Breast cancer is the most common malignancy in women and is the leading cause of death among women world-wide [1]. Despite many advances in the diagnosis and treatment of breast cancer, metastasis remains an insurmountable challenge. Although the molecular mechanisms are not completely understood, it is well established that the formation and growth of new blood vessels is critical for sustained tumor growth and metastasis [2]. Studies have found that benign lesions associated with high vascular density are correlated with an increased risk of developing breast cancer. Traditionally, the mechanism(s) controlling the development of tumor vasculature and perfusion were thought to be endothelial cell-lined vascular networks [3]. Thus, efforts to reduce the growth and spread of breast cancer focused on the mechanism(s) of angiogenesis by which tumors establish a blood supply for survival, growth, and metastasis [4].
Plant Cell. 2008 January; 20(1): 75–87
Guard cells play a critical role in plant growth and development by optimizing gas exchange under variable environments.
Data for this study were collected using …Five works will be examined, all of which …This investigation takes the form of a case-study of the …This study was exploratory and interpretative in nature.This study uses a qualitative case study approach to investigate …The research data in this thesis is drawn from four main sources: …The approach to empirical research adopted for this study was one of …This dissertation follows a case-study design, with in-depth analysis of …By employing qualitative modes of enquiry, I attempt to illuminate the …Qualitative and quantitative research designs were adopted to provide …Both qualitative and quantitative methods were used in this investigation.A holistic approach is utilised, integrating X, Y and Z material to establish …The study was conducted in the form of a survey, with data being gathered via …The methodological approach taken in this study is a mixed methodology based on …A combination of quantitative and qualitative approaches was used in the data analysis.
A 51-year-old man with a diagnosis of myelodysplasia and non-Hodgkin's lymphoma underwent an unmatched allogenic bone marrow transplantation and was treated posttransplant with chronic immunosuppressive medication. Eight months following transplantation, he presented with progressive dysarthria, cognitive and visual decline. Evaluation included brain magnetic resonance (MR) imaging demonstrating multifocal areas of increased T2 and FLAIR (fluid attenuated inversion recovery) signals involving the left frontal, parietal, and occipital lobes. The MR lesions demonstrated diffuse increased signal on DWI (diffusion-weighted images) and normal to low signal on ADC (apparent diffusion coefficients). Contrast-enhanced T1 images were unremarkable. Lumbar puncture revealed a mild elevation in cerebrospinal fluid (CSF) protein. CSF PCR assay for viral DNA fragments were negative on two occasions. Serum serology for HIV was negative as well. A brain biopsy was subsequently performed. The clinical and neuroimaging differential diagnoses as well as neuropathologic correlation are presented.,
Cancer Cell Int. 2008; 8: 9
One emerging strategy is to use the tumor tracking capacity inherent in many stem cell populations to deliver therapeutic agents to the brain cancer cells. Current limitations of the stem cell therapy strategy include that stem cells are treated as a single entity and lack of uniform technology is adopted for selection of clinically relevant sub-populations of stem cells.,
Cancer Cell Int. 2008; 8: 9.
Primary malignant tumors such as high grade gliomas diffusely migrate into the brain early in the disease course, disseminating tumor microsatellites to distant regions of the central nervous system [4]. These tentacles of tumor exist interspersed between normal functional tissues. Complete surgical resection of many malignant brain tumors is not practical by virtue of their anatomical location and the relationship of this diffuse disease relative to eloquent functional tissue. Adjuvant therapies including chemotherapy and radiation therapy are often used in conjunction with surgery for many types of cancer to attempt eradication of the residual tumor [5],
Supports are from the Children's Hospital of Orange County Foundation for Children and Neuroscience Institute as well as from the Austin Ford Tribute and Keck Foundation (S. C. L.). We thank Brent A. Dethlefs; Philip H. Schwartz, PhD; Henry J. Klassen, MD-PhD; Hong Zhen Yin, MD; John H. Weiss, MD-PhD; Yuan-Ping Han, PhD; and Qiang Lu, PhD; Hector W. Ho, MD; Henry Hirschberg, MD-PhD; for their discussions. We thank Saul Puszkin, PhD; Michael P. Lisanti, MD-PhD; Richard G. Pestell, MD-PhD; Joan S. Brugge, PhD; Sunil Nagpal, PhD; Robert A. Koch, PhD; for their support and enthusiasm. We would like to apologize to those authors whose invaluable work was not mentioned and cited in the above.,
Blood. 2006 March 1; 107(5): 2170–2179.
Hematopoietic stem cell (HSC) self-renewal is driven by both intrinsic and extrinsic factors, but the molecular mechanism specifying whether developmental potential is lost or retained during asymmetric cell divisions is unknown. Serial transplantation studies have clearly indicated that self-renewal potential of HSCs is impaired after replicative stress.1,2 HSC activity may be irreversibly lost in a single cell division,3,4 indicating that the epigenetic regulation of gene expression, largely dictated by the histone code, may play an important role. Recently, substantial attention has focused on the role of Polycomb group (PcG) proteins in stem cell self-renewal.,
Blood. 2006 March 1; 107(5): 2170–2179.
