Dataset Information

A Multifunctional LNA Oligonucleotide-Based Strategy Blocks AR Expression and Transactivation Activity in PCa Cells.

ABSTRACT: The androgen receptor (AR) plays a critical role in the development of prostate cancer (PCa) through the activation of androgen-induced cellular proliferation genes. Thus, blocking AR-mediated transcriptional activation is expected to inhibit the growth and spread of PCa. Using tailor-made splice-switching locked nucleic acid (LNA) oligonucleotides (SSOs), we successfully redirected splicing of the AR precursor (pre-)mRNA and destabilized the transcripts via the introduction of premature stop codons. Furthermore, the SSOs simultaneously favored production of the AR45 mRNA in lieu of the full-length AR. AR45 is an AR isoform that can attenuate the activity of both full-length and oncogenic forms of AR by binding to their common N-terminal domain (NTD), thereby blocking their transactivation potential. A large screen was subsequently used to identify individual SSOs that could best perform this dual function. The selected SSOs powerfully silence AR expression and modulate the expression of AR-responsive cellular genes. This bi-functional strategy that uses a single therapeutic molecule can be the basis for novel PCa treatments. It might also be customized to other types of therapies that require the silencing of one gene and the simultaneous expression of a different isoform.

SUBMITTER: Castanotto D

PROVIDER: S-EPMC7723773 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A Multifunctional LNA Oligonucleotide-Based Strategy Blocks AR Expression and Transactivation Activity in PCa Cells.

Castanotto Daniela D Zhang Xiaowei X Rüger Jacqueline J Alluin Jessica J Sharma Ritin R Pirrotte Patrick P Joenson Lars L Ioannou Silvia S Nelson Michael S MS Vikeså Jonas J Hansen Bo Rode BR Koch Troels T Jensen Mads Aaboe MA Rossi John J JJ Stein Cy A CA

Molecular therapy. Nucleic acids 20201027

The androgen receptor (AR) plays a critical role in the development of prostate cancer (PCa) through the activation of androgen-induced cellular proliferation genes. Thus, blocking AR-mediated transcriptional activation is expected to inhibit the growth and spread of PCa. Using tailor-made splice-switching locked nucleic acid (LNA) oligonucleotides (SSOs), we successfully redirected splicing of the AR precursor (pre-)mRNA and destabilized the transcripts via the introduction of premature stop co ...[more]

PMID: 33335793

Similar Datasets

Project description:BACKGROUND:In immunosurveillance, bone-derived immune cells infiltrate the tumor and secrete inflammatory cytokines to destroy cancer cells. However, cancer cells have evolved mechanisms to usurp inflammatory cytokines to promote tumor progression. In particular, the inflammatory cytokine, interleukin-1 (IL-1), is elevated in prostate cancer (PCa) patient tissue and serum, and promotes PCa bone metastasis. IL-1 also represses androgen receptor (AR) accumulation and activity in PCa cells, yet the cells remain viable and tumorigenic; suggesting that IL-1 may also contribute to AR-targeted therapy resistance. Furthermore, IL-1 and AR protein levels negatively correlate in PCa tumor cells. Taken together, we hypothesize that IL-1 reprograms AR positive (AR+ ) PCa cells into AR negative (AR- ) PCa cells that co-opt IL-1 signaling to ensure AR-independent survival and tumor progression in the inflammatory tumor microenvironment. METHODS:LNCaP and PC3 PCa cells were treated with IL-1? or HS-5 bone marrow stromal cell (BMSC) conditioned medium and analyzed by RNA sequencing and RT-QPCR. To verify genes identified by RNA sequencing, LNCaP, MDA-PCa-2b, PC3, and DU145 PCa cell lines were treated with the IL-1 family members, IL-1? or IL-1?, or exposed to HS-5 BMSC in the presence or absence of Interleukin-1 Receptor Antagonist (IL-1RA). Treated cells were analyzed by western blot and/or RT-QPCR. RESULTS:Comparative analysis of sequencing data from the AR+ LNCaP PCa cell line versus the AR- PC3 PCa cell line reveals an IL-1-conferred gene suite in LNCaP cells that is constitutive in PC3 cells. Bioinformatics analysis of the IL-1 regulated gene suite revealed that inflammatory and immune response pathways are primarily elicited; likely facilitating PCa cell survival and tumorigenicity in an inflammatory tumor microenvironment. CONCLUSIONS:Our data supports that IL-1 reprograms AR+ PCa cells to mimic AR- PCa gene expression patterns that favor AR-targeted treatment resistance and cell survival.

