Methylation status of human chorionic gonadotropin beta subunit promoter and TFAP2A expression as factors regulating CGB gene expression in placenta.

Objective: To evaluate mechanisms regulating the expression of CGB genes in placental tissues from uncomplicated pregnancies and chorionic samples from spontaneous miscarriages.

Design: Molecular analyses in human samples.

Setting: Laboratory of molecular biology.

CGB activates ERK and AKT kinases in cancer cells via LHCGR-independent mechanism.

Expression of human chorionic gonadotropin free beta subunit (hCGβ) and its hyperglycosylated variant (hCGβ-H) is a phenomenon confirmed for tumors of different origin. Despite numerous studies, the mechanism of hCGβ action in cancer remains unknown especially that not all tumors secreting hCGβ express the receptor for human chorionic gonadotropin (LHCGR). In the presented study, we verified the hypothesis of hCGβ potential to activate signaling pathways involving extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) kinases with and without the contribution of LHCGR.

An efficient 3D cell culture method on biomimetic nanostructured grids.

Current techniques of in vitro cell cultures are able to mimic the in vivo environment only to a limited extent, as they enable cells to grow only in two dimensions. Therefore cell culture approaches should rely on scaffolds that provide support comparable to the extracellular matrix. Here we demonstrate the advantages of novel nanostructured three-dimensional grids fabricated using electro-spinning technique, as scaffolds for cultures of neoplastic cells.

[Human chorionic gonadotropin--a well-known hormone with unknown functions].

Human chorionic gonadotropin (CG) belongs to the glycoprotein family consisting of LH, FSH and TSH. All of these hormones are composed of two subunits: common to the whole family alpha subunit and hormone-specific beta subunit CG has paracrine effects on several processes such as placentation, implantation, angiogenesis and delaying the apoptosis of corpus luteum. Serum level of CG is used to monitor pregnancy and pregnancy disorders.

Estrogen receptor 2 expression in back muscles of girls with idiopathic scoliosis - relation to radiological parameters.

Deep paravertebral muscles and female sex hormones are potential elements participating in idiopathic scoliosis development. Estrogen acts through estrogen receptors: ESR1 and ESR2. There are no studies describing ESR2 expression in back muscles in girls with idiopathic scoliosis.

Ligation of complement receptor 1 increases erythrocyte membrane deformability.

Microbes as well as immune complexes and other continuously generated inflammatory particles are efficiently removed from the human circulation by red blood cells (RBCs) through a process called immune-adherence clearance. During this process, RBCs use complement receptor 1 (CR1, CD35) to bind circulating complement-opsonized particles and transfer them to resident macrophages in the liver and spleen for removal. We here show that ligation of RBC CR1 by antibody and complement-opsonized particles induces a transient Ca(++) influx that is proportional to the RBC CR1 levels and is inhibited by T1E3 pAb, a specific inhibitor of TRPC1 channels.

Ligation of erythrocyte CR1 induces its clustering in complex with scaffolding protein FAP-1.

The primary identified function of complement receptor 1 (CR1/CD35) on primate erythrocytes is to bind complement-tagged inflammatory particles including microbes and immune complexes. When erythrocytes circulate through liver and spleen, sinusoidal phagocytes remove CR1-adherent particles and erythrocytes return to the circulation. This process of immune adherence clearance is important for host defense and prevention of autoimmunity.

Developmental stage-specific shift in responsiveness to chemokines during human B-cell development.

Objectives: To better understand the role of chemokines during human B-cell development in bone marrow.

Methods: Differentiation stage-specific B cells (pro-B, pre-B, immature, and mature) were analyzed for chemokine receptor expression and for migration to corresponding ligands. We also hypothesized that inflammatory conditions may cause the upregulation of certain chemokine receptors on early B cells, rendering them sensitive to extramedullary chemotactic cues.

Human bone marrow stromal cells express a distinct set of biologically functional chemokine receptors.

Stromal cells isolated from bone marrow (BMSCs), often referred to as mesenchymal stem cells, are currently under investigation for a variety of therapeutic applications. However, limited data are available regarding receptors that can influence their homing to and positioning within the bone marrow. In the present study, we found that second passage BMSCs express a unique set of chemokine receptors: three CC chemokine receptors (CCR1, CCR7, and CCR9) and three CXC chemokine receptors (CXCR4, CXCR5, and CXCR6).

CXCR4 chemokine receptor and integrin signaling co-operate in mediating adhesion and chemoresistance in small cell lung cancer (SCLC) cells.

Small cell lung cancer (SCLC) is an aggressive, rapidly metastazising neoplasm with a high propensity for marrow involvement. SCLC cells express high levels of functional CXCR4 receptors for the chemokine stromal-cell-derived factor-1 (SDF-1/CXCL12). Adhesion of SCLC cells to extracellular matrix or accessory cells within the tumor microenvironment confers resistance to chemotherapy via integrin signaling and thus may be responsible for residual disease and relapses commonly seen in SCLC.

CXC chemokine ligand 12-induced focal adhesion kinase activation and segregation into membrane domains is modulated by regulator of G protein signaling 1 in pro-B cells.

CXCL12-induced chemotaxis and adhesion to VCAM-1 decrease as B cells differentiate in the bone marrow. However, the mechanisms that regulate CXCL12/CXCR4-mediated signaling are poorly understood. We report that after CXCL12 stimulation of progenitor B cells, focal adhesion kinase (FAK) and PI3K are inducibly recruited to raft-associated membrane domains.

Functional expression of CXCR4 (CD184) on small-cell lung cancer cells mediates migration, integrin activation, and adhesion to stromal cells.

Small-cell lung cancer (SCLC) is an aggressive, rapidly metastasizing neoplasm. The chemokine stromal cell-derived factor-1 (SDF-1/CXCL12) is constitutively secreted by marrow stromal cells and plays a key role for homing of hematopoietic cells to the marrow. Here, we report that tumor cells from patients with SCLC express high levels of functional CXCR4 receptors for the chemokine CXCL12.

Sustained activation of cell adhesion is a differentially regulated process in B lymphopoiesis.

It is largely unknown how hematopoietic progenitors are positioned within specialized niches of the bone marrow microenvironment during development. Chemokines such as CXCL12, previously called stromal cell-derived factor 1, are known to activate cell integrins of circulating leukocytes resulting in transient adhesion before extravasation into tissues. However, this short-term effect does not explain the mechanism by which progenitor cells are retained for prolonged periods in the bone marrow.

Functional receptor for C3a anaphylatoxin is expressed by normal hematopoietic stem/progenitor cells, and C3a enhances their homing-related responses to SDF-1.

Complement has recently been implicated in developmental pathways and noninflammatory processes. The expression of various complement components and receptors has been shown in a wide range of circulating myeloid and lymphoid cells, but their role in normal hematopoiesis and stem cell homing has not yet been investigated. We report that normal human CD34(+) cells and lineage-differentiated hematopoietic progenitors express the complement anaphylatoxin C3a receptor (C3aR) and respond to C3a.

CCR5-binding chemokines modulate CXCL12 (SDF-1)-induced responses of progenitor B cells in human bone marrow through heterologous desensitization of the CXCR4 chemokine receptor.

Although the SDF-1 (CXCL12)/CXCR4 axis is important for B-cell development, it is not yet clear to what extent CC chemokines might influence B lymphopoiesis. In the current study, we characterized CC chemokine receptor 5 (CCR5) expression and function of primary progenitor B-cell populations in human bone marrow. CCR5 was expressed on all bone marrow B cells at levels between 150 and 200 molecules per cell.