ShRNA profiling of human Hep2G cells knocked down for SRC-1 expressio to investigate the role of coactivator SRC-1/NcoA-1 for IL-6 target gene induction
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ABSTRACT: This experiment series addresses the role of coactivator SRC-1/NcoA-1 for the induction of interleukin-6 (IL-6) target genes in HepG2 cells. For that purpose, HepG2 human hepatocellular carcinoma cells were manipulated to stably express an shRNA that knocks down SRC-1 expression yielding the HepG2-âSrc1 cells. Either unmanipulated HepG2 or HepG2-âSrc1 cells were then treated for various periods with IL-6. Experiment Overall Design: HepG2 or HepG2-âSrc1 (with silenced SRC-1/NcoA-1 expression) cells were either left untreated or treated with 10 ng/ml IL-6 for 1 or 4 hours. Every experiment was carried out in replicate.
Project description:This experiment series addresses the role of coactivator SRC-1/NcoA-1 for the induction of interleukin-6 (IL-6) target genes in HepG2 cells. For that purpose, HepG2 human hepatocellular carcinoma cells were manipulated to stably express an shRNA that knocks down SRC-1 expression yielding the HepG2-∆Src1 cells. Either unmanipulated HepG2 or HepG2-∆Src1 cells were then treated for various periods with IL-6. Keywords: time course, genetic modification
Project description:We profile the binding of Steroid Receptor Co-activator (SRC1) in LY2 cells, a tamoxifen-resistant cell line, in the presence and absence of tamoxifen using ChIP-sequencing technology. The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid-independent tumour. The p160 steroid coactivataor protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors, drives this tumour adaptability. Here, using discovery studies, we identify ADAM22, a non-protease member of the ADAMs family, as a direct, ER-independent target of SRC-1. Molecular, cellular and in vivo studies confirmed SRC-1 as a regulator of ADAM22. At a functional level, a role for ADAM22 in cellular migration and differentiation was observed. In vivo data from a mouse xenograft model indicated that ADAM22 expression was higher in 4-OHT-treated endocrine-resistant tumours than in tumours derived from isogenic, sensitive cells. Furthermore, in breast cancer patients, ADAM22 expression is an independent predictor of poor disease free survival. SRC-1 can function as a molecular switch which converts a steroid-responsive tumour to a steroid-resistant tumour. The ER-independent SRC-1 target ADAM22 is a potential drug target and a companion predictive biomarker in the treatment of endocrine-resistant breast cancer. Examination of SRC-1 binding in LY2 cells in the presence or absence of tamoxifen treatment. 2 replicates each.
Project description:We profile the binding of Steroid Receptor Co-activator (SRC1) in LY2 cells, a tamoxifen-resistant cell line, in the presence and absence of tamoxifen using ChIP-sequencing technology. The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid-independent tumour. The p160 steroid coactivataor protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors, drives this tumour adaptability. Here, using discovery studies, we identify ADAM22, a non-protease member of the ADAMs family, as a direct, ER-independent target of SRC-1. Molecular, cellular and in vivo studies confirmed SRC-1 as a regulator of ADAM22. At a functional level, a role for ADAM22 in cellular migration and differentiation was observed. In vivo data from a mouse xenograft model indicated that ADAM22 expression was higher in 4-OHT-treated endocrine-resistant tumours than in tumours derived from isogenic, sensitive cells. Furthermore, in breast cancer patients, ADAM22 expression is an independent predictor of poor disease free survival. SRC-1 can function as a molecular switch which converts a steroid-responsive tumour to a steroid-resistant tumour. The ER-independent SRC-1 target ADAM22 is a potential drug target and a companion predictive biomarker in the treatment of endocrine-resistant breast cancer.
