Project description:Non Small Cell Lung Cancer (NSCLC) causes the premature death of over 1 million people worldwide each year, but remains inadequately understood at the molecular level. To provide new insights for NSCLC treatment we performed a molecular characterisation of wild type and platinum drugs resistance in A549 cells. Transcriptome profiling revealed contrasting patterns of gene expression in sensitive and resistant cells and identified genes whose expression was highly correlated with the platinum drugs. Our results revealed a gene set of 15 transcripts whose expression was highly correlated with platinum-resistance in NSCLC A549 cell lines.
Project description:No reliable predictors of susceptibility to gemcitabine chemotherapy exist in pancreatic ductal adenocarcinoma. MicroRNAs (miR) are epigenetic gene regulators with tumorsuppressive or oncogenic roles in various carcinomas. This study assesses chemoresistant PDAC for its specific miR expression pattern. Gemcitabine-resistant variants of two mutant p53 human pancreatic adenocarcinoma cell lines were established. MicroRNA screening was investigated by microarray. Gemcitabine-resistant PANC-1 (PANC-1-GR) and MIA-PaCa-2 (MIA-PaCa-2-GR) cell clones were produced by exposing the parental cells to repeated pulsatile gemcitabine treatment over 3 days with constant sublethal concentrations followed by recovery-periods with agent-free medium until the cells recovered exponentially. Parental PANC-1 cells were treated with 0.4µM gemcitabine cycles for approximately 9 months. Parental MIA-PaCa-2 cells were exposed to 0.06µM gemcitabine cycles for approximately 12 months. Affymetrix GeneChip miRNA microarrays (Affymetrix UK Ltd., High Wycombe, UK) were performed in parental and chemoresistant PANC-1 and MIA-PaCa-2 cells after 29 chemotherapy cycles using the manufacturers´ protocols. The samples were prepared from 1µg of total-RNA in accordance with the Affymetrix FlashTag Biotin HSR RNA Labeling Kit. The targets were hybridized overnight to Affymetrix GeneChip miRNA arrays. Following hybridization, the arrays were washed and stained using the Affymetrix GeneChip Fluidics Station 450 and scanned using the Affymetrix GeneChip Scanner 3000 7G. Microarray data quality was checked as recommended by the manufacturer and by the quality metrics in the Partek Genomics Suite software (Partek Inc., St. Louis, MO).
Project description:No reliable predictors of susceptibility to gemcitabine chemotherapy exist in pancreatic ductal adenocarcinoma. MicroRNAs (miR) are epigenetic gene regulators with tumorsuppressive or oncogenic roles in various carcinomas. This study assesses chemoresistant PDAC for its specific miR expression pattern. Gemcitabine-resistant variants of PANC-1, a mutant p53 human pancreatic adenocarcinoma cell line, were established. MicroRNA screening was investigated by microarray. Gemcitabine-resistant PANC-1 (PANC-1-GR) cell clones were produced by exposing the parental cells to repeated pulsatile gemcitabine treatment over 3 days with constant sublethal concentrations followed by recovery-periods with agent-free medium until the cells recovered exponentially. Parental PANC-1 cells were treated with 0.4µM gemcitabine cycles for approximately 9 months. Affymetrix GeneChip miRNA microarrays (Affymetrix UK Ltd., High Wycombe, UK) were performed in parental and chemoresistant PANC-1 cells after 17 chemotherapy cycles using the manufacturers´ protocols. The samples were prepared from 1µg of total-RNA in accordance with the Affymetrix FlashTag Biotin HSR RNA Labeling Kit. The targets were hybridized overnight to Affymetrix GeneChip miRNA arrays. Following hybridization, the arrays were washed and stained using the Affymetrix GeneChip Fluidics Station 450 and scanned using the Affymetrix GeneChip Scanner 3000 7G. Microarray data quality was checked as recommended by the manufacturer and by the quality metrics in the Partek Genomics Suite software (Partek Inc., St. Louis, MO).
Project description:HCT116 parental, HCT116 5-FU resistant and HCT116 oxaliplatin resistant cells have been transiently treated with with their respective drug (5-FU or oxaliplatin) for 0, 6 12 or 24h in 3 independent experiments.
