bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4830: Prognostic value of circulating tumor cells with podoplanin expression in locally advanced and metastatic head and neck squamous cell carcinoma
Authors: Tseng Ching-Ping , Lin Hung-Chih , Hsieh Chia-Hsun , Wang Hung-Ming , Cheng Ju-Chien
Published: May 2015

Podoplanin (PDPN) is a biomarker for poor prognosis in head and neck squamous cell carcinoma (HNSCC). A prospective study was designed to investigate the prognostic value of circulating tumor cells (CTCs) with PDPN expression (PDPN+-CTCs) in HNSCC patients. Sixty-one healthy donors and fifty-three HNSCC patients with locally advanced and metastatic diseases were enrolled in this study. CTCs were enriched from the peripheral blood by the negative selection method PowerMag that has been validated in our previous study. Enumeration of CTCs was performed by co-immunofluorescence staining using the anti-epithelial cell adhesion molecule (EpCAM) and anti-PDPN antibodies. The CTCs (EpCAM+) and PDPN+-CTCs (EpCAM+PDPN+) counts between the patients and healthy volunteers were statistically different (p < 0.0001). When assessed the progression-free survival (PFS) and overall survival (OS) of the patients, we found that the median PFS for the patient group was 8.6 (95% CI: 4.781-12.419) months and the median OS has not reached 50% after the follow-up duration of 9.1 (5.2-17.1) months. Analysis of the CTCs and PDPN+-CTCs counts revealed that neither of them can be considered as a predictive factor for PFS and OS. Notably, the ratio for the PDPN+-CTCs over total CTCs has progonic value in the assessment of PFS and OS. Based on the ROC curve, the prediction of 6-month death could be revealed at the cutoff value of 20% (AUC: 0.718, sensitivity: 94.7%, specificity: 51.7%, p = 0.011). The patients with PDPN+/EpCAM+-CTCs ratio >20% were associated with poor PFS (hazard ratio (HR): 4.666, 95% CI: 1.373-15.856, p = 0.016) and OS (HR: 12.400, 95% CI: 1.643-93.570, p = 0.015). Kaplan-Meier survival curve further confirmed that the PDPN+/EpCAM+-CTCs ratio had significant impact on PFS (p = 0.006) and OS (p = 0.008). In conclusion, CTCs enumeration clearly differentiates HNSCC patients from healthy individuals, while the PDPN+/EpCAM+-CTC ratio is more important than the absolute CTCs count in determining the degree of malignancy and serves as an independent prognostic factor for PFS and OS.

Citation Format: Ching-Ping Tseng, Hung-Chih Lin, Chia-Hsun Hsieh, Hung-Ming Wang, Ju-Chien Cheng. Prognostic value of circulating tumor cells with podoplanin expression in locally advanced and metastatic head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4830. doi:10.1158/1538-7445.AM2014-4830
Abstract 4859: Hepatocyte growth factor activator inhibitor type 1 suppresses invasion of pancreatic adenocarcinoma cells through inhibition of matriptase/protease-activated receptor-2 axis
Authors: Haruyama Yukihiro , Ye Jing-Jia , Kawaguchi Makiko , Kanemaru Ai , Fukushima Tsuyoshi , Kataoka Hiroaki
Published: May 2015

Previously, we reported that S2-CP8 cells, a metastatic variant of SUIT-2 pancreatic adenocarcinoma cell line, showed markedly decreased expression of hepatocyte growth factor activator inhibitor type 1 (HAI-1) compared to SUIT-2 and acquired EMT phenotype. Matrigel invasion assay revealed that S2-CP8 cells show enhanced invasion compared to SUIT-2 cells in vitro and forced HAI-1 expression alleviate the invasion. Consequently, in vivo study using a nude mouse orthotopic xenograft model showed reduced spontaneous metastasis by the forced HAI-1 expression. This study aimed to clarify molecular mechanisms underlying the HAI-1-mediated suppression of invasion of S2-CP8 cells. In S2-CP8 cells, activity of matriptase, a cognate protease of HAI-1, was clearly suppressed by forced expression of HAI-1. As matriptase is known to activate protease-activated receptor-2 (PAR-2) and PAR-2 agonist enhanced migration and invasion of S2-CP8, we analyzed the role of PAR-2 in HAI-1 loss-induced enhanced invasion of S2-CP8 in vitro. The HAI-1 loss-induced enhanced migration and invasion were significantly alleviated by PAR-2 antagonist, as well as by PAR-2 silencing. Moreover, knock down of matriptase also showed similar suppressive effects on the invasion of S2-CP8 cells. These results indicated that HAI-1 may have a suppressive role in the invasion of pancreatic cancer cells through its regulatory function on matriptase/PAR-2 axis.

