bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3317: Single-cell invasion and chemoresistance of slowly proliferating brain-tumor stem cells
Authors: Siebzehnrubl Florian A. , Silver Daniel J. , Deleyrolle Loic P. , Suslov Oleg , Tugertimur Bugra , Yachnis Antony T. , Brabletz Simone , Brabletz Thomas , Reynolds Brent A. , Steindler Dennis A. 
Published: June 2012

Abstract
Despite intense efforts in basic research and clinical medicine, glioblastoma (GBM) remains one of the most lethal types of cancer. In particular, tumor recurrence after surgical resection, aggressive chemotherapy, and targeted radiation remains an insurmountable obstacle. Recurrence may be attributed to residual cancer stem cells that re-initiate tumor growth after primary clinical intervention. Here, we provide new evidence for a subpopulation of relatively quiescent and chemoresistant cancer stem cells that invade deeply into the parenchyma. We have identified a critical transcription factor that is upregulated in these glioma stem cells, which regulates epithelial-mesenchymal transition (EMT) in other tumors. Knockdown of this transcription factor results in an increased sensitivity to chemotherapeutic agents and reduced tumor cell invasion. We hypothesize that single cell invasion of malignant gliomas is regulated by similar molecular pathways as EMT and metastasis in solid tissue tumors. These pathways allow slowly proliferating glioma stem cells to leave the site of the primary tumor, invade deeply into the surrounding parenchyma and, by virtue of their resistance to chemotherapeutic agents, evade all types of classical brain tumor therapy. This offers a potential novel model for GBM recurrence, and a potential new therapeutic target.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3317. doi:10.1158/1538-7445.AM2011-3317
Abstract 3318: A distinct subpopulation within CD133 positive brain tumor cells shares characteristics with endothelial progenitor cells
Authors: Kim Seung-Ki , Choi Seung Ah , Wang Kyu-Chang , Phi Ji Hoon , Lee Ji Yeoun , Cho Byung-Kyu , Park Chul-Kee , Park Sung-Hye 
Published: June 2012

Abstract
The cell surface marker CD133 was proposed as a brain tumor stem cell marker. However there have been substantial controversies regarding the necessity and role of CD133 in tumorigenesis. This study aimed to characterize CD133 positive cells in brain tumors.
Fresh human brain tumor specimens and whole blood were collected from the same patients [medulloblastoma (N=6), glioblastoma (N=4), ependymoma (N=1), and atypical teratoid/rhabdoid tumor (ATRT, N=2)]. Dual FACS staining for CD133/CD34, functional assay of CD133 positive cells from different origin for tumorigenesis and angiogenesis were done. We also investigated the in vivo tumorigenic potential and histological characteristics of four distinct groups on the basis of expression of CD133/CD34 markers (CD133+, CD133+/CD34+, CD133+/CD34-, and CD133-). CD133 positive brain tumor cells coexpressed significantly higher positivity for CD34 (67.97 ± 5.34 % in CD133 (+) cells vs. 11.96 ± 1.48 % in CD133 (−) cells, P&lt;0.001). CD133 positive brain tumor cells formed neurosphere-like spheroids and differentiated into multiple nervous system lineages contrary to CD133 positive blood cells. Furthermore they showed biological characteristics of endothelial cells including vWF expression, LDL uptake and tube formation in vitro, unlike CD133 negative brain tumors cells. Pathologic analysis of the brains implanted with CD133+ glioma cells showed large, highly proliferative and vascular tumors with widespread necrosis and hemorrhage. Notably pure BTSC (CD133+/CD34-) or EPC (CD133+/CD34+) fraction alone did not generate tumor.
Our data suggest the presence of a distinct subpopulation of CD133 positive cells isolated from human brain tumors, with characteristics of EPCs. Therefore, interpreting the results of experiments carried out with “CD133-positive BTSCs” should be extrapolated with caution.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3318. doi:10.1158/1538-7445.AM2011-3318
Abstract 3329: Magnetic isolation and rare cell gene expression analysis of breast cancer stem cells
Authors: Hardt Olaf , Wild Stefan , Hofmann Kay , Luo Shujun , Wiencek Yvonne , Kantelhardt Eva , Smith Geoffrey P. , Schroth Gary P. , Bosio Andreas , Dittmer Jürgen 
Published: June 2012

