Macrophage migration inhibitory factor is differentially expressed in normal and choriocarcinoma trophoblast cells.

Trophoblast cells are specific for placenta, the organ necessary for development of the fetus. Trophoblast derived choriocarcinoma is a rare cancer, with high metastatic potential, invading surrounding tissues and distant organs. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine involved in a wide range of biological processes, which is increased in almost all human cancers. Expression of MIF in normal and choriocarcinoma trophoblast cells is investigated here, using normal extravillous trophoblast derived cell line HTR-8/SVneo, and choriocarcinoma cell lines JAR and JEG3. Expression of MIF and its receptors CD74 and CXCR2 was investigated at mRNA level using qPCR. Expression of MIF protein was studied using immunofluorescence and western blot, under reducing and native conditions, in whole cell lysates, subcellular fractions and conditioned media. The expression of MIF mRNA was similar in all three cell lines, while CD74 mRNA was more expressed in choriocarcinoma cells (14-fold for JAR, 12-fold for JEG3, p<0.01). CXCR2 mRNA was higher in JEG3 cell line compared to HTR-8/SVneo cells (6-fold, p<0.01). While the cellular level of MIF was similar, the level of secreted MIF was lower in JAR cell conditioned media compared to media of both HTR-8/SVneo (2.8-fold, p<0.01) and JEG3 cells (4.1-fold, p<0.001). Cellular distribution of MIF was similar between the studied cell types. MIF was predominantly cytoplasmic, but also detected in membrane, nuclear soluble and nuclear chromatin fraction. MIF appeared in high molecular weight complexes of >150 kDa under native conditions. A band of 140-145 kDa was consistently present in JEG3 cell lysates, while it was absent or very weak in other cell types. These results show that MIF/CD74 axis is shifted in choriocarcinoma, as previously shown for other cancers, and further justifies research towards the most effective MIF targeting therapeutics.

Expression of tumor associated antigens CA 15-3 and CA 19-9 in trophoblast of the normal human placenta.

Mucin 1 (MUC1) is abundantly expressed by various organs, including human placenta and endometrium. Since glycan modifications of MUC1 are potentially relevant for physiological as well as pathological processes, this study was aimed at establishing an expression profile of two MUC1 glycoepitopes, CA 15-3 and CA 19-9, in trophoblast throughout pregnancy. Immunohistochemical analysis of normal placenta demonstrated that trophoblast cells express both mucin antigens throughout gestation with a distinct staining pattern. The staining of villous trophoblast was non-uniform for both antigens, and stronger for CA 15-3. Only a proportion of extravillous trophoblast of the cell column, in decidual stroma or lining blood vessels was also stained. Whether the studied MUC 1 glycoforms can be linked to trophoblast cells invasion remains to be established.

Interleukin-6 stimulates cell migration, invasion and integrin expression in HTR-8/SVneo cell line.

Interleukin-6 (IL-6) is present in human endometrium throughout menstrual cycle and in pregnancy. Trophoblast also expresses IL-6. IL-6R and its associated signal transducer gp130 were found in trophoblast as well. IL-6 is generally assumed to be relevant for trophoblast invasion. This study was undertaken to determine influence of endogenous and externally added IL-6 on invasion and migration of first trimester of pregnancy trophoblast in vitro. Integrins alpha(5)beta(1) and alpha(1)beta(1) have been shown to play an important role in trophoblast invasion and the effect of IL-6 on the expression of these integrin subunits was studied. We are showing that in both isolated first trimester of pregnancy cytotrophoblast (CTB) and HTR-8/SVneo cell line IL-6 and IL-6R are present. The effect on migration was studied using cell wounding and migration test on HTR-8/SVneo cells. Effect of IL-6 and function blocking anti-IL-6 antibody in Matrigel invasion tests was studied on both cell types. The effect of IL-6 on integrin subunit expression was determined by cell-based ELISA and Western blot on HTR-8/SVneo cells. The results obtained show that exogenous IL-6 has stimulatory effect on cell migration in HTR-8/SVneo and invasion by both cell types. Function blocking anti-IL-6 inhibited unstimulated invasion by isolated first trimester cytotrophoblast and both cell migration and invasion in unstimulated HTR-8/SVneo. Integrin alpha(5) expression was stimulated by IL-6 to 134% (p<0.05), alpha(1) to 135% (p<0.005), and beta(1) to 134% (p<0.001) of control in cell-based ELISA, but also in Western blot. The data obtained show for the first time sensitivity of extravillous trophoblast cell line HTR-8/SVneo to IL-6, in addition to isolated first trimester cytotrophoblast. We conclude that both exogenous and endogenous IL-6 stimulate trophoblast cell migration and invasion, which may be partly attributable to stimulation of expression of the studied integrin subunits.

