Dysregulation of microRNAs is a common feature in human cancers, including breast cancer (BC). Here we describe the epigenetic regulation of miR-148a and miR-152 and their impact on BC cells. Due to the hypermethylation of CpG island, the expression levels of both miR-148a and miR-152 (miR-148a/152) are decreased in BC tissues and cells. DNMT1, the DNA methyltransferase 1 for the maintenance methylation, is aberrantly up-regulated in BC and its overexpression is responsible for hypermethylation of miR-148a and miR-152 promoters. Intriguingly, we found that DNMT1 expression, which is one of the targets of miR-148a/152, is inversely correlated with the expression levels of miR-148a/152 in BC tissues. Those results lead us to propose a negative feedback regulatory loop between miR-148a/152 and DNMT1 in BC. More importantly, we demonstrate that IGF-IR and IRS1, often overexpressed in BC, are two novel targets of miR-148a/152. Overexpression of miR-148a or miR-152 significantly inhibits BC cell proliferation, colony formation, and tumor angiogenesis via targeting IGF-IR and IRS1 and suppressing their downstream AKT and MAPK/ERK signaling pathways. Our results suggest a novel miR-148a/152-DNMT1 regulatory circuit and reveal that miR-148a and miR-152 act as tumor suppressors by targeting IGF-IR and IRS1, and that restoration of miR-148a/152 expression may provide a strategy for therapeutic application to treat BC patients.
miR-148a; miR-152; DNMT1; IGF-IR; IRS1; breast cancer; tumor angiogenesis
This study investigates prospectively the development of single and repeated unintentional injuries from birth to 42 months in a random population sample of new-born children in Quebec (Canada) (N = 1,770). The outcome measures are single unintentional injuries (SUI) and repeated unintentional injuries (RUI). Results showed that the risk factors for SUI differed from the risk factors for RUI. SUI was predicted by mother’s antisocial behavior during high school (OR = 1.72) and mother’s age at first birth (OR = 1.82) with children from older mothers at higher likelihood of SUI. Also, boys (OR = 1.36) and hyperactive children (OR = 1.06) were at increased risk of SUI. RUI was predicted by maternal smoking during pregnancy (OR = 1.68), medication on prescription (OR = 1.53) and medication without prescription (OR = 1.54). Boys (OR = 2.01), children with a difficult temperament (OR = 1.13) and those with single mothers had higher rates of RUI (OR = 2.05). Maternal perception of impact (OR = 1.15) and maternal feelings of self-efficacy (OR = 0.87; marginally significant) were also associated with RUI. These results show that maternal and child risk factors identified during pregnancy and just after birth can predict SUI as well as RUI in early childhood. However, the only common risk factor for SUI and RUI is the child’s sex, with boys being at higher risk than girls. Implications of these findings and suggestions for prevention are discussed.
Early prevention; Unintentional injury; Prenatal smoking; Smoking; Prenatal substance use
The maintenance of genomic stability requires accurate genome replication, repair of DNA damage, and the precise segregation of chromosomes in mitosis. GEN1 possesses Holliday junction resolvase activity in vitro and presumably functions in homology driven repair of DNA double strand breaks. However, little is currently known about the cellular functions of human GEN1. In the present study we demonstrate that GEN1 is a novel centrosome associated protein and we characterize the various phenotypes associated with GEN1 deficiency. We identify an N-terminal centrosome localization signal in GEN1, which is required and sufficient for centrosome localization. We report that GEN1 depletion results in aberrant centrosome numbers associated with the formation of multiple spindle poles in mitosis, an increased number of cells with multi-nuclei, increased apoptosis and an elevated level of spontaneous DNA damage. We find homologous recombination severely impaired in GEN1 deficient cells, suggesting that GEN1 functions as a Holliday junction resolvase in vivo as well as in vitro. Complementation of GEN1 depleted cells with various GEN1 constructs revealed that centrosome association but not catalytic activity of GEN1 is required for preventing centrosome hyper-amplification, formation of multiple mitotic spindles, and multi-nucleation. Our findings provide novel insight into the biological functions of GEN1 by uncovering an important role of GEN1 in the regulation of centrosome integrity.