Abstract
Solid tumors consist of heterogeneous cell types including a subpopulation of stem like cells. Starting from bulk tumor mass, the analysis of these cancer stem cells (CSCs) is hampered by their rare frequency and their characteristics remain hidden.
To address this issue, we have developed a method for the semi-automated dissociation of human tumor tissue yielding a viable single cell suspension. Subsequently, a magnetic cell sorting (MACS) strategy was established allowing for the isolation of CD24-/CD44+ breast CSCs. Using these methods, we isolated breast CSCs from an invasive ductal carcinoma at a purity of 94%. Due to the limited starting material, a few hundred CSCs as well as bulk tumor cells were used for global PCR based RNA amplification. The amplified cDNA was sheared, size selected, and processed for high throughput gene expression analysis on the Illumina Genome Analyzer system. Samples were prepared in triplicate and over 10 million individual purity-filtered reads were analyzed per sample. In addition, Agilent whole genome microarrays were used for validation of expression differences.
Analysis of the sequence tags allowed us to identify novel putative markers overexpressed in breast CSCs. GeneOntology analysis was used to determine functional groups of genes which are differentially regulated between CSCs and bulk tumor cells. We found a strong overrepresentation of genes connected to TGF-beta as well as Wnt/GSK3 signaling supporting the correlation of the CSC phenotype with epithelial-mesenchymal-transition (EMT). Other differentially expressed genes are known to be involved in pluripotency, cell migration, and apoptosis further indicating a stem cell-like fate.Our proof of principle experiment demonstrates the advantage of isolating rare cell populations for subsequent molecular analysis by high throughput sequencing. The analysis of purified CSCs revealed new insights on the regulation, maintenance, and biology that would not have been observed when assessing only the bulk tumor mass. Analyzing the genetic set up of defined tumor subpopulations by Next Generation Sequencing can improve our understanding of cancer and could pioneer targeted diagnostic and therapeutic approaches.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3329. doi:10.1158/1538-7445.AM2011-3329
Abstract 3342: Overexpression of transcription factor Fra-1 drives murine 4TO7 breast cancer stem cells out of dormancy and render them sensitive to chemotherapy
Authors: Lu Dan , Chen Si , Liao Debbie , Liu Ze , Xiang Rong , Reisfeld Ralph 
Published: June 2012

Abstract
Fra-1 is a member of the Fos family of transcription factors, which is highly expressed in multiple tumors and plays important roles in the transformation of malignant cells. Prior studies clearly illustrated some of the mechanisms of Fra-1 involvement in tumor proliferation and metastasis. However, the function of Fra-1 in cancer stem cells (CSCs) still remains to be resolved. We either overexpressed or silenced Fra-1 in murine 4TO7 breast cancer cells, and investigated its effects on regulation of the cell cycle, maintenance of side populations (SP) and determination of sensitivity to chemotherapeutic drugs both in vitro and in vivo. Overexpression of Fra-1 in 4TO7 cells significantly decreased the population of G0/G1-phase cells by DNA content analysis of fixed cells with propidium iodide (PI), as well as the intracellular flow cytometry (FCM) analysis of Ki-67 expression in fixed and permeabilized 4TO7 cells. We also performed the Hoechst 33342 dye exclusion assay, and detected a remarkable decrease of SP cells, which was further confirmed by intracellular staining of cancer stem cell marker Sca-1. Importantly, overexpression of Fra-1 correlated with a significant increase in chemosensitivity to either Doxorubicin (Dox) or cyclophosphamide (CTX) treatment both in vitro and in vivo. In contrast, extinction of Fra-1 increased the proportion of both G0/G1-phase cells and SP cells. These events in turn increased resistance of 4TO7 cells to chemotherapy both in vitro and in vivo. Together, our findings indicate that up- or down- regulation of Fra-1 in murine 4TO7 breast cancer cells can drive CSCs out of or back into dormancy, which may subsequently render them sensitive or resistant to chemotherapeutic drugs. In conclusion, we describe here a novel function of transcription factor Fra-1 in breast CSCs, which may hold important implications for future diagnosis and treatment of breast cancer patients.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3342. doi:10.1158/1538-7445.AM2011-3342
Abstract 3343: Preferential dormancy of Oct4-expressing breast cancer-initiating cells in bone marrow: Role for gap junctional intercellular communication
Authors: Patel Shyam A. 
Published: June 2012

