RNA-seq of E. coli strains overproducing DNA "damage-up" proteins (DDPs)
ABSTRACT: This experiment assesses gene expression changes in response to the overproduction of DNA \"damage-up\" proteins (DDPs). These proteins, when overproduced, activate the SOS DNA damage response and were identified in a genome-wide overproduction screen using the mobile plasmid collection (Saka et al 2005). For the RNA-seq experiments, 7 DDP overproduction strains were compared to an empty vector control strain.
Project description:To investigate the difference of miRNA expression in exosomes derived from A549 cells and its DDP-resistant cell strain A549/DDP, we have employed miRNA microarray expression to discover the difference expression of miRNAs in exosomes derived from A549 and A549/DDP. We conducted RT-qPCR to examine the expression levels of top differential expressed miRNAs, namely, miR-197-5p, miR-4443, miR-642a-3p, miR-27b-3p and miR-100-5p, confirming low variability between two methods. The A549/DDP was established from A549 in our laboratory, by exposing A549 to gradually increasing DDP concentrations, until the final concentration at 1μg/ml. To avoid the influence of drug to the A549/DDP cells, they were cultured in a drug-free medium for at least two weeks before gene expression analysis. After being incubated for 48-72h, the culture medium of cells was harvested. Exosomes were isolated by ultracentrifugation. And miRNA expression of exosomes derived from A549 and A549/DDP was then analzyed.
Project description:Apoptosis is an important process to eliminate cells from tissue which have incurred irreparable DNA damage. While dE2F1/dDP complexes respond to such damage by transcriptionally activating apoptotic genes, previous data suggests that activation of the previously characterized apoptotic target genes of dE2F1/dDP alone may not be the only gene regulation important for gamma irradiation-induced apoptosis. Here we report that following irradiation in dDP mutant 3rd instar larval eye imaginal discs, many genes important for oxidative phosphorylation are down-regulated, which are not down-regulated following irradiation in wild type eye discs. Biological triplicates of wild type, dDP mutant and de2f1, deleted in the posterior, eye discs were untreated or irradiated with 40Gy of gamma radiation. Total RNA was extracted by Trizol from untreated eye discs and from irradiated eye discs 4h after irradiation. RNA was column purified. PCR amplified RNAs were hybridized on Affymetrix Drosophila Genome 2.0 Array.
Project description:WT and dDP-/- mutant larvae RNAs were analyzed on Drosophila 12 x 135 Nimbelgen gene expression microarrays. dDP-/- mutants are described in Frolov et al., 2001. Genes Dev. Aug 15;15(16):2146-60. PMID: 11511545 The complete elimination of E2F/DP function in Drosophila results in upregulation of DNA damage responses. The net effect of E2F regulation in larval tissues is that all classes of E2F target genes are reppressed by E2F/DP complexes. Overall design: Drosophila 12 x 135 Nimbelgen gene expression microarrays were prepared with triplicates of larval RNA from WT and dDP-/- mutant larvae.
Project description:Application of cisplatin (DDP) for treating lung cancer is restricted due to its toxicity and drug resistance. In this study, we aimed to examine whether Jinfukang (JFK), an effective herbal medicine against lung cancer, enhances DDP-induced cytotoxicity in lung cancer cells. Morphologically, we observed JFK increases DDP-induced pro-apoptosis in A549 cells in a synergistic manner. Transcriptome profiling analysis indicated that combination of JFK and DDP regulates genes involved in apoptosis-related signaling pathways. Moreover, we found the combination of JFK and DDP produces synergistic pro-apoptosis effect in other lung cancer cell lines NCI-H1975, NCI-H1650 and NCI-H2228. Particularly, we demonstrated AIFM2 is activated by the combined treatment of JFK and DDP, and partially mediate the synergistic pro-apoptosis effect. Collectively, this study gives the first evidence that activation of AIFM2 contributes to induction of pro-apoptosis by combined treatment with JFK and DDP in human lung cancer cells and provides an insight for its potential clinical application in lung cancer treatment.
Project description:Pseudomonas putida mt-2 metabolizes m-xylene and other aromatic compounds through the enzymes encoded by the xyl operons of the TOL plasmid pWW0 along with other chromosomally-encoded activities. Tiling arrays of densely overlapping oligonucleotides were designed to cover every gene involved in this process, allowing dissection of operon structures and exposing the interplay of plasmid and chromosomal functions. All xyl sequences were transcribed in response to aromatic substrates and the 3'-termini of both upper and lower mRNA operons extended beyond the ir coding regions, i.e., the 3’-end of the lower operon mRNA penetrated into the convergent xylS regulatory gene. Furthermore, xylR mRNA for the master m-xylene responsive regulator of the system was decreased by aromatic substrates, while the cognate upper operon mRNA was evenly stable throughout its full length. RNA-seq confirmed these data at a single-nucleotide level and refined the formerly misannotated xylL sequence. The chromosomal ortho route for degradation of benzoate (the ben, cat clusters and some pca genes) was activated by this aromatic, but not by the TOL substrates, toluene or m-xylene. We advocate this scenario as a testbed of natural 16 retroactivity between a pre-existing metabolic network and a new biochemical pathway implanted through gene transfer. Genome Analyzer IIx system (1x75bp) was used for sequencing total RNA extracted from P. putida (mt-2) containing the plasmid pWW0, in two different physiological states (treated with m-xylene and in C-runout condition).