Project description:Drug resistance in breast cancer is the major obstacle to a successful outcome following chemotherapy treatment. While upregulation of multidrug resistance (MDR) genes is a key component of drug resistance in multiple cancers, the complexity and hierarchy of non-MDR driven drug resistance pathways are still largely unknown. The aim of this study was to identify pathways contributing to anthracycline resistance using isogenic drug resistant breast cancer cell lines. We generated isogenic MDA-MB-231, MCF7, SKBR3 and ZR-75-1 epirubicin-resistant breast cancer cell lines, which were cross-resistant to doxorubicin and SN-38; the SKBR3 cell line was also resistant to taxanes. Epirubicin-resistant cells were morphologically different from native cells, and had alterations in apoptosis and cell cycle profile. Using gene expression and small-molecule inhibitor analyses we identified deregulation of histone H2A and H2B genes in all four cell lines. These genes contribute to several biological pathways, which include cell cycle, chromosomal maintenance, epigenetics, RNA and mitochondrial transcription. Histone deacetylase and cell cycle/DNA damage small molecule inhibitors reversed resistance and were cytotoxic for all four epirubicin-resistant cell lines confirming that histone and cell cycle pathways are associated with epirubicin resistance. This study has established model systems for investigating drug resistance in all four breast cancer subtypes and revealed key pathways that contribute to anthracycline resistance. The global gene expression analysis included 4 parental (anthracycline sensitive) and 4 resistant breast cancer cell lines, in biological triplicates.
Project description:Chemotherapy resistance adversely impacts the treatment of some individuals with esophageal cancer. Identifying chemotherapy resistance might help tailor clinical treatments. In this study the impact of microRNAs on chemotherapy resistance in esophageal cancer was investigated. We used microarrays to detail the global programme of microRNA expression underlying chemotherapy resistance and identified distinct classes of up-regulated microRNAs in generated chemotherapy resistant cell lines. An in-vitro model of acquired chemotherapy resistance in esophageal adeno- (EAC) and squamous cell carcinoma (SCC) cells was used, and microRNA expression profiles for cisplatin or 5-fluorouracil (FU) resistant variants vs. chemotherapy sensitive controls were compared using microarray. These results were further validated using qRT-PCR techniques (not shown in this submission).
Project description:Understanding the mechanism of resistance in platinum-based regimens for the treatment of high-grade serous ovarian cancer (HGSOC) is important for identifying new therapeutic targets to improve the clinical outcome of ovarian cancer patients. Mass spectrometry-based proteomic strategy was applied to spheroidal cisplatin sensitive and resistant HGSOC generated cell lines in the absence and presence of cisplatin drug. A complete expressed HGSOC proteome and phosphoproteome was characterized in cisplatin sensitive and resistant HGSOC cell lines providing insight into the mechanism of resistance development. PCA analysis showed that phosphorylation of a few proteins provides better classification than the whole proteome of the cellular subtypes. Specifically, a distinctive phosphoproteomic signature between cisplatin sensitive and resistant cell lines in the absence of drug was observed. This same phosphoproteomic signature was observed in our cisplatin sensitive cell line in the absence and presence of drug, indicating a vital role for phosphorylation of proteins in resistance development to cisplatin. The most phosphorylated protein was sequestosome (p62/SQSTM1). Differential expressions of apoptosis by the prognostic factor ratio of Bcl-2/Bax and autophagy, known to be regulated by p62/SQSTM1, was validated in the proteome data and by western blot analysis. A significant increase in apoptosis in the presence of cisplatin was observed in only the sensitive cell line while autophagy revealed increased expression in the resistant relative to sensitive cell line. Furthermore, site specific phosphorylation on 20 modified residues of sequestosome was characterized. Elevated expression of phosphorylation of sequestosome in resistant HGSOC cell lines was validated with western blot analysis. Here, we propose phosphorylation of sequestosome to be a marker and key in cisplatin resistance development in HGOSC ovarian cancers by shuttling ubiquitinated proteins to the autophagy pathway and influencing down-regulation of apoptosis.
Project description:One of the main obstacles to therapeutic success in colorectal cancer (CRC) is the development of acquired resistance to treatment with drugs such as 5-fluorouracil (5-FU), the most commonly used drug in CRC patients. Whilst some mechanisms of resistance are well-known, it is clear from the stasis in therapy success rate, that much is still unknown. Here a proteomics approach is taken towards identification using 5-FU resistant sublines of human CRC cell lines generated in-house. Using a multiplexed stable isotope labelling with amino acids in cell culture (SILAC) proteomics strategy, the resistant cell lines, and equivalently passaged 5-FU-sensitive cell lines were compared to parent cell lines grown in Heavy medium using 2D liquid chromatography and Orbitrap Fusion™ Tribrid™ Mass Spectrometry analysis.