Abstract
Breast cancer dormancy in the bone marrow is a clinical problem that is supported by cancer resurgence after years of disease-free survival. This study seeks to explain why, despite aggressive treatment with anti-cancer agents, breast cancer cells (BCCs) can survive for later resurgence. The potential role of stem cell biology in malignancy has been supported by evidence of chemotherapy resistance among tumors and the idea that stem cells and tumor cells share common signaling pathways. Initial screening of primary tissues and BCC lines has demonstrated that the pluripotency marker Oct4 is expressed at low frequency. Thus, in this study, we selected Oct4-expressing BCCs in transfectants with GFP reporter vector under the control of the Oct4 5’ regulatory region. Based on Oct4 expression, we have isolated two subsets. The high expressers show self-renewing properties, long doubling times, increased proportion of cells in G0 phase, sphere formation at &gt;97% efficiency, and serial passaging ability in nude mice. Based on these findings, we designate the high Oct4 expressers as breast cancer-initiating cells (BC-ICs). Functionally, the BC-ICs show preference for forming gap junctional intercellular communication (GJIC) with bone marrow stroma and resist treatment with carboplatin. In summary, the studies provide evidence for the existence of a population of cells within breast cancers that sustains tumor survival and might be the subset of BCCs that adapts dormancy in the bone marrow. These studies are highly significant to subclinical tumor survival and eventual resurgence of breast cancer at metastatic sites.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3343. doi:10.1158/1538-7445.AM2011-3343
Abstract 3345: Enhancer of zeste homolog 2 (EZH2) promotes expansion of breast tumor initiation cells through activation of Notch1-jagged signaling
Authors: Gonzalez Maria E. , Li Xin , Kruger Heather , Toy Kathy , Kleer Celina G. 
Published: June 2012

Abstract
EZH2 is an oncogene which has been recently shown to regulate the differentiation of tissue specific stem cells. However the role of EZH2 on mammary stem cells is unknown. Notch1 signaling has been implicated in cell-fate determination of human mammary stem cells. We hypothesized that EZH2 may contribute to initiation and expansion of mammary stem cells through activation of Notch1 signaling.
Methods: We developed two cell culture models: an inducible EZH2 up regulation system in MCF10A benign mammary cells and a lentivirus-mediated shRNA interference targeting EZH2 in SUM149 breast cancer cells. Mammary stem cells were identified using ALDH1+ and CD44+/CD24- by FACS. The effect of EZH2 on the tumorigenic ability of ALDH-1 positive and negative SUM149 cells was studied in a xenograft mouse model.
Results: We found preferential expression of EZH2 in the stem cell population of normal primary breast cells compared to non stem cells. In MCF10A cells, EZH2 overexpression, (EZ-OV), was predominantly increased in the ALDH-1+ population. When we tested the role of EZH2 in the stem cell population we found that EZH2-OV increased the stem cell population of MCF10A cells while EZH2-KD decreased it in SUM149 cells. Microarray analysis identified Notch1-Jagged1 signaling as the most significantly downregulated targets of EZH2 in ALDH+ vs. ALDH- SUM149 cells. Consistently, EZH2-OV in MCF10A and primary breast cells increased Notch1 mRNA specifically in the ALDH1+ population. EZH2-OV increased Notch1 protein level and promoter activity in MCF10A cells. Mechanistically, Notch1 inhibition by GSI reversed the effect of EZH2-OV in the stem cell population of MCF10A cells. Our in vivo studies demonstrated that EZH2 KD in SUM149 cells decreased the growth of ALDH-1+ cells in xenograft experiments. Consistently, EZH2 KD tumors exhibited decreased Notch1 and Jagged1 protein levels.
Conclusion: Collectively, these results indicate that EZH2 regulates mammary stem cells and requires, at least in part the activation of Notch1 signaling.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3345. doi:10.1158/1538-7445.AM2011-3345
Abstract 3348: Naïve rat umbilical cord matrix stem cells abrogate mammary tumor growth through markedly enhanced tumor immune responses
Authors: Kawabata Atsushi , Ohta Naomi , Seiler Garret , Pyle Marla , Troyer Deryl , Tamura Masaaki 
Published: June 2012

