bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1671: GSK3-beta as a therapeutic target in bladder cancer
Authors: Becker Marie N. , von Roemeling Christina A. , Copland John A. , Williams Christopher R. 
Published: June 2012

Abstract
Bladder cancer is the 5th most commonly diagnosed cancer in the United States. Because superficial bladder cancer (SBC) recurs in about 60% of cases, standard treatment involves tumor resection followed by intravesical therapies to prevent recurrence, as well as lifelong periodic cystoscopy. There is an urgent need for better intravesical therapies to prevent both the recurrence and progression of SBC. Recent evidence has demonstrated that glycogen synthase kinase – 3 beta (GSK3β) plays an important role in pancreatic, ovarian and colon cancers; however, to date the possible role of this important kinase has not been examined in bladder cancer. We propose that GSK3β plays a cancer promoting role in bladder cancer and that inhibition of GSK3β will reduce bladder cancer growth. The GSK3β inhibitor, AR-A014418, has been demonstrated to reduce tumor growth in the previously cited cancers. AR-A014418 reduced cell proliferation of three bladder cancer cell lines (HT1376, T24 and UM-UC-3) with EC50 values of 17.5μM for HT1376, 8μM for T24, and 10μM for UM-UC-3 cells. The effect of AR-A014418 on downstream targets in these cell lines was evaluated by Western blots which indicated an increase in apoptosis in these cells in response to drug treatment as demonstrated by the presence by both PARP and caspase 3 cleavage. The NFkB downstream target XIAP also exhibited reduced protein levels after drug treatment. The HT1376 cell line was transduced with luciferase containing lentivirus particles to generate a luciferase expressing cell line, HT1376-LUC to use for both ectopic and orthotopic models of bladder cancer growth. The efficacy of AR-A014418 in reducing bladder cancer tumor growth was tested in an ectopic mouse model. HT1376-LUC cells mixed with matrigel were transplanted into the right flank of 50 female nude mice. After one week, mice containing tumors with an average volume of 52 mm3 were randomized into four treatment groups of 10 mice each. Mice were treated twice weekly via IP injection with placebo, 1, 5 or 7mg/kg AR-A014418. Tumor sizes were measured and imaged for luciferase activity once weekly. Tumor growth was inhibited by both 5mg/kg and 7mg/kg doses by 19 days of treatment (p &lt; 0.05, Student's T test). Together, the in vitro and in vivo data suggest that GSK3β is a novel target for bladder cancer treatment. Future studies using an orthotopic model of bladder cancer are planned.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1671. doi:10.1158/1538-7445.AM2011-1671
Abstract 1672: Mitochondrial and bacterial peptides act on the formyl peptide receptor (FPR) to promote migration and proliferation in high grade glioblastoma cells
Authors: Boer Jennifer C. , Domanska Urszula M. , Kruizinga Roeliene C. , Boer Ingrid , de Haas Carla J.C. , de Vries Elisabeth G. , Den Dunnen Wilfred F.A. , van Strijp Jos A.G. , Walenkamp Annemiek M. 
Published: June 2012

Abstract
Background: Recently several aberrant molecular pathways and underlying genetic defects are elucidated in astrocytomas, among which the role of the formylpeptide receptor (FPR) malignant behavior. In a highly malignant human astrocytoma cell line FPR promotes cell motility, growth, and angiogenesis by interacting with host-derived agonists originating from necrotic cell material. Until now the only known ligands of FPR are N-formyl peptides, which are cleavage products of bacterial proteins like N-formyl-methionyl-leucyl-phenylalanine (fMLF). In humans the only conserved N-formyl peptides are the cleavage products of mitochondrial proteins. This study aims to identify these peptides as responsible ligands for FPR expressing high grade glioma cells.
Methods: We used FITC-fMLF and flow cytometry to confirm binding to FPR-expressing high grade human gliobastoma cell line U87. In addition, U937 cells (human promonocytic cell line) transfected with the FPR (U937FPR) and empty expression vectors were generated. The hallmark of chemokine receptor activation is a rapid and transient increase in the free intracellular Ca2+ level upon ligand binding. Formylated mitochondrial peptides fMLKLIV/fMLALV and FPR's natural peptide ligand fMLF were used to induce Ca2+ mobilization, chemotaxis as determined by the Neuro Probe® system and proliferation in U87 cells, analyzed by MTT assay.
Results: FITC-fMLF bound to FPR expressing U87 and U937FPR cells. Increasing concentrations of fMLF (10−8 M-10−5 M) caused a dose dependent calcium mobilization in FPR expressing U87 cells. Increasing concentrations of fMLF/fMLKLIV/fMLALV (10−8 M- 10−5M) were tested in U937FPR cells, again showing dose dependent calcium mobilization. In the chemotaxis assay, respectively 22, 20 and 24% of U937FPR cells migrated towards fMLF/fMLKLIV/fMLALV as compared to 4% towards 0.05% FCS. A 2.5 fold increase in migration of U87 cells towards 10−7 M fMLF was found as compared to 0.05% FCS. Respectively 20, 21 and 15% increase in U87 cell proliferation was found when cells were stimulated with 10−6 M fMLF/fMLKLIV/fMLALV.
Conclusions: These results indicate that mitochondrial peptides present in necrotic tumor material serve as ligands for FPR, expressed on high grade human gliobastoma cell line U87. Activation of FPR via N-formyl peptides causes increased cell growth and motility and is a potential target for anti-cancer therapy.
Supported by grant RUG 4622 of the Dutch Cancer Society
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1672. doi:10.1158/1538-7445.AM2011-1672
Abstract 1678: Visualization of thymidine kinase 1 on the surface of cancer cell lines: A potential diagnostic marker and therapeutic target
Authors: Whitehurst Robert A. , Estevez Dagoberto , Sharp Daniel W. , Alegre Melissa M. , Robison Richard A. , O'Neill Kim L. 
Published: June 2012

