bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3616: Androgen deprivation therapy and second primary lung cancer risk in prostate cancer patients in the US Veterans.
Authors: Kang Hyunseok , Pillai Rathi N. , Brandes Johann C.
Published: August 2014

Background

Previous observational studies have consistently reported decreased risk of lung cancers among prostate cancer patients. Recent literature suggests a role of estrogen receptor (ER) beta and aromatase, which can convert testosterone to estrogen, in development and progression of non small cell lung cancers. Second primary lung cancer risk among breast cancer patients appears to be higher in ER negative patients compared to ER positive patients probably from estrogen receptor blockade. As androgen deprivation therapy (ADT) has been well established for more than 70 years as an effective treatment modality for prostate cancer, we hypothesized the hormone modulation may decrease lung cancer risk and investigated the effect of ADT on second primary lung cancer risk among patients with prostate cancer.

Methods

We identified 62,589 men in VA Central Cancer Registry (VACCR) who were diagnosed with prostate cancer between 1999 and 2008, with follow-up available through 2010. The primary outcome was development of lung cancer, determined by VACCR. Descriptive statistics were used to compare basic characteristics between the groups. Cox proportional hazards model was used to assess the influence of ADT on the lung cancer incidence, adjusted for patient characteristics and prostate cancer stage. All the statistical analyses were performed using STATA 10 (Stata Corp, College Station, TX).

Results

Men who had ADT as part of their treatment for prostate cancer tend to be older (median age 71.3 vs 65.7, p < 0.01) and smoke slightly more (72.5% vs 71.4%, p=0.02). As expected, ADT group tend to have higher stage prostate cancers. There were 766 secondary lung cancers diagnosed in the cohort for the follow-up period. ADT group had significantly decreased secondary lung cancer risk by approximately 20% (HR 0.83, 95%CI=0.70-0.97) when adjusted for age, smoking status and prostate cancer stage at presentation.

Conclusion

Our study suggests that ADT in prostate cancer patients is associated with a decreased risk of second primary lung cancers. Independent validation studies and subgroup analyses to clarify the association is warranted.

This work was supported by Veteran's Health Administration 1IK2BX001283-01 and NCI 5P50CA128613-02.

Citation Format: Hyunseok Kang, Rathi N. Pillai, Johann C. Brandes. Androgen deprivation therapy and second primary lung cancer risk in prostate cancer patients in the US Veterans. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3616. doi:10.1158/1538-7445.AM2013-3616
Abstract 363: Activin receptor-like kinase 1 (Alk1) ligands modulate endothelial cell function in vitro and in vivo.
Authors: Davies Gareth C. , Harper James A. , Sainson Richard C. , Brown Lee , Opoku-Ansah Grace , Smith Alison , McCourt Matthew , Legg James W.
Published: August 2014

The TGF-ß type-1 receptor activin receptor-like kinase 1 (Alk1) is predominantly expressed on endothelial cells, regulates vascular morphogenesis, and has been implicated in pathological angiogenesis. Alk1 expression is increased in the vasculature of a broad range of tumours and agents that disrupt of Alk1 signalling in tumour endothelial cells may be potential therapeutics for the treatment of a variety of solid tumours. Alk1 has been described as a receptor for the bone morphogenic proteins, BMP9 and BMP10. In order to study the effects of Alk1 signalling in endothelial cells in vitro and in the vasculature in vivo we used a soluble antagonist Alk1-Fc protein consisting of the extracellular domain of the Alk1 protein fused to the Fc domain of IgG1. In vitro, Alk1-Fc inhibited BMP9-dependent Alk1 signalling via phosphorylation and nuclear translocation of SMAD1/5 in endothelial cells and modulated endothelial cell functions such as an ability to form tube- like structures. In mice, physiological levels of BMP9 could be detected in serum by ELISA, consistent with detectable levels of phosphorylated SMAD1/5 in the lung, a site of high Alk1 vascular expression. In mice, the administration of Alk1-Fc effectively blocked SMAD1/5 phosphorylation in the lung, suggesting that in this tissue Alk1 ligands are the predominant driver of lung SMAD1/5 activation and that signalling is efficiently antagonised by Alk1-Fc. Despite suppression of Alk1 signalling in the lung and expression of Alk1 on the vasculature associated with tumours, Alk1-Fc did not have profound effects on tumour size or microvessel density in mice bearing tumours, however administration of Alk1-Fc in neonatal mice did cause defects in angiogenesis of the retinal vasculature demonstrating that in some contexts Alk1 ligands play an important role in regulating the angiogenic process.