Glutathione S-transferase P1 (GSTP1) is a critical enzyme in the phase II detoxification pathway. One of the common functional polymorphisms of GSTP1 is A→G at nucleotide 313, which results in an amino acid substitution (Ile105Val) at the substrate binding site and reduced catalytic activity. We evaluated the interaction between GSTP1 Val allele and Helicobacter pylori infection, smoking and alcohol consumption, increasing the risk of gastric cancer among the Chinese population. Information on potential gastric cancer risk factors and blood specimens were collected from 618 incident gastric cancer cases and 1,830 non-cancer controls between March 2002 and December 2011 in Liaoning Province, China. GSTP1 Ile105Val was genotyped by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and polymerase chain reaction-restriction fragment length polymorphism. Serum levels of anti-H. pylori IgG were measured by ELISA. Odds ratio (OR) and 95% confidence interval (CI) were calculated using multivariate logistic regression, adjusted by sex and age. The risk of gastric cancer was significantly elevated in patients with the GSTP1 Val/Val genotype (adjusted OR = 3.324; 95% CI = 1.790–6.172). An elevated risk of gastric cancer was observed in patients with H. pylori infection, smoking, or alcohol consumption, and together with the GSTP1 Ile/Val +Val/Val genotype (OR = 3.696; 95% CI = 2.475–5.521; OR = 1.638; 95% CI = 1.044–2.571; OR = 1.641; 95% CI = 0.983–2.739, respectively) (p<0.05). The GSTP1 Val allele shows an interaction with smoking, alcohol consumption, and especially H. pylori infection for increasing the risk of gastric cancer. These findings could demonstrate new pathophysiological pathways for the development of gastric cancer.
Human choriocarcinoma is one of the most aggressive malignant tumors characterized by early hematogenous spread to lung and brain tissues, and may be a cause of death in patients. Choriocarcinoma may occur following pregnancy and during implantation; however, trophoblastic invasion in human pregnancy is tightly regulated. The transforming growth factor-beta 1 (TGF-β1) has been suggested to play a role in controlling this process. In this study, we investigated the impact of TGF-β1 on invasion, as well as its sites of action in the TGF-β1/Smad pathway using a JEG-3 choriocarcinoma cell line. Following the treatment of cells with different doses of TGF-β1, cell invasion was observed. We also detected the expression of TGF-β receptor type I (TβR I) and TGF-β receptor type II (TβR II), Smad4, matrix metalloprotease (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in JEG-3 cells. Our data demonstrated that TGF-β1 promoted the invasive capability of JEG-3 cells depending on the downregulation of TβR I, TβR II, Smad4 and the upregulation of MMP-9 and TIMP-1. These observations suggest that TGF-β1 may play a critical role in the initiation of the trophoblastic invasion process.
transforming growth factor-beta 1; transforming growth factor-beta 1 receptor type I; transforming growth factor-beta 1 receptor type II; Smad4; matrix metalloprotease-9; tissue inhibitors of metalloprotease-1; choriocarcinoma
The ability of the skeleton to adapt to mechanical stimuli diminishes with age in diaphyseal cortical bone, making bone formation difficult for adults. However, the effect of aging on adaptation in cancellous bone, tissue which is preferentially lost with age, is not well characterized. To develop a model for early post-menopausal women and determine the effect of aging on cancellous bone adaptation in the adult mouse skeleton, in vivo tibial compression was applied to adult (26 wk old) osteopenic female mice using loading parameters, peak applied load and peak diaphyseal strain magnitude, that were previously found to be osteogenic in young, growing (10 wk old) mice. A Load-Matched group received the same peak applied loads (corresponding to +2100 με at the medial diaphysis of the tibia) and a Strain-Matched group received the same peak diaphyseal strains (+1200 με, requiring half the load) as the young mice. The effects of mechanical loading on bone mass and architecture in adult mice were assessed using micro-computed tomography and in vivo structural stiffness measures. Adaptation occurred only in the Load-Matched group in both the metaphyseal and diaphyseal compartments. Cancellous bone mass increased 54% through trabecular thickening, and cortical area increased 41% through medullary contraction and periosteal expansion. Adult mice were able to respond to an anabolic stimulus and recover bone mass to levels seen in growing mice; however, the adaptive response was reduced relative to that in 10 wk old female mice for the same applied load. Using this osteogenic loading protocol, other factors affecting pathological bone loss can be addressed using an adult osteopenic mouse model.
