Expression of C4.4A, a Structural uPAR Homolog, Reflects Squamous Epithelial Differentiation in the Adult Mouse and during Embryogenesis
JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY
Authors: Kriegbaum, Mette C.; Jacobsen, Benedikte; Hald, Andreas; Ploug, Michael
Abstract
The glycosylphosphatidylinositol (GPI)-anchored C4.4A was originally identified as a metastasis-associated protein by differential screening of rat pancreatic carcinoma cell lines. C4.4A is accordingly expressed in various human carcinoma lesions. Although C4.4A is a structural homolog of the urokinase receptor (uPAR), which is implicated in cancer invasion and metastasis, no function has so far been assigned to C4.4A. To assist future studies on its function in both physiological and pathophysiological conditions, the present study provide a global survey on C4.4A expression in the normal mouse by a comprehensive immunohistochemical mapping. This task was accomplished by staining paraffin-embedded tissues with a specific rabbit polyclonal anti-C4.4A antibody. In the adult mouse, C4.4A was predominantly expressed in the suprabasal layers of the squamous epithelia of the oral cavity, esophagus, non-glandular portion of the rodent stomach, anus, vagina, cornea, and skin. This epithelial confinement was particularly evident from the abrupt termination of C4.4A expression at the squamo-columnar transition zones found at the ano-rectal and utero-vaginal junctions, for example. During mouse embryogenesis, C4.4A expression first appears in the developing squamous epithelium at embryonic day 13.5. This anatomical location of C4.4A is thus concordant with a possible functional role in early differentiation of stratified squamous epithelia. (J Histochem Cytochem 59:188-201, 2011)
beta 2-Adrenergic Signalling Promotes Cell Migration by Upregulating Expression of the Metastasis-Associated Molecule LYPD3
BIOLOGY-BASEL
Authors: Gruet, Michael; Cotton, Daniel; Coveney, Clare; Boocock, David J.; Wagner, Sarah; Komorowski, Lucie; Rees, Robert C.; Pockley, A. Graham; Garner, A. Christopher; Wallis, John D.; Miles, Amanda K.; Powe, Desmond G.
Abstract
Metastasis is associated with poor prognosis in breast cancer. Although some studies suggest beta-blockers increase survival by delaying metastasis, others have been discordant. This study provides both insights into the anomalous findings and identifies potential biomarkers that may be treatment targets. Cell line models of basal-type and oestrogen receptor-positive breast cancer were profiled for basal levels of adrenoceptor gene/protein expression, and beta 2-adrenoceptor mediated cell behaviour including migration, invasion, adhesion, and survival in response to adrenoceptor agonist/antagonist treatment. Protein profiling and histology identified biomarkers and drug targets. Baseline levels of adrenoceptor gene expression are higher in basal-type rather than oestrogen receptor-positive cancer cells. Norepinephrine (NE) treatment increased invasive capacity in all cell lines but did not increase proliferation/survival. Protein profiling revealed the upregulation of the pro-metastatic gene Ly6/PLAUR Domain-Containing Protein 3 (LYPD3) in norepinephrine-treated MDA-MB-468 cells. Histology confirmed selective LYPD3 expression in primary and metastatic breast tumour samples. These findings demonstrate that basal-type cancer cells show a more aggressive adrenoceptor-beta 2-activated phenotype in the resting and stimulated state, which is attenuated by adrenoceptor-beta 2 inhibition. This study also highlights the first association between ADR beta 2 signalling and LYPD3; its knockdown significantly reduced the basal and norepinephrine-induced activity of MCF-7 cells in vitro. The regulation of ADR beta 2 signalling by LYPD3 and its metastasis promoting activities, reveal LYPD3 as a promising therapeutic target in the treatment of breast and other cancers.