Citation Format: Gareth C. Davies, James A. Harper, Richard C. Sainson, Lee Brown, Grace Opoku-Ansah, Alison Smith, Matthew McCourt, James W. Legg. Activin receptor-like kinase 1 (Alk1) ligands modulate endothelial cell function in vitro and in vivo. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 363. doi:10.1158/1538-7445.AM2013-363
Abstract 3735: Preclinical studies of salinomycin as a therapeutic agent for pediatric high-grade glioma cancer stem cells.
Authors: Moses Emily S. , Chang Judy C. , Hung Jaclyn Y.
Published: August 2014

Brain tumors are the most prevalent childhood solid tumors. In the low-grade astrocytomas complete surgical resection has achieved over 90% five-year survival rate. In contrast, the aggressive anaplastic astrocytoma high-grade 3 and the fast growing glioblastoma multiforme high-grade 4 are often refractory to standard therapies; the majority of these patients at presentation are beyond cure by surgery and or radiotherapy. Emerging data substantiate the idea that a small pool of post-therapy residual cells within a tumor displaying stem-like properties is responsible for relapse. Therefore, selectively targeting these cancer stem-like cells (CSCs) may lead to advances in the treatment of these tumors. Salinomycin, an antibiotic potassium ionophore, has been shown to be highly effective against breast cancer stem cells and other malignancies; however, its potential use has not been studied in childhood astrocytomas. Recent studies indicate that salinomycin exerts its effect on components of the Wnt signaling cascade. In this study, we undertook in vitro and in vivo analyses on the effect of salinomycin on four pediatric high-grade astrocytoma cell lines, UW479 (provided by Dr. John Silber, University of Washington), SF188 (from Dr. Daphne Haas-Kogan, UCSF), SJ-GBM2, and CHLA-200 (COG Cell Culture and Xenograft Repository). Our results indicated that salinomycin was able to inhibit cellular viability in a dose-dependent manner. The soft-agar anchorage independent growth assay showed salinomycin inhibition of colony formation in 3 of the 4 cell lines tested. A decrease in the number of cycling cells (S-phase) was observed in cells treated with salinomycin. Notably, a 95% reduction in the glioma stem cells, read-out as CD133+, and impairment in the ability to form spheres (read-out as self-renewal) was observed. A xenograft mouse model was used to determine the effect of salinomycin on tumor growth in vivo and is ongoing. Salinomycin's modulation of Wnt targets measured by qRT-PCR, western blot analysis, and Bio-Plex protein assays, is in progress. Our data suggest that salinomycin could be exploited for the treatment of the aggressive form of pediatric gliomas.

Citation Format: Emily S. Moses, Judy C. Chang, Jaclyn Y. Hung. Preclinical studies of salinomycin as a therapeutic agent for pediatric high-grade glioma cancer stem cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3735. doi:10.1158/1538-7445.AM2013-3735
Abstract 3752: Induction of lung cancer stem-like cells by chronic exposure to carbon nanotubes.
Authors: Luanpitpong Sudjit , Wang Liying , Manke Amruta , Barr Jamie , Rojanasakul Yon
Published: August 2014

Our previous studies have shown that chronic exposure to single-walled carbon nanotubes (SWCNTs) induces malignant transformation of human lung epithelial cells. Most solid tumors including lung cancer cells are believed to contain poorly differentiated cancer stem-like cells (CSCs) that initiate tumorigenesis and confer resistance to chemotherapy. In this study we investigated whether SWCNT-transformed lung epithelial cells present CSC traits. Similar to human non-small cell lung cancer H460 cells, SWCNT-transformed lung epithelial BEAS-2B cells but not its passage-matched control cells formed tumor spheres in stem cell-selective conditions, indicating the existence of lung CSCs. Lung CSCs have previously been reported to reside in the side population (SP) of parental lung cancer cells. Analysis of SP fractions based on the ability of SP to efflux Hoechst 33342 dye to generate a Hoechst blue-red profile revealed that the SWCNT-transformed cells and H460 cells have high SP fractions, while passage-matched control cells showed no SP, thus confirming the existence of CSC population in SWCNT-transformed and H460 cells. Compared with the corresponding parental cells, the SP cells of SWCNT-transformed and H460 cells acquired apoptosis resistance to various chemotherapy including antimycin A, cisplatin, doxorubicin and etoposide. Together, our results indicate the ability of SWCNT to transform human lung epithelial cells and induce CSCs which could represent a novel mechanism of carcinogenesis induced by CNTs.

Citation Format: Sudjit Luanpitpong, Liying Wang, Amruta Manke, Jamie Barr, Yon Rojanasakul. Induction of lung cancer stem-like cells by chronic exposure to carbon nanotubes. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3752. doi:10.1158/1538-7445.AM2013-3752
Abstract 3797: Regulation and function of the mucin-like glycoprotein podoplanin in glioma.
Authors: Peterziel Heike , Müller Julia , Andreas Danner , Barbus Sebastian , Liu Haikun , Pfenning Philipp , Harter Patrick N. , Mittelbronn Michel , Wick Wolfgang , Schuetz Günther , Radlwimmer Bernhard , Lichter Peter , Hess Jochen , Angel Peter
Published: August 2014

Podoplanin (PDPN) is a mucin like type-1 transmembrane protein consisting of 162 amino acids, which comprises a highly glycosylated extracellular domain and a nine amino acid intracellular domain. The specific expression of PDPN on lymphatic but not on blood vascular endothelial cells has established application as a histological marker for lymphangiogenesis and lymphatic vessels in different species. PDPN is highly expressed in tumors of different origin, including squamous cell cancers, germinal neoplasia and tumors of the central nervous system. Recently, we found strong overexpression of PDPN in human astrocytic brain tumors, specifically in primary glioblastoma multiforme (GB). Regulation of PDPN expression involves increased PI3 kinase activation, subsequent activation of protein kinaseB/Akt and the downstream transcription factor AP-1. Activation of this pathway is mediated by loss of PTEN function, consistently, mice lacking Pten exhibit elevated Pdpn protein levels in the subventricular zone of the brain tissue. Additionally, PDPN expression is subject to negative transcriptional regulation by promoter methylation in human GB and in glioma cell lines. In patients high expression of PDPN is associated with poor prognosis. Silencing of PDPN results in a decrease in proliferation, migration and invasion of glioma cell lines in vitro and slows down the migration in orthotopic brain slices. Consistently, tumor formation after injection of PDPN knock-down cells into SCID mice is significantly reduced compared to tumors after injection of parental cells. These data highlight a functional role of PDPN in glioma progression and suggest targeting of PDPN expression as a promising strategy for the treatment of patients with primary GB.

