Extracellular vesicles (EVs) mediate the intercellular transfer of RNAs, which alter gene expression in target cells. EV heterogeneity has limited progress towards defining their physiological functions and utility as disease-specific biomarkers. CD63 and MHC1 are widely used as markers to purify EVs.
View Article and Find Full Text PDFPiezo2 is a mechanically activated ion channel required for touch discrimination, vibration detection, and proprioception. Here, we discovered that Piezo2 is extensively spliced, producing different Piezo2 isoforms with distinct properties. Sensory neurons from both mice and humans express a large repertoire of Piezo2 variants, whereas non-neuronal tissues express predominantly a single isoform.
View Article and Find Full Text PDFMovement of food-borne pathogens on moist surfaces enables them to migrate towards more favorable niches and facilitate their survival for extended periods of time. Salmonella enterica serovar Typhimurium mutants defective in Osmoregulated periplasmic glucans (OPG) synthesis are unable to exhibit motility on moist surfaces (swarming); however, their mobility in liquid (swim motility) remains unaffected. In order to understand the role of OPG in swarm motility, transcriptomic analysis was performed using cells growing on a moist agar surface.
View Article and Find Full Text PDFIn this study we monitored protein dynamics in response to cisplatin, 5-fluorouracil, and irinotecan with different concentrations and administration modes using "reverse-phase" protein arrays (RPPAs) in order to gain comprehensive insight into the protein dynamics induced by genotoxic drugs. Among 666 protein time-courses, 38% exhibited an increasing trend, 32% exhibited a steady decrease, and 30% fluctuated within 24 h after drug exposure. We analyzed almost 12,000 time-course pairs of protein levels based on the geometrical similarity by correlation distance (dCor).
View Article and Find Full Text PDFI read the Andy Burnham interview with interest (analysis September 26), but many people are disappointed by the Labour Party's lacklustre response to the unpopular Health and Social Care Act and the chaos this legislation has brought to managers and front line staff.
View Article and Find Full Text PDFCurr Protoc Bioinformatics
March 2012
The BLAST-Like Alignment Tool (BLAT) is used to find genomic sequences that match a protein or DNA sequence submitted by the user. BLAT is typically used for searching similar sequences within the same or closely related species. It was developed to align millions of expressed sequence tags and mouse whole-genome random reads to the human genome at a higher speed.
View Article and Find Full Text PDFInterleukin-2 (IL-2) is a pleiotropic cytokine that regulates lymphocyte proliferation and peripheral tolerance. IL-2 activates mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase, and signal transducer and activator of transcription (STAT) pathways and modulates expression of target genes. Systematic analysis of IL-2 target genes has revealed regulation of potential feedback inhibitors of IL-2 signaling, including several suppressor of cytokine signaling (SOCS) family members as well as MAPK pathway-regulating dual specificity phosphatases (DUSPs).
View Article and Find Full Text PDFMolecular profiling of markers involved in the activity of chemotherapeutic agents can shed light on the successes and failures of treatment in patients and can also provide a basis for individualization of therapy. Toward those ends, we have used reverse-phase protein lysate microarrays to evaluate expression of protein components of the nucleotide excision repair (NER) pathways. Those pathways strongly influence the anticancer activities of numerous drugs, including those that are the focus here, cisplatin and ecteinascidin 743 (Et-743; Yondelis, Trabectedin).
View Article and Find Full Text PDFConventional molecular biology techniques have identified a large number of cell signaling pathways; however, the importance of these pathways often varies, depending on factors such as treatment type, dose, time after treatment, and cell type. Here, we describe a technique using "reverse-phase" protein lysate microarrays (RPAs) to acquire multiple dimensions of information on protein dynamics in response to DNA damage. Whole-cell lysates from three cellular stress treatments (IR, UV, and ADR) were collected at four doses per treatment, and each, in turn, at 10 time points, resulting in a single-slide RPA consisting of 10,240 features, including replicates.
