Transcription profiling by array of human pancreatic cancers resistant to EGFR inhibition
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Jimeno A
PROVIDER: S-ECPF-GEOD-9599 | biostudies-other | 2008 Apr
REPOSITORIES: biostudies-other
Similar Datasets
Project description:We used microarrays to identify the expression differences of FKBP5 gene between the pancreatic tumor and normal samples. On average normal samples had more FKBP5 expression compared to tumor samples .Experiment Overall Design: This experiment consists of 36 tumor samples and 16 normal samples; a total of 52 samples. 16 samples consist of both tumor and normal expression data, whereas 20 samples consist of only tumor data.
| S-ECPF-GEOD-16515 | biostudies-other
Project description:We used microarrays to analyze the global expression patterns for 22 commercially available pancreatic cancer cell lines 22 pancreatic cancer cell lines were grown to 80% confluence in DMEM/FBS/PenStrep media and then harvested for total RNA
| S-ECPF-GEOD-21654 | biostudies-other
Project description:Purpose: A number of microarray studies have reported distinct molecular profiles of breast cancers (BC): basal-like, ErbB2-like and two to three luminal-like subtypes. These were associated with different clinical outcomes. However, although the basal and the ErbB2 subtypes are repeatedly recognized, identification of estrogen receptor (ER)-positive subtypes has been inconsistent. Refinement of their molecular definition is therefore needed. Materials and methods: We have previously reported a gene-expression grade index (GGI) which defines histological grade based on gene expression profiles. Using this algorithm, we assigned ER-positive BC to either high or low genomic grade subgroups and compared these to previously reported ER-positive molecular classifications. As further validation, we classified 666 ER-positive samples into subtypes and assessed their clinical outcome. Results: Two ER-positive molecular subgroups (high and low genomic grade) could be defined using the GGI. Despite tracking a single biological pathway, these were highly comparable to the previously described luminal A and B classification and significantly correlated to the risk groups produced using the 21-gene recurrence score. The two subtypes were associated with statistically distinct clinical outcome in both systemically untreated and tamoxifen-treated populations. Conclusions: The use of genomic grade can identify two clinically distinct ER-positive molecular subtypes in a simple and highly reproducible manner across multiple datasets. This study emphasizes the important role of proliferation-related genes in predicting prognosis in ER-positive BC. Experiment Overall Design: dataset of microarray experiments from primary breast tumors used to assess the reationship between GGI, molecular subtypes, and tamoxifen resistance. Experiment Overall Design: No replicate, no reference sample.
| S-ECPF-GEOD-6532 | biostudies-other
Project description:Four vehicle-treated and four HhAntag-treated pancreatic xenograft tumors were profiled for gene expression changes using Affymetrix U133 Plus 2.0 and Affymetrix Mouse Genome 430 2.0 arrays. Keywords: comparative gene expression, hedgehog, hh A primary human pancreatic tumor xenograft (1051178-A) was established by direct implantation of surgical material into female CD1 nu/nu mice of 6-8 weeks of age. Tumors were serially passaged into larger cohorts of mice for efficacy testing and subsequently distributed into tumor volume-matched cohorts upon tumors reaching between 200 to 350 mm3. HhAntag was resuspended in 0.5% methyl-cellulose, 0.2% Tween-80 (MCT) and administered orally twice daily at 75 mg/kg from a 10 mg/ml suspension. MCT alone served as vehicle control. Tumor xenografts (4/group) were excised following 21 days of dosing and RNA was extracted. Preparation of complementary RNA, Human Genome U133 Plus 2.0 array and Mouse Genome 430 2.0 array hybridizations, and subsequent data analysis were carried out using Affymetrix protocols, with signal intensities being determined by the MAS5.0 algorithm.
| S-ECPF-GEOD-11981 | biostudies-other
Project description:Signatures of Oncogenic Pathway Deregulation in Human Cancers. The ability to define cancer subtypes, recurrence of disease, and response to specific therapies using DNA microarray-based gene expression signatures has been demonstrated in multiple studies. Such data is also of substantial importance to the analysis of cellular signaling pathways central to the oncogenic process. With this focus, we have developed a series of gene expression signatures that reliably reflect the activation status of several oncogenic pathways. When evaluated in several large collections of human cancers, these gene expression signatures identify patterns of pathway deregulation in tumors, and clinically relevant associations with disease outcomes. Combining signature-based predictions across several pathways identifies coordinated patterns of pathway deregulation that distinguish between specific cancers and tumor sub-types. Clustering tumors based on pathway signatures further defines prognosis in respective patient subsets, demonstrating that patterns of oncogenic pathway deregulation underlie the development of the oncogenic phenotype and reflect the biology and outcome of specific cancers. Furthermore, predictions of pathway deregulation in cancer cell lines are shown to coincide with sensitivity to therapeutic agents that target components of the pathway, underscoring the potential for such pathway prediction to guide the use of targeted therapeutics. Experiment Overall Design: RNA was extracted from frozen tissue of primary breast tumors for gene array analysis.
