Abstract
Pancreatic ductal adenocarcinoma (PDAC) is thought to derive from the epithelial ductal cells of which the apical pole is facing the lumen of the pancreatic ducts. In physiological state, ...the transmembrane mucin MUC1 is expressed at the apical pole where it protects the cell, senses the environment and modulates signal transduction notably by interacting with EGFR. In tumor cells, the localization of MUC1 glycoprotein is modified. MUC1 expression at the membrane becomes circumferential and accumulates in the cytoplasm. This sequestration is thought to deliver oncogenic signals to the cell, and is used by pathologists on fine-needle aspirates of pancreatic lesions as an indicator of malignancy. However, the mechanisms explaining the modified topography of MUC1 expression in cancer cells are still unknown. Since it was previously demonstrated that endogenous lectins from the galectin family, especially galectin-3 and −4, control the apical targeting of glycoproteins in epithelial cells, our aim was to study the role of galectin-3 in the control of MUC1 expression topography in PDAC, and in the cell invasiveness in vitro. To this end we stably and selectively knocked-down (KD) galectin-3 expression by shRNA approach in the pancreatic polarized CAPAN-1 cells. Three different shRNA targeting LGALS3 mRNA were designed (sh1, sh2, sh3) together with a scramble control one (sc). Sh1 and sh3 cells were selected on the basis of the efficiency of the KD evaluated both at RNA and protein levels. Galectin-3 down-regulation is associated with a decrease of both MUC1 and EGFR protein levels. However, sh1 and sh3 cells expressed 2-fold higher levels of phosphoEGFR in response to EGF treatment than sc cells. The localization of MUC1 and EGFR was studied by confocal microscopy. In sc cells, MUC1 staining mainly concerns the apical surface and the cytoplasm as expected. In sh1 cells, invalidation of galectin-3 led to a strong decrease of MUC1 cytoplasmic labeling. To check the clinical relevance of our data, we performed MUC1 and galectin-3 immunostaining on 16 human PDAC surgically removed in our hospital. In all PDAC, 100% of the tumor cells exhibited a positive and strong MUC1 immunostaining that concerned the cell cytoplasm. By contrast, in normal ductal cells MUC1 staining was restricted to the apical side. Galectin-3 staining was weaker and more heterogeneous than that of MUC1. In all PDAC, 5-80% of the tumor cells were galectin-3 positive with a variable intensity of the immunostaining. Finally, sh1, sh3 and sc cell invasiveness was assessed in vitro on collagen type I matrix. Preliminary results showed that sh1 and sh3 cells lost their in vitro invasive phenotype. In conclusion, our data showed that galectin-3 is responsible for MUC1 cytoplasmic retention in pancreatic tumor cells. Silencing of galectin-3 promotes MUC1 localization at the cell membrane, and increases EGF-induced EGFR phosphorylation.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
Citation Format: {Authors}. {Abstract title} abstract. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1056.
A novel mutation of the ACADM gene Dessein, Anne-Frédérique; Fontaine, Monique; Andresen, Brage S ...
Orphanet journal of rare diseases,
10/2010, Volume:
5
Journal Article
Peer reviewed
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
A female patient, with normal familial history, developed at the age of 30 months an episode of diarrhoea, vomiting and lethargy which resolved spontaneously. At the age of 3 years, the patient ...re-iterated vomiting, was sub-febrile and hypoglycemic, fell into coma, developed seizures and sequels involving right hemi-body. Urinary excretion of hexanoylglycine and suberylglycine was low during this metabolic decompensation. A study of pre- and post-prandial blood glucose and ketones over a period of 24 hours showed a normal glycaemic cycle but a failure to form ketones after 12 hours fasting, suggesting a mitochondrial beta-oxidation defect. Total blood carnitine was lowered with unesterified carnitine being half of the lowest control value. A diagnosis of mild MCAD deficiency (MCADD) was based on rates of 1-.sup.14.sup.C-octanoate and 9, 10-.sup.3.sup.H-myristate oxidation and of octanoyl-CoA dehydrogenase being reduced to 25% of control values. Other mitochondrial fatty acid oxidation proteins were functionally normal. De novo acylcarnitine synthesis in whole blood samples incubated with deuterated palmitate was also typical of MCADD. Genetic studies showed that the patient was compound heterozygous with a sequence variation in both of the two ACADM alleles; one had the common c.985A>G mutation and the other had a novel c.145C>G mutation. This is the first report for the ACADM gene c.145C>G mutation: it is located in exon 3 and causes a replacement of