Citation Format: Yukihiro Haruyama, Jing-Jia Ye, Makiko Kawaguchi, Ai Kanemaru, Tsuyoshi Fukushima, Hiroaki Kataoka. Hepatocyte growth factor activator inhibitor type 1 suppresses invasion of pancreatic adenocarcinoma cells through inhibition of matriptase/protease-activated receptor-2 axis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4859. doi:10.1158/1538-7445.AM2014-4859
Abstract 486: Uncovering novel PERK signaling pathways through chemical-genetic screening
Authors: Maas Nancy L. , Levin Rebecca , Singh Nickpreet , Shokat Kevan , Diehl J. Alan
Published: May 2015

The ER kinase PERK, a key mediator of the Unfolded Protein Response, is known to promote tumorigenesis, cell migration, and metastasis, as well as inhibit anoikis. Though PERK has these and other important cellular functions, only a handful of its direct substrates are currently known. Therefore, in order to provide an expanded view of PERK function and further definition of its signaling networks, we have used a chemical-genetic approach to screen for additional PERK substrates. We find that a mutation in the PERK ATP binding pocket renders it sensitive to bulky ATP analogs both in vitro and in cells. Furthermore, bulky ATPγS analogs were used exclusively by the analog-sensitive version of PERK to label substrates with thiophosphate. After labeling, thiophosphopeptides were affinity purified by covalent capture and subsequently identified by tandem mass spectrometry. Utilization of this analog-sensitive PERK allele for substrate characterization will be discussed.

Citation Format: Nancy L. Maas, Rebecca Levin, Nickpreet Singh, Kevan Shokat, J. Alan Diehl. Uncovering novel PERK signaling pathways through chemical-genetic screening. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 486. doi:10.1158/1538-7445.AM2014-486
Abstract 4861: Pharmacological reversal of caffeine-mediated phagocytic suppression
Authors: Steck Ryan , Hill Spencer , Robison Richard A. , O'Neill Kim L.
Published: May 2015

Caffeine's mechanism of action on immune cells has been an issue of debate for some time. Previous studies suggest caffeine inhibits cyclic AMP (cAMP)-phosphodiesterase, resulting in increased cAMP levels, increased protein kinase A (PKA) activation, and subsequently a decreased pro-inflammatory response. Caffeine is also an antagonist of adenosine receptors, resulting in delayed resolution of inflammation. If the primary effect of caffeine in macrophages was to antagonize adenosine receptors, we would expect caffeine to stimulate phagocytosis. We treated human macrophages with varying concentrations of caffeine (0 - 13mM) and measured their phagocytic ability to engulf fluorescent microspheres. Engulfment rates were measured by flow cytometry. Our results indicate that caffeine suppresses phagocytosis by 22% at physiological concentrations (35 uM- 750uM). At supraphysiological (4-13 mM) levels of caffeine, however, there is no significant decrease in phagocytosis. We wanted to find out if this suppressive effect at physiological concentrations could be blocked with a PKA inhibitor. We tested this by treating the cells with a PKA inhibitor at each of the different caffeine concentrations previously used. Initial results indicate that phagocytosis increased up to 27% in macrophages treated with PKA and caffeine compared to caffeine treated and control cells.These results need further validation but, initial results suggest inhibition of PKA results in increased engulfment, and indicate that the suppressive effects of caffeine on macrophage phagocytosis can be reversed with the treatment of PKA inhibitor suppression can be reversed. Macrophages are highly involved in regulation of inflammation and dysregulation has been implicated in a number of diseases, including cancer. These results suggest further potential for the therapeutic applications of caffeine, its analogs, and PKA inhibitors for the control of inflammation.

Citation Format: Ryan Steck, Spencer Hill, Richard A. Robison, Kim L. O'Neill. Pharmacological reversal of caffeine-mediated phagocytic suppression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4861. doi:10.1158/1538-7445.AM2014-4861
Abstract 4874: CXCR2 signaling axis- a helping hand to KRAS(G12D) mutation in pancreatic cancer initiation
Authors: Purohit Abhilasha , Varney Michelle , Rachagani Satya , Ouellette Michel , Batra Surinder K. , Singh Rakesh K.
Published: May 2015

Pancreatic cancer (PC) is the fourth leading cause of cancer-related deaths in the United States. The high mortality can be accredited to late clinical presentation and early metastasis. Somatic mutations in oncogene KRAS(G12D) are the most common and earliest events during development of PC, suggesting their crucial role in tumor initiation; however, the precise functional molecular mechanism(s) of action remains unclear. CXCR2, a CXC chemokine receptor, and its ligands have also been found to be important in regulating inflammation, angiogenesis, and metastasis in various cancers. The purpose of the current study was to test the functional role of CXCR2 signaling in KRAS(G12D)-induced PC development. Immunohistochemical analysis of tumors derived from PDX-cre-LSL-kras(G12D) mice demonstrated significantly higher expression of Cxcr2 and its ligands Cxcl1 and -3. Expression of Cxcr2 and its ligands Cxcl1 and -3 was observed as early as 10 weeks and increased consistently as the lesions advanced. We demonstrated the direct link between KRAS(G12D) mutation and CXCR2 signaling using cell line models hTERT-HPNE and hTERT-HPNE -E6-E7-st with or without exogenously expressed KRAS(G12D). Real time PCR, ELISA and western blot analysis of these cells revealed that KRAS (G12D) up-regulates the expression of CXCR2 and its ligands at both the transcriptional and protein levels. In order to delineate the significance of CXCR2 in KRAS(G12D) induced autocrine growth, we treated the cell line models with various concentrations of SCH-527123 (CXCR2 antagonist) or CXCR2 neutralizing antibody. Our data shows that KRAS(G12D) bearing cells show significantly (P ≤ 0.05) greater percent inhibition in cell growth in comparison to their control counterparts. Next to evaluate the role of CXCR2 autocrine signaling in KRAS(G12D) induced cell migration, we performed a scratch assay by treating the hTERT-HPNE -E6/E7-st- KRAS(G12D) cells with SCH-527123 for 24 hours. Our data demonstrated a significant inhibition of cell migration in CXCR2 antagonist treated cultures. Together, our data demonstrate that KRAS(G12D) mutation up regulates CXCR2 and its ligands, which, in turn, play key roles in the autocrine regulation of cellular growth and migration in PC.