Project description:BACKGROUND:Breast (BCa) and prostate (PCa) cancers are hormone receptor (HR)-driven cancers. Thus, BCa and PCa patients are given therapies that reduce hormone levels or directly block HR activity; but most patients eventually develop treatment resistance. We have previously reported that interleukin-1 (IL-1) inflammatory cytokine downregulates ER? and AR mRNA in HR-positive (HR+) BCa and PCa cell lines, yet the cells can remain viable. Additionally, we identified pro-survival proteins and processes upregulated by IL-1 in HR+ BCa and PCa cells, that are basally high in HR- BCa and PCa cells. Therefore, we hypothesize that IL-1 confers a conserved gene expression pattern in HR+ BCa and PCa cells that mimics conserved basal gene expression patterns in HR- BCa and PCa cells to promote HR-independent survival and tumorigenicity. METHODS:We performed RNA sequencing (RNA-seq) for HR+ BCa and PCa cell lines exposed to IL-1 and for untreated HR- BCa and PCa cell lines. We confirmed expression patterns of select genes by RT-qPCR and used siRNA and/or drug inhibition to silence select genes in the BCa and PCa cell lines. Finally, we performed Ingenuity Pathway Analysis (IPA) and used the gene ontology web-based tool, GOrilla, to identify signaling pathways encoded by our RNA-seq data set. RESULTS:We identified 350 genes in common between BCa and PCa cells that are induced or repressed by IL-1 in HR+ cells that are, respectively, basally high or low in HR- cells. Among these genes, we identified Sequestome-1 (SQSTM1/p62) and SRY (Sex-Determining Region Y)-Box 9 (SOX9) to be essential for survival of HR- BCa and PCa cell lines. Analysis of publicly available data indicates that p62 and SOX9 expression are elevated in HR-independent BCa and PCa sublines generated in vitro, suggesting that p62 and SOX9 have a role in acquired hormone receptor independence and treatment resistance. We also assessed HR- cell line viability in response to the p62-targeting drug, verteporfin, and found that verteporfin is cytotoxic for HR- cell lines. CONCLUSIONS:Our 350 gene set can be used to identify novel therapeutic targets and/or biomarkers conserved among acquired (e.g. due to inflammation) or intrinsic HR-independent BCa and PCa.

Project description:BackgroundThe proprotein convertase subtilisin/kexin type 9 (PCSK9) is an important factor in the etiology of familial hypercholesterolemia (FH) and is also an attractive therapeutic target to reduce low density lipoprotein (LDL) cholesterol. PCSK9 accelerates the degradation of hepatic low density lipoprotein receptor (LDLR) and low levels of hepatic PCSK9 activity are associated with reduced levels of circulating LDL-cholesterol.Methodology/principal findingsThe present study presents the first evidence for the efficacy of a locked nucleic acid (LNA) antisense oligonucleotide (LNA ASO) that targets both human and mouse PCSK9. We employed human hepatocytes derived cell lines HepG2 and HuH7 and a pancreatic mouse beta-TC3 cell line known to express high endogenous levels of PCSK9. LNA ASO efficiently reduced the mRNA and protein levels of PCSK9 with a concomitant increase in LDLR protein levels after transfection in these cells. In vivo efficacy of LNA ASO was further investigated in mice by tail vein intravenous administration of LNA ASO in saline solution. The level of PCSK9 mRNA was reduced by approximately 60%, an effect lasting more than 16 days. Hepatic LDLR protein levels were significantly up-regulated by 2.5-3 folds for at least 8 days and approximately 2 fold for 16 days. Finally, measurement of liver alanine aminotransferase (ALT) levels revealed that long term LNA ASO treatment (7 weeks) does not cause hepatotoxicity.Conclusion/significanceLNA-mediated PCSK9 mRNA inhibition displayed potent reduction of PCSK9 in cell lines and mouse liver. Our data clearly revealed the efficacy and safety of LNA ASO in reducing PCSK9 levels, an approach that is now ready for testing in primates. The major significance and take home message of this work is the development of a novel and promising approach for human therapeutic intervention of the PCSK9 pathway and hence for reducing some of the cardiovascular risk factors associated with the metabolic syndrome.

Project description:Microarrays are invaluable tools for genome interrogation, SNP detection, and expression analysis, among other applications. Such broad capabilities would be of value to many pathogen research communities, although the development and use of genome-scale microarrays is often a costly undertaking. Therefore, effective methods for reducing unnecessary probes while maintaining or expanding functionality would be relevant to many investigators.Taking advantage of available genome sequences and annotation for Toxoplasma gondii (a pathogenic parasite responsible for illness in immunocompromised individuals) and Plasmodium falciparum (a related parasite responsible for severe human malaria), we designed a single oligonucleotide microarray capable of supporting a wide range of applications at relatively low cost, including genome-wide expression profiling for Toxoplasma, and single-nucleotide polymorphism (SNP)-based genotyping of both T. gondii and P. falciparum. Expression profiling of the three clonotypic lineages dominating T. gondii populations in North America and Europe provides a first comprehensive view of the parasite transcriptome, revealing that ~49% of all annotated genes are expressed in parasite tachyzoites (the acutely lytic stage responsible for pathogenesis) and 26% of genes are differentially expressed among strains. A novel design utilizing few probes provided high confidence genotyping, used here to resolve recombination points in the clonal progeny of sexual crosses. Recent sequencing of additional T. gondii isolates identifies >620 K new SNPs, including ~11 K that intersect with expression profiling probes, yielding additional markers for genotyping studies, and further validating the utility of a combined expression profiling/genotyping array design. Additional applications facilitating SNP and transcript discovery, alternative statistical methods for quantifying gene expression, etc. are also pursued at pilot scale to inform future array designs.In addition to providing an initial global view of the T. gondii transcriptome across major lineages and permitting detailed resolution of recombination points in a historical sexual cross, the multifunctional nature of this array also allowed opportunities to exploit probes for purposes beyond their intended use, enhancing analyses. This array is in widespread use by the T. gondii research community, and several aspects of the design strategy are likely to be useful for other pathogens.

Dataset Information

A Multifunctional LNA Oligonucleotide-Based Strategy Blocks AR Expression and Transactivation Activity in PCa Cells.

Publications

A Multifunctional LNA Oligonucleotide-Based Strategy Blocks AR Expression and Transactivation Activity in PCa Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets