Project description:The objective of this study was to evaluate the efficacy of nicotinamide in a N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced urinary bladder cancer model in mice, and to identify through gene expression profiling the molecular signatures of cancer prevention by nicotinamide. We used 20 mice for microarray experiments: five mice with normal bladders (group I), five with nicotinamide-treated bladders (group II), five with BBN-induced mouse bladder tumors (group III), and five with non-tumorigenic bladders treated with BBN and nicotinamide (group IV). Keywords: Gene expression, Mouse bladder cancer, Cancer prevention
Project description:The objective of this study was to evaluate the efficacy of nicotinamide in a N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced urinary bladder cancer model in mice, and to identify through gene expression profiling the molecular signatures of cancer prevention by nicotinamide. We used 20 mice for microarray experiments: five mice with normal bladders (group I), five with nicotinamide-treated bladders (group II), five with BBN-induced mouse bladder tumors (group III), and five with non-tumorigenic bladders treated with BBN and nicotinamide (group IV). Keywords: Gene expression, Mouse bladder cancer, Cancer prevention Total RNA was isolated using TRIzol reagent (Life Technologies, NY), according to the manufacturer's protocol. The quality and integrity of the RNA were confirmed by agarose gel electrophoresis and ethidium bromide staining, followed by visual examination under ultraviolet light. Five-hundred nanograms of total RNA were used for labeling hybridization according to the manufacturerM-bM-^@M-^Ys protocols (Illumina Mouse-6 BeadChips, version 1.0). Arrays were scanned with an Illumina Bead Array Reader confocal scanner (BeadStation 500GXDW; Illumina, Inc., San Diego, CA) according to the manufacturer's instructions. After scanning, the microarray data were normalized using quantile normalization. Measured gene expression values were log2 transformed and median-centered across genes and samples.
Project description:<p>Exposure to environmental pollutants and human microbiome composition are important predisposition factors for tumour development. Similar to drug molecules, pollutants are typically metabolised in the body, which can change their carcinogenic potential and impact tissue distribution through altered toxicokinetics. Although recent studies demonstrated that human-associated microbes can chemically convert a wide range of xenobiotics and influence the profile and tissue exposure of resulting metabolites, the effect of microbial biotransformation on chemical-induced tumour development remains unclear. Here we show that the depletion of the gut microbiota dramatically reduces the development and severity of nitrosamine-induced urinary bladder cancer in mice, which affects the toxicokinetics of nitrosamines. We causally linked this carcinogen biotransformation to specific gut bacterial isolates in vitro and in vivo using individualized bacterial culture collections and gnotobiotic mouse models, respectively. We tested gut communities from different human donors to demonstrate that microbial carcinogen metabolism varies between individuals and we showed that this metabolic activity applies to structurally related nitrosamine-carcinogens. Altogether, these results suggest gut microbiota carcinogen metabolism as a contributing factor for chemical-induced carcinogenesis, which could open avenues to target the microbiome for improved predisposition risk assessment and prevention of cancer.</p>
Project description:PURPOSE: Despite over 70,000 new cases of bladder cancer in the United States annually, patients with advanced disease have a poor prognosis due to limited treatment modalities. We evaluate the role of Aurora A, identified as an upregulated candidate molecule in bladder cancer, in regulating bladder tumor growth. EXPERIMENTAL DESIGN: Gene expression in human bladder cancer samples was evaluated using RNA microarray and reverse-transcriptase PCR. The specific Aurora kinase A inhibitor MLN8237 (Millennium) was used to determine effects on bladder cancer cell growth using in vitro and in vivo models using malignant T24 and UM-UC-3 and papilloma-derived RT4 bladder cells. RESULTS: Urothelial carcinoma upregulates a set of 13 mitotic spindle associated transcripts, as compared to normal urothelium, including MAD2L1 (7.6-fold), BUB1B (8.8-fold), Aurora kinases A (5.6-fold) and Aurora kinase B (6.2-fold). Application of MLN8237 (10nM-1µM) to the human bladder tumor cell lines T24 and UM-UC-3 induced dose-dependent G2 cell cycle arrest, aneuploidy, mitotic spindle abnormalities, and apoptosis. MLN8237 arrested tumor growth when administered orally over 4 weeks in a mouse bladder cancer xenograft model (p<0.05). Finally, in vitro combination of MLN8237 with either paclitaxel or gemcitabine produced schedule-dependent synergistic antiproliferative effects in T24 cells when administered sequentially. CONCLUSIONS: Mitotic spindle checkpoint dysfunction is a common characteristic of human urothelial carcinoma, and can be exploited with pharmacologic Aurora A inhibition. Future studies that explore the mechanisms of spindle checkpoint failure in bladder cancer and evaluate the therapeutic role of Aurora kinases for bladder cancer patients would be of value. Tissue samples with urothelial cell carcinoma from bladder as well as normal references were collected and the gene expression profiles were compared. No technical replicates.
