Project description:We investigated the effect of Cediranib in human mammary carcinoma cell lines Hs578T, MDA-MB-231 and T47D by cellular and molecular assays. The cellular assays determined the ability to inhibit cell growth (IC50) by MTS assay, cell migration and invasion. Furthermore, using a microRNA-array and qRT-PCR approach we assessed the comparative expression of microRNAs following Cediranib treatment
Project description:Total RNA was isolated from epithelial tissues of different grades and stages of human breast cancer samples using mirVana kit and RNA integrity number (RIN) was determined in Agilent Bioanalyzer (2100) to assess the suitability for microarray assays. Sixteen samples were individually analyzed using miRCURY™ LNA arrays version 11.0 (Exiqon, Denmark). The LNA array slides were scanned using Agilent G2565BA Microarray Scanner System (Agilent Technologies, Inc., USA) and image analysis was carried out using ImaGene 8.0 software (BioDiscovery, Inc., USA). The quantified signals were background corrected (Normexp with offset value 10 14 and normalized using global Lowess (Locally Weighted Scatterplot Smoothing) regression algorithm. Three condition experiment Grade 2, stage II vs its adjacent normals (AN) and Grade 3, stage III vs it AN, Grade 2 vs Grade 3, Grade 2, stage II 5 biological replicates, Grade 3 stage III 5 biological replicates, AN 3 biological replicates each
Project description:Comparisons among breast cancer metastases at different organs revealed distinct microenvironments as characterized by cytokine content. Such microenvironment distinction might be important to dictate how the cancer cells adapt to survival before they successfully colonize. Experiment Overall Design: 58 breast cancer metastases from different organs were profiled and compared by the expression level of over 400 cytokines. 29 samples were incuded in this series. 29 others as well as 7 in the present series were profiled on U133A platforms and included in series GSE14018.
Project description:Tumorigenic breast cancer cells characterized by CD44 expression and low or undetectable CD24 levels (CD44+/CD24-/low) may be resistant to chemotherapy and therefore responsible for cancer relapse. Paired breast cancer core biopsies before and after neoadjuvant chemotherapy or lapatinib were obtained and as single cell suspensions stained using antibodies against CD24, CD44, and lineage markers, and then analyzed by flow cytometry. Mammosphere (MS) formation in culture was compared before and after treatment. Global gene expression differences between cancer cells bearing CD44+/CD24-/low cells and all other sorted cells, and between cancer MS and the primary bulk invasive cancers were analyzed. We report that CD44+/CD24-/low tumorigenic breast cancer cells were intrinsically chemoresistant - chemotherapy led to increased CD44+/CD24-/low cells, increased self-renewal capacity on MS assays, and enhanced tumorigeneicity in immunocompromised SCID/Beige mice. Conversely, in patients with HER2 overexpressing tumors, the EGFR/HER2 tyrosine kinase inhibitor, lapatinib decreased CD44+/CD24-/low cells, with the majority of these patients after conventional therapy achieving pathologic complete response, a validated surrogate marker for long-term survival. Gene transcription pathways that underlie chemoresistant, MS-forming CD44+/CD24-/low cells involve genes belonging to stem cell self-renewal, Wnt signaling, and early development pathways. Experiment Overall Design: Cells from human breast tumors were grown as mammospheres (MS). Experiment Overall Design: Isolated single cell suspensions from primary breast cancers were plated onto non-adherent (polyhema-coated) plastic, counted with a hematocytometer, and 20,000 cells were then seeded into a 6-well ultra-low attachment plate supplemented with 2mL MEGM, with the addition of 2 mL of freshly unfrozen MEGM every 3-4 days. Gene expression profiles were taken of both MS and primary bulk tumors and compared with each other.
Project description:Cancer evolves dynamically, as clonal expansions supersede or overlap one another, driven by shifting selective pressures, mutational processes and disrupted cancer genes. These processes mark the genome, such that a cancer's life history is encrypted in the timing, ploidy, clonality and patterns of somatic mutation. We developed bioinformatic algorithms to decipher this narrative, and applied them to 21 breast cancer genomes. We find that mutational processes evolve across the lifespan of a breast tumor, with cancer-specific signatures of point mutations and chromosomal instability often emerging late but contributing extensive genetic variation. Subclonal diversification is prominent, providing insight into the dynamics of clonal expansion in breast cancer. Most point mutations are found in just a fraction of tumor cells, together with frequent variegation in chromosomal copy number. Every tumor studied here has a dominant subclonal lineage, representing more than 50% of tumor cells. Minimal expansion of these subclones occurs until many hundreds to thousands of mutations have accumulated, implying the existence of long-lived, quiescent lineages of cells that are capable of substantial proliferation upon acquisition of enabling genomic changes. Expansion of the dominant subclone to an appreciable mass may therefore represent the final rate-limiting step in a breast cancer's development, triggering diagnosis.
Project description:Estrogen-responsive genes were identified by transcript profiling of estrogen-treated MCF-7 breast cancer cells. The gene expression profile generated after estrogen treatment was compared with that following inducible expression of c-Myc or c-Zip (a deletion mutant of c-Myc that lacks the N-terminal transactivation domains) in clonal MCF-7 cell lines. Experiment Overall Design: RNA was collected in three independent experiments, each including parental MCF-7 cells treated with 17b-estradiol (E2) or ethanol (EtOH), zinc-treated p-delta-MT-c-Myc cells, zinc-treated p-delta-MT-c-Zip cells and zinc-treated empty vector (p-delta-MT) cells. Cells were arrested for 48 h with 10 nM ICI 182780 and then treated for 6 h with either 100 nM E2 or ethanol vehicle, or 75 mM zinc for the stably transfected cell lines.
Project description:"The human breast cancer (BR) data set (endpoints D and E) was contributed by the University of Texas M. D. Anderson Cancer Center (MDACC, Houston, TX, USA). Gene expression data from 230 stage I-III breast cancers were generated from fine needle aspiration specimens of newly diagnosed breast cancers before any therapy. The biopsy specimens were collected sequentially during a prospective pharmacogenomic marker discovery study between 2000 and 2008. These specimens represent 70-90% pure neoplastic cells with minimal stromal contamination. Patients received 6 months of preoperative (neoadjuvant) chemotherapy including paclitaxel, 5-fluorouracil, cyclophosphamide and doxorubicin followed by surgical resection of the cancer. Response to preoperative chemotherapy was categorized as a pathological complete response (pCR = no residual invasive cancer in the breast or lymph nodes) or residual invasive cancer (RD), and used as endpoint D for prediction. Endpoint E is the clinical estrogen-receptor status as established by immunohistochemistry. RNA extraction and gene expression profiling were performed in multiple batches over time using Affymetrix U133A microarrays. Genomic analysis of a subset of this sequentially accrued patient population were reported previously. For each endpoint, the first 130 cases were used as a training set and the next 100 cases were used as an independent validation set. Gene expression data from 230 stage I-III breast cancers"