Gene array analysisTotal RNA was isolated from passage 1 (young p1) and passage 5 (aged p5) MEFs with a RNeasy mini kit (Qiagen, Venlo, The Netherlands). During cDNA synthesis, samples were labeled with [33P]-deoxycytidine triphosphate (dCTP; MP Biochemicals, Irvine, CA). Mouse filter gene arrays (GF400a; Research Genetics, Invitrogen) were hybridized and analysis was performed as described previously.34 Expression patterns were verified by reverse transcription-polymerase chain reaction (RT-PCR).
Blood. 2006 March 1; 107(5): 2170–2179.
AnimalsTimed pregnant female C57BL/6 mice were used to obtain day 14 postcoitus embryos from which mouse embryonic fibroblasts (MEFs) were isolated. Eight- to 12-week-old female B6.SJL-PtprcaPep3b/BoyJ (CD45.1) mice were used as donors for transplantation and were bred at the Central Animal Facility of the University of Groningen. Eight- to 12-week-old female C57BL/6 (CD45.2) mice were purchased from Harlan (Horst, The Netherlands) and were used as recipients.
Blood. 2006 March 1; 107(5): 2170–2179.
Retroviral overexpression of Ezh2 in HSCsPrimary bone marrow (BM) cells were transduced as previously described with some adjustments.35 Briefly, BM cells were extracted from mice (CD45.1) given intraperitoneal injections of 150 mg/kg 5-fluorouracil (5-FU; Pharmachemie Haarlem, Haarlem, The Netherlands) 4 days earlier. Cells were cultured for 48 hours in StemSpan (StemCell Technologies, Vancouver, BC, Canada) supplemented with 10% FCS, 300 ng/mL PEG-rrSCF (Amgen, Thousand Oaks, CA), 20 ng/mL rmIL-11 (R&D Systems, Minneapolis, MN), 10 ng/mL Flt3 ligand (Amgen), penicillin, and streptomycin. Viral supernatant was harvested 24 and 48 hours after transfection of ecotropic Phoenix cells and inoculated in 6-well plates that were coated with 50 μg retronectin (Takara, Kyoto, Japan). Plates containing the viral supernatant were spun for 1 hour at 800 g at room temperature. Four hours later viral supernatant was removed, and 7.5 × 105 cultured BM cells were inoculated per well together with 4 μg Polybrene (Sigma). At the second transduction 2 μg Polybrene was added. Four days later transduction efficiency was determined by flow cytometry (FACSCalibur; Becton Dickinson, Palo Alto, CA).
Blood. 2006 March 1; 107(5): 2170–2179.
In vitro differentiation of purified HSCsPurified Lin-Sca-1+c-kit+ (LSK) cells were cultured in IMDM (Invitrogen) containing 100 ng/mL PEG-rrSCF (Amgen) and 10 ng/mL GM-CSF (Behringwerke, Marburg, Germany) to stimulate rapid in vitro differentiation. Total cell number was assessed using trypan blue exclusion. At different time points during culturing RNA was isolated for gene expression analysis.
Blood. 2006 March 1; 107(5): 2170–2179.
Western blottingCells were resuspended in PBS, lysed by addition of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) sample buffer, and sonicated. Proteins were separated by 10% SDS-PAGE and transferred to nitrocellulose. After blocking in 3% skim milk, membranes were probed with a 1:100 dilution of mouse anti-Ezh2 mAb (M18EZH2, kindly provided by Prof Dr A. P. Otte, Swammerdam Institute for Life Science, University of Amsterdam, The Netherlands37,38), washed, and incubated with anti-mouse horseradish peroxidase-conjugated secondary antibody (Amersham Biosciences, Buckinghamshire, United Kingdom). Membranes were developed using enhanced chemiluminescence (ECL) reagents (Amersham Biosciences). Equal loading of membranes was verified with rabbit anti-γ-tubulin (Sigma).
Blood. 2006 March 1; 107(5): 2170–2179.
Quantitative PCRTotal RNA was isolated using the RNeasy Mini kit (Qiagen) and standard cDNA synthesis was performed. Quantitative PCRs (qPCRs) were performed in triplicate. PCR amplification, using SYBR Green, was performed in 96-well microtiter plates in an iCycler thermal cycler (Bio-Rad, Hercules, CA). Sample cDNAs were compared with expression of house-keeping genes Gapdh and actin using the relative quantification ΔΔCT technique.39 Relative expression levels in the different LSK populations were estimated by first calculating the number of molecules formed at reaching the CT. By correcting this value for the initial number of cells used, relative expression was determined.
Blood. 2006 March 1; 107(5): 2170–2179.
Statistical analysisStatistical differences between means were assessed using the 2-tailed t test assuming unequal variances and ANOVA with 2 factors. Kaplan-Meier survival analysis was performed for mice that received a tertiary transplant of control or Ezh2-transduced HSCs. Differences in survival were tested for significance using a log-rank test. Statistical analysis was performed using the SPSS (Chicago, IL) statistical package.
