bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3047: Hypoxia leads to deregulation of PI3K/AKT/mTOR signaling in prostate cancer stem cells
Authors: Marhold Maximilian , Tomasich Erwin , Pernicová Zuzana , Fedr Radek , Soucek Karel , Spittler Andreas , Krainer Michael , Horak Peter 
Published: May 2015

Abstract
Tumor initiating subpopulations of cancer cells, also known as cancer progenitor or cancer stem cells (CSCs) were recently identified and characterized in prostate cancer. Emerging evidence suggests that hypoxia-inducible factor 1 alpha (HIF1A) contributes to CSC maintenance and influences the PI3K/AKT/mTOR axis, a pathway which is frequently altered in prostate cancer. In our study, we assessed the effects of hypoxia on PI3K/AKT/mTOR signaling in a subset of basal prostate cancer stem cells in a murine model of prostate cancer. First, we successfully isolated Lin-/Sca-1+/CD49f+ basal stem cell subpopulations from primary prostate tumors of TRAMP (transgenic adenocarcinoma of mouse prostate) mice. We observed a consistent decrease in S6 phosphorylation within the CSC subpopulation, in agreement with an mTOR pathway inhibition. However, AKT phosphorylation in the CSC subpopulation was simultaneously elevated, thus prompting further investigations. To analyze the molecular pathways leading to this deregulation, we used a cell line model and isolated Sca-1+/CD49f+ CSC-like subpopulations from the murine prostate cancer cell line TRAMP-C1 and CD44+/CD49f+ CSC-like subpopulations from the androgen independent human prostate cancer cell line DU145. We used sphere formation assays and expression of Notch 1 and Oct 3/4 to confirm the stem and progenitor cell properties of the sorted subpopulations. We could confirm the decrease in mTOR/S6 signaling and identify the upregulation of AKT through IRS-1 mediated feedback loop in prostate CSC-like cells under hypoxic conditions. This AKT/mTOR deregulation was promptly reversed in normoxia, suggestive of the involvement of hypoxia inducible factors. We found elevated HIF1A protein levels as well as increased target gene expression in CSC subpopulations in vitro and in vivo. Further, lentiviral knockdown of HIF1A restored AKT/mTOR activity in CSC-like cells. We could show that CSC-like prostate cancer cells with elevated expression of basal stem cell markers, such as CD44, Sca-1 or CD49f, show a hypoxic deactivation of feedback inhibition on AKT signaling through IRS-1. In light of these results, we propose that deregulation of the PI3K/AKT/mTOR pathway via HIF1A may be critical for cancer stem cell quiescence and maintenance, slowing down cancer stem cell metabolism and growth via mTOR and promoting their survival via AKT signaling.
Citation Format: Maximilian Marhold, Erwin Tomasich, Zuzana Pernicová, Radek Fedr, Karel Soucek, Andreas Spittler, Michael Krainer, Peter Horak. Hypoxia leads to deregulation of PI3K/AKT/mTOR signaling in prostate cancer stem 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 3047. doi:10.1158/1538-7445.AM2014-3047
Abstract 3048: OMP-59R5 (Anti-Notch2/3) inhibits tumor growth and reduces cancer stem cell frequency in patient derived SCLC xenografts
Authors: Fischer Marcus M. , Shah Jalpa , Cain Jennifer , Cancilla Belinda , Evans James W. , Murriel Christopher L. , Tang Tracy , Wei Jie , Yen Wan-Ching , Zhang Chun , Gurney Austin , Lewicki John , Kapoun Ann M. , Hoey Timothy 
Published: May 2015