Abstract
Thymidine Kinase 1(TK1) is a salvage pathway enzyme that has been shown to be elevated in many different cancer types, including breast, prostate, and colon. Previous research in our lab using plasma membrane separation has shown an increase in TK1 levels associated with the plasma membrane of cancer cells when compared to normal lymphocytes. After membrane separation the plasma membrane of normal lymphocytes showed a TK1 activity of 1,012 CPM/mg protein/hr(N=20) whereas those of cancer cells showed: Jurkat 34,096(N=28), Raji 70,195(N=20), HL60 46,217(N=34), and MDA-MB-435 50,359(N=24). In this study we sought to further investigate this association by visualizing the surface staining of fluorescently tagged antibodies to TK1. Using a primary rabbit anti-TK1 antibody and a secondary goat anti-rabbit antibody conjugated with a FITC fluorochrome we were able to stain the cells and identify TK1 bound to the cell surface. Using a fluorescent microscope we were able to visualize the fluorescent staining of TK1 in various cancer cell lines, including: Raji, Jurkat, HL60, MDA-MB-435, H358, and MCF-7. We compared these results to our control of stained normal lymphocytes, which showed significantly greater levels of staining in cancer cells. Our results further confirm the presence of membrane associated TK1, and provide further evidence of TK1's usefulness as a diagnostic marker and potential therapeutic target.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1678. doi:10.1158/1538-7445.AM2011-1678
Abstract 1682: Identification of RAM (ribonucleoprotein associated molecule) overexpressed in high-grade prostate cancer cells
Authors: Anchi Takashi , Tamura Kenji , Furihata Mutsuo , Satake Hirofumi , Ashida Shingo , Yamasaki Ichiro , Inoue Keiji , Shuin Taro 
Published: June 2012

Abstract
One of the most important problems in hormonal therapy for prostate cancer is the acquirement of hormone-resistant and/or androgen-independent phenotypes. These cells are high-grade and lead to the eventual death. To characterize the molecular features of high-grade prostate cancer, we performed a gene-expression profile analysis by cDNA microarray coupled with laser microbeam microdissection from 10 frozen high-grade prostate cancer tissues and found dozens of trans-activated genes. Among of them, we identified RAM as an overexpressed gene in high-grade prostate cancers. The function of this protein is unknown, but it has a domain structure relating to mRNA splicing. We demonstrated that RAM protein was localized in the nucleus. Knock-down of RAM expression by siRNAs were observed a significant decrease of cell numbers. In contrast, RAM overexpression promoted cell proliferation. These findings suggest that RAM could be involved in cell survival and/or proliferation of prostate cancer, and that it should be a potential molecular target for development of novel therapeutics.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1682. doi:10.1158/1538-7445.AM2011-1682
Abstract 1683: High throughput membrane proteomics for the discovery of oncology targets ideally suited for the development of antibody drug conjugates (ADCs)
Authors: Terrett Jonathan A. , Bozhenok Ludmila , Belanger Blake , Montes Inigo , Aud Dee , Ackroyd Jim , Anderson Amanda , Trang Michael , Barnes Martin , Lamble Harry , Yu Xiaohong , Rohlff Christian 
Published: June 2012

