Over expression of recombinant proteins is known to cause a metabolic burden to the host cells which leads to down regulation of both growth rates and protein expression. Most studies in this regard have been conducted in low density shake flask cultures which does not capture the essential features of an industrial scale bioprocess. In the present work we studied the transcriptomic profiling at different specific growth rates while expressing the recombinant human interferon beta in fed batch cultures with complex media. These conditions mimicked the industrial fermentations for recombinant proteins.
Comparative transcriptomic profile analysis of fed-batch cultures expressing different recombinant proteins in Escherichia coli.
No sample metadata fields
View SamplesThe objective of this work was to design an improved host platform for recombinant protein expression in E. coli. The approach involves first to create a library of the E. coli genomic DNA in different expression vectors and screen for probable transcripts which may lead to slow growing colonies and also simultaneously over-expression of recombinant proteins. To observe its effect on host performance, these genes were knocked out from the E. coli genome. A CG2 strain has been created by knocking in vhb gene gene downstream of the acetate promoter and knocking down ribB gene in DH5 and transformed with Recombinant GFP cloned in pBAD33.
Comparative transcriptomic profile analysis of fed-batch cultures expressing different recombinant proteins in Escherichia coli.
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View SamplesStrong production of recombinant proteins interfere with cellular processes in many ways. The extent of the bacterial stress response is determined by the specific properties of the recombinant protein, and by the rates of transcription and translation. The consideration of bacterial stress and starvation responses is of crucial importance for the successful establishment of an industrial large scale bioprocess. Stress genes can be used as marker genes in order to monitor the fitness of industrial bacterial hosts during fermentation processes. For this purpose, here in our study we have applied transcriptome analysis for the description of general and specific stress and starvation responses of Escherichia coli. Producing recombinant protein (Xylanase) in high cell density fed batch culture.
Comparative transcriptomic profile analysis of fed-batch cultures expressing different recombinant proteins in Escherichia coli.
Treatment
View SamplesPro-inflammatory cytokines were shown to promote growth and survival of cancerous cells. TNF induced RelA:p50 NF-B dimer via the canonical pathway is thought to link inflammation with cancer. Integrating biochemical and computational studies we identify that deficiency of non-canonical signal transducer p100 triggers a positive autoregulatory loop, which instead perpetuates an alternate RelB:p50 containing NF-B activity upon TNF treatment. TNF stimulated RelB:p50 dimer is sufficient for mediating NF-B target gene-expressions and suppressing apoptotic cellular death independent of principal NF-B subunit RelA. We further demonstrate that activating mutations in non-canonical NF-B module deplete multiple myeloma cells of p100, thereby, provoking autoregulatory RelB:p50 activation. Finally, autoregulatory control reinforces protracted pro-survival NF-B response, albeit comprising of RelB:p50, upon TNF priming that protects myeloma cells with dysfunctional p100 from subsequent apoptotic insults. In sum, we present evidence for positive autoregulation mediated through the NF-B system and its potential involvement in human neoplasm.
Non-canonical NFκB mutations reinforce pro-survival TNF response in multiple myeloma through an autoregulatory RelB:p50 NFκB pathway.
Specimen part, Treatment
View SamplesThe analysis of capped RNAs by massively parallel sequencing has identified a large number of previously unknown transcripts, some of which are small RNAs and others are 5 truncated forms of RefSeq genes. The latter may be generated by endonuclease cleavage or by stalling of Xrn1 at defined sites. With the exception of promoter-proximal transcripts the caps on all of these are added post-transcriptionally by a cytoplasmic capping enzyme complex that includes capping enzyme and a kinase that converts 5-monophosphate ends to a diphosphate capping substrate. We previously described a modified form of capping enzyme with dominant negative activity against cytoplasmic capping (DN-cCE). A tet-inducible form of this was used to identify substrates for cytoplasmic capping by treating cytoplasmic RNA from control and induced cells with and without Xrn1. Surviving RNA was analyzed on Affymetrix Human Exon 1.0 arrays and scored for changes in probe intensity as a function of its position on each RefSeq gene to derive a factor (alpha) that could be compared between sets. Notably, transcriptome-wide changes were not evident unless RNA was treated with Xrn1. This analysis identified 2,666 uncapped mRNAs in uninduced cells, 672 mRNAs that appeared in the uncapped pool in cells expressing DN-cCE, and 835 mRNAs that were in both populations. Changes in cap status of 10 re-capping targets and 5 controls were assessed by 3 independent measures; susceptibility to Xrn1, recovery with a biotin-tagged DNA primer after ligating a complementary RNA oligonucleotide to uncapped 5 ends, and binding or exclusion from a high affinity cap-binding matrix comprised of immobilized eIF4E and the corresponding binding domain of eIF4G.
Identification of cytoplasmic capping targets reveals a role for cap homeostasis in translation and mRNA stability.