Citation Format: Heike Peterziel, Julia Müller, Danner Andreas, Sebastian Barbus, Haikun Liu, Philipp Pfenning, Patrick N. Harter, Michel Mittelbronn, Wolfgang Wick, Günther Schuetz, Bernhard Radlwimmer, Peter Lichter, Jochen Hess, Peter Angel. Regulation and function of the mucin-like glycoprotein podoplanin in glioma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3797. doi:10.1158/1538-7445.AM2013-3797
Abstract 3805: Single cell evolution of AKT pathway activation drives T-cell acute lymphoblastic leukemia relapse.
Authors: Blackburn Jessica S. , Liu Sali , Dobrinski Kimberly , Ranalli Jayme , Martinez Sarah , Lee Charles , Langenau David
Published: August 2014

The aggressive and unpredictable behavior of relapsed T-cell acute lymphoblastic leukemia (T-ALL) presents a major clinical challenge, with >70% of children and >90% of adults unable to survive relapsed disease. Relapsed T-ALL often acquires mutations that are not found in the primary malignancy. It is these new mutations that allow clones to survive treatment and drive relapse growth. In order to identify the genes and pathways responsible for T-ALL relapse, we have developed a transgenic zebrafish model of relapsed T-ALL where single fluorescently-labeled leukemic cells are transplanted into genetically identical recipient fish and functionally assessed for differences in relapse growth. Using serial transplantation of single T-ALL cells and >6,000 recipient animals, we have followed single-cell evolution of T-ALL and identified critical drivers of relapse. These experiments showed that 6 of 49 individual T-ALL cells significantly increased their ability to form relapse over time. Analysis of T-ALL clones pre- and post-evolution showed that AKT pathway activation was correlated with increased relapse potential. Subsequent studies utilizing transgenic zebrafish that over-expressed activated AKT in developing T-ALL demonstrated that AKT signaling increased relapse potential 10-fold. Transgenic epistatic experiments revealed that AKT signaling plays two distinct roles in T-ALL relapse: the AKT/mTORC1 pathway directly enhanced relapse potential, while AKT mediated stabilization of the Myc protein increased T-ALL aggressiveness. Moreover, small molecule inhibition of AKT signaling reduced T-ALL relapse potential in vivo by 25-fold and synergized with Dexamethasone, a common cytotoxic chemotherapy, to significantly enhance cell killing in both zebrafish and human T-ALL. Activation of AKT signaling is associated with poor prognosis and drug resistance in human T-ALL, which, together with our work, suggests that AKT will be a useful molecular target in the treatment of T-ALL. Our experiments have documented the functional heterogeneity of single leukemic cells and identified AKT as a critical driver of T-ALL aggression, relapse formation, and insensitivity to therapy. These are first studies performed in any model to follow single cell evolution as it relates to relapse, opening new and exciting avenues of study to uncover genetic pathways that drive cancer malignancy.

Citation Format: Jessica S. Blackburn, Sali Liu, Kimberly Dobrinski, Jayme Ranalli, Sarah Martinez, Charles Lee, David Langenau. Single cell evolution of AKT pathway activation drives T-cell acute lymphoblastic leukemia relapse. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3805. doi:10.1158/1538-7445.AM2013-3805
Abstract 3835: Ex vivo 3D assay: rapid and reliable replication of the in vivo anti-tumor efficacy of c-Met inhibitors.
Authors: Gorynia Sabine , Guo Jianing , Ackermann Andreas , Maier Armin , Krumbach Rebekka , Kelter Gerhard , Vuaroqueaux Vincent , Metz Thomas , Metcalfe Thomas , Fiebig Heiner H.
Published: August 2014

For compounds directed against molecular targets expressed in tumor cells, the ex vivo 3D tumor clonogenic assay (TCA) is a rapid and reliable ex vivo assay with a high predictive value for in vivo tumor sensitivity. Single cell suspensions prepared from patient-derived tumor xenografts (PDX) growing subcutaneously in nude mice or from cultured human tumor cell lines are seeded in semisolid medium and tumor colony formation is monitored in the presence or absence of test compounds over a period of one to three weeks.

Based on experiments with up to 70 PDX, we have demonstrated that the TCA accurately replicates the in vivo sensitivity of PDX towards cMet inhibitors across all major tumor histologies. More specifically, all three NSCLC PDX that regressed in response to cMet inhibition in in vivo efficacy tests were sensitive to several cMet inhibitors in the ex vivo TCA. By contrast, data obtained with a 2D cell proliferation and survival assay did not correlate with the 3D and in vivo situations, suggesting that cMet function does not affect cell survival and proliferation on plastic but confers the capacity for anchorage-independent growth. The correlation of 3D but not 2D data with in vivo sensitivity was confirmed using anti-cMet siRNAs in selected PDX-derived non-small cell lung cancer cell lines. Preliminary immunohistochemical analysis revealed that PDX sensitive to cMet inhibitors expressed high cMet levels while not all PDX expressing high cMet levels were sensitive to cMet inhibitors.