Note: This abstract was not presented at the meeting.

Citation Format: Abhilasha Purohit, Michelle Varney, Satya Rachagani, Michel Ouellette, Surinder K. Batra, Rakesh K. Singh. CXCR2 signaling axis- a helping hand to KRAS(G12D) mutation in pancreatic cancer initiation. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4874. doi:10.1158/1538-7445.AM2014-4874
Abstract 4884: Determination of sphingosine-1-phosphate levels in tissue interstitial fluid and lymphatic fluid utilizing novel collection techniques
Authors: Nagahashi Masayuki , Yamada Akimitsu , Miyazaki Hiroshi , Allegood Jeremy C. , Aoyagi Tomoyoshi , Huang Wei-Ching , Terracina Krista P. , Milstien Sheldon , Spiegel Sarah , Takabe Kazuaki
Published: May 2015

Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid mediator that regulates many processes of cancer progression including angiogenesis. Among the two sphingosine kinases (SphK1 and SphK2), S1P generated by SphK1 inside cells is secreted and exerts its functions by binding to specific G protein-coupled receptors outside the cells. It is known that S1P levels in circulation of SphK1-/- mice are low and SphK2 -/- mice are high compared from controls. Utilizing SphK2 -/- mice, we have recently reported that S1P links inflammation and cancer in colitis-associated colon cancer. Further, we have shown that secreted S1P plays critical roles in tumor microenvironment by stimulating both angiogenesis and lymphangiogenesis. Although it is well established that S1P plays important roles in lymphatic fluid and interstitial fluid (IF), no methodology has been available to date to measure S1P levels in those fluid. Here we introduce for the first time the newly developed methods and measurements of levels of sphingolipids including S1P in IF and lymphatic fluid in both SphK1 -/- and SphK2 -/- mice. We found that S1P levels in the lymphatic fluid and IF are generally low in SphK1-/- mice and high in SphK2-/- mice. Interestingly, however, S1P levels in IF of the colon in SphK2-/- mice are significantly lower compared with wild type mice, where levels in downstream mesenteric lymph nodes and lymphatic fluid are higher, which is in agreement with the previous notion that lymphatic endothelial cells contribute to the S1P levels in the lymphatic fluid. Measurement of sphingolipids in IF and lymphatic fluid will provide new insights into mechanism of their actions in lymphatic progression of cancer.

M.N. is a Japan Society for the Promotion of Science Postdoctoral Fellow. S.S. is supported by NIH R37GM043880, and K.T. by NIH R01CA160688 and Susan G. Komen IIR 1222224.

Citation Format: Masayuki Nagahashi, Akimitsu Yamada, Hiroshi Miyazaki, Jeremy C. Allegood, Tomoyoshi Aoyagi, Wei-Ching Huang, Krista P. Terracina, Sheldon Milstien, Sarah Spiegel, Kazuaki Takabe. Determination of sphingosine-1-phosphate levels in tissue interstitial fluid and lymphatic fluid utilizing novel collection techniques. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4884. doi:10.1158/1538-7445.AM2014-4884
Abstract 4885: Changes in abundance of oral microbiota associated with oral cancer
Authors: Albertson Donna G. , Kuczynski Justin , Bhattacharya Aditi , Huey Bing , Corby Patricia M. , Queiroz Erica L. S. , Nightingale Kira , Kerr Alexander R. , DeLacure Mark D. , Veeramachaneni Ratna , Olshen Adam , Schmidt Brian L.
Published: May 2015

Individual bacteria and shifts in the composition of the microbiome have been associated with human diseases including cancer. To investigate changes in the microbiome associated with oral cancers, we profiled cancers and anatomically matched contralateral normal tissue from the same patient by sequencing 16S rDNA hypervariable region amplicons. In cancer samples from both a discovery and a subsequent confirmation cohort, abundance of Firmicutes (especially Streptococcus) and Actinobacteria (especially Rothia) was significantly decreased relative to contralateral clinically normal samples from the same patient. Significant decreases in abundance of these phyla were observed for pre-cancers, but not when comparing samples from contralateral sites (tongue and floor of mouth) from healthy individuals. Patients with cancer or dysplasia, however, could be distinguished from healthy normal individuals by increased abundance of Prevotella. Weighted UniFrac principal coordinates analysis based on 12 taxa separated most cancers from other samples with greatest separation of node positive cases.

