Project description:Aberrant transcription of the HSATII pericentromeric satellite repeat is present in a wide variety of epithelial cancers. We observed that HSATII expression is induced in colon cancer cells cultured as xenografts or under non-adherent conditions in vitro, but it is rapidly lost in standard 2D cultures. Unexpectedly, physiological induction of endogenous HSATII RNA, as well as introduction of synthetic HSATII transcripts, generate complementary DNA intermediates in the form of DNA:RNA hybrids. Single molecule sequencing of tumor xenografts shows that HSATII RNA-derived DNA (rdDNA) molecules are stably reincorporated within pericentromeric loci, leading to progressive expansion of these regions We analyzed the dynamics of HSATII RNA and DNA level changes using single molecule sequencing (Helicos/SeqLL) in SW620 colon cancer cells transitioned from 2D in vitro culture conditions to growth as mouse xenografts and vice versa.
Project description:This experiment was to look at the change in gene expression in oral epithelial cells infected for 6 h or 24 h with Candida albicans. The intent was to determine what changes were driven by early and late recognition of wild-type. invasive Candida albicans
Project description:The VEGF targeted antiangiogenic drug bevacizumab has shown varying results in clinical trials of breast cancer. Identifying robust biomarkers for selecting patients that may benefit from bevacizumab treatment and for monitoring of response is important for the future use of this drug. Two established xenograft models representing basal-like and luminal-like breast cancer were used to study bevacizumab treatment response on the metabolic and gene expression levels. Mice given no treatment or treated with bevacizumab, doxorubicin or the combination of these two drugs were sacrificed at day 3 or 10. High resolution magic angle spinning magnetic resonance spectroscopy (HR MAS MRS) and gene expression microarray analysis was performed on all tumor samples. Combination treatment with bevacizumab had the strongest growth inhibiting effect in the basal-like tumors, and this was reflected in a significant response in the metabolomic and transcriptomic profiles. In the luminal-like xenografts, addition of bevacizumab did not improve the effect of doxorubicin. On the global transcriptomic level, the largest changes in gene expression were observed for the most efficient treatment in each of the two xenograft models. The metabolite glycerophosphocholine (GPC) showed opposite response in the treated xenografts compared with untreated controls: lower in basal-like tumors and higher in luminal-like tumors. Lower levels of creatine, taurine and glycine were observed in the basal-like xenografts given bevacizumab as monotherapy compared with untreated xenografts. Comparing combination therapy with doxorubicin monotherapy in basal-like xenografts, 14 genes showed significant differential expression, including higher expression of very low density lipoprotein receptor (VLDLR), and lower expression of hemoglobin, theta 1 (HBQ1). Using published gene expression signatures, bevacizumab treated tumors were associated with a more hypoxic phenotype, while no evidence was found for associations between bevacizumab treatment and vascular invasion or increasing tumor grade. This study underlines the importance of characterizing biological differences between subtypes of breast cancer to identify personalized biomarkers for selecting patients for bevacizumab treatment and evaluating response to therapy. 60 samples are analyzed. For each of the two xenograft models, tumors were collected from animals that were untreated or treated with bevacizumab (5 mg/kg), doxorubicin (8 mg/kg) or a combination of the two therapies (n = 6 tumors for each group). Bevacizumab treatment was repeated at day 4 and day 7. Animals were sacrificed and tissue harvested at either day 3 or 10 after treatment, in triplicates within each treatment group. This resulted in 24 tumor samples from each of the models. In addition, untreated and bevacizumab treated luminal-like xenografts not fed with estradiol were included for comparison (n = 12). Note that the untreated controls are overlapping with the samples in the GEO series with accession number: GSE25915.
Project description:RNA-Seq and a species-specific mapping strategy were used to profile the human and mouse transcriptomes of tumour samples taken from 79 PDX models representing multiple cancer types (19 x breast, 37 x lung, 8 x colorectal, 7 x ovarian, 3 x endometrial, 2 x pancreatic, 2 x ampullary, 1 x leukaemia).
Project description:Interactions between the gene products encoded by the mitochondrial and nuclear genomes play critical roles in normal eukaryotic cellular function. Here, we characterized the metabolic and transcriptional properties of A549 lung cancer cells and their isogenic mitochondrial DNA (mtDNA)-depleted rho zero counterparts grown in cell culture and as tumor xenografts in immune-deficient mice. A manuscript summarizing our conclusions is under review. Experiment Overall Design: A549 rho zero and their parental A549 cells were grown in culture and as xenografts in nude mice. All experiments conducted in culture were performed in triplicate (6 experiments total) and all experiments conducted in xenografts were performed in quadruplicate (8 experiments total). A manuscript summarizing our experimental design is under review.
