Publications by authors named "Valerie Fock"

Ewing sarcoma (ES) is a rare aggressive cancer of bone and soft tissue that is mainly characterized by a reciprocal chromosomal translocation. As a result, about 90% of cases express the EWS-FLI1 fusion protein that has been shown to function as an aberrant transcription factor driving sarcomagenesis. ES is the second most common malignant bone tumor in children and young adults.

View Article and Find Full Text PDF

Bone and bone marrow are among the most frequent metastatic sites of cancer. The occurrence of bone metastasis is frequently associated with a dismal disease outcome. The prevention and therapy of bone metastases is a priority in the treatment of cancer patients.

View Article and Find Full Text PDF

The microphthalmia-associated transcription factor (MITF) is a critical regulator of melanocyte development and differentiation. It also plays an important role in melanoma where it has been described as a molecular rheostat that, depending on activity levels, allows reversible switching between different cellular states. Here, we show that MITF directly represses the expression of genes associated with the extracellular matrix (ECM) and focal adhesion pathways in human melanoma cells as well as of regulators of epithelial-to-mesenchymal transition (EMT) such as CDH2, thus affecting cell morphology and cell-matrix interactions.

View Article and Find Full Text PDF
Article Synopsis
  • MITF, TFEB, TFE3, and TFEC are transcription factors involved in cellular processes like melanocyte development and lysosome function, with MITF being significant in melanoma.
  • The study reveals that MITF and TFEB, but not TFE3, directly influence each other's gene expression in melanoma cells.
  • Their relationship is regulated by the mTOR signaling pathway, highlighting the complexity of their interactions in regulating important cellular pathways.
View Article and Find Full Text PDF

The microphthalmia-associated transcription factor (MITF) is at the core of melanocyte and melanoma fate specification. The related factors TFEB and TFE3 have been shown to be instrumental for transcriptional regulation of genes involved in lysosome biogenesis and autophagy, cellular processes important for mediating nutrition signals and recycling of cellular materials, in many cell types. The MITF, TFEB, TFE3, and TFEC proteins are highly related.

View Article and Find Full Text PDF

The MITF transcription factor is a master regulator of melanocyte development and a critical factor in melanomagenesis. The related transcription factors TFEB and TFE3 regulate lysosomal activity and autophagy processes known to be important in melanoma. Here we show that MITF binds the CLEAR-box element in the promoters of lysosomal and autophagosomal genes in melanocytes and melanoma cells.

View Article and Find Full Text PDF
Article Synopsis
  • MITF is a key regulator in melanocytes and melanoma, with the MITF-M isoform being consistently found in the nucleus.
  • Mutational analysis identified specific signals within its structure that enable nuclear localization independent of DNA binding and dimerization.
  • Furthermore, dimerization-deficient mutants of MITF-M are less stable in melanoma cells, highlighting the importance of the bHLH-Zip domain in both localization and stability of the protein.
View Article and Find Full Text PDF

During placentation, foetal trophoblasts invade deeply into maternal tissue to establish a foeto-maternal circulation. We have previously shown that extravillous trophoblast (EVT) lineage cells express ErbB2 and ErbB3, of which the potential as an oncogenic unit is well established. However, a physiological function of this receptor combination in humans remains a puzzling question.

View Article and Find Full Text PDF

Study Question: Do trophoblast subtypes differ in their expression of erythroblastic leukaemia viral oncogene homologue (ERBB) receptor family members and responsiveness towards specific growth factor ligands?

Summary Answer: Our data reveal a reciprocal expression pattern of epidermal growth factor receptor (EGFR)/ERBB4 in proliferative and ERBB2/ERBB3 in invasive trophoblast subtypes, as well as a restricted responsiveness to epidermal growth factor (EGF) and heparin-binding (HB)-EGF.

What Is Known Already: EGFR is expressed by villous cytotrophoblasts (vCTBs), but absent from extravillous trophoblasts (EVTs), which specifically up-regulate ERBB2.

Study Design, Size, Duration: Tissue samples of human first trimester placentae (n = 50) and deciduae (n = 5) obtained from elective pregnancy terminations were used to study trophoblast subtype-specific ERBB receptor expression and responsiveness to recombinant human EGF and HB-EGF.

View Article and Find Full Text PDF

ADAM12, consisting of a membrane-bound (ADAM12L) and a secreted (ADAM12S) form, is expressed exclusively in regenerating and developing tissue as well as in certain cancer types. Strong ADAM12 expression levels have been noticed in the human placenta, and deregulated ADAM12S levels were associated with various pregnancy-related disorders including pre-eclampsia and intrauterine growth restriction. However, the role of ADAM12 in trophoblast motility has not been investigated so far.

View Article and Find Full Text PDF

IL-33, the most recently discovered member of the IL-1 superfamily and ligand for the transmembrane form of ST2 (ST2L), has been linked to several human pathologies including rheumatoid arthritis, asthma, and cardiovascular disease. Deregulated levels of soluble ST2, the natural IL-33 inhibitor, have been reported in sera of preeclamptic patients. However, the role of IL-33 during healthy pregnancy remains elusive.

View Article and Find Full Text PDF

Endostatin, a biological active fragment of the extracellular matrix protein collagen XVIII, is known to interfere with cellular motility in the context of pathological angiogenesis. However, the physiological role of endostatin remains largely elusive. Recent evidence suggested that the inhibitor is produced in human decidual cells of early pregnancy, indicating that endostatin could be involved in diverse reproductive processes, such as implantation and/or placental differentiation.

View Article and Find Full Text PDF