Project description:The ShcA adaptor possesses two phosphotyrosine binding motifs, which include an SH2 and a PTB domain. In the majority of cases, ShcA utilizes its PTB domain to engage activated receptor tyrosine kinases (RTKs). To establish the mportance of this domain during mammary tumorigenesis, we employed a ShcA mutant (R175Q) that no longer binds phospho-tyrosine residues via its PTB domain. We demonstrate that the ShcR175Q mutant delays mammary tumor onset n MMTV/MT transgenic animals. Paradoxically, we observe a robust increase in the growth and angiogenesis of emerging mammary tumors. ShcR175Q-expressing breast cancer cells increase fibronectin secretion and possess elevated levels f integrin α5/β1, the principle fibronectin receptor. Sustained integrin engagement activates Src, which in turn phosphorylates pro-angiogenic RTKs, including PDGFR, FGFR and Met, leading to increased VEGF secretion from ShcR175Q-xpressing breast cancer cells. Finally, we describe a ShcR175Q-dependent gene signature that stratifies breast cancer patients with a high microvessel density. This is the first study to demonstrate that intracellular signaling pathways ownstream of the ShcA PTB domain both positively and negatively regulate tumorigenesis during the various stages of breast cancer progression ShcA mutant (R175Q) vs NT/ShcA cells
Project description:The ShcA adaptor possesses two phosphotyrosine binding motifs, which include an SH2 and a PTB domain. In the majority of cases, ShcA utilizes its PTB domain to engage activated receptor tyrosine kinases (RTKs). To establish the mportance of this domain during mammary tumorigenesis, we employed a ShcA mutant (R175Q) that no longer binds phospho-tyrosine residues via its PTB domain. We demonstrate that the ShcR175Q mutant delays mammary tumor onset n MMTV/MT transgenic animals. Paradoxically, we observe a robust increase in the growth and angiogenesis of emerging mammary tumors. ShcR175Q-expressing breast cancer cells increase fibronectin secretion and possess elevated levels f integrin α5/β1, the principle fibronectin receptor. Sustained integrin engagement activates Src, which in turn phosphorylates pro-angiogenic RTKs, including PDGFR, FGFR and Met, leading to increased VEGF secretion from ShcR175Q-xpressing breast cancer cells. Finally, we describe a ShcR175Q-dependent gene signature that stratifies breast cancer patients with a high microvessel density. This is the first study to demonstrate that intracellular signaling pathways ownstream of the ShcA PTB domain both positively and negatively regulate tumorigenesis during the various stages of breast cancer progression
Project description:Progesterone receptors (PRs) are critical context-dependent transcription factors required for normal uterine (PR-A) and mammary gland (PR-B) development. Progesterone is proliferative in the breast, where PR-target genes include paracrine factors that mediate mammary stem cell self-renewal. In the context of altered signal transduction that typifies breast tumorigenesis, dysregulated (i.e. hyper-phosphorylated) PRs likely contribute to tumor progression by promoting cancer cell pro-survival and proliferation. Notably, in breast cancer cells, progestin-bound PRs induce rapid MAPK activation leading to selective regulation of growth-promoting genes by phosphorylated PR species. Functional domains within PR that interact with c-Src and estrogen receptors (ER) have been identified as indirect routes to MAPK activation. Herein, we describe a common docking (CD) domain located within the PR-B N-terminus, a motif first described in MAPKs that facilitates direct interactions between MAPKs and MEK1 or MAPK-phosphatases (MKPs). Mutation of negatively-charged amino acids, previously determined to be critical for CD domain function in MAPKs, within PR-B (mCD PR) did not alter MEK-binding or progestin-induced rapid signaling (i.e. MAPK activation) and PR transcriptional activity as measured by PRE-luciferase (reporter) assays. Microarray gene-expression analysis revealed that endogenous genes regulated by wt PR, but not mCD PR, are involved in critical cellular pathways regulating growth, proliferation, survival, and cancer. mCD PR failed to undergo ligand-induced phosphorylation on Ser81, a ck2-dependent site required for progestin-regulation of select growth-promoting genes (BIRC3, HSD11β2, HbEGF). Progestin-induced PR Ser81 phosphorylation mapped to CD domain-dependent binding of PR-B to MKP3, but did not require phosphatase activity. Receptors containing either mutant CD domains (mCD PR) or point mutations of Ser81 (S79/81A PR) failed to upregulate STAT5 and Wnt1, key PR-target gene products that act as critical mediators of mammary stem cell expansion. Inhibition of JAK/STAT signaling blocked progestin-induced STAT5 and Wnt1 expression. ChIP assays demonstrated that wt, but not phospho-mutant (S79/81A), PR-B was co-recruited to a PRE-containing enhancer region of the Wnt1 gene along with MKP3, ck2 and STAT5. Our studies reveal a novel scaffolding action of MKP3 mediated by interaction with the PR CD domain and required for ck2-dependent PR Ser81 phosphorylation. Co-regulation of select target genes by phospho-Ser81 PR and phospho-STAT5 is likely a global mechanism required for the activation of growth promoting programs active during normal mammary gland development and relevant to mechanisms of breast cancer progression. The study contains 6 different sample groups measured in triplicate, for a total of 18 individual samples (18 arrays). From parental T47D-Y human breast cancer cell lines, we created three stable clones expressing (1) an empty vector (pSG5), (2) the wild type progesterone receptor isoform B (pSG5-PR-B), or (3) a mutant mutant CD domain PR-B. These cell lines were treated with either (1) vehicle control (ethanol) or (2) R5020 10e-8 M for 6 hours before total RNA harvest. Thus, the experiment contains three cell lines, and two treatments (6 sample groups) treated and analyzed in triplicate (18 microarrays). Standard Illumina HT-12v4 chip controls were used during hybridization.