Citation Format: Donna G. Albertson, Justin Kuczynski, Aditi Bhattacharya, Bing Huey, Patricia M. Corby, Erica L. S. Queiroz, Kira Nightingale, Alexander R. Kerr, Mark D. DeLacure, Ratna Veeramachaneni, Adam Olshen, Brian L. Schmidt. Changes in abundance of oral microbiota associated with oral cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4885. doi:10.1158/1538-7445.AM2014-4885
Abstract 4886: Targeting WNT1-inducible signaling pathway protein 2 (WISP2) alters human breast cancer cell susceptibility to specific lysis through regulation of KLF-4 and miR-7 expression
Authors: Akalay Intissar , chouaib salem , thiery jean-paul
Published: May 2015

The molecular basis for the resistance of tumor cells to cell-mediated cytotoxicity remains poorly understood and thus poses a major challenge for cancer immunotherapy. The present study was designed to determine whether the WNT1-inducible signaling pathway protein-2 (WISP2, also referred to as CCN5), a key regulator of tumor cell plasticity, interferes with tumor susceptibility to Cytotoxic T Lymphocytes (CTL)-mediated lysis. We found that targeting WISP2 signaling in human breast adenocarcinoma MCF7 cells impairs CTL-mediated cell killing by a mechanism involving Kruppel-like factor-4 (KLF-4) induction and microRNA-7 (miR-7)downregulation. Inhibition of TGF-β signaling using the A83-01 inhibitor in MCF7-shWISP2 cells resulted in a significant reversal of the Epithelial-to-Mesenchymal Transition (EMT) phenotype, the expression of stem cell marker KLF-4 and a partial recovery of target susceptibility to CTLs. More importantly, we showed that silencing of KLF-4 was accompanied by a reduction in MCF7-shWISP2 resistance to CTLs. Using human breast cancer tissues, we demonstrated the coexpression of KLF-4 with EMT markers and TGF-β pathway. More importantly, we found that KLF-4 expression was accompanied by miR-7 inhibition, which is partly responsible forimpairing CTL-mediated lysis. Thus, our data indicate that WISP2 plays a role in regulating tumor cell susceptibility through EMT by inducing the TGF-β signaling pathway, KLF-4 expression and miR-7 inhibition. These studies indicate for the first time that WISP2 acts as an activator of CTL-induced killing and suggests that the loss of its function promotes evasion of immunosurveillance and the ensuing progression of the tumor.

Citation Format: Intissar Akalay, salem chouaib, jean-paul thiery. Targeting WNT1-inducible signaling pathway protein 2 (WISP2) alters human breast cancer cell susceptibility to specific lysis through regulation of KLF-4 and miR-7 expression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4886. doi:10.1158/1538-7445.AM2014-4886
Abstract 4904: β-catenin silencing enhances radiation sensitivity through antagonizing effect of AMPK against Ku70/80 in head and neck cancer cells
Authors: Chang Hyo Won , Nam Hae Yun , Kim Mi R. , Lee Hyang J. , Seo Ji Hyun , Lee So Yeon , Kim Seong Who , Kim Sang Yoon
Published: May 2015

The Wnt/β-catenin pathway regulates the cell growth and survival following radiation in various types of cancer cells. Our previous report show that activation of the Wnt/β-catenin signaling pathway is a key radioprotective mechanism in irradiated head and neck cancer (HNC) cells. However, the molecular mechanisms by which β-catenin regulates radiation sensitivity are not clear. Here we attempted to elucidate the mechanism of cell death following radiation by studying how β-catenin silencing controls the radiation sensitivity of radioresistant HNC cells.

Of nine cell lines examined, the most radioresistant cell line (AMC-HN-9) were selected for this experiments. β-catenin silencing using small interfering RNA(siRNA) down-regulated β-catenin expression up to 72 h, which was confirmed by western blot analysis. The sensitivity to radiation was anlayzed by clonogenic analysis and MTT assay. As a result, β-catenin silencing remarkably decreased the survival of irradiated AMC-HN-9 cells and the cell viability also significantly reduced more by the combination treatment with β-catenin siRNA and radiation (0.37±0.034 fold) than when treated with β-catenin siRNA or radiation alone (0.68±0.055 fold and 0.90±0.043 fold, respectively). Interestingly, whereas expression of Ku70/80 was up regulated in AMC-HN-9 cells following irradiation (4Gy), in the cells treated with combination of radiation and β-catenin siRNA, Ku70/80 expression was dramatically decreased. In additionally, when exposed to radiation after β-catenin silencing, the up-regulation of irradiation-induced Ku80 completely was prevented by β-catenin silencing-induced AMPK.

Taken together, these results suggest that suppression of Ku70/80 expression through β-catenin silencing-induced AMPK is associated with its radio-sentitizing effect in AMC-HN-9 cells, thus supporting a novel radiosensitive mechanism of radioresistant HNC cells.

Citation Format: Hyo Won Chang, Hae Yun Nam, Mi Ra Kim, Hyang Ju Lee, Ji Hyun Seo, So Yeon Lee, Seong Who Kim, Sang Yoon Kim. β-catenin silencing enhances radiation sensitivity through antagonizing effect of AMPK against Ku70/80 in head and neck cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4904. doi:10.1158/1538-7445.AM2014-4904
Abstract 4907: Upregulation of furin is associated with the invasiveness of cumulatively irradiated cancer cells
Authors: Lee Myungjin , Rhu Changhwan , Kim Seong Who , Kim Sang Yoon
Published: May 2015

Furin, a subtilisin/kesin-like proprotein convertase (PC), activates membrane-bound MT1-MMP, which facilitates pro-gelatinase A (MMP2). These activated MT1-MMP and MMP2 are involved in cancer cell invasion and metastasis. In this study, we investigate the contribution of MMP2 activated by furin to cellular invasiveness of cumulatively irradiated cells.