Project description:Gliomas are mostly incurable secondary to their diffuse infiltrative nature. Thus, specific therapeutic targeting of invasive glioma cells is an attractive concept. As cells exit the tumor mass and infiltrate brain parenchyma, they closely interact with a changing micro-environmental landscape that sustains tumor cell invasion. In this study, we used a unique microarray profiling approach on a human glioma stem cell (GSC) xenograft model to explore gene expression changes in situ in invading glioma cells compared to tumor core, as well as changes in host cells residing within the infiltrated microenvironment relative to the unaffected cortex. Replicate sets of mice (n=4) were inoculated with either of two different GSC's derived from from human glioma, and each mouse had samples taken from the tumor mass, the infiltrating area and the mouse brain parenchyma, resulting in 3 samples per animal. The tumor mass and infiltrating samples were hybridized on human U133Plus2 Arrays, whereas the infiltrating samples and mouse brain parenchyma were hybridized on mouse
Project description:Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy. On the basis of its histopathology and molecular-genomic changes ovarian cancer has been divided into subtypes, each with distinct biology and outcome. The aim of this study was to develop a panel of patient-derived EOC-xenografts that recapitulate the molecular and biological heterogeneity of human ovarian cancer. Thirty-four EOC-xenografts were successfully established, either subcutaneously or intraperitoneally, in nude mice. The xenografts were histologically similar to the corresponding patient tumor and comprised all the major ovarian cancer subtypes. After orthotopic transplantation in the bursa of the mouse ovary, they disseminate into the organs of the peritoneal cavity and produce ascites, typical of ovarian cancer. Gene expression analysis and mutation status indicated a high degree of similarity with the original patient and discriminate different subsets of xenografts. They were very responsive, responsive and resistant to cisplatin, resembling the clinical situation in ovarian cancer. This panel of patient-derived EOC-xenografts that recapitulate the recently type I and type II classification serves to study the biology of ovarian cancer, identify tumor-specific molecular markers and develop novel treatment modalities. EOC-xenografts collected from subcutis, abdominal masses and ascitic fluid of mice engrafted with tumors at different passages (from 1 to 6) and from patient specimens, underwent one-color microarray-based gene expression profiling. To assess the amount of human- and mouse-derived cells in the xenograft tumors, total RNA was evaluated by species specific qPCR assays for beta actin. Only samples with a human RNA content > 75% were analyzed. Nine patient specimens and 62 xenograft samples (representing 29 EOC-xenograft models) underwent gene expression analysis with SurePrint G3 Human GE V2 8x60K microarrays.
Project description:The traditional method for studying cancer in vitro is to grow immortalized cancer cells in two-dimensional (2D) monolayers on plastic. However, many cellular features are impaired in these unnatural conditions and big alterations in gene expression in comparison to tumors have been reported. Three-dimensional (3D) cell culture models have become increasingly popular and are suggested to be better models than 2D monolayers due to improved cell-to-cell contacts and structures that resemble in vivo architecture. The aim of this study was to compare gene expression patterns of MCF7 breast cancer cells when grown as xenografts, in 2D, in polyHEMA coated anchorage independent 3D models and in Matrigel on-top 3D cell culture models. Surprisingly small variations in gene expression patterns were observed between the models indicating that 3D and xenograft are not always that different from 2D cell cultures. Gene expression analysis of MCF7 breast cancer cells cultured as xenografts for 43 days, in two dimensional cultures for seven days (2D7d), in polyHEMA three dimensional cell culture models for four and seven days (PH7d and PH7d), and in Matrigel three dimensional cultures for four and seven days (MG4d and MG7d). Two biological replicates was included for each sample.
Project description:The traditional method for studying cancer in vitro is to grow immortalized cancer cells in two-dimensional (2D) monolayers on plastic. However, many cellular features are impaired in these unnatural conditions and big alterations in gene expression in comparison to tumors have been reported. Three-dimensional (3D) cell culture models have become increasingly popular and are suggested to be better models than 2D monolayers due to improved cell-to-cell contacts and structures that resemble in vivo architecture. The aim of this study was to develop a simple high-throughput 3D drug screening method and to compare drug responses in JIMT1 breast cancer cells when grown in 2D, in polyHEMA coated anchorage independent 3D models and in Matrigel on-top 3D cell culture models. We screened 102 compounds with multiple concentrations and biological replicates for their effects on cell proliferation. The cells were either treated immediately upon plating or they were allowed to grow in 3D for four days prior to the drug treatment. Big variations in drug responses were observed between the models indicating that comparisons of culture model influenced drug sensitivities cannot be made based on effects of a single drug. However, we show with the 63 most prominent drugs that, in general, JIMT1 cells grown on Matrigel were significantly more sensitive to drugs than cells grown in 2D cultures, while responses of cells grown in polyHEMA resembled those of 2D. Furthermore, comparison of gene expression profiles of the cell culture models to xenograft tumors indicated that cells cultured in Matrigel and as xenografts most closely resembled each other. In this study we also suggest that 3D cultures can provide a platform for systematic experimentation of larger compound collections in a high-throughput mode and be used as alternatives for traditional 2D screens towards better comparability to in vivo state. Gene expression analysis of JIMT1 breast cancer cells cultured as xenografts for 43 days, in two dimensional cultures for seven days (2D7d), in polyHEMA three dimensional cell culture models for four and seven days (PH7d and PH7d), and in Matrigel three dimensional cultures for four and seven days (MG4d and MG7d). Two biological replicates was included for each sample.