Abstract
Mesenchymal stem cells derived from the umbilical cord matrix (UCMSC) have great potential for therapeutic use in multiple diseases including cancer. We have demonstrated that un-engineered naïve human and rat UCMSC attenuate growth of several organ type tumors (Ayuzawa et al., Cancer Lett.2009; Ganta et al., Cancer Res, 2009, Doi et al., Cytotherapy 2010). Since UCMSC are easy to prepare in relatively large quantities and are poorly immunogenic in allogeneic transplantation, they are potentially useful in cancer therapy. However, the mechanism by which UCMSC attenuate tumor growth has not been studied rigorously. Hence, the objectives of this study were to examine the ability of UCMSC to control the growth of mammary tumors and to determine possible mechanisms by which UCMSC attenuate the tumor growth. Intratumoral injection of rat UCMSC markedly attenuated tumor growth of orthotopic Mat B III autografts in female F344 rat mammary gland. Histopathology of the tumors in the rat UCMSC group indicated that a large number of lymphocytes had infiltrated into the peritumoral area and were occasionally observed in the intratumoral area. Immunohistochemistry revealed that although CD3+ T lymphocytes were located mainly in the peritumoral area rather than in the intratumoral area, CD20+ cells were rarely seen suggesting that the majority of infiltrated lymphocytes in the rat UCMSC treated tumors were T cells. In addition, the treatment of rat UCMSC increased the CD 8+ cell infiltration throughout tumor tissue. CD68+ cells were scarcely observed in the tumors of the PBS control group but not in the rat UCMSC treated group. Transwell culture system-based in vitro migration assay revealed that rat UCMSC significantly enhanced migration of peripheral blood mononuclear cells. These results suggest that naïve rat UCMSC attenuated mammary tumor growth at least in part by markedly enhanced host immune responses against tumors. This research demonstrates that naïve rat UCMSC can be used as powerful anti-cancer therapeutic cells for breast cancer treatment. This work was supported by the Kansas State University (KSU) Terry C. Johnson Center for Basic Cancer Research, KSU CVM Dean's Fund, NIH P20 RR017686, p20 RR1556, R21CA135599 and Kansas Bioscience Authority research fund.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3348. doi:10.1158/1538-7445.AM2011-3348
Abstract 3363: Iron deficiency suppress EMT through downregulation of N-cadherin in esophageal cancer
Authors: Nishitani Seishi , Noma Kazuhiro , Watanabe Shinichiro , Onishi Teppei , Ohara Toshiaki , Tomono Yasuko , Hashimoto Yuuri , Tazawa Hiroshi , Fujiwara Toshiyoshi 
Published: June 2012

