Fascin, Ezrin And NGAL/NGALR Expression In Normal Embryos And Adult Tissues

Fascin is an actin-bundling protein. Ezrin, a membrane–cytoskeleton linker protein, is a member of the ERM (Ezrin-Radixin-Moesin) family. NGAL (Neutrophil gelatinase-associated lipocalin), a member of the lipocalin family, was a secretory protein and also might link to cytoskeleton. In recent 10 years, a great quantity of experimental results containing our group indicated that abnormal expression of Fascin, Ezrin and NGAL in many tumors such as breast cancer, colon carcinoma, gstric carcinoma, pancreatic cancer, esophageal carcinoma and thyroid neoplasm related to malignant characteristics-tumor cell invasion and metastasis. Base on these, in this paper we plan to study expression of cytoskeleton-associated protein― Fascin, Ezrin and NGAL, and NGALR (NGAL Receptor) in human embryonic, fetal and normal adult tissues with comparison the in tumors in order to provide further information on their functions.Tissue microarray technology was used to perform immunohistochemical experiments on expression of Fascin, Ezrin, NGAL, and NGALR in human embryos and fetuses at 4-22 weeks of gestation and adult specimens. Firstly, Fascin was present in the neural tube at 4 weeks'gestation. At 8-12 weeks'gestation, homogenous gene expression was seen in cells of the cerebellum and gastrointestinal tract. In later developmental stages and in adults, Purkinje cells of the cerebellum and glandular epithelium of the gastrointestinal tract showed no expression. Fascin was expressed in the cortex and medulla of the adrenal gland at 8-12 weeks'gestation, whereas immunoreactivity decreased from the zona glomerulosa through the zona reticularis and was essentially negative in the adrenal medulla of adults. Significant expression of fascin was seen throughout development in neurons, follicular dendritic cells of lymphoid tissue, basal layer cells of stratified squamous epithelia, mesenchyme and vascular endothelial cells. Simple columnar epithelia of the biliary duct, colon, ovary, pancreas and stomach were all negative for fascin expression. Secondly, Ezrin was widely expressed in the gastrointestinal tract throughout the human developmental stages studied. At 6-8 weeks gestation, ezrin protein was expressed in epithelial cells, and this staining pattern was particularly pronounced in gastric parietal cells the brush border of mature absorptive cells lining the villus in later developmental stages and adults. Throughout neural development, ezrin was only found in the neural tube at 4 weeks'gestation. Ezrin was also expressed in the cortex and medulla of the adrenal gland at 8-12 weeks'gestation, whereas immunoreactivity increased from the zona glomerulosa through the zona reticularis and was essentially negative in the adrenal medulla of adults. Distinguished expression of ezrin was seen throughout development in the kidney, spleen, lymph nodes, and cells of stratified squamous epithelia. However, ezrin was undetected in lung, liver, heart and blood vessels. Thirdly, NGAL was expressed in the medulla of the adrenal gland and epithelium of the lung alveolus at 8-12 weeks'gestation, which exhibited negative staining in later developmental stages and in adults. Neuroepithelium of the neural tube showed NGAL-negative at 4 weeks'gestation, which was detected in stellate cells in later developmental stages. In the cerebellum, there was no reactivity found in all cells of Purkinje cell layer but showed pronounced immunoreactivity in adult. Noticeable staining was seen throughout development epithelium of renal tubule and some gland epithelium of gastrointestinal tract, while undetected in the heart and liver. Fourthly, NGALR was seen throughout development in epithelium of renal tubule and some gland epithelium of gastrointestinal tract but not in the heart and liver. Therefore, these results demonstrate that expression of Fascin, Ezrin, NGAL and NGALR are time- and tissue-specific.