Abstract
Antibody Drug Conjugates (ADCs) are showing tremendous promise for cancer patients as recently demonstrated by the dramatic responses reported in breast cancer and Hodgkin's Lymphoma clinical trials to the ADCs T-DM1 and SGN-35. We have developed proteomics methods to enrich for membrane proteins that are expressed preferentially in cancer cells over normal cells. Potential ADC targetable proteins are then validated using the proprietary OGAP database as well as conventional expression analysis tools. The proteomics processes have identified novel cancer specific proteins as well as cancer specific isoforms of known proteins. These targets are then combined with large panels of antibodies to discover potential therapeutics with properties desirable for the development of ADCs. Antibodies are selected which : a) preferentially bind to tumor cells over normal cells, b) have good specificity and affinity, c) show high prevalence in target cancer indications by IHC, d) internalize on antigen binding, e) bind to relevant tox species tissues as they bind to human tissues. Here we describe the proteomics processes and use of the OGAP database and demonstrate the development of candidate therapeutic antibodies with the potential to become ADCs, which are directed to novel targets and cancer specific isoforms.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1683. doi:10.1158/1538-7445.AM2011-1683
Abstract 1696: Regulation of sensitivity to the platinum-containing drugs by the sec61 translocon
Authors: Abada Paolo B. , Howell Stephen B. 
Published: June 2012

Abstract
The Sec61 protein translocon is a multimeric complex that allows the transport of proteins across or laterally into a lipid bilayer. Components of the sec61 complex are involved in retrotranslocation, Golgi structure and vesicle transport. We have discovered that one component of this complex, the sec61β subunit, modulates cellular sensitivity to the platinum-containing drugs. As part of an effort to enhance sensitivity to the platinum drugs we sought to determine the mechanism of this effect. Sec61β expression in human 2008 ovarian cancer cells was constitutively knocked down by infection with a lentivirus producing an shRNA targeting sec61β, and knockdown was confirmed by qRT-PCR and western blot analysis which demonstrated a 96% reduction in mRNA expression and 87% reduction at the protein level. Effects on drug sensitivity were measured using an SRB assay, and platinum drug accumulation was quantified by inductively coupled plasma mass spectrometry. Sec61β knockdown (KD) did not alter cell viability or growth rate but resulted in 8-, 16.8- and 9-fold resistance to cisplatin, carboplatin, and oxaliplatin, respectively. Resistance to several other clinically relevant chemotherapeutics including paclitaxel, doxorubicin, vincristine, and etoposide was also increased but to a smaller extent (1.7 to 7-fold). Sec61β KD reduced the cellular accumulation of cisplatin to 67% of that in the parental cells. Given that transporters and chaperones that manage copper homeostasis regulate platinum drug accumulation and efflux, their expression in 2008 sec61β KD cells was analyzed by western blot. Among these, ATP7A was found to be 2-fold over-expressed while no change in ATP7B, ATOX1, or CTR2 could be detected. This increase in ATP7A expression was not altered by pretreatment with copper, cisplatin, or the copper chelator bathocuproine disulfonate. We conclude that the sec61β translocon modulates the cytotoxicity of many chemotherapeutic agents with the largest effect being on sensitivity to the platinum drugs. Sec61β regulates expression of the copper export transporter ATP7A that we have previously shown to control platinum drug sequestration and efflux.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1696. doi:10.1158/1538-7445.AM2011-1696
Abstract 1704: A role for glucosylceramide synthase in resistance to oxaliplatin in colorectal cancer
Authors: Madigan James P. , Rosenberg Daniel W. 
Published: June 2012

Abstract
Colorectal cancer (CRC) is the second leading cause of cancer deaths in the U.S. Nearly 25 percent of patients who present with CRC have already developed metastatic disease. While combination therapies for metastatic CRC have improved median survival times, most patients inevitably become resistant to chemotherapy. Chemoresistance is thus the major cause of treatment failure in CRC patients, and accordingly, the development of novel therapies aimed at overcoming chemoresistance is of paramount importance. Many commonly used chemotherapeutic agents act by inducing cell death by increasing cellular levels of the bioactive sphingolipid, ceramide. In addition to serving well-known structural functions in the cell membrane, sphingolipids are increasingly recognized as important cellular signaling molecules. Studies have demonstrated that human colorectal tumors contain decreased concentrations of ceramide in comparison to normal colonic mucosa. Furthermore, multi-drug resistant cancer cells often display an altered sphingolipid content, with the presence of increased levels of the pro-survival ceramide metabolites. In this study we have examined the role of the ceramide-metabolizing enzyme, glucosylceramide synthase (GCS), in the mechanism of resistance to oxaliplatin. These studies utilize a series of oxaliplatin-resistant isogenic colorectal cancer cell lines. While much evidence has been presented establishing the role of GCS in resistance to a variety of chemotherapeutic agents, a role for GCS in oxaliplatin resistance has yet to be examined. Our studies demonstrate that oxaliplatin-resistant CRC cell lines have ∼ 2-fold more GCS protein with increased levels of the pro-survival ceramide metabolite, glucosylceramide, in comparison to the parental cell lines. We further demonstrate that inhibition of GCS by either pharmacological inhibitors or an RNAi-mediated gene knockdown results in reduced cellular glucosylceramide levels, with a concomitant increased sensitivity towards oxaliplatin. Furthermore, inhibition of GCS causes a reversion of an observed epithelial-mesenchymal transition phenotype observed in oxaliplatin-resistant CRC cell lines. Our results may offer a possible strategy with which to augment chemotherapeutic drug effectiveness in CRC.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1704. doi:10.1158/1538-7445.AM2011-1704
Abstract 1705: Comparison of uptake mechanisms for different anthracyclines in leukemic cells
Authors: Karim Hazhar , Bogason Alex , Vitols Sigurd 
Published: June 2012