Abstract
[Introduction] Epithelial-Mesenchymal-transition(EMT) plays a great roles in cancer metastasis and invasion.Mecanism of EMT remains controversial, but it is recognized that some protein change their expression, including E-cadherin and N-cadherin.It is reported that downregulation of N-cadherin reduce cancer metastasis and invasiveness.
Iron metabolism and its relationship with cancer cell were studied for a long time. Iron overload is known to induce some kinds of cancer, which suggests that prevention of iron overload is a therapeutic strategy of cancer prevention. Iron deficiency is also known to suppress the tumor growth in vivo study. But the efficacy is not superior to the ordinary chemotherapy, it's not a standard therapeutic strategy of cancer. Recently, it is reported that iro metabolism is essential for EMT, and iron defficiency downregulate EMT change. In this study, we demonstrated that iron deficiency downregulate the expression of the EMT protein, N-cadherin, and suppressed the ability of metastasis and invasiveness. This result suggests that Iron controlled treatment can be novel therapeutic agent for cancer under EMT. [Matherials and Methods] TE-1,TE-4,TE-8 and TE-10 esophageal squamous cell carcinoma, OE19 and OE33 esophageal adenocarcinoma cell lines were used in this study. In vitro study, cell viability was determined by XTT assay. Iron chelator deferasirox was prepared in vitro study to make iron deficient condition. To determine that iron deficiency suppresses EMT and invasiveness of cancer cell line, western blotting analysis, the three-dimensional spheroid model analysis and migration assay were done. In vivo study, Normal diet and Iron deficient diet were fed for 3 weeks before implantation of TE-4 cells in athymic male nude mice(n=8/group). After implantation, each diet was fed continually. [Results]Deferasirox reduces proliferation of all cell line in a concentration manner. According to western blotting analysis, deferasirox induces reduction of N-cadherin protein in TE-4 and TE-10 cell lines. N-cadherin downregulation declines invasiveness of TE-4 and TE-10 cell lines in the three-dimensional spheroid model analysis and migration assay. In vivo study, tumor growth was suppressed in iron deficient diet group (tumor volume: normal diet vs iron deficient diet = 30.7±1.1 vs 10.9±2.2) [Conclusion]Iron controlled treatment can be novel therapeutic agent for invasiveness of cancer under EMT.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3363. doi:10.1158/1538-7445.AM2011-3363
Abstract 3373: Aberrant expression of TG2 reprograms mammary epithelial cells by inducing mesenchymal transition (EMT) and stem cell-like characteristics
Authors: Kumar Anupam , Xu Jia , Hui Gao , y Dihu , Reuben James , Mehta Kapil 
Published: June 2012

Abstract
The “Incurable” nature of metastatic breast cancer (MBC) poses a major clinical challenge in successful treatment of breast cancer. Despite significant advances in early detection and disease management, the prognosis of MBC patients remains poor with an estimated 5-year survival rate of 26%. Understanding the molecular pathways/factors responsible for the progression of MBC is critical for improved clinical outcomes. We and others previously found that metastatic breast cancer cells express high basal levels of the proinfflamtory protein tissue transglutaminase (TG2) and that its expression is associated with metastatic and drug-resistant phenotypes in breast cancer cells. However, mechanisms that underlie TG2-mediated metastatic transformation of breast cells remained elusive.
To understand the significance of TG2 in MBC, we stably transfected TG2 in non-transformed breast mammary epithelial cells (MCF10A and MCF12A). Interestingly, TG2 expression induced marked changes in the morphology of cells from cobblestone looking cells to elongated mesenchymal like appearance. Study of various epithelial and mesenchymal markers revealed the loss of epithelial (e-cadherin and β-catenin) and gain of mesenchymal (vimentin and fibronectin) markers in TG2 expressing cells. Moreover, TG2 expression resulted in constitutive activation of Akt and NF-kB and upregulated transcription repressors like, Snail1, Zeb1, Zeb2 and twist1. Interestingly, TGF-β a known inducer of EMT, failed to induce EMT in MCF10A cells transfected with TG2 Sh-RNA. TG2 expression in MCF10A cells was associated with increased invasion, disrupted polarity, increased resistance to doxorubicin, and ability of cells to grow and form colony in soft-agar. Next we determined weather TG2-induced EMT promotes the stem cell phenotype. Study of breast stem cell markers revealed that TG2 expression is associated with dramatic increase in CD44high/CD24low cell subpopulation. Moreover, mammosphere-forming ability of both normal and cancerous breast epithelial cells was significantly augmented by TG2 expression. TG2-derived stem cells showed increase in self-renewal ability and they terminally differentiated into basal and/or luminal cell types in response to prolactin treatment. These results imply that aberrant expression of TG2 could reactivate a comprehensive program in differentiated mammary epithelial cells to endow them stem cell-like properties for successful colonization and macromatastasis. These results also supported the contention that TG2 could serve as a promising therapeutic target for treatment of MBC.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3373. doi:10.1158/1538-7445.AM2011-3373