View Article and Find Full Text PDFMathematical simulations of the p53-Mdm2 feedback loop suggest that both proteins will exhibit impulsive expression characteristics in response to high cellular stress levels. However, little quantitative experimental evaluation has been done, particularly of the phosphorylated forms. To evaluate the mathematical models experimentally, we used lysate microarrays from an isogenic pair of gamma-ray-irradiated cell lysates from HCT116 (p53(+/+) and p53(-/-)).
View Article and Find Full Text PDFT lymphocytes play a central role in controlling adaptive immune responses. IL-2 critically regulates both T cell growth and death and is involved in maintaining peripheral tolerance, but the molecules involved in these and other IL-2 actions are only partially known. We now provide a comprehensive compendium of the genes expressed in T cells and of those regulated by IL-2 based on a combination of DNA microarrays and serial analysis of gene expression (SAGE).
View Article and Find Full Text PDFMapping tumor cell protein networks in vivo will be critical for realizing the promise of patient-tailored molecular therapy. Cancer can be defined as a dysregulation or hyperactivity in the network of intracellular and extracellular signaling cascades. These protein signaling circuits are the ultimate targets of molecular therapy.
View Article and Find Full Text PDFMutations that inactivate the retinoblastoma (Rb) pathway are common in human tumors. Such mutations promote tumor growth by deregulating the G1 cell cycle checkpoint. However, uncontrolled cell cycle progression can also produce new liabilities for cell survival.
View Article and Find Full Text PDFWe tested the hypothesis that the effects on gene expression of altered DNA methylation by 5-aza-2'-deoxycytidine (5-aza-CdR) and genetic (DNMT knockout) manipulation of DNA are similar, and distinct from Trichostatin A (TSA)-induced chromatin decondensation. Surprisingly, the effects of 5-aza-CdR were more similar to those of TSA than to DNMT1, DNMT3B, or double DNMT somatic cell knockout. Furthermore, the effects of 5-aza-CdR were similar at one and five days exposure, suggesting active demethylation or direct influence of both drugs on the stability of methylation and/or chromatin marks.
View Article and Find Full Text PDFAs humans contain a currently active L1 (LINE-1) non-LTR retrotransposon family (Ta-1), the human genome database likely provides only a partial picture of Ta-1-generated diversity. We used a non-biased method to clone Ta-1 retrotransposon-containing loci from representatives of four ethnic populations. We obtained 277 distinct Ta-1 loci and identified an additional 67 loci in the human genome database.
View Article and Find Full Text PDFORD protein is required for accurate chromosome segregation during male and female meiosis in Drosophila melanogaster. Null ord mutations result in random segregation of sister chromatids during both meiotic divisions because cohesion is completely abolished prior to kinetochore capture of microtubules during meiosis I. Previous analyses of mutant ord alleles have led us to propose that the C-terminal half of the ORD protein mediates protein-protein interactions that are essential for sister-chromatid cohesion.
View Article and Find Full Text PDFBecause most potential molecular markers and targets are proteins, proteomic profiling is expected to yield more direct answers to functional and pharmacological questions than does transcriptional profiling. To aid in such studies, we have developed a protocol for making reverse-phase protein lysate microarrays with larger numbers of spots than previously feasible. Our first application of these arrays was to profiling of the 60 human cancer cell lines (NCI-60) used by the National Cancer Institute to screen compounds for anticancer activity.
View Article and Find Full Text PDFColon and ovarian cancers can be difficult to distinguish in the abdomen, and the distinction is important because it determines which drugs will be used for therapy. To identify molecular markers for that differential diagnosis, we developed a multistep protocol starting with the 60 human cancer cell lines used by the National Cancer Institute to screen for new anticancer agents. The steps included: (a) identification of candidate markers using cDNA microarrays; (b) verification of clone identities by resequencing; (c) corroboration of transcript levels using Affymetrix oligonucleotide chips; (d) quantitation of protein expression by "reverse-phase" protein microarray; and (e) prospective validation of candidate markers on clinical tumor sections in tissue microarrays.
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