In conclusion, for cMet inhibitors the TCA replicates in vivo sensitivities of PDX to a high degree. Due to its short duration the TCA is an excellent tool for the screening of large numbers of cMet inhibitors and PDX. As all of the PDX qualified for use in the TCA (>200) have been extensively molecularly characterised (gene expression, gene copy number variation and mutation analysis) this assay is also an excellent tool for generating high quality biomarker hypotheses during the preclinical profiling of molecules intended for oncology indications.

Citation Format: Sabine Gorynia, Jianing Guo, Andreas Ackermann, Armin Maier, Rebekka Krumbach, Gerhard Kelter, Vincent Vuaroqueaux, Thomas Metz, Thomas Metcalfe, Heiner H. Fiebig. Ex vivo 3D assay: rapid and reliable replication of the in vivo anti-tumor efficacy of c-Met inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3835. doi:10.1158/1538-7445.AM2013-3835
Abstract 3839: Development of a 3-dimensional synthetic lethality screening approach targeting KRas-mut cells.
Authors: Tsuji Toshiya , Sapinoso Lisa M. , Lin I-Lin , Xu Shuichan , Boylan John F.
Published: August 2014

Three-dimensional (3D) in vitro models have been used in cancer research to overcome limitations of 2D systems. 3D in vitro models recapitulate many aspects of actual tumors including hypoxia, metabolism, proliferation gradients, cell-cell and cell-matrix interactions and closer clinical gene expression profiles than those seen in 2D. Importantly, some cancer drugs showed high potency only in the 3D environment compared to 2D (Muranen, et al, Cancer Cell, 2012). In order to identify improved cancer drugs, we established a simple and versatile 3D spheroid culture approach for high-throughput screening for compounds that selectively kill cancer cells with certain genetic backgrounds. We used HCT116 (parental: HCT116/KRas-mut) and an isogenic counterpart that expresses a genetically modified KRas gene (HCT116/KRas-wt) for 3D cell culture. To validate this approach, HCT116/KRas-mut and HCT116/KRas-wt were cultured separately, treated with 15 selected tool compounds and viability was measured using a caspase 3/7 assay. We found 4 compounds that induced caspase 3/7 activity only in 3D culture of HCT116/KRas-mut and not in 2D. Furthermore, 5 compounds were predominantly sensitive to HCT116/KRas-wt cells in 3D culture, but not in HCT116/KRas-mut 3D culture. These results indicate that the more physiological relevant 3D synthetic lethal screen is an attractive approach to cancer drug discovery and may identify compounds missed in conventional 2D culture model screens.

Citation Format: Toshiya Tsuji, Lisa M. Sapinoso, I-Lin Lin, Shuichan Xu, John F. Boylan. Development of a 3-dimensional synthetic lethality screening approach targeting KRas-mut cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3839. doi:10.1158/1538-7445.AM2013-3839
Abstract 3845: Developing a novel 3D model to study colon cancer cell invasion.
Authors: Adams Rosie
Published: August 2014

Introduction: Colon cancer is the fifth most diagnosed in the UK, with nearly 22,000 cases diagnosed in 20101 with a five-year survival rate of 54.75%2. The formation of distant metastases also influences patient survival, causing a decline from 93% for the earliest stage tumours down to below 7% for tumours with distant metastases3. Previous literature has highlighted the limitations of two-dimensional (2D) cancer cell migration assays4. These include alterations in gene expression of cells and the provision of a migration substrate that does not closely reflect that of the in vivo environment. This project aims to mimic the in vivo situation to investigate factors that affect cancer cell invasion; including the expression of EMT markers and signalling by developing a three-dimensional (3D) model of colon cancer. Methods: This project utilises commercial scaffold known as Alvetex®5 and two colon cancer cell lines (SW480 and SW620) were used to look at the differences between pre- and post-metastatic colon cancer respectively. Both cell lines were cultured prior to analysis using various biochemical assays and histological processing. Results: Our data show a difference in cell penetration between the two cell lines. The later stage SW620 cells, which have a more motile phenotype in 2D, migrate and penetrate the scaffold to a greater extent than the earlier stage, less invasive, SW480 cells. This reflects a known difference in the level of EMT markers between the two cell lines, a result of the Wnt signalling pathway. This model also allows for the use of the known chemoattractant Insulin-like Growth Factor (IGF) to encourage cell penetration. IGF has been shown to play an important role in cancer cell migration. The use of IGF results in a 54% increase in cell penetration by the SW480 cell line, but not the SW620 cell line. Discussion: Our data shows great potential for further development of a 3D cancer invasion model using these scaffolds. This model provides a more realistic 3D environment and will be a tool for chemoattractant and co-culture studies to determine the mechanism of invasion utilised by these cells and to develop this model further to obtain an assay which is closer to the in vivo situation.

Acknowledgements: This work was carried out with funding from the Grevillea Trust, Reinnervate Limited and BBSRC.