Refractory metastatic choriocarcinoma treated surgically with polychemotherapy--case report.

The authors present the course of treatment of refractory metastatic choriocarcinoma in a 49-year-old woman was treated surgically by hysterectomy and resection of suprarenal gland metastases. During the treatment the patient received 15 courses of polychemotherapy with different protocols. After five years of treatment and seven years of follow-up there is no evidence of recurency of the disease.

Implantation of the human embryo: research lines and models. From the implantation research network 'Fruitful'.

Infertility is an increasing problem all over the world, and it has been estimated that 10-15% of couples in fertile age have fertility problems. Likewise induced unsafe abortion is a serious threat to women's health. Despite advances made in assisted reproduction techniques, little progress has been made in increasing the success rate during fertility treatment. This document describes a wide range of projects carried out to increase the understanding in the field of embryo implantation research. The 'Fruitful' research network was created to encourage collaborations within the consortium and to describe our different research potentials to granting agencies or private sponsors.

A specific wheat germ agglutinin-immunoreactive protein in human placenta.

In this study we examined human placenta for the presence of molecules antigenically related to a plant lectin, wheat germ agglutinin. The initial results of immunolocalization using polyclonal antibodies against wheat germ agglutinin showed that human placenta contains protein(s) recognized specifically. Staining of syncytiotrophoblast brush border and cytotrophoblast, granular in appearance was observed in first trimester human placenta. Specific binding was also seen in trophoblast-derived JAr and BeWo carcinoma cells. Isolation of wheat germ agglutinin-immunoreactive material from human placenta was achieved by ion-exchange- and affinity-chromatography on anti-wheat germ agglutinin-immunoglobulin G-Sepharose. The placental protein having molecular mass of 66 kD was identified as specific. The protein of 66 kD was characterized as a calcium-dependent, asialofetuin-binding molecule.

Galectin-1 and -3 in cells of the first trimester placental bed.

The beta-galactoside-binding proteins galectin-1 and -3 are thought to modulate cell-extracellular matrix interactions in cell adhesion and migration. In this study, their occurrence in human trophoblast has been investigated. In the first trimester placenta galectin-1 is expressed in the cytotrophoblast of the mid and distal cell columns, but absent from the villous and proximal column cytotrophoblast. The villous syncytiotrophoblast was also positive. Galectin-3, on the other hand, was uniformly localized in the villous cytotrophoblast and mid and distal cell columns. Immunolocalization of these proteins in placental bed tissue has shown that galectin-1 and -3 are not present in cytokeratin-positive interstitially migrating cytotrophoblast. The co-localization of galectin-1 with extracellular laminin in cultures of cytotrophoblast, choriocarcinoma or decidual stromal cells is consistent with a role in the organization of extracellular matrix and the regulation of cell motility.

Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

Laminins 2 and 4 are expressed by human decidual cells.

