DNA-binding properties of ARID family proteins

The ARID (A–T Rich Interaction Domain) is a helix–turn–helix motif-based DNA-binding domain, conserved in all eukaryotes and diagnostic of a family that includes 15 distinct human proteins with important roles in development, tissue-specific gene expression and proliferation control. The 15 human ARID family proteins can be divided into seven subfamilies based on the degree of sequence identity between individual members. Most ARID family members have not been characterized with respect to their DNA-binding behavior, but it is already apparent that not all ARIDs conform to the pattern of binding AT-rich sequences. To understand better the divergent characteristics of the ARID proteins, we undertook a survey of DNA-binding properties across the entire ARID family. The results indicate that the majority of ARID subfamilies (i.e. five out of seven) bind DNA without obvious sequence preference. DNA-binding affinity also varies somewhat between subfamilies. Site-specific mutagenesis does not support suggestions made from structure analysis that specific amino acids in Loop 2 or Helix 5 are the main determinants of sequence specificity. Most probably, this is determined by multiple interacting differences across the entire ARID structure

Διερεύνηση των σχέσεων της γονικότητας με την ακαδημαϊκή αυτορρύθμιση και τα κίνητρα

Προηγούμενες έρευνες που αφορούν τη γονικότητα, ανέδειξαν τη συμβολή της θετικής συμπεριφοράς των γονέων στην ανάπτυξη της ακαδημαϊκής αυτορρύθμισης και των κινήτρων. Ως έννοια, η ακαδημαϊκή αυτορρύθμιση αναφέρεται στη μετατροπή των νοητικών δεξιοτήτων σε ακαδημαϊκές, ενώ τα κίνητρα χωρίζονται σε εξωτερικά και σε εσωτερικά. Σκοπός της παρούσας έρευνας είναι η διερεύνηση της σχέσης της γονικότητας με την ακαδημαϊκή αυτορρύθμιση και τα κίνητρα. Στην έρευνα συμμετείχαν 202 μαθητές που φοιτούσαν στη Β’ Γυμνασίου και στη Β’ Λυκείου σε τέσσερα διαφορετικά σχολεία της Κεφαλονιάς. Χορηγήθηκαν τρία εργαλεία, ένα για τη μέτρηση της γονικής συμπεριφοράς (Parental Behaviour), ένα για την μέτρηση της ακαδημαϊκής αυτορρύθμισης (Ακαδημαϊκή αυτορρύθμιση των μαθητών – SRQ-A) και ένα για τη μέτρηση των κινήτρων (Ερωτηματολόγιο αυτοαξιολόγησης κινήτρων για σχολική μάθηση). Τα αποτελέσματα επιβεβαίωσαν τις προηγούμενες έρευνες και την υπάρχουσα γνώση για τη θετική συσχέτιση των υποστηρικτικών γονικών πρακτικών, της αυτοπροσδιοριζόμενης ρύθμισης και των εσωτερικών κινήτρων. Οι έφηβοι που αναφέρουν ότι λαμβάνουν ζεστασιά από τους γονείς τους, αναμένεται να χρησιμοποιούν και τρόπους με τους οποίους ρυθμίζουν τη συμπεριφορά τους. Στα αποτελέσματα της παρούσας έρευνας, παρατηρούνται διαφορές στους μέσους όρους ανάμεσα στους μαθητές των δύο τάξεων και μεταξύ των δύο φύλων. Σε κάθε περίπτωση, οι χαμηλοί μέσοι όροι που παρατηρούνται αναδεικνύουν την ανάγκη για περαιτέρω έρευνες στον ελληνικό πληθυσμό καθώς την εφαρμογή προγραμμάτων με σκοπό την ενίσχυση της ακαδημαϊκής αυτορρύθμισης.Previous surveys on parental behavior (parenting) have highlighted the contribution of positive parenting behavior to the development of academic self-regulation and motivation. As a concept, academic self-regulation refers to the conversion of cognitive skills into academic, while motivation is divided into external and intrinsic. The purpose of this research is to investigate the relationship between parenting and academic self-regulation and motivation. The survey involved 202 students attending the second class of junior high and the second class of lyceum in four different schools at the island of Cephalonia. Three tools, one for Parental Behavior, one for measuring academic self-regulation (Academic Self-Regulating Students - SRQ-A) and one for measuring the motives of teenagers (Academic Motivation Self rating inventory) were provided. The results confirmed previous research and existing knowledge of the positive correlation between supportive parenting practices, identified regulation and intrinsic motivation. Teens who report warmth behavior from their parents, are expected to use ways to regulate their behavior. In the results of the present study, there are differences in the averages between students of both classes and between the two sexes. In any case, the low averages observed highlight the need for further research in the Greek population as well as the implementation of programs aimed at enhancing academic self-regulation