Citation Format: Rosie Adams. Developing a novel 3D model to study colon cancer cell invasion. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3845. doi:10.1158/1538-7445.AM2013-3845
Abstract 3847: High-throughput 3D screening reveals differences in drug sensitivities between culture models of JIMT1 breast cancer cells .
Authors: Hongisto Vesa J. , Nyberg Sandra , Fey Vidal , Mpindi John-Patrick , Kallioniemi Olli , Perälä Merja
Published: August 2014

The traditional method for studying cancer in vitro is to grow immortalized cancer cells in two-dimensional (2D) monolayers on plastic. However, many cellular features are impaired in these unnatural conditions and big alterations in gene expression in comparison to tumors have been reported. Three-dimensional (3D) cell culture models have become increasingly popular and are suggested to be better models than 2D monolayers due to improved cell-to-cell contacts and structures that resemble in vivo architecture.

The aim of this study was to develop a simple high-throughput 3D drug screening method and to compare drug responses in JIMT1 breast cancer cells when grown in 2D, in polyHEMA coated anchorage independent 3D models and in Matrigel on-top 3D cell culture models. We screened 102 compounds with multiple concentrations and biological replicates for their effects on cell proliferation. The cells were either treated immediately upon plating or they were allowed to grow in 3D for four days prior to the drug treatment. Big variations in drug responses were observed between the models indicating that comparisons of culture model influenced drug sensitivities cannot be made based on effects of a single drug. However, we show with the 63 most prominent drugs that, in general, JIMT1 cells grown on Matrigel were significantly more sensitive to drugs than cells grown in 2D cultures, while responses of cells grown in polyHEMA resembled those of 2D. Furthermore, comparison of gene expression profiles of the cell culture models to xenograft tumors indicated that cells cultured in Matrigel and as xenografts most closely resembled each other. In this study we also suggest that 3D cultures can provide a platform for systematic experimentation of larger compound collections in a high-throughput mode and be used as alternatives for traditional 2D screens towards better comparability to in vivo state.

Citation Format: Vesa J. Hongisto, Sandra Nyberg, Vidal Fey, John-Patrick Mpindi, Olli Kallioniemi, Merja Perälä. High-throughput 3D screening reveals differences in drug sensitivities between culture models of JIMT1 breast cancer cells . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3847. doi:10.1158/1538-7445.AM2013-3847
Abstract 3852: Bcl-xL and IL-6 act independently and synergistically to accelerate plasmacytopoiesis and plasma cell tumor formation in Balb/c mice.
Authors: Sakai Tomomi , Kovalchuk Alexander L. , Morse Herbert
Published: August 2014

Accelerated development of spontaneous plasma cell tumors (PCT) occurs in mucosal-associated lymphoid tissues of mice bearing both IL-6 and BCL-XL transgenes (double transgenic (dTg)). 91% of dTG mice developed PCTs at a mean age of 89 days. In contrast, 53% of the IL-6 Tg mice developed PCTs at a mean age of 301 days and 12% BCL-XL Tg mice developed PCTs with a mean age of 433 days. The PCTs formed primarily in Peyer's Patches, medullary cords of the mesenteric lymph node and/or the lamina propria of small intestinal villi where they were preceded by massive plasma cell hyperplasia. To investigate the molecular basis of the cooperation between IL-6 and BCL-xL transgenes to accelerate PCT development we performed detailed analysis of cell lines developed from dTG mice and and spontaneous or pristane-induced tumors of Bcl-xL TG mice. All the tumors carry Ig/Myc-deregulating chromosomal translocations, which are thought to be the initiating event of PCT development. Therefore we focused on finding possible differences in secondary alterations. Although the subsets were poorly distinguished by microarray-based gene expression profiling, there were significant differences in the expression of p21, p19ARF, p53, HUWE1 and pRb as determined by western blotting and qPCR. DTG tumors were characterized by alterations in pathways governing expression of pRb that included increased expression of INK4A and down regulation of pRb itself as well as down regulation of p19ARF. Most notably we discovered discordance between protein and mRNA levels for pRb and p19Arf. Efforts to understand the molecular basis for these distinctions and their contributions to the biology of these PCT subsets are in progress.

Citation Format: Tomomi Sakai, Alexander L. Kovalchuk, Herbert Morse. Bcl-xL and IL-6 act independently and synergistically to accelerate plasmacytopoiesis and plasma cell tumor formation in Balb/c mice. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3852. doi:10.1158/1538-7445.AM2013-3852
Abstract 3899: PCB153-induced angiogenesis depends on redoxsensitive Pyk2 signaling.
Authors: Das Jayanta K. , Felty Quentin H.
Published: August 2014

Estrogenic chemicals have been shown to increase the expression of the growth factor VEGF in breast cancer cells. Hence, there is some concern that environmental exposure to estrogenic chemicals such as polychlorinated biphenyls (PCBs) may excacerbate the growth of breast cancer via angiogenesis. Highly metastatic breast cancer cells exposed to PCB153 have been reported to produce a significantly greater amount of ROS compared to non-metastatic breast cancer cells. A number of paracrine effects have been reported in tumors exposed to estrogen, however, the role of estrogen-induced ROS in signaling tumor angiogenesis remains to be defined. We previously reported that PCB-induced angiogenesis can be blocked by