Cell line
View SamplesOsteosarcoma (OS) is one of the most aggressive bone malignancy. Sub-optimal therapy has irretrievably compromised chances of survival of OS patients for years. Also lack of extensive research on this rare disease has hindered its therapeutic development. Cisplatin (CDDP) is an integral part of current treatment regime for OS. However, despite the proven benefits of CDDP, acquisition of resistance impedes therapy. Also, the molecular effects post CDDP insult in OS cells is poorly understood. Hence, we characterized molecular alterations associated with CDDP-exposure and resistance in OS cells. Resistance to CDDP in OS cells was developed and deep sequencing of mRNA was performed. It depicted an altered transcriptomic signature of resistant cells with enrichment of pathways regulating proliferation. Overall, a significant up-regulation of coding-RNAs and down-regulation of non-coding-RNAs were obtained. Further, analysis of immediate effect of CDDP-shock showed an increase in autophagy and JNK signaling, acting as a pro-survival strategy. Regulatory connections between MAPK signaling and autophagy favoring survival under CDDP-shock was elucidated. Taken together, this is the first study portraying not only global transcriptomic alterations in resistant OS cells but also showing key molecular changes associated with CDDP-insult in OS cells. Our results can be better utilized for future therapeutic benefit. Overall design: We analyzed 5 samples, each being the representative of stages in the acquisition of chemoresistance. Control was the parental HOS cell line with which other comparisons are/will be made in future.
Transcriptomic analysis associated with reversal of cisplatin sensitivity in drug resistant osteosarcoma cells after a drug holiday.
Specimen part, Cell line, Treatment, Subject
View SamplesBackgropund:In a major paradigm shift in the last decade, the knowledge about a whole class of non-coding RNAs known as miRNAs has emerged, which have proved these to be important regulators of a wide range of cellular processes by the way of modulation of gene expression. It is reported that some of these miRNAs are modified by addition or deletion of nucleotides at their ends, after biogenesis. However, the biogenesis and functions of these modifications are not well studied in eukaryotes, especially in plants. In this study, we examined the miRNA modifications in different tissues of the various plants, namely rice, tomato and Arabidopsis and identified some common features of such modifications. Results:We have analyzed different aspects of miRNA modifications in plants. To achieve this end, we developed a PERL script to find the modifications in the sequences using small RNA deep sequencing data. The modification occurs in both mature and passenger (star) strands, as well as at both the 5'' and 3'' ends of miRNAs. Interestingly, we found a position-specific nucleotide biased modification, as evident by increased number of modification at the 5'' end with the presence of Cytosine (nucleotide ''C'') at the 3’end of the miRNA sequence. The level of modifications is not strictly dependent on the abundance of miRNA. Our study showed that the modification events are independent of plant species, tissue and physiological conditions. Our analysis also indicates that the RNAi enzyme, namely, the RNA dependent RNA polymerase 6 (RDR6) may not have any role in Arabidopsis miRNA modifications. Some of these modified miRNAs are bound to AGO1, suggesting their possible roles in biological processes. Conclusions:This is a first report that reveals that 5'' nucleotide additions are preferred for mature miRNA sequences with 3’ terminal ‘C’ nucleotide. Our analysis also indicates that the miRNAs modifications involving addition of nucleotides to the 5’ or 3’ end are independent of RDR6 activity and are not restricted by plant species, physiological conditions and tissue types. The results also indicate that such modifications might be important for biological processes. Overall design: small RNA profiles of wild type and RDR6 (-) of Arabidopsis plants were generated using deep sequencing data.
3' and 5' microRNA-end post-biogenesis modifications in plant transcriptomes: Evidences from small RNA next generation sequencing data analysis.
Subject
View SamplesWe sought to apply the technologies of gene expression profiling to detect genes significant in the aetiology of cervical carcinoma . We investigated 14 normal (NAD), 11 low grade squamous intrapepithelial lesions (LSIL), 21 high grade squamous intraepithelial lesions (HSIL) and 28 squamous cell carcinomas by Affymetrix GeneChip whole transcriptome profiling. Two SCC cell lines were also included in the cohort. Normal and SILS were profiled using the Affymetrix U133A platform, while SCCs and Cell lines were profiled using the Affymetrix U133A plus 2.0 array.
Gain and overexpression of the oncostatin M receptor occur frequently in cervical squamous cell carcinoma and are associated with adverse clinical outcome.
Specimen part, Cell line
View SamplesIn addition to being causally linked to the formation of multiple tumor types, tobacco use has been associated with decreased anticancer treatment efficacy and reduced survival time. A detailed understanding of the cellular mechanisms that are affected by tobacco smoke should facilitate the development of improved preventive and therapeutic strategies. We have investigated the effects of a tobacco smoke (TS) extract on the transcriptome of MSK-Leuk1 cells, a cellular model of oral leukoplakia. Using Affymetrix HGU133 Plus 2 arrays, 411 differentially expressed probesets were identified. The observed transcriptome changes were grouped according to functional information, and translated into molecular interaction network maps and signaling pathways. Pathways related to cellular proliferation, inflammation, apoptosis and tissue injury appeared to be perturbed. Analysis of networks connecting the affected genes identified specific molecular interactions, hubs and key transcription regulators affected by TS. Thus TS was found to induce several EGFR ligands forming an EGFR-centered molecular interaction network, as well as several AhR-dependent genes, including the xenobiotic metabolizing enzymes CYP1A1 and CYP1B1. Notably, the latter findings in vitro are consistent with our parallel finding that levels of CYP1A1 and CYP1B1 were increased in oral mucosa of smokers. Collectively, these results offer insights into the mechanisms underlying the procarcinogenic effects of TS and raise the possibility that inhibitors of EGFR or AhR signaling will prevent or delay the development of tobacco smoke-related tumors. Moreover, the inductive effects of TS on xenobiotic metabolizing enzymes may help explain reduced efficacy of chemotherapy, and suggest targets for chemopreventive agents in smokers.
Effects of tobacco smoke on gene expression and cellular pathways in a cellular model of oral leukoplakia.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Global target mRNA specification and regulation by the RNA-binding protein ZFP36.
Cell line, Treatment
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