| S-ECPF-GEOD-3143 | biostudies-other
Project description:Current prognostic factors are poor at identifying patients at risk of disease recurrence following surgery for stage II colon cancer. Here we describe a DNA microarray based prognostic assay using clinically relevant formalin fixed paraffin embedded (FFPE) samples.
| S-ECPF-MTAB-863 | biostudies-other
Project description:Understanding the complex molecular mechanisms underlying resistance to endocrine therapy is a major challenge in the treatment of estrogen receptor-positive (ER+) breast cancers. We have previously demonstrated that glial cell line-derived neurotrophic factor (GDNF) signaling via the receptor tyrosine kinase RET promotes estrogen independent activation of ER. Here we have addressed the relevance of GDNF-RET signaling in response to aromatase inhibitor treatment and explored the efficacy of using RET inhibitors in breast cancer models of aromatase inhibitor response and resistance. A GDNF-response gene set, identified from gene expression profiling, was demonstrated to be an independent prognostic marker of poor patient outcome and, importantly, to be predictive of poor response to aromatase inhibitor treatment and development of resistance. The relevance of these findings was validated first by demonstrating an association of RET protein expression in an independent cohort of aromatase inhibitor resistant patient samples. Second, in in vitro models, GDNF-mediated RET signaling was demonstrated to enhance the survival of aromatase inhibitor resistant cells and to increase resistance in aromatase inhibitor sensitive cells. These effects could be reversed by targeting GDNF/RET signaling with the RET selective inhibitor NVP-BBT594 thus identifying GDNF-RET signaling as a potential therapeutic target, particularly in breast cancers resistant to aromatase inhibitors.MCF7 cells were E2-deprived by culturing in phenol red-free RPMI 1640 supplemented with 10% DCC for 3 days and then serum-starved overnight in the presence or absence of fulvestrant (ICI182,780) (100 nM). The following day, cells were treated with GDNF (20 ng/ml) for 0, 4, 8, 24 and 48 hours in the presence or absence of fulvestrant (ICI182,780) (100 nM).
| S-ECPF-MEXP-3662 | biostudies-other
Project description:We used microarrays to profile 30 human primary breast tumors and determine global gene expression patterns and molecular subtypes Experiment Overall Design: RNA from SNAP frozen human tumor biopsies was analyzed on Affymetrix mircroarrays
| S-ECPF-GEOD-12763 | biostudies-other
Project description:Breast cancer outcome is highly variable. Whether inadvertent exposure to environmental xenobiotics evokes a biological response promoting cancer aggressiveness and a higher probability of tumor recurrence remains unknown. To determine specific molecular alterations, which arise in high-risk breast tissue in the presence of the ubiquitous xenoestrogen, bisphenol A (BPA), we employed non-malignant random periareolar fine needle aspirates (RPFNA) in a novel functional assay. Early events induced by BPA in epithelial-stromal cocultures derived from the contralateral tissue of breast cancer patients included gene expression patterns, which facilitate apoptosis evasion, endurance of microenvironmental stress, and cell cycle deregulation without a detectable increase in cell number. This BPA response profile was significantly associated with breast tumors characterized by high histologic grade (p<0.001), and large tumor size (p=0.002), resulting in decreased recurrence-free patient survival (p<0.001). Our assays demonstrate a biological 'fingerprint' of probable prior exposure to endocrine disrupting agents, and suggest a scenario in which their presence in the microenvironmental milieu of high-risk breast tissue could play a deterministic role in establishing and maintaining tumor aggressiveness and poor patient outcome. Experiment Overall Design: The study included twelve patients undergoing breast biopsy or surgery for breast cancer. Random periareolar fine needle aspirates (RPFNA) were collected from the unaffected contralateral breast of these patients. Control and hormone treated RPFNA cell cultures were analyzed using Affymetrix GeneChip(TM) arrays
| S-ECPF-GEOD-10270 | biostudies-other
Project description:The aim of our study was to assess the impact of simvastatin on the amount of cytosolic lipid droplets (LDs), which are implicated in many biological processes including proliferation, inflammation, carcinogenesis, apoptosis, necrosis or growth arrest. Human pancreatic cancer cells MiaPaCa-2 were treated with simvastatin (6 and 12 _M) for 24 hours. Changes in expression of genes related to lipid metabolism in the simvastatin-treated cells were examined by DNA microarray analysis. The treatment of the cells with simvastatin increased their intracellular content of LDs, partially due to the uptake of cholesterol and triacylglycerides from medium; but in particular, due to enhanced synthesis of triacylglycerides as proved by detection of significant overexpression of genes related to de novo synthesis of triacylglycerides and phospholipids. Further, simvastatin markedly influenced expression of genes directly affecting cell proliferation and signaling.
| S-ECPF-MTAB-1501 | biostudies-other