Pyk2 siRNA. Therefore, the goal of this study was to determine whether Pyk2 small molecule inhibitors block PCB-induced vascularization in a 3-D breast tumor model. Human umbilical vein endothelial cells (HUVEC) or brain microvascular endothelial cells (hCMEC/D3) were used to study the effect of small molecule inhibitors. The effect of Pyk2 inhibition on breast tumor spheroid angiogenesis was tested in a 3-D co-culture of MDA-MB-231 breast cancer cells. MDA-MB-231 cells exposed to PCB153 produced ROS most likely H2O2; therefore we determined whether external H2O2 exposure increased DNA synthesis of vascular endothelial cells. Our results showed a significant increase in DNA synthesis from exposure to H2O2 for

18hrs. Breast tumor spheroids treated with PF431396 or Pyk2 siRNA showed a significant reduction in microvessel sprouting and length when compared to control. Confocal microscopy of endothelial cells co-cultured with smooth muscle cells and fibroblasts further showed a significant increase in endothelial cell branching when exposed to PCB153. The effects of PCB153 on endothelial cells in co-culture were inhibited by treatments with the ROS scavenger

N-acetylcysteine. We have provided evidence for the role of Pyk2 redox signaling in the aggressive angiogenic phenotype of endothelial cells. Our results suggest that metastatic breast cancer cells exposed to PCBs release ROS that may directly activate the redox sensitive kinase Pyk2 in neighboring endothelial cells. Consequently, Pyk2 redox signaling in neighboring endothelial cells may promote the aggressive spread of breast cancer.

Citation Format: Jayanta K. Das, Quentin H. Felty. PCB153-induced angiogenesis depends on redoxsensitive Pyk2 signaling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3899. doi:10.1158/1538-7445.AM2013-3899
Abstract 3906: Magnolol suppresses vascular endothelial growth factor-induced angiogenesis by inhibiting Ras-dependent mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways.
Authors: Kim Ki Mo , Kim No Soo , Kim Jinhee , Park Jong-Shik , Yi Jin Mu , Lee Jun , Bang Ok-Sun
Published: August 2014

Magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, has been reported to possess anti-cancer activity. Recent studies have also demonstrated that magnolol inhibits cell growth and induces the apoptosis of cancer cells. However, the effects of magnolol on vascular endothelial growth factor (VEGF)-induced angiogenesis in endothelial cells have not been studied. In the present study, we have used human umbilical vein endothelial cells (HUVECs) to investigate the anti-angiogenic effect and molecular mechanism of magnolol. Magnolol inhibited the VEGF-induced proliferation, chemotactic motility and tube formation of HUVECs in vitro as well as the vessel sprouting of the aorta ex vivo. Furthermore, magnolol inhibited VEGF-induced Ras activation and subsequently suppressed extracellular signal-regulated kinase (ERK), phosphatidylinositol-3-kinase (PI3K)/Akt and p38, but not Src and focal adhesion kinase (FAK). Interestingly, the knockdown of Ras by short interfering RNA produced inhibitory effects that were similar to the effects of magnolol on VEGF-induced angiogenic signaling events, such as ERK and Akt/eNOS activation, and resulted in the inhibition of proliferation, migration, and vessel sprouting in HUVECs. In combination, these results demonstrate that magnolol is an inhibitor of angiogenesis and suggest that this compound could be a potential candidate in the treatment of angiogenesis-related diseases.

Citation Format: Ki Mo Kim, No Soo Kim, Jinhee Kim, Jong-Shik Park, Jin Mu Yi, Jun Lee, Ok-Sun Bang. Magnolol suppresses vascular endothelial growth factor-induced angiogenesis by inhibiting Ras-dependent mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3906. doi:10.1158/1538-7445.AM2013-3906
Abstract 3907: Expression of vascular endothelial growth factor a (VEGF-A) in advanced gallbladder cancer.
Authors: Letelier Pablo , Buchegger Kurt , Ili Carmen , Garcia Patricia , Brevi Priscilla , Sandoval Alejandra , Leal Pamela , Riquelme Ismael , Roa Juan Carlos
Published: August 2014

Gallbladder cancer (GBC) is a highly fatal disease with poor prognosis and few therapeutic alternatives. Molecular mechanisms involved in GBC pathogenesis remain poorly understood. The Vascular Endothelial Growth Factor A (VEGF) is a potent proangiogenic agent involved in the carcinogenesis of many human tumors and it is an attractive target for cancer therapy. The aim of this study was characterize VEGF expression in advanced gallbladder cancer and determine it's relationships with clinicopathologic features and utility as a prognostic factor. VEGF expression was examined by immunohistochemistry (IHC) in tissue microarrays containing 224 advanced gallbladder carcinomas and 39 cases of chronic cholecystitis (CC). The advanced GBC were classified as low or high expression to evaluate the association of VEGF expression level with clinical variables. Statistical analysis was performed using univariate analyses with a significance level of P<0.05; survival analysis was performed by the Kaplan- Meier method with the log-rank test. High expression of VEGF was observed in 183 of 224 (81%) tumors and 2 of 39 (5.1%) of chronic cholecystitis (P<0.0001). The VEGF expression had a significant relationship with clinical or pathological features included histological grade and TNM stage (P<0.05). Moreover, 5-year survival analysis indicated that high expression of VEGF is associated with a poor prognosis in patients with advanced gallbladder cancer (P = 0.0116). Our results indicate that VEGF is highly expressed in gallbladder cancer and correlates with poor prognostic, suggesting that VEGF expression could be used as a biomarker for predicting malignant behavior and to identify a subset of patients who may benefit from anti-VEGF therapies.