glutamine to glutamate at position 24 of the mature protein (Q24E). Associated with heterozygosity for c.985A>G mutation, this mutation is responsible for a mild MCADD phenotype along with a clinical story corroborating the emerging literature view that patients with genotypes representing mild MCADD (high residual enzyme activity and low urinary levels of glycine conjugates), similar to some of the mild MCADDs detected by MS/MS newborn screening, may be at risk for disease presentation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Deciphering the mechanisms underlying skeletal muscle-cell differentiation in mammals is an important challenge. Cell differentiation involves complex pathways regulated at both transcriptional and ...post-transcriptional levels. Recent observations have revealed the importance of small (20-25 base pair) non-coding RNAs (microRNAs or miRNAs) that are expressed in both lower organisms and in mammals. miRNAs modulate gene expression by affecting mRNA translation or stability. In lower organisms, miRNAs are essential for cell differentiation during development; some miRNAs are involved in maintenance of the differentiated state. Here, we show that miR-181, a microRNA that is strongly upregulated during differentiation, participates in establishing the muscle phenotype. Moreover, our results suggest that miR-181 downregulates the homeobox protein Hox-A11 (a repressor of the differentiation process), thus establishing a functional link between miR-181 and the complex process of mammalian skeletal-muscle differentiation. Therefore, miRNAs can be involved in the establishment of a differentiated phenotype - even when they are not expressed in the corresponding fully differentiated tissue.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Preterm delivery during pregnancy (<37 weeks' gestation) is a leading cause of perinatal mortality and morbidity. Treating bacterial vaginosis during pregnancy can reduce poor outcomes, such as ...preterm birth. We aimed to investigate whether treatment of bacterial vaginosis decreases late miscarriages or spontaneous very preterm birth.
PREMEVA was a double-blind randomised controlled trial done in 40 French centres. Women aged 18 years or older with bacterial vaginosis and low-risk pregnancy were eligible for inclusion and were randomly assigned (2:1) to three parallel groups: single-course or triple-course 300 mg clindamycin twice-daily for 4 days, or placebo. Women with high-risk pregnancy outcomes were eligible for inclusion in a high-risk subtrial and were randomly assigned (1:1) to either single-course or triple-course clindamycin. The primary outcome was a composite of late miscarriage (16–21 weeks) or spontaneous very preterm birth (22–32 weeks), which we assessed in all patients with delivery data (modified intention to treat). Adverse events were systematically reported. This study is registered with ClinicalTrials.gov, number NCT00642980.
Between April 1, 2006, and June 30, 2011, we screened 84 530 pregnant women before 14 weeks' gestation. 5630 had bacterial vaginosis, of whom 3105 were randomly assigned to groups in the low-risk trial (n=943 to receive single-course clindamycin, n=968 to receive triple-course clindamycin, and n=958 to receive placebo) or high-risk subtrial (n=122 to receive single-course clindamycin and n=114 to receive triple-course clindamycin). In 2869 low-risk pregnancies, the primary outcome occurred in 22 (1·2%) of 1904 participants receiving clindamycin and 10 (1·0%) of 956 participants receiving placebo (relative risk RR 1·10, 95% CI 0·53–2·32; p=0·82). In 236 high-risk pregnancies, the primary outcome occurred in 5 (4·4%) participants in the triple-course clindamycin group and 8 (6·0%) participants in the single-course clindamycin group (RR 0·67, 95% CI 0·23–2·00; p=0·47). In the low-risk trial, adverse events were more common in the clindamycin groups than in the placebo group (58 3·0% of 1904 vs 12 1·3% of 956; p=0·0035). The most commonly reported adverse event was diarrhoea (30 1·6% in the clindamycin groups vs 4 0·4% in the placebo group; p=0·0071); abdominal pain was also observed in the clindamycin groups (9 0·6% participants) versus none in the placebo group (p=0·034). No severe adverse event was reported in any group. Adverse fetal and neonatal outcomes did not differ significantly between groups in the high-risk subtrial.
Systematic screening and subsequent treatment for bacterial vaginosis in women with low-risk pregnancies shows no evidence of risk reduction of late miscarriage or spontaneous very preterm birth. Use of antibiotics to prevent preterm delivery in this patient population should be reconsidered.
French Ministry of Health.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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