Role of Esrrg in the Fibrate-Mediated Regulation of Lipid Metabolism Genes in Human ApoA-I Transgenic Mice

We have used a new ApoA-I transgenic mouse model to identify by global gene expression profiling, candidate genes that affect lipid and lipoprotein metabolism in response to fenofibrate treatment. Multilevel bioinformatical analysis and stringent selection criteria (2-fold change, 0% false discovery rate) identified 267 significantly changed genes involved in several molecular pathways. The fenofibrate-treated group did not have significantly altered levels of hepatic human APOA-I mRNA and plasma ApoA-I compared with the control group. However, the treatment increased cholesterol levels to 1.95-fold mainly due to the increase in high-density lipoprotein (HDL) cholesterol. The observed changes in HDL are associated with the upregulation of genes involved in phospholipid biosynthesis and lipid hydrolysis, as well as phospholipid transfer protein. Significant upregulation was observed in genes involved in fatty acid transport and β-oxidation, but not in those of fatty acid and cholesterol biosynthesis, Krebs cycle and gluconeogenesis. Fenofibrate changed significantly the expression of seven transcription factors. The estrogen receptor-related gamma gene was upregulated 2.36-fold and had a significant positive correlation with genes of lipid and lipoprotein metabolism and mitochondrial functions, indicating an important role of this orphan receptor in mediating the fenofibrate-induced activation of a specific subset of its target genes.National Institutes of Health (HL48739 and HL68216); European Union (LSHM-CT-2006-0376331, LSHG-CT-2006-037277); the Biomedical Research Foundation of the Academy of Athens; the Hellenic Cardiological Society; the John F Kostopoulos Foundatio

SUMOylation of DRIL1 Directs Its Transcriptional Activity Towards Leukocyte Lineage-Specific Genes

DRIL1 is an ARID family transcription factor that can immortalize primary mouse fibroblasts, bypass RASV12-induced cellular senescence and collaborate with RASV12 or MYC in mediating oncogenic transformation. It also activates immunoglobulin heavy chain transcription and engages in heterodimer formation with E2F to stimulate E2F-dependent transcription. Little, however, is known about the regulation of DRIL1 activity. Recently, DRIL1 was found to interact with the SUMO-conjugating enzyme Ubc9, but the functional relevance of this association has not been assessed. Here, we show that DRIL1 is sumoylated both in vitro and in vivo at lysine 398. Moreover, we provide evidence that PIASy functions as a specific SUMO E3-ligase for DRIL1 and promotes its sumoylation both in vitro and in vivo. Furthermore, consistent with the subnuclear localization of PIASy in the Matrix-Associated Region (MAR), SUMO-modified DRIL1 species are found exclusively in the MAR fraction. This post-translational modification interferes neither with the subcellular localization nor the DNA-binding activity of the protein. In contrast, DRIL1 sumoylation impairs its interaction with E2F1 in vitro and modifies its transcriptional activity in vivo, driving transcription of subset of genes regulating leukocyte fate. Taken together, these results identify sumoylation as a novel post-translational modification of DRIL1 that represents an important mechanism for targeting and modulating DRIL1 transcriptional activity

The clinical significance of inflammatory cytokines in primary cell culture in endometrial carcinoma

Endometrial cancer is the most common malignancy of the female genital tract, and the incidence and mortality rates from this disease are increasing. Although endometrial carcinoma has been regarded as a tissue‐specific disease mediated by female sex steroid pathways, considerable evidence implicates a role for an inflammatory response in the development and propagation of endometrial cancer. We hypothesized that if specific patterns of cytokine expression were found to be predictive of adverse outcome, then selective receptor targeting may be a therapeutic option. This study was therefore undertaken to determine the relationship between cytokine production in primary cell culture and clinical outcome in endometrial adenocarcinoma. Fresh endometrial tissues were fractionated into epithelial and stromal fractions and cultured. After 6–7 days, supernatants were collected and cells enumerated. Batched aliquots were assayed using ELISA kits specific for CSF‐1, GMCSF, G‐CSF, TNF‐α, IL‐6, IL‐8, and VEGF. Data were compared using ANOVA, Fisher's exact, and log rank tests. Increased epithelial VEGF production was observed more often in tumors with Type 2 variants (p = 0.039) and when GPR30 receptor expression was high (p = 0.038). Although increased stromal VEGF production was detected more often in grade 3 endometrioid tumors (p = 0.050), when EGFR expression was high (p = 0.003), and/or when ER/PR expression was low (p = 0.048), VEGF production did not correlated with overall survival (OS). Increased epithelial CSF‐1 and TNF‐α production, respectively, were observed more often in tumors with deep myometrial invasion (p = 0.014) and advanced stage (p = 0.018). Increased CSF‐1 (89.5% vs. 42.9%, p = 0.032), TNF‐α (88.9% vs. 42.9%, p = 0.032, and IL‐6 (92.3% vs. 61.5%, p = 0.052) also correlated with low OS. In Cox multivariate models, CSF‐1 was an independent predictor of low survival when stratified by grade (p = 0.046) and histology (p = 0.050), and TNF‐α, when stratified by histology (p = 0.037). In this study, high CSF‐1, TNF‐α, and IL‐6 production rates identified patients at greatest risk for death, and may signify patients likely to benefit from receptor‐specific therapy