During pregnancy, the resident stromal cells of the endometrium differentiate to become decidual cells and produce a pericellular basement membrane. We used immunofluorescence and Western blotting with a panel of monoclonal Ab specific for various laminin subunits to examine the composition of decidual laminin. The stromal cell basement membrane contained subunits alpha 2 (M), beta 1 (B1), beta 2 (S), and gamma 1 (B2). Low levels of alpha 1 could also be detected. The glandular and vascular basement membranes of decidual tissue contained subunits alpha 1 (A), beta 1, and gamma 1. An extract was produced from decidual extracellular matrix. Western blots of nonreducing gels showed the presence of high molecular weight complexes containing alpha 2, beta 1, beta 2, and gamma 1. These data indicated that laminins 2 and 4 are coexpressed by decidual cells. Laminin 1 was present in the extract as a minor component. In contrast, cultured stromal cells expressed laminin 1 as the major secreted variant. Immunolocalization was carried out using tissue from various stages of the nonpregnant cycle. The alpha 2 chain polypeptide was absent in the proliferative phase of the cycle but present in late secretory phase in perivascular areas where predecidual differentiation occurs. Reverse transcriptase-PCR experiments confirmed the presence of alpha 2 chain mRNA in decidua but showed that this transcript is detectable throughout the nonpregnant cycle. The results showed that laminins 2 and 4 are hormonally regulated products of decidual cells. The composition of the vascular and epithelial basement membranes remained constant throughout the cycle.

Comment: effect of cytokines on prolactin production by human decidual stromal cells in culture: studies using cells freed of bone marrow-derived contaminants.

Human decidua contains resident decidual cells alongside a population of bone marrow-derived cells, among which macrophages and large granular lymphocytes are most abundant. We hypothesized that soluble effectors produced by bone marrow-derived cells may modulate the function of the decidual cells. To investigate this, a cell purification protocol was devised that involved digestion of first-trimester decidua with collagenase and hyaluronidase to produce a mixed stromal cell suspension from which the bone marrow-derived cells were removed using immunomagnetic beads coated with anti-CD45. The resulting stromal cells were maintained in culture in the presence of progesterone and were found to produce PRL. The effect of a panel of cytokines on PRL production was examined. Tumor necrosis factors-alpha and -beta had a dose-dependent inhibitory effect, and tumor necrosis factor receptors were identified on the cells. Interleukin 1 alpha and 1 beta, platelet-derived growth factor, and transforming growth factor-beta 1 were also found to inhibit PRL production, and platelet-derived growth factor and transforming growth factor-beta 1 stimulated cell proliferation. These findings suggest an interaction between the immune and endocrine systems in regulating the maternal environment of early pregnancy.

Coincubation--an experimental approach to the study of decidual-trophoblast interaction.

Coincubation of trophoblast and decidual tissue explants was used for the study of placental-endometrial interaction in early pregnancy. To this end two types of experiments were performed: coincubation with (type A) and without (type B) direct tissue contact. The rate of incorporation of [14C]leucine into cytosol proteins in both tissues was employed for the estimation of total protein synthesis. Prolactin production in vitro was used as a specific marker of the decidual and hCG of the trophoblast cell function. The results show that the type A coincubation experiments produced a strong inhibition of cytosol protein synthesis in both tissues. PRL production by the decidual tissue and hCG production by the trophoblast tissue was reduced. In the type B coincubation experiments protein synthesis and prolactin production by the decidual tissue remained within the control range. In the trophoblast tissue explants protein synthesis and hCG production were depressed. The degree of inhibition was, however, lower than that in type-A experiments. Based on these results it was concluded that the in vitro model of coincubation of trophoblast and decidual tissue explants is suitable for the study of the role of tissue interactions in vitro.

Effect of cAMP on cytosol protein phosphorylation in placental tissue of different gestational age.

Phosphorylation of cytosol proteins in placental tissue of different gestational age has been studied. Cytosol protein phosphorylation was stimulated by exogenous cAMP only in term placentae and remained unchanged in first and second trimester placentae. Exogenous proteins, histone and casein, were intensively phosphorylated by cytosol kinases with maximal activities in first trimester cytosol preparations. Exogenous cAMP stimulated histone phosphorylation, but it had no effect on casein phosphorylation. On the basis of the obtained results it can be concluded that endogenous protein phosphorylation in first and second trimester placental cytosol is cAMP independent.