Project description:Background Estrogen and progesterone are potent breast mitogens. In addition to steroid hormones, multiple signaling pathways input to estrogen receptor (ER) and progesterone receptor (PR) actions via posttranslational events. Protein kinases commonly activated in breast cancers phosphorylate steroid hormone receptors (SRs) and profoundly impact their activities. Methods To better understand the role of modified PRs in breast cancer, we measured total and phospho-Ser294 PRs in 209 human breast tumors represented on 2754 individual tissue spots within a tissue microarray and assayed the regulation of this site in human tumor explants cultured ex vivo. To complement this analysis, we assayed PR target gene regulation in T47D luminal breast cancer models following treatment with progestin (promegestone; R5020) and antiprogestins (mifepristone, onapristone, or aglepristone) in conditions under which the receptor is regulated by Lys388 SUMOylation (K388 intact) or is SUMO-deficient (via K388R mutation to mimic persistent Ser294 phosphorylation). Selected phospho-PR-driven target genes were validated by qRT-PCR and following RUNX2 shRNA knockdown in breast cancer cell lines. Primary and secondary mammosphere assays were performed to implicate phospho-Ser294 PRs, epidermal growth factor signaling, and RUNX2 in breast cancer stem cell biology. Results Phospho-Ser294 PR species were abundant in a majority (54%) of luminal breast tumors, and PR promoter selectivity was exquisitely sensitive to posttranslational modifications. Phospho-PR expression and target gene programs were significantly associated with invasive lobular carcinoma (ILC). Consistent with our finding that activated phospho-PRs undergo rapid ligand-dependent turnover, unique phospho-PR gene signatures were most prevalent in breast tumors clinically designated as PR-low to PR-null (luminal B) and included gene sets associated with cancer stem cell biology (HER2, PAX2, AHR, AR, RUNX). Validation studies demonstrated a requirement for RUNX2 in the regulation of selected phospho-PR target genes (SLC37A2). In vitro mammosphere formation assays support a role for phospho-Ser294-PRs via growth factor (EGF) signaling as well as RUNX2 as potent drivers of breast cancer stem cell fate. Conclusions We conclude that PR Ser294 phosphorylation is a common event in breast cancer progression that is required to maintain breast cancer stem cell fate, in part via cooperation with growth factor-initiated signaling pathways and key phospho-PR target genes including SLC37A2 and RUNX2. Clinical measurement of phosphorylated PRs should be considered a useful marker of breast tumor stem cell potential. Alternatively, unique phospho-PR target gene sets may provide useful tools with which to identify patients likely to respond to selective PR modulators that block PR Ser294 phosphorylation as part of rational combination (i.e., with antiestrogens) endocrine therapies designed to durably block breast cancer recurrence.
Project description:The pathogenesis of spontaneous preterm birth (PTB) is largely unknown. We conducted RNA-seq transcriptomic analysis, qRT-PCR and ELISA on fresh placental villous tissue from 20 spontaneous preterm and 20 spontaneous term deliveries, to identify genes and signalling pathways involved in the pathogenesis of PTB. Our differential gene expression, gene ontology and pathway analysis revealed several dysregulated genes, including OCLN, OPTN, KRT7, WNT7A, RSPO4, BAMBI, NFATC4, SLC6A13, SLC6A17, SLC26A8 and KLF8, associated with altered trophoblast functions. We identified dysregulated Wnt, oxytocin and cellular senescence signalling pathways in preterm placentas, where augmented Wnt signalling could play a pivotal role in the pathogenesis of PTB due to its diverse biological functions. We provide fresh molecular insight into the pathogenesis of spontaneous PTB, which may drive further studies to develop new predictive biomarkers and therapeutics.