Using previously established AMC-HN3 and AMC-HN8 cell line from laryngeal carcinoma patient, we have generated isogenic model of cumulatively irradiated AMC-HN3R and AMC-HN8R cell line, respectively. AMC-HN3R cells were increased furin expression with upregulation of MT1-MMP/MMP2 and their invasiveness by two fold (p < 0.05) compared to AMC-HN3, while AMC-HN8R cells had no differences compared to AMC-HN8. In case of AMC-HN3R, inhibition of furin activity with the synthetic inhibitor decanoyl-Arg-Val-Lys-Arg-chloromethyl-keton, CMK, showed a significant decrease of MT1-MMP/MMP2 and in vitro cellular invasiveness. Tumors obtained after subcutaneous (s.c.) inoculation of AMC-HN3R cells were larger, developed earlier and increased more furin than the tumor of parent cells, AMC-HN3. Although AMC-HN3R and AMC-HN8R cells identically undergo EMT, inhibition of furin activity decreases activated MMP2 and invasive potential of HN3R cell line unlike HN8R cell line, suggesting that furin is a potentially useful target for therapeutics.

Citation Format: Myungjin Lee, Changhwan Rhu, Seong Who Kim, Sang Yoon Kim. Upregulation of furin is associated with the invasiveness of cumulatively irradiated cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4907. doi:10.1158/1538-7445.AM2014-4907
Abstract 4909: Novel radiation mitigators and cancer chemoprevention drugs
Authors: Schiestl Robert H. , Rivina Yelena , Davoren Michael
Published: May 2015

The possibility of a radiation disaster from a nuclear detonation or accident has existed for over 50 years and spawned much of the basic research in radiobiology in the 1950-60s. The recent Fukushima accident was yet another reminder that there remains a dire need to develop novel therapies against radiation-induced toxicities. Here we report on the development of two novel radiation countermeasure therapies: Yel001 and Yel002. These small, biologically active, drug-like molecules were uncovered in the DEL high throughput assay reducing radiation-induced cyto- and geno-toxicity in yeast. Radiation-modulating activity was further confirmed in yeast plate-based DEL Assay: addition of either Yel001 or Yel002 to irradiated cultures reduced cell death and genomic instability. Further, Yel compounds increases survival to 75% in vivo following an LD100/30 dose of ionizing radiation (IR) with the first therapeutic injection administered 24 hours post exposure followed by injections at 48,72,96, and 120 hours. Additionally, treatment with Yel001 and Yel002 compounds reduces radiation-induced leukemia from 90% to to 50% and 40% respectively. Of note, treatment with either Yel001 or Yel002 reduced spontaneous leukemia rate from 10% to 0%. Furthermore, Yel002 significantly prolonged the life of Atm deficient mice. Treatment with Yel002 following IR accelerates the recovery of the hematopoietic cells and protects stem cells after sub-lethal exposures. In addition, treatment with Yel002 reduces I131, EMS, MMS, UV, cigarette smoke extract as well as nitrogen mustard induced toxicity as well as genotoxicity showing a broad application spectrum. Proteomics shows that Yel002 induces DNA repair mediated by Atm signaling, homologous recombination, nonhomologous end joining, base excision repair, DNA damage binding proteins and chromosome segregation functions. Toxicity has not been observed in neither in vitro or in vivo administrations, even in a two generation teratogenicity assay. Overall, Yel compounds have much potential as stockpile therapies for radiation-induced lethality and cancer as well as spontaneous cancer: they are highly effective when administered up to 24hours post exposure, they reduce radiation-induced sequelae such as leukemia, and appear to have an acceptable toxicity profile.

Citation Format: Robert H. Schiestl, Yelena Rivina, Michael Davoren. Novel radiation mitigators and cancer chemoprevention drugs. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4909. doi:10.1158/1538-7445.AM2014-4909
Abstract 4915: High degree of G2/M arrest induced by Polo-like kinase 1 (PLK1) inhibition is associated with radiosensitization
Authors: Wong Nelson , Khan Mohamed
Published: May 2015

Inhibition of polo-like kinase 1 (PLK1) seems to be a plausible avenue for sensitizing cancer cells to radiation. It has been demonstrated that normal cells tolerate PLK1 depletion well, when compared to cancer cells, suggesting a wide therapeutic index. This has been confirmed with our results from proliferation assays conducted with two primary human cell lines and various cancer cell lines. Recently, it has been shown that head-and-neck squamous cell carcinoma and medulloblastoma cells can be radiosensitized by PLK1 inhibition. Furthermore, PLK1 is involved in repair of DNA double-strand breaks. Together, these results suggest that PLK1 inhibition is a particularly attractive means of radiosensitization.

To further investigate the radiosensitization property of PLK1 inhibition, clonogenic assays were carried out. Various cancer cell lines were treated with specific PLK1 inhibitor BI 2536 and subjected to various doses of ionizing radiation. The cancer cell lines were of breast, colorectal, and pancreatic origin. We found that some, but not all, cancer cells were radiosensitized by pre-treatment with BI 2536. Mutational statuses of p53 and KRAS were examined, but no relationship between the mutational statuses and radiosensitization by BI 2536 treatment was found.

