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PROVIDER: PRJNA934346 | ENA |
REPOSITORIES: ENA
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Project description:Unknown are the mechanisms of tolerance and persistence associated to several compounds in A.baumannii clinical isolates. Using transcriptomical and microbiological studies, we found a link between bacterial tolerance mechanisms to clorhexidine as well as the development of persistence in presence of imipenem in an A.baumannii strain belonging to ST-2 clinical clone (carbapenem-resistant with OXA-24 ß-lactamase and AbkAB TA system by plasmid). Interestingly, in A.baumannii ATCC17978 strain (carbapenem-susceptible isolate which carries AbkAB TA system by plasmid) showed persistence in presence of imipenem.
2018-02-09 | GSE110207 | GEO
Project description:Resistance to oxaliplatin (OXA) is a complex process affecting the outcomes of metastatic colorectal cancer (CRC) patients treated with this drug. The NF-kBsignalling pathway deregulation has been proposed as an important mechanism involved in this phenomenon. Here, we show that NF-kBwas hyperactivated in in vitro models of OXA-acquired resistance but was attenuated by the addition of Curcumin, a non-toxic NF-kB inhibitor. The concomitant combination of Curcumin+OXA was more effective and synergistic in cell lines with acquired resistance to OXA, leading to the reversion oftheir resistant phenotype, through the inhibition of the NF-kBsignalling cascade. Transcriptomic profiling revealed the up-regulation of three NF-KB-regulated CXC-chemokines, CXCL8, CXCL1 and CXCL2, in the resistant cells thatwere more efficiently down-regulated after OXA+Curcumin treatment as compared to the sensitive cells. Moreover, CXCL8 and CXCL1 gene silencing made resistant cells more sensitive to OXA through the inhibition of the Akt/NF-kBpathway. High expression of CXCL1 in FFPE samples from explant cultures of CRC patients-derived liver metastaseswas associated with response to OXA+Curcumin.In conclusion, we suggest that combination of OXA+Curcumincould be an effective treatment in CRC patients after progression to OXA-based chemotherapy being CXCL1a good candidate predictive marker to this treatment.
2016-12-07 | GSE76092 | GEO
Project description:Oxaliplatin is a member of the family of Pt-containing chemotherapeutic agents that also include cisplatin (CDDP) and carboplatin. OXA is distinguished from these two older drugs by its different spectrum of activity both in preclinical models and in clinical trials. It is the only platinum analogue to have activity in colon cancer, a disease for which this drug has now become a mainstay of therapy. It mainly forms intrastrand adducts between two adjacent guanine residues or guanine and adenine, disrupting DNA replication and transcription. OXA has been reported to be involved in the Nucleotide Excision Repair Pathway (NER), p38 kinase activation, PI3K/AKT pathway and caspases cascade activation through apoptotic intrinsic pathway. However, the downstream molecular events underlying the cytotoxic effects of this chemotherapeutic agent have not been well characterized. This study was developed in order to clarify the multifactoriality of the resistance acquisition process and to identify genes and pathways that could play a role as markers in OXA sensitivity. Keywords: Drug resistance The goal of our experiment was to determine a gene expression profile that discriminates between the OXA-sensitive colorectal cancer cell lines HT29, LoVo, DLD1 and LS513 group and the group of OXA-resistant derived cell lines HTOXAR3, LoVOXAR3, DLDOXAR3 and LSOXAR3 in order to clarify the multifactoriality of the resistance acquisition process and to identify genes and pathways that could play a role as markers in OXA sensitivity. The experimental design used was âRNA-Referenceâ and âDye-Swapâ. Each cell line was analyzed in duplicate, with RNA reference (Stratagene) as reference sample and labeled each biological condition once by Cy3 and once by Cy5. Taking the average of two arrays thus labeled, cancel the dye effect on any particular gene. In total we used 16 slides.
2010-05-26 | E-GEOD-10405 | biostudies-arrayexpress
Project description:The nosocomial pathogen Acinetobacter baumannii is a frequent cause of hospital acquired infections worldwide, and a challenge for treatment due to its evolved resistance to antibiotics, including carbapenems. To gain insight on A. baumannii antibiotic resistance mechanisms, we analyzed the protein interaction network of a multidrug-resistant A. baumannii clinical strain Ab5075. Using in vivo chemical cross-linking and mass spectrometry, we identified 2,068 non-redundant cross-linked peptide pairs containing 245 intra- and 398 inter- molecular interactions. Outer membrane proteins OmpA and YiaD, and carbapenemase Oxa-23 are hubs of the identified interaction network. Eighteen novel interactors of Oxa-23 were identified. Interactions of Oxa-23 with outer membrane porins OmpA and CarO were verified with co-immunoprecipitation analysis. Furthermore, transposon mutagenesis of oxa-23 or interactors of Oxa-23 demonstrated changes in meropenem or imipenem sensitivity in Ab5075. These results provide the first view of a porin-localized toxin inactivation model and increase understanding of bacterial antibiotic resistance mechanisms.
