Fetal expressed gene analysis in maternal blood: a new tool for noninvasive study of the fetus.
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Chorionic Gonadotropin↗
Biomedical subjects
Michel Vidaud
Publications and source records attributed to Michel Vidaud.
Placenta-specific INSL4 expression is mediated by a human endogenous retrovirus element.
The human insulin-family genes regulate cell growth, metabolism, and tissue-specific functions. Among these different members, only INSL4 gene shows a predominant placenta-specific expression. Here, we show that the human INSL4 gene is tightly clustered with three other members of the human insulin superfamily (RLN1, RLN2, and INSL6) within a 176-kilobase genomic segment on chromosome region 9p23.3-p24.1. We also report evidence that INSL4 is probably the only insulin-like growth factor gene to be primate-specific. We identified an unexpected human endogenous retrovirus (HERV) element inserted into the human INSL4 promoter with a sequence similar to that of env gene, flanked by two long terminal repeats(LTRs). The emergence of INSL4 gene and genomic insertion of HERV appear to have occurred after the divergence of New World and Old World monkeys ( approximately 45 million years ago). Transient transfection experiments showed that the placenta-specific expression of INSL4 is mediated by the 3' LTR of the HERV element, and that the latter may have a major role in INSL4 up-regulation during human cytotrophoblast differentiation into syncytiotrophoblast. Finally, we identified an INSL4 alternatively spliced mRNA species that encodes putative novel INSL4-like peptides. These data support the view that ancient retroviral infection may have been a major event in primate evolution, especially in the functional evolution of the human placenta.
5' Flanking Region↗
Increased incidence of ERBB2 overexpression and TP53 mutation in inflammatory breast cancer.
Inflammatory breast cancer (IBC) is one of the most aggressive forms of breast cancer. We studied the biological characteristics of these tumours by comparing the overexpression of oncogenes ERBB2, MYC, CCND1 and RHOC and TP53 gene mutation rates in IBC with those found in locally advanced and not otherwise specified breast cancers. The prevalence of the TP53 mutation was much higher in IBC than in the two other types of cancer (57% vs 30). Unexpectedly, however, in IBC tumours, histological grade was independent of TP53 status. In addition, ERBB2 overexpression was twice as frequent in inflammatory as in non-inflammatory tumours, whereas the frequencies of MYC, CCND1 and RHOC overexpression did not vary significantly among the three types of breast cancer. These findings suggest that IBC tumours constitute a distinct subset with a specific pathogenesis. Given the importance of TP53 and ERBB2 in the response to treatments, our observations have important therapeutic implications for the clinical management of IBC patients.
Breast Neoplasms↗
Development of a real-time polymerase chain reaction assay for the diagnosis of human herpesvirus-6 infection and application to bone marrow transplant patients.
A quantitative real-time PCR assay was developed for human herpesvirus-6 (HHV-6) genome based on TaqMan technology. After choosing a region of interest into the U65-U66 genes of HHV-6 genome, its nucleotide sequence was determined among four HHV-6 strains (one variant A and three variants B) to exclude a variability of sensitivity due to interstrain sequence differences. A plasmid containing HHV-6 target sequences identical to those of reference type viruses was constructed with the aim of standardisation. This HHV-6 genomic quantitation assay has a threshold sensitivity of ten copy equivalents (EqCop) per reaction. In order to test the feasibility of this assay directly on human samples, the technique was applied to the quantitation of HHV-6 genome in 30 blood samples from healthy subjects as well as 31 blood samples and three samples of cerebrospinal fluid (CSF) from 21 bone marrow transplant (BMT) recipients and four patients with a haematological disease but not treated by bone marrow transplantation. HHV-6 load ranged between 0.00015 and 0.0008 equivalent DNA copy number (EqCop) per 100 peripheral blood mononuclear cells (PBMCs) in healthy subjects whereas it ranged from <10 to 7500 EqCop per 100 PBMCs, and from <10 to 415,820 EqCop per 100 microl of whole CSF in patients. The efficacy of treatment with antiherpetic drug was associated with a decrease of the viral load in the CSF of one patient. This method leads to relevant results in term of range of quantitation, sensitivity, and safety against contamination by amplicons, and might constitute a useful tool for the follow-up of BMT recipients particularly in the presence of antiherpetic therapy.
