Project description:We recently identified the nonreceptor tyrosine kinase syk as a tumor suppressor in pancreatic ductal adenocarcinoma cells. Reintroduction of syk into Panc1 cells promoted a more differentiated phenotype and retarded invasion and tumorigenic growth. Gene array analysis identified over 2,000 transcripts differentially expressed at FDR<0.01. Among these were members of the MMP2 axis, which were subsequently shown to regulate Panc1 invasion. Experiment Overall Design: Affymetrix global gene arrays were used to analyse differences in gene expression patterns in Panc1 cells stably reexpressing syk, or vector-only mock controls. RNA was harvested from cells grown under identical conditions in standard culture.
Project description:We recently identified the nonreceptor tyrosine kinase syk as a tumor suppressor in pancreatic ductal adenocarcinoma cells. Reintroduction of syk into Panc1 cells promoted a more differentiated phenotype and retarded invasion and tumorigenic growth. Gene array analysis identified over 2,000 transcripts differentially expressed at FDR<0.01. Among these were members of the MMP2 axis, which were subsequently shown to regulate Panc1 invasion. Keywords: Genetic manipulation (stable transgene expression)
Project description:Parental and resistant CCRF-CEM cells were treated for 48 hr with a sublethal dose of FK866 (5 nM) or DMSO (Mock, control treatment). This comparison enables the identification of the specific transcriptional alterations induced by FK866 in parental or resistant cells. Keywords: transcriptome profiling, FK866, drug resistance
Project description:We sought to examine changes in gene expression of PANC1 cells with acquired resistance to oxaliplatin chemotherapy. Cultures of PANC1 cells, an established pancreatic cancer cell line, were exposed to oxaliplatin chemotherapy over multiple passages and acquired a stable drug-resistant phenotype labeled as PANC1OR. Previously reported immunofluorescence and western blots indicate that PANC1OR exhibit increased EMT (increased cytoskeletal vimentin, decreased E-cadherin and fibroblast-like morphology). Here we sought to examine more broadly the differential expression of genes associated with acquired drug resistance in these cells.
Project description:Comparison of the whole genome gene expression level of an enrofloxacin and tetracycline resistant E. coli strain with the wildtype it was derived from. The process of drug adaptation of E. coli MG1655 wildtype cells is further descibed in van der Horst, M, J.M. Schuurmans, M. C. Smid, B. B. Koenders, and B. H. ter Kuile (2011) in Microb. Drug Resist. 17:141-147. Resistance to amoxicillin was induced in E. coli by growth in the presence of stepwise increasing antibiotic concentrations. To investigate consequences of the aquisition of amoxicillin resistance the transcriptomic profile of sensitive and resistant cells was compared in the absence and presence of sub-inhibitory (0.25xMIC) amoxicillin concentrations was compared. Total RNA of 3 biological replicates of E. coli MG1655 wildtype cells and drug resistant cells cultured with (0.25xMIC) or without the drug was hybridized on a 12x135k custom designed microarraychip against one common reference.
Project description:Comparison of the whole genome gene expression level of an enrofloxacin and tetracycline resistant E. coli strain with the wildtype it was derived from. The process of drug adaptation of E. coli MG1655 wildtype cells is further descibed in van der Horst, M, J.M. Schuurmans, M. C. Smid, B. B. Koenders, and B. H. ter Kuile (2011) in Microb. Drug Resist. 17:141-147. Resistance to amoxicillin was induced in E. coli by growth in the presence of stepwise increasing antibiotic concentrations. To investigate consequences of the aquisition of amoxicillin resistance the transcriptomic profile of sensitive and resistant cells was compared in the absence and presence of sub-inhibitory (0.25xMIC) amoxicillin concentrations was compared.
Project description:Targeted therapy studies with small molecules against kinases, such as spleen tyrosine kinase (SYK), are underway in patients with acute myeloid leukemia (AML) and show promising initial results. Identifying the potential mechanism of resistance and finding new drug combinations to overcome them, however, is essential for the long-term success of these targeted agents. Here, we conducted a genome-scale ORF resistance screen and identified activation of the RAS/MAPK/ERK signaling pathway as one major mechanism of resistance to SYK inhibition. This finding was validated in AML cell lines with innate and acquired resistance to a SYK inhibitor and in AML samples from patients who developed resistance to SYK inhibition. In order to circumvent this resistance, we demonstrate the synergistic activity of a MEK Inhibitor in combination with a SYK inhibitor in RAS mutated cells, as well as in entospletinib-resistant AML cells.
Project description:Pancreatic ductal adenocarcinoma (PDAC) often presents at late clinical stages, and most patients are managed solely through palliative chemotherapy. With no approved treatment modalities for patients who progress on broad-spectrum chemotherapy, we set to identify druggable targets to prevent or reverse resistance to the first line anti-neoplastic Gemcitabine. In our first experiment, we used the well-established Panc1 cell line as an in vitro model of PDAC. Panc1 cells were incubated with a tolerable dose of Gemcitabine in vitro, and examined alterations in gene expression via single cell RNA sequencing. In our subsequent studies, we incubated Panc1 cells with increasing doses of Gemcitabine for several passages, until viable in approximately 10x the known IC50 value. These cells were designated Panc1-GR. Based on our observations in the prior experiment, Panc1-GR cells were compared to those treated with wither the Calmodulin inhibitor W-7, Calcium chelator BAPTA-AM, or the calcium channel blocker Amlodipine. Through these efforts, we hope to better understand the mechanisms of Gemcitabine resistance in PDAC, as well as introduce new therapeutic strategies to reverse drug resistant phenotypes in the clinic.
Project description:Comparison of the whole genome gene expression level of an amoxicillin resistant E. coli strain with the wildtype it was derived from. The process of amoxicillin adaptation of E. coli MG1655 wildtype cells is further descibed in van der Horst, M, J.M. Schuurmans, M. C. Smid, B. B. Koenders, and B. H. ter Kuile (2011) in Microb. Drug Resist. 17:141-147. Resistance to amoxicillin was induced in E. coli by growth in the presence of stepwise increasing antibiotic concentrations. To investigate consequences of the aquisition of amoxicillin resistance the transcriptomic profile of sensitive and resistant cells was compared in the absence and presence of sub-inhibitory (0.25xMIC) amoxicillin concentrations was compared.