Project description:Experimental aim: identification of SRC-2 and SRC-3-related genes in MCF-7 breast cancer cells. Experimental workflow: 1. shRNA transduction. MCF-7 cells were transduced with a mix of lentiviral particles containing five individual lentiviral pLKO.1-puro short hairpin (sh) RNA plasmids targeting different sequences on SRC-2 or SRC-3 mRNA and a pLKO.1-puro empty vector control. The puromycin selections were maintained for three weeks to obtain cells containing stably integrated shRNA. 2. Sample preparation. RNA was extracted from eight independent replicates expressing the pLKO.1-puro empty shRNA vector (shKTR), from eight replicates of SRC-2 shRNA expressing cells (shSRC-2), and from seven replicates of SRC-3 shRNA expressing cells (shSRC-3). 300 ng of total RNA from each cell sample was biotin-labelled and amplified.
Project description:Cell transformation by the Src tyrosine kinase is characterized by extensive changes in gene expression. To describe these changes, investigators have relied extensively on the study of immortalized rodent cell lines or heterogeneous tumor samples that limit the identification of differentially expressed genes or may not represent the full spectrum of biological processes regulated during transformation. In this study, we took advantage of transformation-deficient and temperature sensitive mutants of the Rous sarcoma virus to characterize the patterns of gene expression in two types of primary cells, namely chicken embryo fibroblasts (CEF) and chicken neuro-retinal (CNR) cells. Keywords: viral transformation of primary cells, transformation, transformation deficient mutant, temperature sensitive mutant, v-Src Chicken embryo fibroblasts (CEF) were infected with the wild-type strain Schmidt-Ruppin A RSV or non-transforming strain NY315 RSV or the non-transforming control virus RCASBP(A) to assess genes involved in v-Src-dependent transformation of CEF. Chicken embryo fibroblasts (CEF) were infected with the temperature sensitve strain NY72-4 RSV and cultured either at non-permissive temperature (41.5M-KM-^ZC) or permissive temperature (37M-KM-^ZC) to assess genes involved in v-Src-dependent transformation of CEF. Chicken neuroretina cells (CNR) were infected with the temperature sensitve strain NY72-4 RSV and cultured either at non-permissive temperature (41.5M-KM-^ZC) or permissive temperature (37M-KM-^ZC) to assess genes involved in v-Src-dependent transformation of CNR and compared to CEF.
Project description:The NLRP3 inflammasome is a multi-protein complex that triggers the activation of the inflammatory protein caspase-1 and the maturation of the cytokine IL-1 in response to microbes and other danger signals in host cells. Here, we sought a deeper understanding of how the NLRP3 inflammasome is regulated. We found that inflammasome activation induced the Src family kinase Lyn to phosphorylate NLRP3 at Tyr918, and that this phosphorylation of NLRP3 correlated with a subsequent increase in its ubiquitination, which facilitated its proteasome-mediated degradation. NLRP3 tyrosine phosphorylation and ubiquitination was abrogated in Lyn-deficient macrophages, which produced increased amounts of IL-1. Furthermore, mice lacking Lyn were highly susceptible to LPS-induced septic shock in an NLRP3-dependent manner. Our data demonstrate that Lyn-mediated tyrosine phosphorylation of NLRP3 is a prerequisite for its ubiquitination, thus dampening NLRP3 inflammasome activity.
Project description:We reported that stable expression of constitutively active intra cellular Notch (ICN), in quail neuroretina (QNR) cells transformed by a conditional v-Src mutant (QNR/v-src cells), resulted in the suppression of their transformed properties. Acquisition of a normal phenotype coincided with a major switch in cell identity, as these undifferentiated QNR/v-src cells acquired characteristics of glial differentiation. Similar loss of transformation and gene reprogramming can be achieved in QNR/v-src cells, stably expressing the human CBF protein, RBP-Jk, whose activity was rendered ligand independent by fusion to the VP16 transactivator. These major phenotypic changed are correlated with a dominant interference with signaling effectors, regulating cell morphology and cytoskeleton organization. To understand the mechanisms by which Notch signaling activation suppressed v-Src induced cell transformation and induced differentiation, we compared the transcription profile of QNR cells transformed by a v-Src mutant encoding a temperature sensitive oncoprotein (QNR/v-src), with that of cells stably expressing ICN (QNR/v-src/ICN) or RBP-Jk-VP16 (QNR/v-src/RBP-Jk-VP16). Total RNA was extracted from QNR/v-src, QNR/v-src/ICN or QNR/v-src/RBP-Jk-VP16 cells maintained at permissive (37°C) or restrictive (41°C) temperature. cDNA from QNR/v-src cells was probed with that of QNR/v-src/ICN or QNR/v-src/RBP-Jk-VP16 at both temperature on microarrays spotted with 13,000 cDNA from chicken EST collections designed by the genomic facility of the Fred Hutchinson Cancer Research Center (Seattle). For two sets of sample, dye swap experiments were performed.