The contribution of dynamic stromal remodeling during mammary development to breast carcinogenesis

Breast cancer is a heterogeneous disease whose prognosis varies depending upon the developmental stage of the breast tissue at diagnosis. Notably, breast cancers associated with pregnancy exhibit increased rates of metastasis and poorer long-term survival compared to those diagnosed after menopause. However, postmenopausal breast cancers associated with obesity exhibit a more aggressive behavior and confer decreased overall patient survival compared to those diagnosed in non-obese individuals. Since the mammary gland is a dynamic tissue that undergoes significant changes throughout a woman's lifetime, especially during pregnancy and following menopause, we present evidence to support the notion that changes occurring throughout development within the mammary stromal compartment may account for some of the biological differences in breast cancer subtypes and behaviors

Inefficient purifying selection: the mammalian Y chromosome in the rodent genus Mus

Two related genes with potentially similar functions, one on the Y chromosome and one on the X chromosome, were examined to determine if they evolved differently because of their chromosomal positions. Six hundred fifty-seven base pairs of coding sequence of Jarid1d ( Smcy ) on the Y chromosome and Jarid1c ( Smcx ) on the X chromosome were sequenced in 13 rodent taxa. An analysis of replacement and silent substitutions, using a counting method designed for samples with small evolutionary distances, showed a significant difference between the two genes. The different patterns of replacement and silent substitutions within Jarid1d and Jarid1c may be a result of evolutionary mechanisms that are particularly strong on the Y chromosome because of its unique properties. These findings are similar to results of previous studies of Y chromosomal genes in these and other mammalian taxa, suggesting that genes on the mammalian Y evolve in a chromosome-specific manner.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46987/1/335_2005_Article_50.pd

Loss of amphiregulin reduces myoepithelial cell coverage of mammary ducts and alters breast tumor growth

Abstract Background Amphiregulin (AREG), a ligand of the epidermal growth factor receptor, is not only essential for proper mammary ductal development, but also associated with breast cancer proliferation and growth. In the absence of AREG, mammary ductal growth is stunted and fails to expand. Furthermore, suppression of AREG expression in estrogen receptor-positive breast tumor cells inhibits in-vitro and in-vivo growth. Methods We crossed AREG-null (AREG−/−) mice with the murine luminal B breast cancer model, MMTV-PyMT (PyMT), to generate spontaneous breast tumors that lack AREG (AREG−/− PyMT). We evaluated tumor growth, cytokeratin-8 (K8)-positive luminal cells, cytokeratin-14 (K14)-positive myoepithelial cells, and expression of AREG, Ki67, and PyMT. Primary myoepithelial cells from nontumor-bearing AREG+/+ mice underwent fluorescence-activated cell sorting and were adapted to culture for in-vitro coculture studies with AT-3 cells, a cell line derived from C57Bl/6 PyMT mammary tumors. Results Intriguingly, PyMT-induced lesions progress more rapidly in AREG−/− mice than in AREG+/+ mice. Quantification of K8+ luminal and K14+ myoepithelial cells in non-PyMT AREG−/− mammary glands showed fewer K14+ cells and a thinner myoepithelial layer. Study of AT-3 cells indicated that coculture with myoepithelial cells or exposure to AREG, epidermal growth factor, or basic fibroblast growth factor can suppress PyMT expression. Late-stage AREG−/− PyMT tumors are significantly less solid in structure, with more areas of papillary and cystic growth. Papillary areas appear to be both less proliferative and less necrotic. In The Cancer Genome Atlas database, luminal-B invasive papillary carcinomas have lower AREG expression than luminal B invasive ductal carcinomas. Conclusions Our study has revealed a previously unknown role of AREG in myoepithelial cell development and PyMT expression. AREG expression is essential for proper myoepithelial coverage of mammary ducts. Both AREG and myoepithelial cells can suppress PyMT expression. We find that lower AREG expression is associated with invasive papillary breast cancer in both the MMTV-PyMT model and human breast cancer