aging; bone adaptation; mechanical loading; cancellous bone; cortical bone
Primary soft tissue non-Hodgkin lymphoma (NHL) of the extremities is very rare. The clinical features of NHL mimic those of other soft tissue tumors, particularly sarcoma; however, they should be differentiated, as the treatment and prognosis are completely different. In this study, the case of a 68-year-old female with a giant mass, movement disorder, numbness and painful sensations in the right thigh is presented. Magnetic resonance (MR) imaging revealed a huge circle-shaped mass. Fine needle aspiration cytology (FNAC) of the tumor demonstrated neoplastic small, round cells. The tentative diagnosis was of a mesenchymal sarcoma. The right thigh was amputated. On histological examination of the amputated extremity, the diagnosis was found to be large B cell lymphoma. Primary soft tissue NHL of the extremities is a systemic malignant disease and is sensitive to chemo-therapy and radiotherapy. The histological diagnosis should be identified as far as possible before the tumor is widely excised.
non-Hodgkin lymphoma; soft tissue; amputation; extremity
CARS holography captures both the amplitude and the phase of a complex anti-Stokes field, and can perform three-dimensional imaging by digitally focusing onto different depths inside a specimen. The application of CARS holography for bio-imaging is demonstrated. It is shown that holographic CARS imaging of sub-cellular components in live HeLa cells can be achieved.
(180.5655) Raman microscopy; (090.1995) Digital holography; (180.6900) Three-dimensional microscopy
In the title organic–inorganic hybrid salt, C6H14N+·Br−, N—H⋯Br hydrogen bonds link the cations and anions, forming extended hydrogen-bonded chains along the c axis.
Hydroxypropyl-sulfobutyl-β-cyclodextrin (HP-SBE-β-CD) inclusion complex was developed and used as a drug delivery system for DTX (DTX/HP-SBE-β-CD). The objective of the present study was to evaluate and compare the biological properties of DTX/HP-SBE-Β-CD with Taxotere®. The pharmacokinetics, biodistribution, antitumor efficacy in vivo and in vitro, and safety evaluation of DTX/HP-SBE-β-CD were studied. The most significant finding was that it was possible to prepare a Polysorbate-80-free inclusion complex for DTX. Studies based on pharmacokinetics, biodistribution, and antitumor efficacy indicated that DTX/HP-SBE-β-CD had similar pharmacokinetic properties and antitumor efficacy both in vitro and in vivo as Taxotere®. Fortunately, this new drug delivery system attenuated the side effects when used in vivo. As a consequence, DTX/HP-SBE-β-CD may be a promising alternative to Taxotere® for cancer chemotherapy treatment with reduced side effects. The therapeutic potential against a variety of human tumors and low toxicity demonstrated in a stringent study clearly warrant clinical investigation of DTX/HP-SBE-β-CD for possible use against human tumors.
antitumor efficacy; biodistribution; DTX/HP-SBE-β-CD; pharmacokinetics; safety evaluation
In the structure of the title molecular salt, 2C6H14N+·C10H6O6S2
2−, the asymmetric unit consists of one 2-methylpiperidinium cation and one-half of a naphthalene-1,5-disulfonate anion; the anion lies across a centre of symmetry. In the crystal, the cations and anions are linked through N—H⋯O hydrogen bonds, forming a two-dimensional network.
The asymmetric unit of the title compound, 2C6H14N+·C10H6O6S2
2−, contains one 3-methylpiperidinium cation and one-half of the centrosymmetric naphthalene-1,5-disulfonate anion. In the crystal, anions and cations are linked through N—H⋯O hydrogen bonds into layers parallel to (101).
In the crystal structure of the title molecular salt, C6H14N+·Br−, N—H⋯Br hydrogen bonds link the cations and anions to form a one-dimensional network.
