Project description:BACKGROUND. Perineural invasion (PNI) is the dominant pathway for local invasion in prostate cancer. To date, only few studies have investigated the molecular differences between prostate tumors with PNI and those without it. METHODS. To evaluate the involvement of both microRNAs and protein-coding genes in PNI, we determined their genome-wide expression with a custom microRNA microarray and Affymetrix GeneChips in 50 prostate adenocarcinomas with PNI and 7 without it. In-situ hybridization and immunohistochemistry was used to validate candidate genes. RESULTS. Unsupervised classification of the 57 adenocarcinomas revealed two clusters of tumors with distinct global microRNA expression. One cluster contained all non-PNI tumors and a subgroup of PNI tumors. Significance analysis of microarray data yielded a list of microRNAs associated with PNI. At a false discovery rate (FDR) < 10%, 19 microRNAs were higher expressed in PNI tumors than in non-PNI tumors. The most differently expressed microRNA was miR-224. In-situ hybridization showed that this microRNA is expressed by perineural cancer cells. The analysis of protein-coding genes identified 34 transcripts that were differently expressed by PNI status (FDR <10%). These transcripts were down-regulated in PNI tumors. Many of those encoded metallothioneins and proteins with mitochondrial localization and involvement in cell metabolism. Consistent with the microarray data, perineural cancer cells tended to have lower metallothionein expression by immunohistochemistry than nonperineural cancer cells. CONCLUSIONS. Although preliminary, our findings suggest that alterations in microRNA expression, mitochondrial function, and cell metabolism occur at the transition from a non-invasive prostate tumor to a tumor with PNI. Keywords: Disease State analysis
Project description:Androgen receptor (AR)-negative castration-resistant prostate cancer (CRPC) is highly aggressive and resistant to current therapies. BET bromodomain protein BRD4 binds to super-enhancers (SEs) that drive high expression of oncogenes in many cancers. A BET inhibitor JQ1 has been found to suppress malignant phenotypes of prostate cancer cells, however, the target genes of JQ1 remains largely unknown. Here we show that SE-associated genes specific for AR-negative CRPC PC3 cells include the genes involved in migration and invasion and that JQ1 impairs migration and invasion of PC3 cells. We identified the long non-coding RNA MANCR, which is markedly down-regulated by JQ1 and found that BRD4 binds to the MANCR locus. MANCR knockdown led to a significant decrease in migration and invasion of PC3 cells. RNA sequencing analysis revealed that expression of the genes involved in migration and invasion is altered by MANCR knockdown. In summary, our data demonstrate that MANCR has a critical role for cellular migration and invasion abilities of PC3 cells.
Project description:Approximately half of all microRNAs reside within intronic regions and are often co-transcribed with their host genes. However, most studies on intronic microRNAs focus on individual microRNAs, and conversely most studies on protein-coding and non-coding genes frequently ignore any intron-derived microRNAs. We hypothesize that the individual components of such multi-genic loci may play cooperative or competing roles in driving disease progression, and that examining the combinatorial effect of these components would uncover deeper insights into their functional importance. To address this, we perform systematic analyses of intronic microRNA:host loci in colon cancer. We observe that the FTX locus, comprising of a long non-coding RNA FTX and multiple intronic microRNAs, is highly upregulated in cancer and demonstrate that cooperativity within this multi-component locus promotes cancer growth. In addition, we show that FTX interacts with DHX9 and DICER and delineate its novel roles in regulating A-to-I RNA editing and microRNA expression. These results show for the first time that a long non-coding RNA can regulate A-to-I RNA editing, further expanding the functional repertoire of long non-coding RNAs. We further demonstrate the inhibitory effects of intronic miR-374b and -545 on the tumor suppressors PTEN and RIG-I to enhance the proto-oncogenic PI3K-AKT signaling. Finally, we show that intronic miR-421 may exert an autoregulatory effect on miR-374b and -545. Taken together, our data unveil the intricate interplay between intronic microRNAs and their host transcripts in the modulation of key signaling pathways and disease progression, adding new perspectives to the functional landscape of multi-genic loci.