Citation Format: Pablo Letelier, Kurt Buchegger, Carmen Ili, Patricia Garcia, Priscilla Brevi, Alejandra Sandoval, Pamela Leal, Ismael Riquelme, Juan Carlos Roa. Expression of vascular endothelial growth factor a (VEGF-A) in advanced gallbladder cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3907. doi:10.1158/1538-7445.AM2013-3907
Abstract 3926: Molecular imaging of VEGFR expression modulation by antiangiogenic therapy in mouse model of human breast cancer.
Authors: Zhu Wenlian , Kato Yoshinori , Mease Ronnie C. , Sarkar Susanta , Backer Marina V. , Backer Joseph M. , Artemov Dmitri
Published: August 2014

Antiangiogenic therapy targeting VEGF/VEGFR signaling is an important strategy for cancer treatment, which is currently used in mono-therapy or combination therapy settings. However, the emerging resistance to antiangiogenic therapy as well as varied clinical response calls for the development of early, preferably noninvasive, markers of treatment response. In this study we used a recently developed molecular imaging tracer, site-specifically 99mTc-labeled engineered single-chain VEGF derivative, to monitor the VEGF receptor expression during the course of sunitinib antiangiogenic therapy in orthotopic human breast cancer model MDA-MB-231. The treatment protocol included two cycles of therapy delivered daily for 5 days (80mg/kg, orally) with a 5-day vacation between the cycles. Micro SPECT/CT imaging was performed longitudinally up to day 16. Animals in the control group received vehicle solution only. Tumors were excised and stained for the expression of CD31 endothelial cell marker. Experimental results suggest a highly heterogeneous vascular regression response to the first round of treatment, with significantly decreased tracer uptake and CD31 prevalence in some but not all tumors. As judged by the increase in tracer uptake and CD31 prevalence, a significant vascular rebound took place in all tumors after the vacation period. Judging by the same criteria, the second round of treatment was significantly less effective than the first round. Taken together, these results suggests that noninvasive molecular imaging of VEGF receptors reflects vascular regression and rebound in individual tumors and can provide clinically relevant information for monitoring and scheduling antiangiogenic therapy.

Citation Format: Wenlian Zhu, Yoshinori Kato, Ronnie C. Mease, Susanta Sarkar, Marina V. Backer, Joseph M. Backer, Dmitri Artemov. Molecular imaging of VEGFR expression modulation by antiangiogenic therapy in mouse model of human breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3926. doi:10.1158/1538-7445.AM2013-3926
Abstract 3973: Effects of anti-PD-1 and anti-4-1BB antibody treatment on melanoma-specific T cells in a murine model of melanoma.
Authors: Robinson John L. , Kodumudi Krithika , Weber Amy , Sarnaik Amod , Pilon-Thomas Shari
Published: August 2014

Adoptive cell therapy with tumor infiltrating lymphocytes (TIL) is a promising immunotherapeutic approach and has resulted in durable response rates of 20-30% in patients with metastatic melanoma. However, several limitations exist to prevent the widespread implementation of adoptive cell therapy, including inadequate infiltration of tumor-specific T cells into tumors and anemic expansion of tumor-specific T cells in vitro. One such factor is PD-1 expression on T cells that plays an important role in T cell exhaustion. Agonistic co-stimulatory molecules such as 4-1BB which is transiently expressed on activated T cells can reverse T cell exhaustion and enhance anti-tumor immune response. In this study, we have examined two approaches to improve the frequency of tumor-specific T cells in tumors and TIL cultures. First, we examined whether blocking PD-L1/PD-1 signaling increased the infiltration of tumor-specific T cells in the murine B16 melanoma model. Mice bearing B16 tumors were treated with NrIgG or anti-PD-1 antibodies. T cells were isolated from B16 tumors on day 18 after tumor injection. Increased IFN-γ production following B16 restimulation was observed in TIL isolated from mice treated with anti-PD-1 antibody (1445 ± 48 pg/ml) compared to TIL isolated from mice treated with control antibody (748 ± 25 pg/ml, p<0.001). In addition, we examined whether the expansion of T cells during TIL culture in vitro could be augmented by targeting the co-stimulatory molecule, 4-1BB. T cells were isolated from B16 tumors and cultured in vitro with 10 mcg/mL anti-4-1BB antibody. After 5 days, increased B16-specific IFN-γ was measured in TIL cultured with anti-4-1BB antibody (1865 ± 64 pg/ml, p<0.001 compared to TIL cultured with control antibody). Combination treatment with anti-PD-1 antibody therapy in vivo and anti-4-1BB antibody in vitro demonstrated synergistic effects, with increased levels of IFN-γ (4440 ± 486 pg/ml) produced by B16-specific TIL. These findings suggest that anti-PD-1 antibody treatment in combination with in vitro 4-1BB antibody treatment can enhance the frequency of tumor-specific T cells isolated from B16 melanoma. This may represent a potential strategy to increase the effectiveness of TIL therapy in patients with melanoma.

