Pathogenèse du cancer de l'endomètre de type I : de l'hyperplasie au cancer [Pathogenesis of type I endometrial carcinoma: From hyperplasia to cancer]

Les carcinomes de l'endomètre sont classés en deux types cliniques (types I et II), cinq types histologiques et quatre types moléculaires. Le type I correspond à l'adénocarcinome endométrioïde de grade 1 ou 2, précédé par des lésions d'hyperplasie atypique. Ce cancer est souvent révélé à un stade précoce par des saignements vaginaux postménopausiques et son pronostic est globalement favorable. Les facteurs de risque à l'origine de la majorité des cas (indice de masse corporelle [IMC] élevé, diabète de type II, traitement hormonal substitutif, tamoxifène) agissent par le biais d'une hyperestrogénie non contrecarrée par la progestérone. Moins de 5 % des cas surviennent dans le contexte d'un syndrome de Lynch (anomalie germinale d'un gène de réparation de l'ADN, à transmission autosomique dominante) chez des femmes plus jeunes dont l'IMC est typiquement bas. Les cancers de l'endomètre de type II (carcinomes séreux, à cellules claires, indifférenciés), plus rares, sont des tumeurs agressives diagnostiquées typiquement chez des femmes plus âgées et à un stade plus avancé, de pronostic défavorable.

Sub lethal mercuric chloride toxicity induced stress related alterations in the epithelial lining of foot of the freshwater mussel Lamellidens marginalis (Lamarck)

Sub lethal (0.2 ppm) mercuric chloride induced stress related histopathological alterations in the epithelial linings of foot (podium) of the edible freshwater mussel Lamellidens marginalis (Lamarck) were studied using histochemical techniques up to 60 days of exposure. The histomorphological changes were manifested only slowly and its intensity was somewhat proportional to the duration of exposure. The immediate response of the exposed mussels was the altered mucous secretion. There was a progressive incorporation of sulphated glycoproteins into the secretory contents of the mucous cells especially in the first half of the experiment. Marked histopathological changes including necrosis, appearance of pyknotic nuclei, sloughing of epithelial cells and appearance of non-tissue spaces, etc., started appearing during the later half of the experiment. The fag end of the experiment, which witnessed prominent histomorphological changes, was accompanied by highly decreased mucous secretion. KEYWORDS: heavy metal toxicity, mercuric chloride, Lamellidens marginalis, freshwater mussel, histopathology.

Analysis of the role of the transcription factor C/EBPβ in controlling uterine functions during early pregnancy

Embryo implantation into the endometrium is a complex biological process involving the integration of steroid hormone signaling, endometrial tissue remodeling and maternal- fetal communications. A successful pregnancy is the outcome of the timely integration of these events during the early stages of implantation. The involvement of ovarian steroid hormones, estrogen (E) and progesterone (P), acting through their cognate receptors, is essential for uterine functions during pregnancy. The molecular mechanisms that control the process of implantation are undergoing active exploration. Through our recent efforts, we identified the transcription factor, CCAAT Enhancer Binding Protein Beta (C/EBPb) as a prominent target of estrogen and progesterone signaling in the uterus. The development of a C/EBPb-null mouse model, which is infertile, presented us with an opportunity to analyze the role of this molecule in uterine function. We discovered that C/EBPb functions in two distinct manners: (i) by acting as a mediator of E-induced proliferation of the uterine epithelium and (ii) by controlling uterine stromal cell differentiation, a process known as decidualization, during pregnancy. My studies have delineated important mechanisms by which E regulates C/EBPb expression to induce DNA replication and prevent apoptosis of uterine epithelial cells during E-induced epithelial growth. In subsequent studies, I analyzed the role of C/EBPb in decidualization and uncovered a unique mechanism by which C/EBPb regulates the synthesis of a unique laminin-containing extracellular matrix (ECM) that supports stromal cell differentiation and embryo invasion. In order to better define the role of laminin in implantation, we developed a laminin gamma 1-conditional knockout mouse model. This is currently an area of ongoing investigation. The information gained from our analysis of C/EBPb function in the uterus provides new insights into the mechanisms of steroid hormone action during early pregnancy. Ultimately, our findings may aid in the understanding of dysregulation of hormone-controlled pathways that underlie early pregnancy loss and infertility in women.