The asymmetric unit of the title compound, (C6H14N)2[SbCl5], contains one cation and half of the anion on a special position (specifically, the SbIII ion and three chloride anions are situated on a mirror plane). In the [SbCl5]2− unit, the SbIII ion is coordinated by five chloride anions [Sb—Cl = 2.3721 (11)–2.6656 (12) Å] in a distorted square-pyramidal geometry. However, one chloride anion from a neighbouring [SbCl5]2− unit provides a short Sb⋯Cl contact of 3.3600 (12) Å and completes the Sb coordination environment up to an elongated octahedron. In the crystal, N—H⋯Cl hydrogen bonds link cations and anions into columns propagating along .
The asymmetric unit of the title salt, (C6H14N)3[FeCl4]Cl2, consists of a tetrahedral tetrachloroferrate anion, three independent 2-methylpiperidinium cations and two chloride ions. All the piperidine rings adopt chair conformations. In the crystal, the organic cations and the free chloride anions are linked into chains parallel to the a axis by N—H⋯Cl hydrogen bonds.
The title compound, (C7H10N)3[SbCl5]Cl·H2O, consists of 4-methylanilinium cations, Cl− and [SbCl5]2− anions and water molecules. The five Cl atoms bound to Sb [Sb—Cl = 2.4043 (9)–2.6262 (11) Å] form a square-pyramidal coordination environment. In addition, two [SbCl5]2− anions related by an inversion center are joined by Sb⋯Cl interactions [Sb⋯Cl = 3.7273 (14) Å] into an [Sb2Cl10]4− dimer with two bridging Cl atoms. The anions, water molecules and ammonium groups of the cations are linked by N—H⋯Cl, N—H⋯O and O—H⋯Cl hydrogen bonds, forming layers parallel to the ac plane. The benzene rings of the 4-methylanilinium cations are packed between these layers.
The asymmetric unit of the crystal structure of the title compound, [Cd2Cl4(C5H8N2)3]n, contains two CdII cations, three 1-ethyl-1H-imidazole ligands, and four Cl− anions. The two CdII atoms have quite different coordination environments: one is octahedrally coordinated by four Cl atoms and two N atoms from two 1-ethyl-1H-imidazole ligands, and the second is in a severely distorted fivefold coordination by four Cl atoms and one N atom from a 1-ethyl-1H-imidazole ligand. Adjacent CdII cations are interconnected alternately by pairs of chloride bridges, generating an infinite step-like chain along the a axis. One ethyl group of the 1-ethyl-1H-imidazole ligand is disordered over two sets of sites with a 0.668 (13):0.332 (13) site-occupancy ratio.
The title compound, [Cu(C2O4)(C5H8N2)2]n, is composed of one-dimensional linear chains running parallel to the a axis. In the chain, trans-[Cu(imidazole)2]2+ units are sequentially bridged by bis-bidentate oxalate ligands, resulting in an octahedral CuO4N2 donor set. The Cu⋯Cu separation through the oxalate bridge is 5.620 (5) Å. Both the Cu atoms and the C—C bond of the oxalate bridge are bisected by inversion centres.
DifA is a methyl-accepting chemotaxis protein (MCP)-like sensory transducer that regulates exopolysaccharide (EPS) production in Myxococcus xanthus. Here mutational analysis and molecular biology were used to probe the signaling mechanisms of DifA in EPS regulation. We first identified the start codon of DifA experimentally; this identification extended the N terminus of DifA for 45 amino acids (aa) from the previous bioinformatics prediction. This extension helped to address the outstanding question of how DifA receives input signals from type 4 pili without a prominent periplasmic domain. The results suggest that DifA uses its N-terminus extension to sense an upstream signal in EPS regulation. We suggest that the perception of the input signal by DifA is mediated by protein-protein interactions with upstream components. Subsequent signal transmission likely involves transmembrane signaling instead of direct intramolecular interactions between the input and the output modules in the cytoplasm. The basic functional unit of DifA for signal transduction is likely dimeric as mutational alteration of the predicted dimeric interface of DifA significantly affected EPS production. Deletions of 14-aa segments in the C terminus suggest that the newly defined flexible bundle subdomain in MCPs is likely critical for DifA function because shortening of this bundle can lead to constitutively active mutations.