Abstract
Aims: The mechanisms behind cellular anthracycline uptake are not completely understood. It is of great interest to gain more insight into cellular uptake mechanisms since this could possibly be used to increase the selectivity of the drugs. We therefore compared the uptake of 5 different anthracyclines, daunorubicin (DNR), doxorubicin (DOX), epirubicin (EPI), idarubicin (IDA), and pirarubicin (PIRA) by leukemic cells and also investigated the possible involvement of specific carriers.
Methods: HL-60 cells were incubated with increasing concentrations of anthracyclines for 1 hour and cellular drug uptake was determined. The cells were also preincubated with various protein inhibitors or nucleosides and then with the anthracyclines after which drug uptake was determined with HPLC. Apoptosis was determined with propidium iodine staining and flow cytometry.
Results: Of all anthracyclines studied DNR, IDA and PIRA had the highest cellular uptake with a sharp increase in uptake at extracellular concentrations &gt; 1 µM. Uptake of DOX, DNR and IDA was greatly reduced at 0°C. Suramin, a purinergic-2-receptor inhibitor, strongly inhibited the uptake of all anthracyclines except PIRA and dipyridamole, a nucleoside transport inhibitor, only inhibited the uptake of DNR. The addition of nucleosides reduced the uptake of DNR, IDA and PIRA.
Conclusion: Our results suggest different uptake mechanisms for various anthracyclines. We found evidence for carrier mediated uptake mechanisms, the data support the involvement of the nucleoside transporter family. Furthermore, our results also indicate an involvement of purinergic-2-receptor signalling in anthracycline uptake.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1705. doi:10.1158/1538-7445.AM2011-1705
Abstract 1708: Induction of GDF15 by cisplatin triggers apoptotic cell death in ovarian cancer cells
Authors: Izaguirre Daisy I. , Zu Zhifei , Tsang-Lee Yvonne T. , Mok Samuel , Wong Kwong-Kwok 
Published: June 2012

Abstract
Ovarian cancer is the fifth most common cause of death among women. The overall five year survival is 45.6% as a result of late diagnosis when treatment is mostly ineffective. Current treatment consists of complete resection followed by a combination of a taxane and a platinum -based chemotherapy regardless of the subtype. After standard treatment, 70% of patients will develop chemoresistance, creating a major challenge in the treatment of this type of cancer. Therefore, there is great interest in understanding the mechanisms by which tumors develop resistance. From the microarray data of a high grade serous ovarian cancer cell line (A2780) treated with varying concentrations of cisplatin and at varying time points, we identified four genes (CDKN1A, FDXR, TP53I3 and GDF15) which were significantly up-regulated by cisplatin in a time and dose dependent manner. The time and dose dependent upregulation of these genes were further validated by real-time RT-PCR and Western blot analysis in A2780 and two other ovarian cancer cell lines. We further tested whether GDF15 expression correlated with cisplatin response. RNA and protein from 6 different cell lines with different IC50 to cisplatin revealed a positive correlation between GDF15 induction and sensitivity to cisplatin. To further investigate the role GDF15 plays in the chemoresponse of ovarian cancer cell, we knocked down the expression of GDF15 by shRNA. Ovarian cancer cells with GDF15 knockdown showed a decrease in PARP cleavage, suggesting a pro-apoptotic role for GDF15. Thus, our results suggest that induction of GDF15 by cisplatin is one of the mechanisms that triggers apoptotic cell death in ovarian cancer cells. On the other hand, we were not able to detect an induction of GDF15 by cisplatin in a cisplatin resistant cell line A2780cp20. Thus, the lost of GDF15 induction could be one of the mechanisms of developing chemoresistance. Future studies to decipher the mechanism by which cisplatin induces GDF15 expression have the potential of identifying new targets that could circumvent chemoresistance to cisplatin.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1708. doi:10.1158/1538-7445.AM2011-1708