CYR61 and TAZ Upregulation and Focal Epithelial to Mesenchymal Transition May Be Early Predictors of Barrett’s Esophagus Malignant Progression

Barrett's esophagus is the major risk factor for esophageal adenocarcinoma. It has a low but non-neglectable risk, high surveillance costs and no reliable risk stratification markers. We sought to identify early biomarkers, predictive of Barrett's malignant progression, using a meta-analysis approach on gene expression data. This in silico strategy was followed by experimental validation in a cohort of patients with extended follow up from the Instituto Português de Oncologia de Lisboa de Francisco Gentil EPE (Portugal). Bioinformatics and systems biology approaches singled out two candidate predictive markers for Barrett's progression, CYR61 and TAZ. Although previously implicated in other malignancies and in epithelial-to-mesenchymal transition phenotypes, our experimental validation shows for the first time that CYR61 and TAZ have the potential to be predictive biomarkers for cancer progression. Experimental validation by reverse transcriptase quantitative PCR and immunohistochemistry confirmed the up-regulation of both genes in Barrett's samples associated with high-grade dysplasia/adenocarcinoma. In our cohort CYR61 and TAZ up-regulation ranged from one to ten years prior to progression to adenocarcinoma in Barrett's esophagus index samples. Finally, we found that CYR61 and TAZ over-expression is correlated with early focal signs of epithelial to mesenchymal transition. Our results highlight both CYR61 and TAZ genes as potential predictive biomarkers for stratification of the risk for development of adenocarcinoma and suggest a potential mechanistic route for Barrett's esophagus neoplastic progression.

Characterization of in vitro effects of patulin on intestinal epithelial and immune cells

The intestinal mucosa is the first biological barrier encountered by natural toxins, and could possibly be exposed to high amounts of dietary mycotoxins. Patulin (PAT), a mycotoxin produced by Penicillium spp. during fruit spoilage, is one of the best known enteropathogenic mycotoxins able to alter functions of the intestine (Maresca et al., 2008). This study evaluated the effects of PAT on barrier function of the gut mucosa utilizing the intestinal epithelial cell model Caco-2, and scrutinized immunomodulatory effects using human peripheral blood mononuclear cells (PBMC) and human blood monocyte-derived dendritic cells (moDCs) as test systems. PAT exposure reduced Caco-2 cell viability at concentrations above 12 mM. As expected, the integrity of a polarized Caco-2 monolayer was affected by PAT exposure, as demonstrated by a decrease in TER values, becoming more pronounced at 50 mM. No effects were detected on the expression levels of the tight junction proteins occludin, claudin-1 and claudin-3 at 50 mM. However, the expression of zonula occludens-1 (ZO-1) and myosin light chain 2 (MLC2) declined. Also, levels of phospho-MLC2 (p-MLC2) increased after 24 h of exposure to 50 mM of PAT. T cell proliferation was highly sensitive to PAT with major effects for concentrations above 10 nM of PAT. The same conditions did not affect the maturation of moDC. PAT causes a reduction in Caco-2 barrier function mainly by perturbation of ZO-1 levels and the phosphorylation of MLC. Low doses of PAT strongly inhibited T cell proliferation induced by a polyclonal activator, but had no effect on the maturation of moDC. These results provide new information that strengthens the concept that the epithelium and immune cells of the intestinal mucosa are important targets for the toxic effects of food contaminants like mycotoxins

Nuclear alterations in nasal mucosa epithelial cells of students exposed to formaldehyde

Introduction: Formaldehyde is a compound with a wide range and is commonly used in anatomy and pathology laboratories. At room temperature is quickly volatilized to a pungent and suffocating gas and its inhalation has been correlated to nuclear alterations in different tissues. We aimed to investigate whether exposure to this compound was correlated with the appearance of cytotoxic and genotoxic features in the nasal epithelial cells of students enrolled in a human anatomy course. Material and Methods: This prospective study collected periodically nasal cells from mucosa of 17 volunteers from two different undergraduate programs with different workloads of practical lessons in an anatomy laboratory, 30 and 90 hours per semester. Cells were staining according to Feulgen method and nuclear morphology was analyzed to detect possible damage. Dunn's post hoc test was used in the statistical analysis. Pearson's correlation was performed for gender, age and questionnaire responses. Results: Epithelial cells showed indicators of cytotoxicity and mutagenicity. Students with a more extensive workload in anatomy laboratory displayed a more severe profile with an increase in karyorrhexis (p < 0.05) over time. The micronucleus analysis showed difference between first and second collection (p < 0.01), although it was not maintained over the time. Students with a less extensive workload display no differences in most of cytological features. Despite karyorrhexis was present in a greater number of cells, for this group no significant difference was observed between any range. The same was observed to karyolysis and micronucleus (p > 0.05). Conclusion: Individuals exposed for short periods of time to formaldehyde are subject to the toxic action of this gas. Karyorrhexis was the most frequently observed cytotoxic feature and micronucleus showed an increase between the first time point. The patterns observed between the student's groups suggest a negative effect due to exposure time.