Abstract
Small cell lung cancer (SCLC) is a devastating disease with very poor prognosis and few treatment options. We have established patient derived xenografts from SCLC tumors and determined that Notch pathway target genes are up-regulated in this disease relative to normal lung tissues and relative to other tumor types. We examined the in vivo efficacy of OMP-59R5, an antibody that was initially identified by binding to Notch2 and was subsequently shown to block signaling of both human and mouse Notch2 and Notch3. We performed in vivo growth inhibition and tumorigenicity studies with this Notch2/3 antibody alone or in combination with chemotherapeutic agents in a panel of six patient-derived SCLC xenograft models. We found that OMP-59R5 treatment significantly reduced tumor recurrence in combination with chemotherapy in five of the six models. Through a serial transplantation study from a sensitive tumor, we found that OMP-59R5 in combination with chemotherapy (cisplatin plus irinotecan) profoundly reduced the cancer stem cell (CSC) frequency. In contrast, treatment with chemotherapeutic agents alone had the opposite effect and increased CSC frequency. In minimal residual disease models, we analyzed the ability of OMP-59R5 to delay tumor recurrence following chemotherapy-induced tumor regression. While chemotherapeutic agent-treated tumors re-grew rapidly following treatment termination, the growth of recurrent tumors was delayed by OMP-59R5. We also evaluated changes in gene expression post treatment and found that OMP-59R5 modulated the expression of Notch pathway, epithelial-to-mesenchymal transition, stromal and vasculature genes. Furthermore, we observed an increase in expression of neuroendocrine differentiation markers after OMP-59R5 treatment in sensitive tumors. Following up on these preclinical findings, OMP-59R5 is currently being evaluated for safety and efficacy in combination with cisplatin and etoposide for treatment of SCLC in an ongoing Phase 1b/2 clinical trial (PINNACLE).
Citation Format: Marcus M. Fischer, Jalpa Shah, Jennifer Cain, Belinda Cancilla, James W. Evans, Christopher L. Murriel, Tracy Tang, Jie Wei, Wan-Ching Yen, Chun Zhang, Austin Gurney, John Lewicki, Ann M. Kapoun, Timothy Hoey. OMP-59R5 (Anti-Notch2/3) inhibits tumor growth and reduces cancer stem cell frequency in patient derived SCLC xenografts. [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 3048. doi:10.1158/1538-7445.AM2014-3048
Abstract 3049: Regulation of cancer cell stemness by delta-like 1 homolog (Drosophila) and prohibitins
Authors: Lin Qun , Begum Asma , Yu Chenye , Hu Ming-Yeah , Kim Yuri , Yun Zhong 
Published: May 2015

Abstract
Cancer stem cell characteristics, especially their self-renewal and clonogenic potential, play an essential role in malignant progression and response to anti-cancer therapies. Currently, it remains largely unknown which pathways are involved in the regulation of cancer cell stemness and differentiation. Previously, we found that delta-like 1 homolog (Drosophila) or DLK1, a developmentally regulated gene, plays a critical role in regulation of differentiation, self-renewal, and tumorigenic growth of neuroblastoma cells. In order to gain mechanistic understanding of the involvement of DLK1 in intracellular signal transduction, we identified DLK1-interacting proteins using an affinity purification approach. As reported herein, we have found that DLK1 specifically interacts with the prohibitin (PHB) complex via the DLK1 cytoplasmic domain. PHB1 and the closely related PHB2 are encoded by evolutionarily conserved genes and possess diverse functions from mitochondrial structural integrity and oxidative phosphorylation to gene transcription in the nucleus. We have found that DLK1 regulates mitochondrial membrane potential and production of reactive oxygen species (ROS). Our data further reveal a role of PHBs and especially PHB2 in the regulation of cancer cell self-renewal as well as their clonogenic potential. Hence, the DLK1-PHB interaction constitutes a new signaling mechanism that promotes the maintenance of cancer cell stemness.
This work was supported by a grant from the National Institutes of Health to ZY (R01CA125021). YK was supported in part by an institutional postdoctoral training grant (T32) from the National Institutes of Health and an Anna Fuller Fund Fellowship from Yale School of Medicine.
Citation Format: Qun Lin, Asma Begum, Chenye Yu, Ming-Yeah Hu, Yuri Kim, Zhong Yun. Regulation of cancer cell stemness by delta-like 1 homolog (Drosophila) and prohibitins. [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 3049. doi:10.1158/1538-7445.AM2014-3049
Abstract 3054: Snail-induced epithelial-mesenchymal transition generates the properties of cancer stem cells in head and neck cancer cells
Authors: Ota Ichiro , Masui Takashi , Mikami Shinji , Yamanaka Toshiaki , Hosoi Hiroshi 
Published: May 2015