Project description:The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid independent tumour. The p160 steroid coactivator protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors drives this tumour adaptability. Here, using discovery studies we identify ADAM22, a non-protease member of the ADAMs family, as a direct target of SRC-1, independent of estrogen receptor(ER). Molecular, cellular, in vivo and clinical studies confirmed SRC-1 as a regulator of ADAM22 and established a role for ADAM22 in endocrine resistant tumour progression. ADAM22 has the potential to act as a therapeutic drug target and a companion predictive biomarker in the treatment of endocrine resistant breast cancer. 14 samples representing 4 conditions were analysed. Samples were transfected with either a siRNA targetting SRC1 or a control scrambled siRNA. Samples were subject to tamoxifen treatment or untreated.
Project description:The non-receptor tyrosine kinase SRC is upregulated in various human cancers and plays crucial roles in cancer progression by promoting invasion and metastasis. We show that the transforming growth factor beta (TGF-β/SMAD pathway directly upregulates SRC during the epithelial-mesenchymal transition. In human epithelial MCF10A cells, TGF-β1 treatment markedly upregulated mRNA expression of SRC. Knockout of SMAD4 suppressed upregulation of SRC by TGF-β1. ChIP-sequencing analysis revealed that SRC was transcribed from the SRC1A promoter, which interacted with SMAD2 and SMAD4, in response to TGF-β1. These findings demonstrate that a direct interaction of the activated SMAD complex with the SRC1A promoter directly upregulates SRC and suggest that TGF-β contributes to SRC upregulation in the tumor microenvironment, where TGF-β-mediated tumor progression takes place.
Project description:The restoration of catalytic activity to mutant enzymes by small molecules is well-established for in vitro systems. Here we show that the protein tyrosine kinase Src R388A mutant can be rescued in live cells using the small molecule imidazole. Cellular rescue of a v-Src homolog was rapid and reversible and conferred predicted oncogenic properties. Using chemical rescue in combination with mass spectrometry, six known Src kinase substrates were confirmed, and several new protein targets identified. Chemical rescue data suggests that c-Src is active under basal conditions. Rescue of R388A c-Src also allowed contributions of Src to the MAP kinase pathway to be clarified. This chemical rescue approach is likely to be of broad utility in cell signaling. We were also interested in examining the impact of Src rescue on the kinetics of gene expression. Chronic gene expression changes in v-Src transformed colon cancer and NIH3T3 cells have been reported, but the chemical rescue method permits insights into rapid kinetic changes. We used gene microarray analysis of imidazole activated Src, 1 h after imidazole treatment of 8A7F cells as well as 6N7F control cells, a set of several genes show increases (>1.7-fold) at 1 h in the 8A7F cells and another set show decreases (>1.7-fold) at 1 h with minimal changes in 6N7F control cells. Thirteen of these genes were further analyzed using real-time RT-PCR and most of the genes tested showed similar changes using both techniques. These gene changes were not reported in cells chronically transformed with v-Src or rapidly stimulated with growth factors suggesting that rapid initiation of Src-mediated tyrosine phosphorylation may induce a specialized pattern of gene expression changes. However, these earlier experiments were done under different conditions which may also contribute to gene effects. Keywords: time course, cell type comparison