Regulation of epithelial chloride transport by tyrosine phosphorylation

Background: Chloride transport proteins are involved in a variety of human diseases and thus represent important drug targets. They are regulated in part through the amount present at the plasma membrane and tyrosine phosphorylation has been described as a novel regulator.

Endometrial tuberculosis simulating an ovarian cancer

Female genital tuberculosis remains a major health problem in developing countries and is an important cause of infertility. As symptoms, laboratory data and physical fndings are non-specifc, its diagnosis can be diffcult. We describe a case of a 39-year-old woman suffering from peri-umbilical pain and increased abdominal size for one year, anorexia, asthenia, weight loss, occasionally dysuria and dyspareunia, and four months amenorrhea. Laboratory data revealed cancer antigen 125 (CA-125) level of 132.3 U/mL, erythrocyte sedimentation rate of 42 mm/h, and gamma-globulins of 2.66 g/dL. Computer Tomography scan showed loculated ascites. It was initially suspected a carcinomatous origin, but ascites evaluation was negative for malignant cells. Magnetic Resonance Imaging from another hospital showed endometrial heterogeneity. Therefore, an endometrial biopsy was performed demonstrating an infammatory infltrate with giant cells of type Langhans and bacteriological culture identifed Mycobacterium tuberculosis

Preoperative assessment of deep myometrial and cervical invasion in endometrial carcinoma: comparison of magnetic resonance imaging and histopathologic evaluation

This study aimed to evaluate the accuracy of magnetic resonance imaging (MRI) in the detection of deep myometrial invasion and cervical extension by endometrial carcinoma. This prospective study included 101 patients with histologically documented endometrial carcinoma, between July 1998 and April 2004. The findings of preoperative pelvic MRI were compared with histological diagnosis. From 101 cases studied by pelvic MRI, 43 were classified as deep myometrial invasion (50% of myometrium), where the pathological evaluation confirmed as having deep myometrial invasion. Cervical extension in the MRI study was found in 19 cases. Pathologic study found cervical extension and/or invasion in 31 cases including all cases identified by MRI. The accuracy, sensitivity and specificity of MRI were 95%, 89%, 100%, detecting deep myometrial invasion and 88%, 61%, 100%, detecting cervical invasion, respectively. The high accuracy achieved makes MRI an adequate method for determine the depth of myometrial and cervical invasion in endometrial carcinoma.

Dual Roles of Diadenosine Polyphosphates in Corneal Epithelial Cell Migration

Purpose. To investigate the influence of diadenosine polyphosphates on the rate of corneal epithelial cell migration. Methods. Primary corneal epithelial cell cultures were obtained from New Zealand White rabbits. Immunocytochemical experiments were performed by fixing the cells with 4% paraformaldehyde (PFA) and incubated with cytokeratin 3 primary antibody, which was subsequently incubated with a secondary IgG mouse labeled with FITC, and the cells were observed under confocal microscopy. Migration studies were performed by taking confluent monolayers that were wounded with a pipette tip and challenged with different di- and mononucleotides with or without P2 antagonist (n = 8 each treatment). For concentration–response analysis, compounds were tested in doses ranging from 10−8 to 10−3 M (n = 8). The stability of the dinucleotides was assayed by HPLC, with an isocratic method (n = 4). Results. Cells under study were verified as corneal epithelial cells via the immunocytochemical analysis. Cell migration experiments showed that Ap4A, UTP, and ATP accelerated the rate of healing (5, 2.75, and 3 hours, respectively; P < 0.05; P < 0.001), whereas Ap3A, Ap5A, and UDP delayed it (6.5, 10, and 2 hours, respectively; P < 0.05). ADP did not modify the rate of migration. Antagonists demonstrated that Ap4A and Ap3A did activate different P2Y receptors mediating corneal wound-healing acceleration and delay. Concerning the possible degradation of the dinucleotides, it was almost impossible to detect any products resulting from their cleavage. Conclusions. Based on the pharmacological profile of all the compounds tested, the two main P2Y receptors that exist in these corneal cells are a P2Y2 receptor accelerating the rate of healing and a P2Y6 receptor that delays this process.

Role of phospholipase A(2) and tyrosine kinase in Clostridium difficile toxin A-induced disruption of epithelial integrity, histologic inflammatory damage and intestinal secretion

Clostridium difficile-associated disease causes diarrhea to fulminant colitis and death. We investigated the role of phospholipase A(2) (PLA(2)) inhibitors, aristolochic acid (AA), bromophenacyl bromide BPB and quinacrine (QUIN) on the C. difficile toxin A-induced disruption of epithelial integrity, histologic inflammatory damage and intestinal secretion. Toxin A caused severe hemorrhagic and inflammatory fluid secretion at 6-8 h in rabbit ileal segments, an effect that was significantly inhibited by QUIN (71%, P < 0.01), AA (87%, P < 0.0001) or by BPB (51%, P < 0.01). The secretory effect of toxin A was also inhibited in segments adjacent to those with AA (89%, P < 0.01). Furthermore, QUIN or AA substantially reduced the histologic damage seen after 6-8 h in rabbit ileal segments. The cyclooxygenase inhibitor, indomethacin, also significantly inhibited (96%; n = 6) the secretory effects of toxin A in ligated rabbit intestinal segments. The destruction by toxin A of F-actin at the light junctions of T-84 cell monolayers was not inhibited by AA or BPB. AA or QUIN had no effect on the T-84 cell tissue resistance reduction over 8-24 h after toxin A exposure. All the inhibitors were shown to be effective in the doses administered direct in ileal loops to inhibit PLA(2) activity. The data suggest that PLA(2) is involved in the major pathway of toxin A-induced histologic inflammatory damage and hemorrhagic fluid secretion. Cop. right (C) 2008 John Wiley & Sons, Ltd.

Rôle de la qualité des tapis de cellules endométriales en co-culture autologue sur le développement embryonnaire

Introduction : La fécondation in vitro est de mieux en mieux connue et en amélioration constante, cependant les taux d’implantation et de grossesse sont encore bas (environ 35% par fécondation in vitro). Un des enjeux de l’amélioration de la fécondation in vitro est le développement embryonnaire et l’implantation. Pour cela, la co-culture des embryons sur un tapis de cellules endométriales maternelles autologues peut être utilisée pour améliorer le développement embryonnaire (taux d’embryon se développant jusqu’à J5 : blastocyste) et l’implantation. L’objectif de l’étude est d’étudier le lien entre la qualité du tapis cellulaire et le développement embryonnaire. Matériel et méthodes : Cette étude est une sous analyse de l’essai clinique randomisé en double aveugle OvoGen, comparant le taux de blastulation et de grossesse dans deux groupes randomisés : le groupe étude, dans lequel les embryons se développent sur un tapis cellulaire endométrial maternel et le groupe contrôle, dans lequel les embryons sont cultivés dans du milieu conventionnel. Nous avons analysé la qualité des tapis cellulaire du groupe étude (confluence des cellules, taux de cellules épithéliales et vitalité des cellules stromales) par rapport au développement embryonnaire et au taux de grossesse. Résultats : 50 tapis de cellules endométriales maternelles et 291 embryons sur les puits ont été analysés de 2012 à 2015 à la clinique ovo (Montréal, Québec). La qualité des embryons n’était pas changée par la qualité des tapis (p=0,65 pour la confluence, p=0,25 pour le taux de glande et p=0,92 pour la viabilité des cellules). En revanche, le taux de grossesse augmentait quand la confluence diminuait (p=0,022) et lorsque la viabilité des cellules stromales augmentait (p=0,001). De plus, la qualité des tapis était dépendante de la date de la biopsie : la biopsie faite à J7 après l’ovulation permettait une meilleure qualité de puits (confluence augmentée, p=0,045, taux de glande augmenté p=0,004 et viabilité stromales augmentée p=0,001) que la biopsie faite à J5 post ovulation. Discussion : Aucune des nombreuses études sur la co-culture ne porte sur la qualité des tapis cellulaire. Il est intéressant de noter que le taux de grossesse augmente avec la diminution de la confluence et l’augmentation de la viabilité des cellules stromales dans les puits contenant les embryons transférés. Comme il a déjà été démontré, (1)le jour de la biopsie endométriale influe sur la qualité du tapis cellulaire en coculture et pour que celui-ci soit de bonne qualité, il faut que l’endomètre soit réceptif (après J19 du cycle). Conclusion : Nous avons montré que la qualité des tapis cellulaires dépendait du jour de la biopsie d’endomètre et que cette qualité pouvait influencer le bénéfice de la co-culture. Il serait intéressant d’étudier la réceptivité de l’endomètre au moment de la biopsie avant utilisation des cellules en co-culture pour optimiser la qualité du tapis cellulaire.