Abstract
Head and neck squamous cell carcinoma (HNSCC) is known to its rapid clinical progression and poor prognosis. Notably, regional and distant metastases in HNSCC correspond to an extremely poor prognosis with limited treatment options. The treatment resistance and tumor recurrence are important clinical problems in the management of HNSCC. Epithelial-mesenchymal transition (EMT) is a key process in successful execution of many steps such as invasion and metastasis for cancer cells. Snail is one of master regulators that promote EMT in many types of malignancies including HNSCC. Recently, it has been reported that Snail-induced EMT could induce cancer stem cell (CSC)-like phenotype in a number of tumor types. Herein, we investigated the role of Snail in inducing EMT properties and CSC-like phenotype in HNSCC. We constructed HNSCC cell lines transfected with Snail. E-cadherin was analyzed using western blotting and immunofluorescence staining. Cell migration and invasion were assessed using wound healing assay and modified Boyden chamber assay, respectively. CSC markers of HNSCC, CD44 and aldehyde dehydrogenase 1 (ALDH1), were also evaluated with western blotting, and chemosensitivity was assessed with WST-8 assay. Introduction of Snail induced EMT properties in HNSCC cells and enhanced cell migration and invasion. Moreover, Snail-induced EMT gained CSC-like phenotype and was associated with increased chemoresistance. These results suggest that Snail can be one of the attractive targets for the development of therapeutic strategies in HNSCC.
Citation Format: Ichiro Ota, Takashi Masui, Shinji Mikami, Toshiaki Yamanaka, Hiroshi Hosoi. Snail-induced epithelial-mesenchymal transition generates the properties of cancer stem cells 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 3054. doi:10.1158/1538-7445.AM2014-3054
Abstract 3062: Isolation and characterization of circulating tumor cells (CTCs) from peripheral blood specimens of patients with advanced solid tumor malignancies (using ApoStream™ instrumentation)
Authors: Balasubramanian Priya , Wang Lihua , Lawrence Scott M. , Navas Tony , Kummar Shivaani , Hollingshead Melinda , Owusu Francis , Parchment Ralph E. , Tomaszewski Joseph E. , Doroshow James H. , Kinders Robert J. 
Published: May 2015

Abstract
Circulating tumor cells (CTCs) isolated from the peripheral blood of cancer patients provide prognostic information and may inform treatment decisions. Current strategies for CTC isolation and characterization commonly employ epithelial marker-specific antibody capture of fixed cells from blood and detection based on cytokeratin (CK) expression. Our laboratory is currently evaluating an antibody-independent CTC enrichment technology, ApoStream™, which isolates live CTCs from blood, enabled by critical dissimilarities in morphology and dielectric properties of CTCs and blood cells rather than surface marker expression. CTCs isolated with the ApoStream™ instrument are amenable to further high resolution phenotypic characterization, enabling unambiguous identification of enriched cells as malignant cells. We previously reported on the utility of ApoStream™ technology for the isolation of CTCs from patients with advanced alveolar soft part sarcoma (ASPS) with unambiguous confirmation of CTCs by break-apart fluorescent in situ hybridization (FISH) for ASPL-TFE3 gene translocation. Here, we show the isolation of viable CTCs from patients with advanced solid tumors from ongoing clinical studies at the NCI. Since during progression, cancer cells undergo epithelial to mesenchymal transitions (EMT) and mesenchymal to epithelial transitions (MET), we sought to characterize ApoStream™-isolated CTCs using a multiplex phenotyping assay for CD45 (hematopoietic marker), EMT markers (CK, EpCAM, β-catenin and Vimentin), and tumor specific markers (MUC1 and CEA). A user-defined processing algorithm and CTC scoring criteria developed using Definiens® software was used for rare cell detection and enumeration. Our current efforts are focused on evaluating the utility of ApoStream™-isolated CTCs for assessing pharmacodynamic effects of anticancer agents on DNA damage response in patients with refractory solid tumors. Funded by NCI Contract No. HHSN261200800001E.
Citation Format: Priya Balasubramanian, Lihua Wang, Scott M. Lawrence, Tony Navas, Shivaani Kummar, Melinda Hollingshead, Francis Owusu, Ralph E. Parchment, Joseph E. Tomaszewski, James H. Doroshow, Robert J. Kinders. Isolation and characterization of circulating tumor cells (CTCs) from peripheral blood specimens of patients with advanced solid tumor malignancies (using ApoStream™ instrumentation). [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 3062. doi:10.1158/1538-7445.AM2014-3062
Abstract 3063: Molecular characterization of individual circulating tumor cells by RNA sequencing
Authors: Patel Jaymala , Foulk Brad , Bhargava Vipul , Smirnov Denis A. 
Published: May 2015