Project description:To investigate the mechanisms of cancer cell migration during perineural invasion in pancreatic cancer, we injected fluorescently labelled MiaPaCA-2 cells in the sciatic nerves and collected the leader and lagger cells.
Project description:This SuperSeries is composed of the following subset Series: GSE26022: [Gene Expression Training Set] Protein-coding and MicroRNA Biomarkers of Recurrence of Prostate Cancer Following Radical Prostatectomy GSE26242: [Gene Expression Validation Set] Protein-coding and MicroRNA Biomarkers of Recurrence of Prostate Cancer Following Radical Prostatectomy GSE26245: [miRNA Training Set] Protein-coding and MicroRNA Biomarkers of Recurrence of Prostate Cancer Following Radical Prostatectomy GSE26247: [miRNA Validation Set] Protein-coding and MicroRNA Biomarkers of Recurrence of Prostate Cancer Following Radical Prostatectomy Refer to individual Series
Project description:Pseudogenes, non-coding homologs of protein-coding genes, were once considered non-functional evolutional relics. Recent studies have shown that pseudogene transcripts can regulate their parental transcripts by sequestering shared microRNAs, thus acting as competing endogenous RNAs (ceRNAs). In this study, we utilize an unbiased screen to identify the ferritin heavy chain 1 (FTH1) transcript and multiple FTH1 pseudogenes as targets of several oncogenic miRNAs in prostate cancer. We characterize the critical role of this FTH1 gene:pseudogene:microRNA network in regulating tumorigenesis in prostate cancer, and show that impairing microRNA binding and subsequent ceRNA crosstalk results in complete phenotype rescue. Our results also demonstrate that pseudogenes are able to regulate intracellular iron levels, which are crucial for multiple physiological and pathophysiological processes. In summary, we describe a novel and extensive gene:pseudogene ceRNA network comprising multiple microRNAs and multiple pseudogenes derived from a single parental gene, which regulates iron storage and tumorigenesis in prostate cancer.
Project description:Recent findings have shown that inhibitors targeting BET (bromodomain and extraterminal domain) proteins, such as the small molecule JQ1, are potent growth inhibitors of many cancers and hold promise for cancer therapy. However, some reports also have revealed that JQ1 can activate additional oncogenic pathways and may affect EMT (epithelial mesenchymal transition). Therefore, it is important to address the potential unexpected effect of JQ1 treatment, such as cell invasion and metastasis. Here, we showed that in prostate cancer, JQ1 inhibited cancer cell growth but promoted invasion and metastasis in a BET protein independent manner. Multiple invasion pathways including EMT, BMP (bone morphogenetic protein) signaling, chemokine signaling and focal adhesion pathway were activated by JQ1 to promote invasion. Notably, JQ1 induced upregulation of invasion genes through inhibition of FOXA1, an invasion suppressor in prostate cancer. JQ1 directly interacted with FOXA1, inactivated FOXA1 binding to its interacting repressors, TLE3, HDAC7 and NFIC, thus blocking FOXA1 repressive function and activating the invasion genes. Our finding indicates that JQ1 has an unexpected effect of promoting invasion in prostate cancer. Thus, the ill effect of JQ1 or its derived therapeutic agents could not be ignored during cancer treatment, especially in FOXA1 related cancers.
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified androgen-regulated long non-coding RNA, CTBP1-AS, located in the antisese region of CTBP1 gene. CTBP1-AS activate AR signaling by epigenetically repress AR-associated cofactors such as CTBP1 by interactign with RNA-binding protein PSF and recruiting HDAC complex to the target promoters. In order investigated the PSF target genes, we performed ChIP-seq analysis of PSF binding sites in prostate cancer cell line, LNCaP cells. We identified androgen dependent PSF binding regions in prostate cancer cell genome. We observed PSF bindings around the promoters of androgen repressed genes such as CTBP1, p53 and SMAD3. ChIP-sequence analysis of PSF binding sites in prostate cancer cells