Adult↗
CGA gene (coding for the alpha subunit of glycoprotein hormones) overexpression in ER alpha-positive prostate tumors.
OBJECTIVE: The precise role of estrogen, estrogen receptor (ER) and ER-responsive genes in prostate carcinogenesis is unclear. Paradoxically, estrogens and antiestrogens are used in the treatment of advanced metastatic prostate cancers. Recently, we identified CGA gene coding for the alpha subunit of glycoprotein hormones as a new ER alpha-responsive gene in human breast cancer cells. The aim of this study was to explore the role of CGA in the second major hormone-related cancer, i.e. prostate cancer. PATIENTS AND METHODS: We quantified CGA mRNA in nine cases of benign prostatic hyperplasia (BPH) and 23 sporadic prostate tumors (TP) by using a real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay. RESULTS: CGA overexpression (> 10 S.D. above the mean in normal prostate tissues (NP)) was observed in 39% of the TP (ranging from 4.4 to 174.5 times the level in NP) and in none of the BPH samples. CGA overexpression was not accompanied by overexpression of the CGB, LHB, TSHB or FSHB genes to produce ectopic glycoprotein hormones. CGA gene overexpression correlated with ER alpha normal expression (P = 0.016), but not with ER beta or androgen receptor (AR) expression status. CONCLUSION: These results point to CGA gene as a member of a novel dysregulated pathway in prostate cancer. CGA should therefore be considered for investigation as possible novel molecular marker in clinical applications and as possible new potential therapeutic target.
Breast Neoplasms↗
Inhibition of rat liver fibrogenesis through noradrenergic antagonism.
The effect of adrenergic innervation and/or circulating catecholamines on the function of liver fibrogenic cells is poorly understood. Our aim was to investigate the effects of noradrenergic antagonism on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Two weeks of CCl4 induced an approximately 5-fold increase in the area of fibrosis as compared with controls. The addition of 6-hydroxydopamine (OHDA), a toxin that destroys noradrenergic fibers, decreased fibrosis by 60%. After 6 weeks of CCl4, the area of fibrosis increased about 30-fold in CCl4-treated animals and was decreased by 36% with OHDA. At 2 weeks, OHDA abrogated the CCl4-induced increase in mRNA level of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), an inhibitor of extracellular matrix degradation, and it greatly reduced it at 6 weeks. Finally, when rats treated with CCl4 for 2 weeks also received prazosin, an antagonist of alpha1-adrenergic receptors, fibrosis was decreased by 83%. In conclusion, destruction of noradrenergic fibers or antagonism of noradrenergic signaling through alpha1 receptors inhibited the development of liver fibrosis. Because adrenoreceptor antagonists have a very sound safety profile, they appear as attractive drugs to reduce liver fibrogenesis.
Adrenergic Agents↗
Effect of matrigel on human extravillous trophoblasts differentiation: modulation of protease pattern gene expression.
The human placenta is characterized by extensive trophoblast invasion of the uterus. Indeed, extravillous cytotrophoblast cells invade the decidua and the upper third of uterine spiral arteries in the myometrium. This invasion is reflected in situ by the expression of specific markers. In order to study this invasion process, we have established an in vitro culture model of human extravillous trophoblast isolated from first trimester chorionic villi. The aim of this study was to investigate the effect of a composite matrix, the Matrigel required for the culture of this homogenous population of extravillous trophoblasts (EVCT), on their in vitro differentiation. The effect of Matrigel was studied on different markers characterized by immunocytochemistry and by real-time polymerase chain reaction assay of transcripts. In addition, the expression of 12 different matrix metalloproteases and their inhibitors were investigated. We show that human extravillous cytotrophoblasts acquire an invasive phenotype on Matrigel associated with a specific pattern of protease gene expression. This in vitro model will be of interest to study the cellular mechanisms involved in abnormal trophoblast invasion observed in poor placentation and preeclampsia.