Project description:Oxidative stress that originates from reactive oxygen species (ROS) is an inevitable consequence of aerobic respiration in bacteria. Three transcription factors (TFs), OxyR, SoxR, and SoxS play a critical role in transcriptional regulation of the defense system. However, the full genome-wide regulatory potential of them remains elusive. Here, we comprehensively reconstruct genome-wide OxyR, SoxR, and SoxS transcriptional regulatory networks in Escherichia coli under oxidative stress. Integrative data analysis reveals that OxyR, SoxR, and SoxS regulons are comprised of 38 genes in 28 transcription units (TUs), 11 genes in 10 TUs, and 34 genes in 25 TUs, respectively, significantly expanding the current knowledge of their regulatory networks. Comparison of them to other stress-response regulatory networks highlights minimal overlap between their regulons, indicating that E. coli has a series of relatively distinct stress responses covering the range of different stresses. We also demonstrate that these intricate networks coordinate detoxification process with DNA and protein damage repair, cell wall synthesis, divalent metal ion homeostasis, as well as metabolic robustness to produce overall response of E. coli to oxidative stress. A total of eight samples were analyzed. WT, ΔoxyR, ΔsoxR, and ΔsoxS mutant cells were cultured in M9 minimal media with 0.2% glucose. Then cells were treated with 250 uM of paraquat at mid-log pahse for 20 min with agitation.
Project description:To investigate the difference of miRNA expression between lung cancer cell A549 and its DDP-resistant cell strain A549/DDP, we have employed miRNA microarray expression to discover the difference expression of miRNAs of A549 cells and A549/DDP. We conducted RT-qPCR to examine the expression levels of top differential expressed miRNAs, namely, miR-197-5p, miR-4443, miR-642a-3p, miR-27b-3p and miR-100-5p, confirming low variability between two methods. The A549/DDP was established from A549 in our laboratory, by exposing A549 to gradually increasing DDP concentrations, until the final concentration at 1μg/ml. To avoid the influence of drug to the A549/DDP cells, they were cultured in a drug-free medium for at least two weeks before gene expression analysis. miRNA expression of A549 and A549/DDP was then analzyed.
Project description:The response to acid stress is a fundamental process in bacteria. Three transcription factors, GadE, GadW, and GadX (GadEWX) are known to play a critical role in the transcriptional regulation of glutamate-dependent acid resistance (GDAR) system in Escherichia coli K-12 MG1655. However, the regulatory role of GadEWX in coordinating interacting cellular functions is still unknown. Here, we comprehensively reconstruct genome-wide GadEWX transcriptional regulatory network in E. coli K-12 MG1655 under acidic stress. Integrative data analysis reveals that GadEWX regulons are comprised of 45 genes in 31 transcription units (TUs), significantly expanding the current knowledge of the GadEWX regulatory network. We demonstrate that GadEWX directly and coherently regulate several proton efflux/influx and generating/consuming enzymes with pairs of negative-feedback loops to maintain pH homeostasis by controlling proton flow. In addition, GadEWX regulate genes with assorted functions including molecular chaperones, acid resistance, stress response, and other regulatory activities. These results present a comprehensive understating on how GadEWX simultaneously coordinates many other cellular processes to produce the overall response of E. coli to acid stress. A total of six samples were analyzed. GadE-8-myc, GadW-8 -myc, and GadX-8-myc tagged cells were cultured in M9 glucose minimal media at pH 5.5 with biological duplicates.
Project description:Cisplatin is the first-line agent utilized for the clinical treatment of a wide variety of solid tumors including gastric cancer. However, the intrinsic or acquired cisplatin resistance is often occurred in patients with gastric cancer and resulted in failure of cisplatin therapy. In order to investigate if miRNA involves in cisplatin resistance of human gastric cancer, we first screened and compared the expression of miRNAs between cisplatin resistant gastric cancer cell lines SGC-7901/DDP and BGC-823/DDP and their sensitive parental cells by miRNAs microarray. Overall design: Total miRNAs expression was examined in SGC-7901,SGC7901/DDP,BGC-823,BGC-823/DDP four cell lines.