Project description:MicroRNAs play an important role in the pathogenesis of different types of cancer including bladder cancer. MiR-21 has been identified to have an oncogenic function, while its inhibition suppresses tumor growth. Here, we followed an integrated bioinformatics and molecular analyses to identify the molecular mediators of miR-21 oncogenic function in bladder cancer and evaluate the therapeutic potential of a chemically-modified miR-21 inhibitor in bladder xenografts. MiR-21 expression was found to up-regulated in human bladder cancers relative to normal tissues and miR-21 inhibition suppressed bladder cancer cell properties, including growth, invasiveness and anchorage-independence. Intravenous administration of an antisense oligonucleotide against miR-21 harboring locked-nucleic-acid (LNA-miR-21) modifications blocked bladder tumor growth in vivo. Transcriptomic analysis of 28 bladder cancer cell lines revealed a gene signature that negatively correlated with miR-21 expression levels. Bioinformatics and 3’UTR luciferase assay analyses revealed a direct interaction between miR-21 the 3’UTR of PPP2R2A gene. Inhibition of PPP2R2A expression induced bladder cancer growth, suggesting its tumor suppressor function. Gene profiling followed by IPA network analysis revealed that PPP2R2A regulates the ERK1/2 molecular network. Taken together, PPP2R2A is the functional mediator of miR-21 oncogenic activity on bladder cancer and LNA-miR-21 could have a therapeutic potential in bladder cancer patients.
Project description:PURPOSE: Despite over 70,000 new cases of bladder cancer in the United States annually, patients with advanced disease have a poor prognosis due to limited treatment modalities. We evaluate the role of Aurora A, identified as an upregulated candidate molecule in bladder cancer, in regulating bladder tumor growth. EXPERIMENTAL DESIGN: Gene expression in human bladder cancer samples was evaluated using RNA microarray and reverse-transcriptase PCR. The specific Aurora kinase A inhibitor MLN8237 (Millennium) was used to determine effects on bladder cancer cell growth using in vitro and in vivo models using malignant T24 and UM-UC-3 and papilloma-derived RT4 bladder cells. RESULTS: Urothelial carcinoma upregulates a set of 13 mitotic spindle associated transcripts, as compared to normal urothelium, including MAD2L1 (7.6-fold), BUB1B (8.8-fold), Aurora kinases A (5.6-fold) and Aurora kinase B (6.2-fold). Application of MLN8237 (10nM-1µM) to the human bladder tumor cell lines T24 and UM-UC-3 induced dose-dependent G2 cell cycle arrest, aneuploidy, mitotic spindle abnormalities, and apoptosis. MLN8237 arrested tumor growth when administered orally over 4 weeks in a mouse bladder cancer xenograft model (p<0.05). Finally, in vitro combination of MLN8237 with either paclitaxel or gemcitabine produced schedule-dependent synergistic antiproliferative effects in T24 cells when administered sequentially. CONCLUSIONS: Mitotic spindle checkpoint dysfunction is a common characteristic of human urothelial carcinoma, and can be exploited with pharmacologic Aurora A inhibition. Future studies that explore the mechanisms of spindle checkpoint failure in bladder cancer and evaluate the therapeutic role of Aurora kinases for bladder cancer patients would be of value.
Project description:Both FGF and WNT pathways play important roles in embryonic development, stem cell self-renewal and are frequently deregulated in breast cancer. To study the cooperation between FGF and WNT signaling, we have generated a mouse model, MMTV-WNT1/MMTV-iFGFR1 (WNT/iR1), in which we could chemically overactivate iFGFR1 in a ligand-independent manner.