Base Sequence↗
Effects and regulation of connective tissue growth factor on hepatic stellate cells.
Connective tissue growth factor (CTGF) is a 38-kd protein involved in several human fibrotic disorders including atherosclerosis and skin and renal fibrosis. Although it has been shown that human and experimental liver fibrosis is associated with CTGF expression through up-regulation of CTGF mRNA by hepatic stellate cells (HSC), the role of CTGF in the liver has not yet been determined. The aim of the present study was to assess the effects of CTGF on rat primary HSC and its regulation in a well-established model of in vitro liver fibrogenesis. Incubation of primary HSC with recombinant CTGF induced a significant migratory (2.3-fold, 50 ng/ml CTGF) and proliferative effect (1.8-fold, 100 ng/ml CTGF). Type I collagen mRNA expression, as assessed by a real-time RT-PCR procedure, was also increased when cells were incubated in the presence of CTGF (2-fold, 50 ng/ml). Transforming growth factor-beta1 (TGF-beta1) strongly stimulated CTGF mRNA expression, a direct mechanism observed in the absence of any intermediate protein synthesis. Furthermore, spontaneous activation of HSC plated on plastic and stimulation by vascular endothelial growth factor, lipid peroxidation products (HNE, MDA), acetaldehyde, and platelet-derived growth factor (PDGF)-BB significantly up-regulated CTGF mRNA expression in HSC. PDGF-induced CTGF stimulation might be related in part to TGF-beta1 secretion because CTGF mRNA up-regulation observed after PDGF-BB stimulation was abrogated in the presence of neutralizing TGF-beta1 antibody. In conclusion, this study extends the role of CTGF in HSC activation and suggests that CTGF up-regulation might be a central pathway during HSC activation.
Animals↗
Dystroglycan expression in hepatic stellate cells: role in liver fibrosis.
Dystroglycan is a membrane component of the dystrophin-glycoprotein transmembrane complex. Its expression is required for the spatial organization of laminin on the cell surface and for basement membrane assembly. In view of the constitution of a perisinusoidal basement membrane during liver fibrosis, we studied dystroglycan expression in liver fibrosis. Dystroglycan mRNA and protein expression were investigated by immunofluorescence, Western blot, and quantitative RT-PCR (TaqMan) in normal human and rat liver and in isolated rat hepatic stellate cells. On Western blot, a 43-kd band corresponding to beta-dystroglycan was observed in protein extracted from normal and fibrotic human and rat livers. The specific 43-kd protein was also detected in lysates from rat hepatic stellate cells but not from hepatocytes. By immunofluorescence, patchy deposits of beta-dystroglycan were detected on membrane of hepatic stellate cells in culture. On Western blot and quantitative RT-PCR, an up-regulation of beta-dystroglycan was shown during spontaneous activation of hepatic stellate cells in culture. Direct evidence for the role of dystroglycan in laminin-hepatic stellate cell interaction was shown because specific antibody directed against alpha-dystroglycan inhibited partially hepatic stellate cell adhesion on laminin-coated plates. This mechanism was calcium dependent because EDTA inhibited cell/laminin adhesion, an effect reversed by addition of Ca(2+). This study shows that dystroglycan is expressed on the membrane of hepatic stellate cells and is up-regulated during liver fibrosis. Dystroglycan interaction with laminin should be implicated in the concentration of pericellular laminin and in the constitution of a perisinusoidal basement membrane during liver fibrosis.
Animals↗
Implication of copper zinc superoxide dismutase (SOD-1) in human placenta development.
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Cell Differentiation↗