Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor with high mortality rates. Merkel cell polyomavirus (MCPyV), identified in the majority of MCC, may drive tumorigenesis via viral T antigens. However, mechanisms underlying pathogenesis in MCPyV-negative MCC remain poorly understood. To nominate genes contributing to pathogenesis of MCPyV-negative MCC, we performed DNA microarray analysis on 30 MCCs. MCPyV status of MCCs was determined by PCR for viral DNA and RNA. 1593 probe-sets were differentially expressed between MCPyV-negative and -positive MCC, with significant differential expression defined as at least 2-fold change in either direction and p-value of 0.05. MCPyV-negative tumors showed decreased RB1 expression, whereas MCPyV-positive tumors were enriched for immune response genes. Validation studies included immunohistochemistry demonstration of decreased RB protein expression in MCPyV-negative tumors and increased peritumoral CD8+ T lymphocytes surrounding MCPyV-positive tumors. In conclusion, our data suggest that loss of RB1 expression may play an important role in tumorigenesis of MCPyV-negative MCC. Functional and clinical validation studies are needed to determine whether this tumor suppressor pathway represents an avenue for targeted therapy.
Distinct gene expression profiles of viral- and nonviral-associated merkel cell carcinoma revealed by transcriptome analysis.
Specimen part
View SamplesBackground: Castration-resistant prostate cancer (CRPC) represents a therapeutic challenge for current medications.
Integrative genomic, transcriptomic, and RNAi analysis indicates a potential oncogenic role for FAM110B in castration-resistant prostate cancer.
Sex, Specimen part, Disease, Disease stage, Cell line, Treatment, Race
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MiR-130a, miR-203 and miR-205 jointly repress key oncogenic pathways and are downregulated in prostate carcinoma.
Specimen part, Cell line
View SamplesMicro RNAs (miRNAs) miR-130a, miR-203 and miR-205 are jointly downregulated in prostate cancer and act as repressors of AR-signaling. MiRNAs are small non-coding RNAs that regulate the expression of specific mRNA targets mainly by translational repression, mRNA deadenylation or cleavage. Reconstitution of these lost miRNAs in the LNCaP PCa cell line cause morphology changes, growth arrest, and apoptosis, increasing when the miRNAs were co-expressed. This series identifies direct targets of miR-130a, miR-203, and miR-205 by AGO2-RNA co-immunoprecipitation as described by (Beitzinger et al. 2007) upon miRNA reconstitution in LNCaP cells and analyzing AGO2-bound mRNAs using Affymetrix Genechips. Relative levels of AGO2 bound versus total RNA expression were compared between miRNA reconstituted and miR-scr transfected samples.
MiR-130a, miR-203 and miR-205 jointly repress key oncogenic pathways and are downregulated in prostate carcinoma.
Specimen part, Cell line
View SamplesMicro RNAs (miRNAs) miR-130a, miR-203 and miR-205 are jointly downregulated in prostate cancer and act as repressors of AR-signaling. MiRNAs are small non-coding RNAs that regulate the expression of specific mRNA targets mainly by translational repression, mRNA deadenylation or cleavage. Reconstitution of these lost miRNAs in the LNCaP PCa cell line cause morphology changes, growth arrest, and apoptosis, increasing when the miRNAs were co-expressed. Bioinformatic target prediction, mRNA expression and protein expression analysis upon overexpression of these miRNAs congruently identified targets known to be overexpressed in PCa and to be involved in AR trans-activation. This series profiles loss in mRNA expression in LNCaP cells transfected with one of the three miRNAs miR-130a, miR-203 and miR-205 compared to LNCaP cells transfected with a scramble miRNA.
MiR-130a, miR-203 and miR-205 jointly repress key oncogenic pathways and are downregulated in prostate carcinoma.