Abstract
Background: Numbers of circulating tumor cells (CTC) measured with the CellSearch system in patients with metastatic carcinomas are associated with poor survival. Such association with clinical outcome suggests that CTCs play an important role in metastatic process. Molecular characterization of CTCs can provide important insights into phenotypic characteristics of cells necessary to participate in this process. Moreover, detailed molecular characterization of CTCs at various points of the disease course may be useful in understanding of evolution of tumors and aid in selection of optimal therapeutic regimens. Like most other CTC isolation instruments CellSearch is a CTC-enrichment device that efficiently captures CTCs while also retaining few thousands non-specifically captured white blood cells. To obtain deep molecular profiles of CTCs isolation of single cells is required and development of specialized next-generation sequencing protocols is necessary.
Method/Results: We developed a workflow to enable isolation of single CTCs or pools of few CTCs following enrichment with the FDA approved CellSearch platform. Experiments with cancer cell lines spiked into donor blood showed 80% cellular recovery from blood using CellSearch and subsequent 40-50% capture of individual cancer cells using Fluidigm C1 Single Cell system. Following analysis of gene expression via RNAseq expression of ∼5000 genes can be detected in isolated tumor cells. We will discuss reagents and molecular approaches utilized to ensure efficient isolation and quality assessment of nucleic acids recovered from isolated tumor cells. We will discuss impact of sample preservation has on transcriptome profiling. We will share insights into prostate and lung cancers that one can gain from such analysis.
Conclusion: Characterization of individual CTCs by RNA sequencing is a promising approach to characterize metastatic processes and tumor evolution.
Citation Format: Jaymala Patel, Brad Foulk, Vipul Bhargava, Denis A. Smirnov. Molecular characterization of individual circulating tumor cells by RNA sequencing. [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 3063. doi:10.1158/1538-7445.AM2014-3063
Abstract 3078: Isolation and in vitro culturing of human circulating tumor cells
Authors: Bobek Vladimir , Kolostova Katarina 
Published: May 2015

Abstract
The CTC-enrichment based on the size of the cells, is addressing the problem of reduced EpCAM expression, but filtration shows relatively low sensitivity and specificity, because small CTCs may escape of the detection, whereas big leukocytes may contaminate population of CTCs Isolation by size of epithelial tumor cells is based on use of filters, which preferentially capture tumor cells bigger than 8 uM.
Our filtration device (MetaCell®, Metacell s.r.o., Ostrava, Czech Republic) isolates tumor cells by size from a blood sample up to 6 ml. Moreover immunocytochemistry and FISH assays can be performed on the filter. The protocol enables to isolate viable cells, allowing further in vitro experiments. Furthermore, tumor cells can be isolated without using an antibody-based approach, suggesting that the device can be used for the isolation of a large spectrum of tumor cells, including cell of non-epithelial origin.
We presented the successful isolation and cultivation of CTC/DTC of the following cancer: NSCLC, mesothelioma, oesophageal cancer, colorectal cancer, gastric cancer, pancreatic cancer, leiomyosarcoma, prostate cancer, malignant melanoma and renal cancer.
Citation Format: Vladimir Bobek, Katarina Kolostova. Isolation and in vitro culturing of human circulating tumor 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 3078. doi:10.1158/1538-7445.AM2014-3078
Abstract 310: Identification of secreted proteins that reflect intracellular autophagy dynamics in melanoma
Authors: Akl Adam , Xu Xiaowei , Piao Shengfu , Amaravadi Ravi K. , Speicher David W. 
Published: May 2015

