of the shelterins were measured. TRF1 and TRF2 protein levels were increased in all patients compared to normal B cells. TRF2 was also increased in the cytoplasm of CLL cells. Following drug induced apoptosis in CLL cells TRF2 levels decreased but not TRF1 levels. In summary, these studies suggest that the short telomeres in CLL may be related to increased oxidative stress in these cells. TRF1 and TRF2 levels were increased in CLL cells regardless of telomere length suggesting that abnormalities in these proteins may also be involved in telomere shortening. Ongoing studies are evaluating the mechanisms responsible for the shelterin changes in CLL cells and whether altering the levels of these proteins can influence cell death.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4983. doi:1538-7445.AM2012-4983