Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Identification of novel androgen-regulated pathways and mRNA isoforms through genome-wide exon-specific profiling of the LNCaP transcriptome

ABSTRACT: Androgens drive the onset and progression of prostate cancer (PCa) by modulating androgen receptor (AR) transcriptional activity. Although several microarray-based studies have identified androgen-regulated genes, here we identify in-parallel global androgen-dependent changes in both gene and alternative mRNA isoform expression by exon-level analyses of the LNCaP transcriptome. While genome-wide gene expression changes correlated well with previously-published studies, we additionally uncovered a subset of 226 novel androgen-regulated genes. Gene expression pathway analysis of this subset revealed gene clusters associated with, and including the tyrosine kinase LYN, as well as components of the mTOR (mammalian target of rapamycin) pathway, which is commonly dysregulated in cancer. We also identified 1279 putative androgen-regulated alternative events, of which 325 (~25%) mapped to known alternative splicing events or alternative first/last exons. We selected 30 androgen-dependent alternative events for RT-PCR validation, including mRNAs derived from genes encoding tumour suppressors and cell cycle regulators. Of seven positively-validating events (~23%), five events involved transcripts derived from known AR gene targets. In particular, we found a novel androgen-dependent mRNA isoform derived from an alternative internal promoter within the TSC2 tumour suppressor gene, which is predicted to encode a protein lacking an interaction domain required for mTOR inhibition. We confirmed that expression of the alternative TSC2 mRNA isoform was directly regulated by androgens. Furthermore, by chromatin immunoprecipitation, we observed recruitment of AR to the alternative promoter region at early timepoints following androgen stimulation, which correlated with expression of alternative transcripts. Together, our data suggest that alternative mRNA isoform expression might mediate the cellular response to androgens, and may have roles in clinical PCa. Total 8 samples were analysed. 4 control (LNCaP cells grown in RPMI-1640 media with charcoal-stripped 10% FBS devoid of steroids) and 4 treatment (LNCaP cells grown in media devoid of steroid, and subsequently treated with 10nM R1881 synthetic androgen analogue for 24 hours).

ORGANISM(S): Homo sapiens

SUBMITTER: Prabhakar Rajan

PROVIDER: E-GEOD-32875 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:Macrophages play a critical role in innate immunity, and the expression of early response genes orchestrate much of the initial response of the immune system. Macrophages undergo extensive transcriptional reprogramming in response to inflammatory stimuli such as Lipopolysaccharide (LPS). To identify gene transcription regulation patterns involved in early innate immune responses, we used two genome-wide approaches - gene expression profiling and chromatin immunoprecipitation-sequencing (ChIP-seq) analysis. We examined the effect of 2 hrs LPS stimulation on early gene expression and its relation to chromatin remodeling (H3 acetylation; H3Ac) and promoter binding of Sp1 and RNA polymerase II phosphorylated at serine 5 (S5P RNAPII), which is a marker for transcriptional initiation. Our results indicate novel and alternative gene regulatory mechanisms for certain proinflammatory genes. We identified two groups of up-regulated inflammatory genes with respect to chromatin modification and promoter features. One group, including highly up-regulated genes such as tumor necrosis factor (TNF), was characterized by H3Ac, high CpG content and lack of TATA boxes. The second group, containing inflammatory mediators (interleukins and CCL chemokines), was up-regulated upon LPS stimulation despite lacking H3Ac in their annotated promoters, which were low in CpG content but did contain TATA boxes. Genome-wide analysis showed that few H3Ac peaks were unique to either +/-LPS condition. However, within these, an unpacking/expansion of already existing H3Ac peaks was observed upon LPS stimulation. In contrast, a significant proportion of S5P RNAPII peaks (approx 40%) was unique to either condition. Furthermore, data indicated a large portion of previously unannotated TSSs, particularly in LPS-stimulated macrophages, where only 28% of unique S5P RNAPII peaks overlap annotated promoters. The regulation of the inflammatory response appears to occur in a very specific manner at the chromatin level for specific genes and this study highlights the level of fine-tuning that occurs in the immune response. 4 pairs of THP-1 cells either stimulated with LPS or not This submission represents transcriptome component of study.

Project description:Sub-thalamic deep brain stimulation (DBS) reversibly modulates ParkinsonM-bM-^@M-^Ys disease (PD) motor symptoms, providing an unusual opportunity to compare leukocyte transcripts in the same subjects before and after neurosurgery and after disconnecting the stimulus (ON-and OFF-stimulus). Here, we report rapid stimulus-induced and largely reversible changes in PD leukocyte transcripts, which were larger in scope than the disease-induced changes. These transcript changes classified advanced pre- from post-surgery PD patients and discriminated patients from controls. Moreover, the extent of changes correlated with the neurological efficacy of the DBS neurosurgery, and covered both regulatory pathways and individual transcript changes, e.g. SNCA, PARK7 and the splicing factor SFRS1. Following 1 hour OFF-stimulus, these changes were largely reversed. We extracted from these differences a modified transcripts signature which discriminated controls from advanced PD patients, pre- from post-surgery and ON-from OFF-stimulus conditions. A further gene-list independent analysis detected reversed pathways. Our findings suggest future uses of this approach and the discovered molecular signature for early diagnostics of PD and for identifying novel targets for therapeutic intervention in this and other DBS-treatable neurological diseases. 27 Total samples were analyzed. Study design included four conditions. PD patients (n=7) leukocyte blood samples were examined at 3 time points, and healthy control subjects (n=6) were examined once each. Samples were taken 1 day prior to sub-thalamic nucleous (STN) DBS treatment, several months after STN-DBS treatment upon optimal stimulation and following one hour electrical stimulation cessation. The off stimulation caused recruitment of the disease symptoms as measured by the Unified Parkinson's Disease Rating Scale motor section (UPDRS-III). The different stages are designated: S1 (pre-treatment), S2 (post STN-DBS) and S3 (upon off stimulation). All patients were on dopamine replacement therapy (DRT) when examined pre- and post-DBS off stimulation (albeit with reduced therapy dose post-DBS). To reduce biological variability among the samples which is not related to the study, only male subjects were included in this study. Samples from six age- and gender- matched healthy control subjects served to detect disease modified transcripts and for pre- and post- treatment comparisons. The study was approved by the human review board at the Hadassah University Hospital, Ein-Kerem (no. 6-07.09.07) in accordance with the Declaration of Helsinki. All study participants signed informed consent.

Dataset Information

Identification of novel androgen-regulated pathways and mRNA isoforms through genome-wide exon-specific profiling of the LNCaP transcriptome

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets