We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful Selective Androgen Receptor Modulators (SARMs). As one of the approaches, we used a DNA microarray analysis to demonstrate that differently conformed receptors facilitate distinct patterns of gene expression in LNCaP cells. Interestingly, we observed a complete overlap in the identity of genes expressed following treatment with mechanistically distinct AR ligands. However, it was differences in the kinetics of gene regulation that distinguished these compounds. Follow-up studies, in cell-based assays of AR action, confirmed the importance of these alterations in gene expression. Together these studies demonstrate an important link between AR structure, gene expression and biological outcome.
Linking ligand-induced alterations in androgen receptor structure to differential gene expression: a first step in the rational design of selective androgen receptor modulators.
No sample metadata fields
View SamplesThe Wilms tumor 1 gene (WT1) encodes a transcription factor involved in cell growth and development. As we previously reported WT1 expression is hardly detectable in normal hepatic tissue but is induced in liver cirrhosis. Although WT1 has been found to be overexpressed in a number of malignancies, the role of WT1 in hepatocarcinogenesis has not been clarified. We found that WT1 is expressed in several human hepatocellular carcinoma (HCC) cell lines including PLC/PRF/5 and HepG2, and in HCC tumor tissue in 42% of patients. WT1 small interfering RNAs did not affect proliferation rate of HCC cells but abrogated their resistance to anoikis. Transcriptome analysis of PLC/PRF/5 cells after WT1 knockdown demonstrated upregulation of 251 genes and downregulation of 321. Ninety per cent of the former corresponded to metabolic genes mostly those characterizing the mature hepatocyte phenotype. On the contrary, genes that decreased upon WT1 inhibition were mainly related to defense against apoptosis, cell cycle and tumor progression. In agreement with these findings WT1 expression increased the resistance of liver tumor cells to doxorubicin, a compound used to treat HCC. Interestingly, doxorubicin strongly enhanced WT1 expression in both HCC cells and normal human hepatocytes. Among different chemotherapeutics, induction of WT1 transcription was restricted to topoisomerase 2 inhibitors. When WT1 expression was prohibited doxorubicin caused a marked increase in caspase-3 activation. In conclusion, WT1 is expressed in a substantial proportion of HCC contributing to tumor progression and resistance to chemotherapy, suggesting that WT1 may be an important target for HCC treatment.
Wilms' tumor 1 gene expression in hepatocellular carcinoma promotes cell dedifferentiation and resistance to chemotherapy.
No sample metadata fields
View SamplesBackground & Aims. Glycine N-methyltransferase (GNMT) is an essential regulator of the total transmethylation flux in the mammalian liver. Distinct DNA methylation patterns are characteristic of liver development, hepatic de-differentiation and liver disease progression, processes in which the levels of GNMT decrease dramatically by mechanisms still poorly understood. Interestingly, putative binding sites for the microRNA miRNA-873-5p were identified in the 3´UTR of GNMT suggesting a potential role for miRNA-873-5p in GNMT regulation. Results. We have identified that the hepatic expression of miRNA-873-5p was increased in a cohort of cirrhotic and liver cancer patients associated with a down-regulation of GNMT levels. Moreover, during liver development, hepatic de-differentiation and fibrosis, the elevation of miRNA-873-5p coincided with the reduction of GNMT expression, indicating that miRNA-873-5p specifically targets the expression of GNMT. Under these circumstances, inhibition of miRNA-873-5p induced GNMT levels and decreased global CpG methylation and transmethylation flux. Indeed, reestablishment of GNMT expression by miRNA-873-5p inhibition reduced hepatocyte de-differentiation, and abolished completely the mortality produced after bile duct ligation as a result of decreased proinflamatory and profibrogenic markers. miRNA-873-5p knockdown-mediated antifibrotic effect was significantly blunted if its effect on GNMT was blocked. Conclusion. Taken together, our studies highlight the role of miRNA-873-5p as a key regulator of GNMT expression, paving the way for new therapeutical approaches in liver de-differentiation and fibrosis. Overall design: Genome-wide changes in gene Expression in mouse livers from BDL treated or not with anti-miR-873 were generated by RNAseq.