Since PLK1 inhibition causes G2/M arrest, which is the cell cycle phase that is known to be more sensitive to ionizing radiation, we assessed the percentage of cancer cells at G2/M phase when treated with or without BI 2536. Cells were treated with BI 2536 for 24 hrs before they were fixed, stained with propidium iodide, and analyzed with flow cytometry. The degree of G2/M arrest induction was assessed by G2/M induction index, as defined by % of G2/M cells before treatment / % of G2/M cells after treatment. We found that the G2/M induction indices were significantly higher with the cells that can be radiosensitized with PLK1 inhibition, when compared to those of the cells that cannot be radiosensitized. Therefore, we conclude that high G2/M induction index is predictive of radiosensitization with PLK1 inhibition. Future experiments of this project include determining the G2/M induction index threshold required for achieving radiosensitization and indentifying the molecular basis of such association.

Citation Format: Nelson Wong, Mohamed Khan. High degree of G2/M arrest induced by Polo-like kinase 1 (PLK1) inhibition is associated with radiosensitization. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4915. doi:10.1158/1538-7445.AM2014-4915
Abstract 4916: Efficiacy of NU7441-encapsulated PLGA nanoparticles in radiation sensitization of prostate cancer cells
Authors: Menon Jyothi U. , Tumati Vasu , Hsieh Jer-Tsong , Nguyen Kytai T. , Saha Debabrata
Published: May 2015

Introduction: Prostate cancer remains the leading cause of cancer-related mortality in men with an estimated 241,740 new cases and 28,170 deaths expected by end of 2012. Conventional cancer treatments such as radiation therapy can be ineffective due to radiation resistance of prostate cancer cells. This resistance arises due to their increased DNA double strand break (DSB) repair ability, especially through Non-Homologous End Joining (NHEJ). In this study, we have developed biodegradable and biocompatible poly lactic-co-glycolic acid (PLGA)-based nanoparticles containing the potent radio-sensitizer NU7441 (8-dibenzothiophen-4-yl-2-morpholin-4-yl-chromen-4-one) for radiation sensitization of prostate cancer cells by inhibiting DNA-dependent protein kinase, which regulates NHEJ.

Methods: PLGA nanoparticles encapsulating NU7441 and iron oxide as an imaging and targeting agent were prepared by a standard double emulsion technique and characterized for size and surface charge. R11 peptide was surface conjugated onto the nanoparticles for prostate cancer-specific targeting. Stability studies in de-ionized (DI) water and serum were conducted over 5 days followed by drug release studies in DI water at 37oC. Further, in vitro studies were done to study cytocompatibility with prostate epithelial cells (PZ-HPV7) and cellular uptake by prostate cancer cells (PC3). DSB repair kinetics of prostate cancer cells following nanoparticle uptake was studied using a DSB repair assay.

Results: Our nanoparticles had an average size of 274.13+ 79.96 nm and showed good stability in water and serum for 5 days. The nanoparticles also showed bi-phasic NU7441 release within 21 days at 37oC and >80% PZ-HPV7 cell viability up to 2000 µg/ml nanoparticle concentration. Further, the particles were selectively uptake by PC3 cells in a dose and magnetic field-dependent manner and showed effective radiation sensitization of these cells in vitro.

Conclusions: Our results thus demonstrate that R11-conjugated PLGA-iron oxide nanoparticles containing NU7441 are biocompatible and can be potentially used to radio-sensitize prostate cancer cells in vivo.

Citation Format: Jyothi U. Menon, Vasu Tumati, Jer-Tsong Hsieh, Kytai T. Nguyen, Debabrata Saha. Efficiacy of NU7441-encapsulated PLGA nanoparticles in radiation sensitization of prostate cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4916. doi:10.1158/1538-7445.AM2014-4916
Abstract 4918: In vitro radiosensitization of human neuroblastoma cells with iron oxide - titanium dioxide core-shell nanocomposites conjugated with 3,4-Dihydroxyphenylacetic acid (DOPAC)
Authors: Mirzoeva Salida , Liu William , Bolling James R. , Shah Karna R. , Hirschmugl Carol , Sedlmair Julia , Paunesku Tatjana , Woloschak Gayle E.
Published: May 2015

Radiation therapy plays an important role in controlling tumor growth in cancers, including neuroblastoma, one of the most frequent extra cranial solid tumors in children. However, tumor radioresistance remains to be a major obstacle in clinical radiotherapy. In this study, we explored titanium dioxide core-shell nanocomposites conjugated with DOPAC (DOPAC-NCs) as radiosensitizers. Human neuroblastoma SK-N-AS and SK-N-DZ cell cultures were treated with or without of increasing concentrations of DOPAC-NCs (200-3000 nM) prior to irradiation. One hour later, cells were irradiated with a single dose of gamma radiation (0 - 10 Gy). Seventy-two hours following radiation treatment, cell proliferation/viability was assessed by MTS assay. Sham-irradiated cells served as a control. We have found that treatment of SK-N-AS and SK-N-DZ cells with DOPAC-NCs affected cell survival in a dose-dependent manner. Our data also demonstrated the evidence of DOPAC-NCs radiosensitization to gamma radiation. For examples, cell survival of SK-N-AS cells irradiated with 5 Gy and pre-treated with 1000 nM of DOPAC-NCs was as low as 35.6%. Oppositely, without radiation, treatment with the same concentration of DOPAC-NCs had no effect on cell viability.

These findings provide in vitro evidence that DOPAC-NCs may be developed and employed as radiosensitizers in neuroblastoma radiation therapy.

Citation Format: Salida Mirzoeva, William Liu, James R. Bolling, Karna R. Shah, Carol Hirschmugl, Julia Sedlmair, Tatjana Paunesku, Gayle E. Woloschak. In vitro radiosensitization of human neuroblastoma cells with iron oxide - titanium dioxide core-shell nanocomposites conjugated with 3,4-Dihydroxyphenylacetic acid (DOPAC). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4918. doi:10.1158/1538-7445.AM2014-4918
Abstract 4925: Targeted metabolic profiling of gliomas and glioma stem cells identifies methionine as a differentially regulated metabolite: Proof of principle supporting methionine-pet imaging
Authors: Palanichamy Kamalakannan , Krishnan Thirumoorthy , Sebastian Nikhil , Singh Rajbir , Kanji Suman , Chakravarti Arnab
Published: May 2015

Purpose: At present, 18F-Fluorodeoxyglucose(FDG)-positron emission tomography (PET) is the most commonly used diagnostic imaging modality in clinical practice for predicting prognosis in malignant brain tumors. The diffusive nature of glioblastoma (GBM) often makes FDG-PET detection inaccurate and there is no diagnostic gold-standard for GBM. Thus, it is necessary to find new criteria independent of conventional FDG-PET diagnosis to delineate tumor versus normal tissues. Molecular imaging using 11C-Methionine-PET (Met-PET) is one of the most promising approaches to this challenge.

Methods: We employed a targeted metabolomic approach to study the extracellular and intracellular levels of methionine in established (ATCC) and patient derived primary glioblastoma (GBM) cell lines, glioma stem cells (GSC) and normal human astrocytes (NHA) to gain a better understanding of methionine uptake. Methylthioadenosine phosphorylase (MTAP) is an enzyme that plays a vital role in polyamine metabolism and methionine salvage. Therefore, we determined the expression profile of MTAP in these cells using RT-qPCR. We then extracted the intracellular and extracellular metabolites of GBM, GSC and NHA to estimate their methionine levels using LC-MS Quadropole Time of Flight (Q-TOF) and LC-MS Triple Quad (QQQ) instruments. Thus, by using metabolic fingerprints of methionine, we quantified methionine accumulation / uptake in GBM, GSC and NHA.

Results and Conclusion: PET provides real-time information of metabolism through the behavior of single molecules. Despite clinical trials advocating Met-PET imaging as a superior imaging modality compared to FDG-PET for brain tumors, to date Met-PET has not been widely used in clinical diagnostics. Through this metabolic profiling of gliomas, we have shown for the first time that GBM and GSC accumulate methionine when compared to NHA. Uptake studies through exogenous addition of methionine in GBM, GSC and NHA show a significant uptake of methionine by GBM and GSC when compared to NHA. The results of our study establish the scientific basis for Met-PET imaging in GBM and provide a rationale for incorporating Met-PET imaging in future brain tumor clinical trials to evaluate its prognostic value.

Citation Format: Kamalakannan Palanichamy, Thirumoorthy Krishnan, Nikhil Sebastian, Rajbir Singh, Suman Kanji, Arnab Chakravarti. Targeted metabolic profiling of gliomas and glioma stem cells identifies methionine as a differentially regulated metabolite: Proof of principle supporting methionine-pet imaging. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4925. doi:10.1158/1538-7445.AM2014-4925
Abstract 4941: A humanized bone model for preclinical monitoring of prostate cancer lesions by intravital multiphoton microscopy
Authors: Dondossola Eleonora , Alexander Stephanie , Alexander Steve , Holzapfel Boris M. , Logothetis Christopher J. , Hutmacher Dietmar W. , Friedl Peter
Published: May 2015

Bone metastases are the initial site of progression and account for many of the complications experienced by men with metastatic prostate cancer (PCa), including resistance to therapy. The purpose of our study is to determine whether intravital multiphoton microscopy (iMPM) integrated with a novel mouse model can better inform clinical development of molecular therapeutics targeting bone metastases. iMPM can overcome limitations of existing models by monitoring the dynamic reciprocal cell-cell interplay at the center of PCa bone metastasis. To study PCa-stromal cell interactions and therapy response in bone, we established a humanized neo-bone in the mouse dermis, using grafted electrospun polycaprolactone scaffolds functionalized with human mesenchymal stem cells differentiated to osteoblasts. After in vivo maturation, bone scaffolds served for co-implantation of human fluorescent PCa cells (PC3) followed by multi-parameter iMPM through a body window, including: collagen and bone matrix (second harmonic generation), mineralized matrix (calcein blue), osteoblasts (H2B/mCherry in human mesenchymal stem cells), adipocytes and bone surface (third harmonic generation), blood vessels, stromal phagocytes and osteoclasts (fluorescence-labeled dextran), and PC3 cells (nuclear H2B eGFP with cytoplasmatic DsRed2). Using multi-parameter 3D reconstruction, tumor growth and invasion, reactive remodeling of the stroma and neovessel organization were monitored longitudinally, providing a baseline for evaluating preclinical disease and therapy response. The model provides new insight into PCa bone metastases and will be used to more efficiently develop and prioritize biologically founded therapy for clinical development.