Project description:Progesterone receptors (PRs) are critical context-dependent transcription factors required for normal uterine (PR-A) and mammary gland (PR-B) development. Progesterone is proliferative in the breast, where PR-target genes include paracrine factors that mediate mammary stem cell self-renewal. In the context of altered signal transduction that typifies breast tumorigenesis, dysregulated (i.e. hyper-phosphorylated) PRs likely contribute to tumor progression by promoting cancer cell pro-survival and proliferation. Notably, in breast cancer cells, progestin-bound PRs induce rapid MAPK activation leading to selective regulation of growth-promoting genes by phosphorylated PR species. Functional domains within PR that interact with c-Src and estrogen receptors (ER) have been identified as indirect routes to MAPK activation. Herein, we describe a common docking (CD) domain located within the PR-B N-terminus, a motif first described in MAPKs that facilitates direct interactions between MAPKs and MEK1 or MAPK-phosphatases (MKPs). Mutation of negatively-charged amino acids, previously determined to be critical for CD domain function in MAPKs, within PR-B (mCD PR) did not alter MEK-binding or progestin-induced rapid signaling (i.e. MAPK activation) and PR transcriptional activity as measured by PRE-luciferase (reporter) assays. Microarray gene-expression analysis revealed that endogenous genes regulated by wt PR, but not mCD PR, are involved in critical cellular pathways regulating growth, proliferation, survival, and cancer. mCD PR failed to undergo ligand-induced phosphorylation on Ser81, a ck2-dependent site required for progestin-regulation of select growth-promoting genes (BIRC3, HSD11β2, HbEGF). Progestin-induced PR Ser81 phosphorylation mapped to CD domain-dependent binding of PR-B to MKP3, but did not require phosphatase activity. Receptors containing either mutant CD domains (mCD PR) or point mutations of Ser81 (S79/81A PR) failed to upregulate STAT5 and Wnt1, key PR-target gene products that act as critical mediators of mammary stem cell expansion. Inhibition of JAK/STAT signaling blocked progestin-induced STAT5 and Wnt1 expression. ChIP assays demonstrated that wt, but not phospho-mutant (S79/81A), PR-B was co-recruited to a PRE-containing enhancer region of the Wnt1 gene along with MKP3, ck2 and STAT5. Our studies reveal a novel scaffolding action of MKP3 mediated by interaction with the PR CD domain and required for ck2-dependent PR Ser81 phosphorylation. Co-regulation of select target genes by phospho-Ser81 PR and phospho-STAT5 is likely a global mechanism required for the activation of growth promoting programs active during normal mammary gland development and relevant to mechanisms of breast cancer progression.
Project description:As a critical adaptor protein, Shc1 contains SH2 and PTB domains for scaffolding tyrosine phosphorylation-dependent protein complexes, therefore regulating growth factor receptor signaling networks. The three tyrosine phosphorylation sites (pY) on the CH1 linker region of SHC1 provide additional docking sites for recruiting additional dimension of signaling complexes. The affinity purification-mass spectrometry (AP-MS) method with synthetic phosphopeptides provides an unbiased discovery approach but is often limited by the length of synthetic peptides. Here, we chemically synthesized the CH1 region (Shc1CH1) covering 107 amino acids with the 239, 240, and 313 pY sites by multiple chemical peptide ligations. Combing with AP-MS and accurate label-free quantification, we explored the site-specific interactome of these distinct phospho-forms of Shc1 and identified the enhanced complex assembly around the double-phosphorylated Y239/204 sites. We also found that Plcg1 and Plcg2 interacted with pY313 strongly and specifically. Besides, we demonstrated that the AP-MS with the mouse Shc1CH1 probes could evaluate the subcellular EGFR/HER2 signaling in three human cell lines. Overall, long synthetic peptides assembled via peptide ligation widened the scope of peptide-based AP-MS approach for the analysis of site-specific interactomes of proteins with long phosphorylated docking sites.