MiR-873-5p acts as an epigenetic regulator in early stages of liver fibrosis and cirrhosis.
Age, Cell line, Treatment, Subject
View SamplesTargets of Retinoic Acid (RA) and 3,4-didehydroretinoic acid (ddRA) were identified in primary human epidermal keratinocytes grown in the presence of atRA or ddRA for 4 and 24 hours.
The effect of two endogenous retinoids on the mRNA expression profile in human primary keratinocytes, focusing on genes causing autosomal recessive congenital ichthyosis.
Treatment
View SamplesPurpose: using RNA-seq as a screening tool to determine candidate genes of interest within a genetically defined neural subpopulation in the zebrafish embryonic spinal cord. Results: The early embryonic spinal cord displays patterns of spontaneous activity that generate the earliest motor behavior in the zebrafish. We show the behavior and the neural activity to be inhibited by environmental levels of light. Since at these young ages the fish is blind, and since restricted illumination patterns on the trunk of the fish can elicit a photo-response, we hypothesized that the photo-inhibition is an intrinsic property of the active central pattern generator network within the spinal cord. We FACS-isolated cells from this network as well as those from a panneuronal population and sequenced mRNAs. Through differential expression analysis we identified vertebrate ancient long opsin a as a candidate and then further validated its function in the circuit through knockdown and rescue experiments. Overall design: RNA sequencing of 2 FACS purified neural populations from zebrafish spinal cord.
A spinal opsin controls early neural activity and drives a behavioral light response.
No sample metadata fields
View SamplesThe equilibrium between cellular differentiation and proliferation is fundamental for tissue homeostasis. This is particularly important for the liver, a highly differentiated organ with systemic metabolic functions still endowed with unparalleled regenerative potential. Hepatocellular de-differentiation and uncontrolled proliferation are at the basis of liver carcinogenesis. We have identified SLU7, a pre-mRNA splicing regulator inhibited in hepatocarcinoma as a pivotal gene for hepatocellular homeostasis. SLU7 knockdown in human liver cells and mouse liver resulted in profound changes in pre-mRNA splicing and gene expression, leading to impaired glucose and lipid metabolism, refractoriness to key metabolic hormones, and reversion to a fetal-like gene expression pattern. Hepatocellular proliferation and a switch to a tumor-like glycolytic phenotype were also observed. Mechanistically, SLU7 governed the splicing and/or expression of essential genes for hepatocellular differentiation like SRSF3 and HNF4a, and was identified as a critical factor in cAMP-regulated gene transcription. SLU7 is therefore central for hepatocyte identity and quiescence.
Splicing regulator SLU7 is essential for maintaining liver homeostasis.
Cell line
View SamplesThe adaptor protein Lnk is an important negative regulator of HSC homeostasis and self-renewal. This study aims to investigate the role of Lnk in HSC aging. Here we performed expression profiling of bone marrow CD150+CD48-LSK LT-HSCs from young and old WT and Lnk-/- mice. Results identify select Lnk-mediated pathways with potential involvement in HSC self-renewal and aging.
Lnk deficiency partially mitigates hematopoietic stem cell aging.
Specimen part
View SamplesTHREE INDEPENDENT REPLICATES AND ARE THE CONTROL NON-INFECTED CELLS:
Modulation of NB4 promyelocytic leukemic cell machinery by Anaplasma phagocytophilum.
No sample metadata fields
View SamplesRecessive retinitis pigmentosa (RP) is often caused by nonsense mutations that lead to low mRNA levels as a result of nonsense-mediated decay. Some RP genes are expressed at detectable levels in leukocytes as well as in the retina. We designed a microarray-based method to find recessive RP genes based on low lymphoblast mRNA expression levels
Insights from retinitis pigmentosa into the roles of isocitrate dehydrogenases in the Krebs cycle.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An FGFR3/MYC positive feedback loop provides new opportunities for targeted therapies in bladder cancers.
Cell line
View Samples