Citation Format: John L. Robinson, Krithika Kodumudi, Amy Weber, Amod Sarnaik, Shari Pilon-Thomas. Effects of anti-PD-1 and anti-4-1BB antibody treatment on melanoma-specific T cells in a murine model of melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3973. doi:10.1158/1538-7445.AM2013-3973
Abstract 3976: PD-1 blockade combined with TEGVAX (TLR agonists-enhanced GVAX) can induce regression of established palpable tumors.
Authors: Malm Ian-James , Fu Juan , Pardoll Drew , Kim Young J.
Published: August 2014

Background: Cell-based vaccines have been developed for several types of tumors, but these vaccines have two critical shortcomings that weaken their clinical efficacy. The first of which is a limited capability to activate antigen presenting cells. Second, they fail to address critical immune checkpoint molecules that dampen the subsequent T-cell response against the established tumor. In order to optimize the activation of antigen presenting cells capable of marshaling both an innate and adaptive immune response against the tumor, we formulated a GM-CSF secreting tumor cell vaccine with multiple TLR agonists. To address the immune checkpoint signaling pathway, we combined our formulated vaccine with a blocking αPD-1 antibody in two mouse models of established tumor - one with melanoma and the other with tongue cancer.

Methods: To optimize in vivo efficacy of anti-tumor T-cell response, we engineered TEGVAX, a GM-CSF secreting cell-based tumor vaccine formulated with GLA (TLR4 agonist) and R848 (TLR7/8 agonists), molecules that are amenable for clinical translation. We then combined TEGVAX with αPD-1 blocking antibody (G4 clone) in the murine B16 melanoma and SCCFVII tongue cancer model. Furthermore, we studied immunological parameters that correlated with in vivo anti-tumor response.

Results: In both B16 and SCCFVII treatment models, TEGVAX demonstrated statistically significantly (p<0.01) enhanced anti-tumor responses in comparison to the parental cell vaccine in vivo. For tumor bearing mice treated with TEGVAX, these potent anti-tumor responses were correlated with a statistically significant increase in CD4+ and CD8+ T-cells that secrete IFNγ in the tumor microenvironment. TEGVAX treated mice also had significantly higher levels of tumor antigen p15E-specific cell mediated killing in vivo. Blockade of the PD-1 immune checkpoint pathway further augmented the therapeutic potential of TEGVAX and induced the regression of established B16 and SCCFVII tumors.

Conclusion: When combined with αPD-1 antibody, TEGVAX was able to induce regression of established B16 and SCCFVII tumors. Our results with these combinatorial immunotherapeutic strategies provide preclinical evidence to support the translation of these reagents for HNSCC or melanoma patients that are refractory to standard treatment modalities.

Citation Format: Ian-James Malm, Juan Fu, Drew Pardoll, Young J. Kim. PD-1 blockade combined with TEGVAX (TLR agonists-enhanced GVAX) can induce regression of established palpable tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3976. doi:10.1158/1538-7445.AM2013-3976
Abstract 3977: Mark cancer cells for CTL attack through coating with viral antigenic peptides.
Authors: Hung Chien-Fu
Published: August 2014

Selectively coating tumor cells with foreign antigenic peptide may render coated tumor susceptible to immune recognition and elimination, thereby bypassing immune tolerance. Here we create a therapeutic chimeric protein comprised of a tumor-homing module fused to a functional cargo domain containing foreign antigenic peptide. The tumor-homing module is comprised of mesothelin-specific single chain variable fragment that specifically binds to mesothelin, commonly overexpressed in ovarian tumors. The functional cargo domain is comprised of Fc (IgG2a) protein and MHC class I-restricted foreign CD8+ T cell epitope flanked by furin cleavage sites, which can be recognized by furin highly expressed in the tumor microenvironment. We show that our therapeutic protein specifically loaded antigenic epitope onto MHC class I of bound tumor cells, rendering them susceptible to antigen-specific CD8+ T cell-mediated killing for potent antitumor effects in vitro and in vivo. Our findings have important implications for bypassing immune tolerance to enhance cancer immunotherapy.Selectively coating tumor cells with foreign antigenic peptide may render coated tumor susceptible to immune recognition and elimination, thereby bypassing immune tolerance. Here we create a therapeutic chimeric protein comprised of a tumor-homing module fused to a functional cargo domain containing foreign antigenic peptide. The tumor-homing module is comprised of mesothelin-specific single chain variable fragment that specifically binds to mesothelin, commonly overexpressed in ovarian tumors. The functional cargo domain is comprised of Fc (IgG2a) protein and MHC class I-restricted foreign CD8+ T cell epitope flanked by furin cleavage sites, which can be recognized by furin highly expressed in the tumor microenvironment. We show that our therapeutic protein specifically loaded antigenic epitope onto MHC class I of bound tumor cells, rendering them susceptible to antigen-specific CD8+ T cell-mediated killing for potent antitumor effects in vitro and in vivo. Our findings have important implications for bypassing immune tolerance to enhance cancer immunotherapy.

Citation Format: Chien-Fu Hung. Mark cancer cells for CTL attack through coating with viral antigenic peptides. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3977. doi:10.1158/1538-7445.AM2013-3977