MicroRNA profiling of human breast cancer cell line MCF7 under conditions of hypoxia
ABSTRACT: Hypoxia results in the changes in expression of many genes, the majority of which are mediated via the transcriptional activity of the hypoxia inducible factor (HIF) complex. However, other mechanisms of gene regulation by hypoxia are likely and include control of mRNA stability, regulation of mRNA translation and regulation mediated by micrornas. The aim of this study is to identify microRNAs which expression is regulated by hypoxia. We chose the breast cancer line MCF7 for study as we had previously characterised the expression of the components of the HIF system in that cell line and undertaken an extensive study of the gene expression profile in response to hypoxia, a prolyl hydroxylase inhibitor dimethyloxalylglycine and HIF-1a isoform manipulations (Eldvidge. G.P. et al. (2006) JBC, vol. 281, 22, 15215-15226).
Clinical cancer research : an official journal of the American Association for Cancer Research 20080301 5
<h4>Purpose</h4>MicroRNA (miRNA) expression alterations have been described in cancer. Many cancers are characterized by areas of hypoxia, enhanced hypoxia-inducible factor (HIF) levels, and increased expression of hypoxically regulated genes, all of which correlate with patient outcome. We examined hypoxia-induced miRNA expression changes to identify markers of survival in breast cancer.<h4>Experimental design</h4>We used microarrays to analyze miRNA expression changes induced by hypoxia in MCF ...[more]
Project description:specific pathogen-free female BALB/c mice aged 7-8 weeks (Animal Resources Centre, Perth, Western Australia) were systemically sensitised by intraperitoneal injection of 50 µg of alum-precipitated chicken egg OVA (Grade V, ?98% pure, Sigma Australia) 21 and 7 days before inhalational challenge, then exposed to aerosolised OVA in a whole body inhalation exposure chamber (Unifab Corporation, Kalamazoo, MI). Chronic low-level challenge involved exposure to ?3 mg/m3 aerosolised OVA for 30 minutes/day on 3 days/week for up to 6 weeks. Particle concentration within the chamber was continuously monitored using a DustTrak 8520 instrument (TSI, St Paul, MN). All experimental procedures complied with the requirements of the Animal Care and Ethics Committee of the University of New South Wales (reference numbers: 06/119B and 08/09B). Mice were sacrificed after 1,2,4 and 6 weeks of OVA exposure. Control groups included naïve mice and mice that were not sensitised but were challenged for 6 weeks with aerosolised OVA.
Project description:Mating is a complex process that causes many behavioral and physiological changes, but the factors triggering these changes and the underlying molecular processes are not well characterized. Honey bee queens provide a convenient system for dissecting these factors (e.g., physical manipulation, insemination volume, insemination substance) via instrumental insemination. We examined the effects of carbon dioxide (CO2), a commonly used anesthetic in instrumental insemination that causes changes similar to those observed after mating, and physical manipulation, which presumably mimics the act of copulation, on the brain transcriptional changes in honey bee queens. We found significant gene overlap between our study and previous mating studies in honey bee queens and Drosophila. This suggests that molecular pathways regulating the mating process are conserved across different mating regimes of honey bees as well as across insect orders.
Project description:Cell Lines, Cultures and HCC Tumor Tissues. <br>Malignant and non-malignant hepatocyte cell lines were obtained from the American Type Culture Collection (Manassas, VA) and cultured as recommended by the supplier. Total RNA from three paires of normal human liver tissue and from hepatocellular carcinoma was obtained from BioChain Institute, Inc. (Hayward, CA).<br><br>Isolation of MicroRNA. <br>Total RNA was obtained from cell lines and tissue samples using the Totally RNA isolation kit (Ambion, Austin, TX). The miRNA fraction was obtained by flashPAGE purification using the flashPAGE Fractionator System (Ambion, Austin, TX). The size of the microRNA fractions were confirmed using an Agilent 2100 Bioanalyzer (Agilent Technologies, Inc., Palo Alto, CA).
Project description:The time course experiment was designed as follow: (1) Mesenchymal stem cell (indifferentiated cells)/ time 0h; (2) After 24 h of osteogenic induction; (3) After 48 h of osteogenic induction (4) After 7 days of osteogenic induction.
Project description:Identification of the régulation pathways implied in adventitious root formation control in Arabidopsis etiolated seedlings. 2 mutants : a null allele and a weak allele of the ARGONAUTE gene. 4 repetitions in 2 pools for each sample.
Project description:The aim of this study was to identify alarm (fast) and acclimation phase (delayed) changes in the gene expression pattern in leaves of maize (CM 109 genotype) subjected to moderate chilling for 28 hours.
Project description:This experiment evaluates quick (alarm) response to chilling in chilling-sensitive maize plants.<br>Maize inbred line cm109 were grown in optimal conditions until third leaf was fully developed. <br>At this stage plants were divided into three experimental variants: k0 - control plants, frozen<br>at the beginning of daylight, k4 - control plants kept in the same conditions and frozen after 4 hours<br>since beginning of daylight, c4 - plants kept in 14 deg. C for 4 hours since "dawn". At the mentioned<br>moments, leaves were harvested and frozen in liquid nitrogen for RNA isolation.
Project description:Newly emerged adult workers (24 hours old) were infected with 50,000 Nosema apis spores in sucrose solution. Controls were fed sucrose. Workers were maintained in cages in an incubator and collected at 2 and 7 days post-infection. Fat body tissue was dissected (eviscerated abdomen) and whole genome expression in this tissue was compared across treatments and collection time points using microarrays.
Project description:MicroRNAs are small non-coding molecules about 18-24 nucleotides long which can regulate expression of up to 60% of genes in a cell. So they are involved in many cellular processes. It has been demonstrated that miRNAs are involved in pathological processes, in particular in cancer and may be promising targets for differential diagnosis and therapy of cancer. This study is aimed at finding microRNAs involved in the development of melanoma, which could be potential targets for personalized treatment of this disease.