Abstract
Autophagy, a catabolic process that maintains cellular homeostasis, is a primary therapy resistance mechanism in cancer. Emerging studies indicate that autophagy is involved in secretion through non-classical mechanisms. However, the effects of autophagy-mediated secretion on the tumor microenvironment are poorly understood. Further, while autophagy is a potential cancer therapeutic target, efforts to inhibit autophagy in clinical trials have been hampered by sub-optimal methods to quantitatively monitor tumor autophagy levels. Here, we leveraged the recent findings that autophagy is implicated in non-classical secretion to identify secreted proteins associated with autophagy in melanoma. The conditioned media of low autophagy WM793 melanoma cells was compared to its highly autophagic metastatic derivative, 1205Lu, using quantitative proteomics. These comparisons identified secreted proteins associated with high autophagy, such as IL-1β, IL-8, LIF, FAM3C, and DKK3, which have previously been implicated in tumorigenesis. These proteins were shown to be elevated in supernatants of an independent panel of high autophagy melanoma cell lines compared with low autophagy cells, suggesting a mechanistic link between autophagy level and secretion of these proteins. In addition, secretion of these proteins increased when melanoma cells with intrinsically low autophagy levels were treated with an autophagy-inducing tat-Beclin 1 peptide. Further supporting a mechanistic link, Atg7 silencing in an intrinsically high autophagy cell line resulted in significantly decreased secretion. Finally, serum collected from untreated metastatic melanoma patients with high tumor autophagy levels exhibited higher levels of these proteins than serum from low autophagy patients. These results suggest that autophagy-related secretion affects the tumor microenvironment and that measurement of extracellular autophagy-associated secreted proteins in tumors and in plasma can serve as surrogates for intracellular autophagy dynamics in tumor cells.
Citation Format: Adam Akl, Xiaowei Xu, Shengfu Piao, Ravi K. Amaravadi, David W. Speicher. Identification of secreted proteins that reflect intracellular autophagy dynamics in melanoma. [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 310. doi:10.1158/1538-7445.AM2014-310
Abstract 3101: Precise matching of medulloblastoma mouse models to their human counterparts
Authors: Pöschl Julia , Stark Sebastian , Neumann Philipp , Gröbner Susanne , Jones David , Northcott Paul , Lichter Peter , Pfister Stefan , Kool Marcel , Schüller Ulrich 
Published: May 2015

Abstract
Mouse models are indispensible tools to study the biology of a tumor and to perform preclinical treatment studies. Medulloblastoma is a very heterogeneous disease with some subgroups being associated with very poor clinical outcome. A lot of effort has been put into the generation of appropriate mouse models. The usage of these models, however, has become debatable with the advances in human medulloblastoma subtyping. In order to precisely characterize the available variety of mouse models we matched genetics and gene expression patterns of 140 murine and 423 human medulloblastomas. Ctnnb1 mutated mouse tumors significantly matched to human WNT medulloblastoma using agreement of differential gene expression (ADGEX) and k-means clustering analysis. Mouse models that have been generated based on Myc or Mycn alterations variably matched to the human Group 3 medulloblastoma depending on the model and the mathematical algorithm, but none of the available models matched to Group 4 tumors. Interestingly, models with Ptch1 or Smo mutations selectively matched to SHH medulloblastomas of adulthood, but the genetic make-up was not the main determinant of the age-dependent gene expression fingerprint. We emphasize important chances and drawbacks of current medulloblastoma models and suggest that the phenotype of medulloblastoma subtypes is orchestrated by distinct combinations of genetics, epigenetics, and cells of origin.
Citation Format: Julia Pöschl, Sebastian Stark, Philipp Neumann, Susanne Gröbner, David Jones, Paul Northcott, Peter Lichter, Stefan Pfister, Marcel Kool, Ulrich Schüller. Precise matching of medulloblastoma mouse models to their human counterparts. [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 3101. doi:10.1158/1538-7445.AM2014-3101