Expression of C4.4A, a structural uPAR homolog, reflects squamous epithelial differentiation in the adult mouse and during embryogenesis

TY - JOUR

T1 - Expression of C4.4A, a structural uPAR homolog, reflects squamous epithelial differentiation in the adult mouse and during embryogenesis

AU - Kriegbaum, Mette Camilla

AU - Jacobsen, Benedikte

AU - Hald, Andreas

AU - Ploug, Michael

PY - 2011/2/1

Y1 - 2011/2/1

N2 - 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.

AB - 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.

KW - Animals

KW - Cell Adhesion Molecules

KW - Cell Differentiation

KW - Embryonic Development

KW - Epithelial Cells

KW - Female

KW - GPI-Linked Proteins

KW - Gene Expression Regulation, Developmental

KW - Humans

KW - Immunohistochemistry

KW - Male

KW - Mice

KW - Phenotype

KW - Protein Transport

KW - Rats

KW - Receptors, Urokinase Plasminogen Activator

KW - Reproduction

KW - Sequence Homology, Amino Acid

U2 - 10.1369/0022155410394859

DO - 10.1369/0022155410394859

M3 - Journal article

C2 - 21339181

SN - 0022-1554

VL - 59

SP - 188

EP - 201

JO - Journal of Histochemistry and Cytochemistry

JF - Journal of Histochemistry and Cytochemistry

IS - 2

ER -