2016-12-22 | PXD004236 | Pride
Project description:Carbapenem Resistant Acinetobacter baumannii harboring the OXA-24/40-like resistance mechanism OXA-72
| PRJNA554907 | ENA
Project description:The efficacy of hepatic arterial infusion chemotherapy (HAIC) with oxaliplatin (OXA) and 5-fluorouracil (5-Fu) for treating advanced perihilar cholangiocarcinoma (pCCA) has been demonstrated, yet the survival benefits of HAIC for pCCA patients vary. Here, we aimed to screen out HAIC resistance-related bile microRNAs (miRNAs) and explore the functions of specific bile miRNAs in pCCA based on high-throughput sequencing. Levels of bile miR-532-3p,miR-1250-5p, and miR-4772-5p were related to the survival of advanced pCCA patients after HAIC. However, only overexpression of miR-532-3p promoted OXA/5-Fu resistance, and downregulation of its expression improved sensitivity to OXA/5-Fu. Mechanistic investigations revealed secreted protein acidic and rich in cysteine (SPARC) as the direct target of miR-532-3p. Our study reveals that bile miR-532-3p, miR-1250-5p, and miR-4772-5p may serve as survival biomarkers in advanced pCCA patients after HAIC and that bile miR-532-3p promotes resistance to HAIC with OXA and 5-Fu via negatively regulating SPARC expression.
2024-11-02 | GSE280797 | GEO
Project description:Oral squamous cell carcinoma (OSCC) represents a major malignancy in the oral and maxillofacial region. The primary therapeutic agents, 5-fluorouracil (5FU) and oxaliplatin (OXA), often encounter the challenge of chemoresistance, leading to treatment failure. The WNT/β-catenin signaling pathway, closely tied with chemoresistance, offers a promising therapeutic avenue. This study delves into this potential connection. 5FU-resistant and OXA-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells were analyzed by RNA sequencing analysis, which was then substantiated via RT-qPCR and western blot. The influence of the WNT signaling on OSCC drug resistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor, MSAB, was probed for its capacity to boost the efficacy of 5FU or OXA. Through transcriptome sequencing, successfully derived 5FU-resistant and OXA-resistant cell lines revealed a conspicuous activation of the WNT/β-catenin signaling pathway in the drug-resistant cells. WNT3 was identified as a pivotal factor contributing to chemoresistance in OSCC. Counteracting β-catenin notably augmented the therapeutic potency of 5FU and OXA. Our study underscored the activation of the WNT/β-catenin signaling pathway in resistant OSCC cell lines. By modulating WNT signaling activity, drug resistance in OSCC cells may be effectively circumvented.
2024-05-15 | GSE248792 | GEO
Project description:Oxaliplatin is a member of the family of Pt-containing chemotherapeutic agents that also include cisplatin (CDDP) and carboplatin. OXA is distinguished from these two older drugs by its different spectrum of activity both in preclinical models and in clinical trials. It is the only platinum analogue to have activity in colon cancer, a disease for which this drug has now become a mainstay of therapy. It mainly forms intrastrand adducts between two adjacent guanine residues or guanine and adenine, disrupting DNA replication and transcription. OXA has been reported to be involved in the Nucleotide Excision Repair Pathway (NER), p38 kinase activation, PI3K/AKT pathway and caspases cascade activation through apoptotic intrinsic pathway. However, the downstream molecular events underlying the cytotoxic effects of this chemotherapeutic agent have not been well characterized. This study was developed in order to clarify the multifactoriality of the resistance acquisition process and to identify genes and pathways that could play a role as markers in OXA sensitivity. Keywords: Drug resistance
2008-02-07 | GSE10405 | GEO
Project description:Background: It remains unclear how high-risk Escherichia coli lineages, like sequence type (ST) 131, initially adapt to carbapenem exposure in its progression to becoming carbapenem resistant. Methods: Carbapenem mutation frequency was measured in multiple subclades of extended-spectrum β-lactamase (ESBL) positive ST131 clinical isolates using a fluctuation assay followed by whole genome sequencing (WGS) characterization. Genomic, transcriptomic, and porin analyses of ST131 C2/H30Rx isolate, MB1860, under prolonged, increasing carbapenem exposure was performed using two distinct experimental evolutionary platforms to measure fast vs. slow adaptation. Results: All thirteen ESBL positive ST131 strains selected from a diverse (n=184) ST131 bacteremia cohort had detectable ertapenem (ETP) mutational frequencies with a statistically positive correlation between initial ESBL gene copy number and mutation frequency (r = 0.87, P<1e-5). WGS analysis of mutants showed initial response to ETP exposure resulted in significant increases in ESBL gene copy numbers or mutations in outer membrane porin (Omp) encoding genes in the absence of ESBL gene amplification with subclade specific adaptations. In both experimental evolutionary platforms, MB1860 responded to initial ETP exposure by increasing blaCTX-M-15 copy numbers via modular, insertion sequence 26 (IS26) mediated pseudocompound transposons (PCTns). Transposase activity driven by PCTn upregulation was a conserved expression signal in both experimental evolutionary platforms. Stable mutations in Omp encoding genes were detected only after prolonged increasing carbapenem exposure consistent with clinical observations. Conclusions: ESBL gene amplification is a conserved response to initial carbapenem exposure, especially within the high-risk ST131 C2 subclade. Targeting such amplification could assist with mitigating carbapenem resistance development.
2024-08-04 | GSE273456 | GEO