Project description:Introduction: Breast radiotherapy is currently â??one size fits allâ?? regardless of breast cancer subtype (eg. luminal, basal). However, recent clinical data suggests that radiation response may vary significantly among subtypes. Therefore, current practice leads to over- or under-treatment of women whose tumors are more or less radiation responsive. We hypothesized that this clinical variability may be due, in part, to differences in cellular radiation response. Methods: We exposed 16 biologically-diverse breast tumor cell lines to 0 or 5GY radiation. Microarray analysis was performed on RNA harvested from those cell lines. Samples were run in triplicate. Following quality assessment, differential gene expression analysis was performed using a two-way multiplicative linear mixed-effects model. A candidate radiation response biomarkers with biologically plausible role in radiation response, were identified and confirmed at the RNA and protein level with qPCR and Western blotting assays. Induction in human breast tumors was confirmed in 32 patients with paired pre- and post-radiation tumor samples using IHC and microarray analysis. Quantification of protein was performed in a blinded manner and included positive and negative controls. The objective of our study was to identify genomic determinants of radiation sensitivity using clinical samples as well as breast tumor cell lines. In order to identify differences in the radiation response gene expression profiles of specific breast cancer subtypes, we exposed 16 biologically-diverse breast tumor cell lines to 0 or 5GY radiation. Microarray analysis was performed on RNA harvested from those cell lines. Samples were run in triplicate. Following quality assessment, differential gene expression analysis was performed using a two-way multiplicative linear mixed-effects model. Candidate radiation response biomarker with a biologically plausible role in radiation response, were identified and confirmed at the RNA and protein level with qPCR and Western blotting assays. Induction of the genes of interest were further evaluated and confirmed in human breast tumors in 32 breast cancer patients with paired pre- and post-radiation tumor samples using IHC and microarray analysis assays.
Project description:Mitotic chromosomes are among the most recognizable structures in the cell, yet for over a century their internal organization remains largely unsolved. We applied chromosome conformation capture methods, 5C and Hi-C, across the cell cycle and revealed two alternative three-dimensional folding states of the human genome. We show that the highly compartmentalized and cell-type-specific organization described previously for non-synchronous cells is restricted to interphase. In metaphase, we identify a homogenous folding state, which is locus-independent, common to all chromosomes, and consistent among cell types, suggesting a general principle of metaphase chromosome organization. Using polymer simulations, we find that metaphase Hi-C data is inconsistent with classic hierarchical models, and is instead best described by a linearly-organized longitudinally compressed array of consecutive chromatin loops.
Project description:Environmental factors, including pesticides, have been linked to autism and neurodegeneration risk using retrospective epidemiological studies. Here, we sought to prospectively identify chemicals that share transcriptomic signatures with neurological disorders by exposing mouse cortical neuron-enriched cultures to hundreds of chemicals commonly found in the environment and on food. We find that rotenone, a pesticide associated with Parkinsonâs disease risk, and certain fungicides, including pyraclostrobin, trifloxystrobin, famoxadone, and fenamidone, produce transcriptional changes in vitro that are similar to those seen in brain samples from humans with autism, advanced age and neurodegeneration (Alzheimerâs disease, Huntingtonâs disease). These chemicals stimulate free radical production and disrupt microtubules in neurons, effects that can be reduced by pretreating with a microtubule stabilizer, an antioxidant, or with sulforaphane. Our study provides an approach to prospectively identify environmental chemicals that transcriptionally mimic autism and other brain disorders. 405 total samples, consisting of 297 unique chemicals and vehicle controls.
Project description:Human breast cancer cell line MDA-MB-231 was transduced with lentivirus vector expressing non-specific control (NS) and CFH knockdown (shCFH1) sequences.
Project description:Half of all human transcription factors use C2H2 zinc finger domains to specify site-specific DNA binding and yet very little is known about their role in gene regulation. Based on in vitro studies, a zinc finger code has been developed that predicts a binding motif for a particular zinc finger factor (ZNF). However, very few studies have performed genome-wide analyses of ZNF binding patterns and thus it is not clear if the binding code developed in vitro will be useful for identifying target genes of a particular ZNF. We performed genome-wide ChIP-seq for ZNF263, a C2H2 ZNF that contains 9 finger domains, a KRAB repression domain, and a SCAN domain and identified more than 5000 binding sites in K562 cells. Our results suggest that ZNF263 binds to a 24 nt site which differs from the motif predicted by the zinc finger code in several positions. Interestingly, many of the ZNF263 binding sites are located within the transcribed region of the target gene. Although ZNFs containing a KRAB domain are thought to function mainly as transcriptional repressors, many of the ZNF263 target genes are expressed at high levels. To address the biological role of ZNF263, we identified genes whose expression was altered by treatment of cells with ZNF263-specific siRNAs. Our results suggest that ZNF263 can have both positive and negative effects on transcriptional regulation of its target genes. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf Examination of ZNF263 ChIP-seq in K562 cells.
Project description:We hypothesized that adipocytes can be triggered by asbestos fibers to produce an inflammatory response. Microarray-based gene expression analysis was thus carried out to identify potential inflammation-related candidates with altered expression in adipocytes following asbestos exposure. We found changes in the expression of some inflammation-related genes in adipocytes treated with the different types of asbestos fibers Cultured adipocytes were treated with 3 different types of asbestos fibers: chrysotile, crocidolite and amosite fibers at 10 mg/cm2 for 72 hours. Physiological saline was used as a control. Microarray was performed with duplicate for each sample.
Project description:We generated high-throughput sequencing (ChIP-seq) data for genome wide occupancy of hDot1L and RNAPII-5p in human embryonic carcinoma cell. Performing ChIP-seq for hDot1L and RNAPII-5p in NCCIT cell lines (embryonic carcinoma cell lines in human).
Project description:Drug target identification is a critical step towards the understanding of the mechanism of action of a drug, which will help to improve the current therapeutic regime and to expand the drug’s therapeutic potential. However, current in vitro affinity chromatography-based and in vivo activity- based protein profiling (ABPP) approaches generally face difficulties discriminating specific drug targets from non-specific ones. Here we describe a novel approach combining isobaric tag for relative and absolute quantitation (iTRAQ) with Clickable ABPP, named ICABPP, to specifically and comprehensively identify the protein targets of andrographolide (Andro), a natural product with known anti-inflammation and anti-cancer effects, in live cancer cells. We identified a spectrum of specific targets of Andro, which furthered our understanding of the mechanism of action of the drug. We found that Andro has a potential novel application as the tumor metastasis inhibitor, which was validated through cell migration and invasion assays. Moreover, we have unveiled the target binding mechanism of Andro with a combination of drug analogue synthesis, protein engineering and mass spectrometry-based approaches and determined the drug-binding sites of two protein targets, NF-kappaB and actin.
Project description:The experiment was performed to reveal transcriptomic alterations in melanoma cells caused by dacarbazine (DTIC) treatment. Two primary cell cultures were exposed to dacarbazine at a final concentration of 1 mg/mL. The whole transcriptome was investigated in the cells treated with DTIC compared to a negative control group.
Project description:Analysis of cultured human amnion mesenchymal cells treated with synthetic glucocorticoid dexamethasone for 48 hours. Results provide insight into the molecular response of the human amnion to glucocorticoids.