Cell line
View SamplesIn parallel with the inconsistency in observational studies and chemoprevention trials, the molecular mechanisms by which selenium may affect prostate cancer risk have not been elucidated. We conducted a randomized, placebo-controlled intervention trial to examine the effects of a short-term intervention with selenized yeast on whole-genome expression profiles in non-malignant prostate tissue. Twenty-three men receiving prostate biopsies were randomly assigned to take 300 g selenized yeast per day (n=12) or placebo (non-selenized yeast, n=11) during a median intervention period of 35 (interquartile range: 31-35) days. Prostate specimens, collected from the transition zone before and after intervention, of 15 participants (n=8 selenium, n=7 placebo) were available for analysis using Affymetrix GeneChip Human 1.0 ST Arrays. Pathway and gene set enrichment analyses revealed that the intervention with selenium resulted in a down-regulated expression of genes involved in signaling pathways related to cellular adhesion, migration, invasion, remodeling and immune responses. Specifically, expression of the well-established epithelial marker E-cadherin was up-regulated, while mesenchymal markers, such as vimentin and fibronectin, were down-regulated after the intervention with selenium. This implies an effect of selenium on the epithelial-to-mesenchymal transition (EMT). Moreover, selenium affected expression of genes involved in wound healing and inflammation, processes which are both related to EMT. In conclusion, our data showed that selenium affected expression of genes implicated in EMT, mainly represented by a change in the direction of the epithelial rather than the mesenchymal phenotype.
A short-term intervention with selenium affects expression of genes implicated in the epithelial-to-mesenchymal transition in the prostate.
Sex, Specimen part, Time
View SamplesMicroRNA-520f regulates EMT, as it activates CDH1 (mRNA) and E-cadherin (protein) expression, and it suppresses tumor cell invasion. We have characterized miR-520f target genes through whole genome transcriptional profiling of miRNA transfected pancreas cancer cells (PANC-1).
miRNA-520f Reverses Epithelial-to-Mesenchymal Transition by Targeting <i>ADAM9</i> and <i>TGFBR2</i>.
Cell line, Treatment
View SamplesThe PI3K/mammalian target of rapamycin (mTOR) pathway is dysregulated in over 50% of human GBM but remains a challenging clinical target. Inhibitors against PI3K/mTOR mediators have limited clinical efficacy as single agents. Gene expression profiling after PI3K/mTOR inhibition treatment was analyzed by Affymetrix microarrays.
MSK1-Mediated β-Catenin Phosphorylation Confers Resistance to PI3K/mTOR Inhibitors in Glioblastoma.
Specimen part, Cell line
View SamplesThe pretreatment karyotype of leukemic blasts is currently the key determinant in therapy decision-making in acute myeloid leukemia (AML). However, approximately fifty percent of AML patients, often carrying a normal karyotype, are currently unclassifiable based these established methods. Gene expression profiling has proven to be valuable for risk stratification of AML.
Prediction of molecular subtypes in acute myeloid leukemia based on gene expression profiling.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesInterleukin-6 (IL-6) is an important growth factor for estrogen receptor-alpha (ER) positive breast cancer, and elevated serum IL-6 is associated with poor prognosis. We firstly demonstrated that pSTAT3 is the primary downstream IL-6 signaling pathway in ER-positive breast cancer, using ten different breast cancer cell lines. Three-dimensional cultures of these cell lines were also used to develop a 17-gene IL-6 specific gene signature that could be used to identify IL-6 driven disease. This signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. To further validate this IL-6 signature, we obtained 36 human ER-positive breast cancer tumor samples with matched serum for gene expression profiling and determination of an IL-6 pathway activation score (PAS). Patients with high IL-6 PAS were also enriched for elevated serum IL-6 (>=10 pg/ml). We then utilized a murine MCF-7 xenograft model to determine the role of IL-6 in ER-positive breast cancer and potential anti-IL-6 therapy in vivo. When IL-6 was administered in vivo, MCF-7 cells engrafted without the need for estrogen supplementation. Subsequently, we prophylactically treated mice at MCF-7 engraftment with an anti-IL-6 antibody (siltuximab), fulvestrant or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, when tumors were allowed to grow to 125 mm3 before treatment, siltuximab alone demonstrated tumor regressions in 90% (9/10) of tumors. Given the established role for IL-6 in ER+ breast cancer, this data demonstrates the potential for anti-IL-6 therapeutics.
Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer.
Specimen part
View Samples