In the title compound, [Cu(C8H4O4)(C3H4N2)2]n, the CuII atom is four-coordinated by two carboxylate O atoms from two different terephthalate ligands and two N atoms from two imidazole ligands in a slightly distorted square-planar coordination environment. Each terephthalate ligand acts as a bis-monodentate ligand that binds two CuII atoms, thus forming two unique chains extending parallel to . The imidazole ligands are attached on both sides of the chains.
The reaction of 4-bromo-3-methylanilinium perchlorate and 18-crown-6 in methanol solution yielded the title compound, C7H9BrN+·ClO4
−·C12H24O6. The protonated 4-bromo-3-methylamine unit contains one –NH3
+ substituent, resulting in a 1:1 supramolecular rotator–stator structure, (C7H9Br—NH3
+)(18-crown-6), through three bifurcated N—H⋯(O,O) hydrogen bonds between the ammonium group of the cation and the O atoms of the crown ether molecule.
Pertactin (PRN) is an autotransporter protein produced by all members of the Bordetella bronchiseptica cluster, which includes B. pertussis, B. parapertussis, and B. bronchiseptica. It is a primary component of acellular pertussis vaccines, and anti-PRN antibody titers correlate with protection. In vitro studies have suggested that PRN functions as an adhesin and that an RGD motif located in the center of the passenger domain is important for this function. Two regions of PRN that contain sequence repeats (region 1 [R1] and R2) show polymorphisms among strains and have been implicated in vaccine-driven evolution. We investigated the role of PRN in pathogenesis using B. bronchiseptica and natural-host animal models. A Δprn mutant did not differ from wild-type B. bronchiseptica in its ability to adhere to epithelial and macrophage-like cells in vitro or to establish respiratory infection in rats but was cleared much faster than wild-type bacteria in a mouse lung inflammation model. Unlike wild-type B. bronchiseptica, the Δprn mutant was unable to cause a lethal infection in SCID-Bg mice, but, like wild-type bacteria, it was lethal for neutropenic mice. These results suggest that PRN plays a critical role in allowing Bordetella to resist neutrophil-mediated clearance. Mutants producing PRN proteins in which the RGD motif was replaced with RGE or in which R1 and R2 were deleted were indistinguishable from wild-type bacteria in all assays, suggesting that these sequences do not contribute to PRN function.
In the title zwitterionic molecule, C6H5N5, the tetrazole and pyridine rings are nearly coplanar, making a dihedral angle of 2.08 (1)°. In the crystal, molecules are connected by classical N—H⋯N and weak C—H⋯N hydrogen bonds.
Myxococcus xanthus, a Gram-negative soil bacterium, undergoes multicellular development when nutrients become limiting. Aggregation, which is part of the developmental process, requires the surface motility of this organism. One component of M. xanthus motility, the social (S) gliding motility, enables the movement of cells in close physical proximity. Previous studies demonstrated that the cell-surface associated exopolysaccharide (EPS) is essential for S motility and the Dif proteins form a chemotaxis-like pathway that regulates EPS production in M. xanthus. DifA, a homologue of methyl-accepting chemotaxis proteins (MCPs) in the Dif system, is required for EPS production, S motility and development. In this study, a spontaneous extragenic suppressor of a difA deletion was isolated in order to identify additional regulators of EPS production. The suppressor mutation was found to be a single base-pair insertion in cheW7 at the che7 chemotaxis gene cluster. Further examination indicated that mutations in cheW7 may lead to the interaction of Mcp7 with DifC (CheW-like) and DifE (CheA-like) to reconstruct a functional pathway to regulate EPS production in the absence of DifA. In addition, the cheW7 mutation was found to partially suppress a pilA mutation in EPS production in a difA+ background. Further deletion of difA from the pilA cheW7 double mutant resulted in a triple mutant that produced wild-type levels of EPS, implying that DifA (MCP-like) and Mcp7 compete for interactions with DifC and DifE in the modulation of EPS production.