Project description:The protein modules known as SH2 (Src-homology-2) domains are key players in the signal transduction of animals. Two questions arise: Do such modules exist in plants, and when did SH2 domains evolve? Here I show that the Arabidopsis genome contains three strong candidates for plant SH2 proteins (referred to as PASTA1, 2 and 3 : GI:25513455, At1g78540, At1g17040 respectively) with homology to the SH2 domains and the adjacent linker region of STAT proteins (Signal Transducer and Activator of Transcription). The three characteristics features of a STAT protein sequence1, namely, (i) the SH2 domain with a conserved arginine residue crucial for binding to a phospho-tyrosine residue (ii) a tyrosine residue outside the C-terminus of the SH2-domain for phosphorylation during signalling and (iii) a DNA-binding domain, are conserved in the PASTA3 protein. However, PASTA 1 and 2 proteins lack a tyrosine in a similar position. PASTA proteins are not homologous to STAT proteins outside the SH2 and linker regions. The three PASTA proteins are 70 to 80 % identical to one another. Gene expression studies with PASTA2 reveal that it is expressed in roots, stem, leaves, flowers and green siliques. Preliminary indications are that plants homozygous for PASTA2 do not have any obvious phenotype, most likely due to redundancies. This microarray experiment is an attempt to compare the gene expression of a mutant plant homozygous for PASTA2 with that of the wild type plant. This might give clues about the possible function of PASTA2 in Arabidopsis. Experimenter name = Latha Kadalayil; Experimenter phone = 023-8059 5512; Experimenter department = University of Southampton; Experimenter address = School of Biological Sciences; Experimenter address = Univ. Southampton; Experimenter address = Bassett Crescent East; Experimenter address = Southampton; Experimenter zip/postal_code = SO16 7PX; Experimenter country = UK Experiment Overall Design: 2 samples were used in this experiment
Project description:Aberrant regulation of NF-kB pathway is believed to be a major event contributing to malignant transformation and progression of prostate cancer (PCa). P65 consists of a DNA-binding and dimerization domain (RHD), nuclear localization signal (NLS) and transactivation domains (TA1 and TA2). The c-terminal 30 amino acids (TA1 domain) comprise the most important transactivation domain and NF-kB transactivation may be regulated by multiple phosphorylation in this domain. This p536 is located in TA1 domain and is conserved in human, mouse, chicken. We previously discovered that p536 is present in majority of PCa and associated with ERG expression indicating that ERG can significantly enhance phosphorylation of p65 at Ser536 in vivo. We have successfully generated a dominant negative (DN) p65 which has been mutated (S536A) such that it cannot be phosphorylated at Ser 536 and cannot carry out Ser536 phosphorylation dependent functions. We also generated two mutants S536D and S536E which are the phosphomimetic mutant that resembles phospho-p65 and can be detected by anti-phospho-p65 antibody. We carried out microarray studies and discovered a set of p536 regulated genes compared with wild type p65 regulated gene set.
Project description:<p>Pulmonary tuberculosis (PTB) and diabetes mellitus (DM) are common chronic diseases that threaten human health. Patients with DM are susceptible to PTB, an important factor that aggravates the complications of diabetes. However, the molecular regulatory mechanism underlying the susceptibility of patients with DM to PTB infection remains unknown. Healthy subjects, patients with primary PTB and patients with primary PTB complicated by DM were recruited according to inclusion and exclusion criteria. Peripheral whole blood was collected, and alteration profiles and potential molecular mechanisms were further analyzed using integrated bioinformatics analysis of metabolomics and transcriptomics. In this study, transcriptional data revealed that lipocalin 2 (LCN2), defensin alpha 1 (DEFA1), peptidoglycan recognition protein 1 (PGLYRP1) and integrin subunit alpha 2b (ITGA2B) were significantly upregulated, while chloride intracellular channel 3 (CLIC3) significantly down-regulated in PTB-DM by contrast to HC group. Additionally, the IL-17, PI3K-AKT and PPAR signaling pathways are important for PTB infection and regulation of PTB-complicated diabetes. Metabolomic data showed that glycerophospholipid metabolism, carbon metabolism and fat digestion and absorption processes were enriched in the differential metabolic analysis. Finally, integrated analysis of both metabolomic and transcriptomic data indicated that the NOTCH1/JAK/STAT signaling pathway is important in PTB complicated by DM. In conclusion, PTB infection altered the transcriptional and metabolic profiles of patients with DM. Metabolomic and transcriptomic changes were highly correlated in PTB-infected patients with DM. Peripheral metabolite levels may be used as biomarkers for PTB management in patients with DM.</p><p><strong>IMPORTANCE:</strong> The comorbidity of diabetes mellitus (DM) significantly increases the risk of tuberculosis infection and adverse tuberculosis treatment outcomes. Most previous studies have focused on the relationship between the effect of blood glucose control and the outcome of anti-tuberculosis treatment in pulmonary tuberculosis (PTB)-DM; however, early prediction and the underlying molecular mechanism of susceptibility to PTB infection in patients with DM remain unclear. Here, transcriptome sequencing and untargeted metabolomics were performed to elucidatethe key molecules and signaling pathways involved in PTB infection and the susceptibility of patients with diabetes to PTB. Our findings contribute to the development of vital diagnostic biomarkers for PTB or PTB-DM and provide acomprehensive understanding of molecular regulation during disease progression.</p>