Citation Format: Eleonora Dondossola, Stephanie Alexander, Steve Alexander, Boris M. Holzapfel, Christopher J. Logothetis, Dietmar W. Hutmacher, Peter Friedl. A humanized bone model for preclinical monitoring of prostate cancer lesions by intravital multiphoton microscopy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4941. doi:10.1158/1538-7445.AM2014-4941
Abstract 4952: Germline variation modulates susceptibility to aggressive disease development in a mouse model of prostate tumorigenesis
Authors: Williams Kendra A. , Bupp Sujata , Patel Shashank , Andreas Jonathan , Zhang Suiyuan , Molinolo Alfredo , Gutkind Silvio , Crawford Nigel
Published: May 2015

Although prostate cancer is common, with over 238,000 new cases being diagnosed in the US in 2012, it typically runs an indolent course with most men succumbing to unrelated disease processes. This is reflected in the low prostate cancer-specific mortality, with approximately 29,000 men succumbing in the same period. It is of critical importance to identify modifiers that increase susceptibility to aggressive disease to allow physicians to more accurately identify men at risk of fatal disease forms. The goal of this work is to map prostate tumor progression and metastasis modifier loci mapping using the C57BL/6-Tg(TRAMP)8247Ng/J (TRAMP) mouse model of aggressive neuroendocrine prostate carcinoma. We hypothesize that germline variation influences tumor progression and metastasis in prostate cancer.

The effect of germline variation in TRAMP mice was investigated by crossing it to Collaborative Cross progenitor strains and quantifying tumor progression and metastasis in transgene-positive F1 males. Those strains with the greatest phenotypic variation from the wildtype TRAMP C57BL6/J mice were chosen for modifier mapping using an F2 intercross approach. F2 mice were genotyped using a linkage panel consisting of 1,449 SNPs and modifier loci analyzed using j/qtl. The greatest number of loci achieving genomewide significance were observed in the TRAMPxNOD/ShiLtJ F2 cross (n=232). Modifier loci associated with primary tumor growth were observed on chromosomes 4, 7 and 8. Additionally, loci associated with metastasis were observed on chromosomes 1, 11, 13 and 17.

We have therefore identified multiple loci associated with aggressive disease development in a mouse model of prostate cancer. Candidate gene identification is ongoing, and focuses upon characterizing cis-eQTLs in TRAMPxNOD/ShiLtJ F2 primary tumors. Additionally, we are performing high resolution modifier mapping in TRAMPxJ:DO F1 mice. Our eventual aim is to confirm the relevance of candidate genes identified in the TRAMP mouse in human association cohorts.

Citation Format: Kendra A. Williams, Sujata Bupp, Shashank Patel, Jonathan Andreas, Suiyuan Zhang, Alfredo Molinolo, Silvio Gutkind, Nigel Crawford. Germline variation modulates susceptibility to aggressive disease development in a mouse model of prostate tumorigenesis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4952. doi:10.1158/1538-7445.AM2014-4952
Abstract 4959: High-resolution MALDI imaging mass spectrometry demonstrated the correlation between phosphatidylinositol profiles and invasion/metastasis in human breast cancer
Authors: Kawashima Masahiro , Kawaguchi-Sakita Nobuko , Sugimoto Masahiro , Sato Taka-Aki , Tanaka Koichi , Toi Masakazu
Published: May 2015

High-resolution matrix-assisted laser desorption/ionization imaging mass spectrometry (HR-MALDI IMS) is an emerging application for lipid research that provides a detailed histological distribution of ionized lipids within tissue section. Phosphatidylinositol (PI) is one of the major classes of membrane phospholipid. The cellular membrane fluidity and signal transduction activity could be modulated by the alteration of fatty acid composition of PIs. Especially, PI-3kinase pathway, which can be activated by the phosphorylation of PIs, has become a great concern in breast cancer treatment. Although the amount of PIs is known to increase in human breast cancer tissues, it remains unclear how PIs are distributed in cancerous tissues. In this study, we investigated the detailed spatial distribution of PIs in breast tissues obtained from 24 patients, including 23 invasive ductal carcinoma (IDC), 4 ductal carcinoma in situ (DCIS), and 4 fibrocystic change lesions by using HR-MALDI IMS. The distribution of PIs was visualized at the resolution of 10um. 10 PIs with different fatty acid composition were detected in breast tissues. High-resolution analysis revealed the fatty acid composition of PIs was altered specifically in cancer cell clusters compared to stromal cells and non-malignant epithelia. PIs carrying monounsaturated fatty acid (MUFA) and PIs carrying polyunsaturated fatty acid (PUFA) showed the specific localization to cancer cell clusters. However, the proportion of PIs carrying MUFA and PIs carrying PUFA showed a clear inverse correlation in cancer cells. When we compared the PI profiles of IDC, DCIS, and FC, it was suggested that the accumulation of PIs carrying PUFA was occurred during the step of invasion. Moreover, lymph node metastasis well correlated with the accumulation of PIs carrying PUFA in cancer cells. HR-MALDI IMS firstly demonstrated the possible association between the PI profiles of breast cancer cells and their invasion/metastasis ability. Although this is a preliminary study, HR-MALDI IMS could be a useful modality to visualize the reprogramming of the lipid metabolism which reflects the cancer cell phenotype.

Citation Format: Masahiro Kawashima, Nobuko Kawaguchi-Sakita, Masahiro Sugimoto, Taka-Aki Sato, Koichi Tanaka, Masakazu Toi. High-resolution MALDI imaging mass spectrometry demonstrated the correlation between phosphatidylinositol profiles and invasion/metastasis in human breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4959. doi:10.1158/1538-7445.AM2014-4959