Sources/Clones
Accurate, Biodesign (ID2C3), Biogenesis (20/24), Chemicon (15E2), Immunotech (ID2C3) and Serotec (ID2C3).
Fixation/Preparation
HIER is required for fixed paraffin-embedded sections. Fixation in Carnoy's solution or methacarn preserves immunoreactivity. The antibody is also immunoreactive in fresh cell preparations and frozen sections.
Background
Microvilli increase the absorptive surface of epithelial cells by as much as 20 times. They comprise a highly specialized plasma membrane of a thick extracellular coat of polysaccharide and digestive enzymes and a core comprising a central rigid bundle of 20-30 parallel actin filaments that extend from the tip of the microvillus down to the cell cortex. The actin filaments are all oriented with their plus ends pointing away from the cell body and are held together at regular intervals by actin-bundling proteins. Besides fimbrin, which occurs in microspikes and philopodia, the most important bundling protein is villin, which is found only in microvilli. Like fimbrin, villin crosslinks actin filaments into tight parallel bundles, but in a different actin-binding sequence and is capable of stimulating the formation of long microvilli in cultured fibroblasts which do not normally contain villin and have only a few small microvilli.
Villin, a 95 kD, Ca2+ -regulated actin-binding protein, is found in absorptive cells of the small and large intestines, in ductal cells of the pancreas and biliary system and in the cells of the proximal renal tubules. Villin is also found in undifferentiated normal and tumoral cells of intestinal origin in vivo and in cell culture so that its expression is seen in cells that do not necessarily display microvilli-lined brush borders (Robine et al, 1985).
Applications
Villin has been employed as a marker of gastrointestinal tumors, particularly those from the colon, stomach and pancreas, all such tumors staining positive in one study (Bacchi & Gown, 1991). Gallbladder and hepatocellular carcinomas were also shown to express villin (Moll et al, 1987). A subset of non-gastrointestinal tumors, including some adenocarcinomas of the ovary, endometrium and kidney, were also positive (Moll et al, 1987; Bacchi & Gown, 1991). Lung adenocarcinomas were rarely positive and no staining was observed in breast carcinoma or mesothelioma. The presence of villin in renal carcinomas is variable and is frequently seen in clear cell and chromophilic tumors but not in chromophobe cell tumors (Moll et al, 1987). Villin also appears to be expressed in the tubular and glandular areas of better differentiated tumors and is not observed in sarcomatoid renal carcinoma, leading to the suggestion that it may be a potential grading marker (Grone et al, 1986). Its expression in renal carcinomas suggests that they display proximal rather than distal tubular differentiation. It is also observed in the glandular areas of Wilm's tumor (Droz et al, 1990).
Comments
Villin shows apical localization but may also be seen in the basement membrane area surrounding tumor nests (West et al, 1988). Clone ID2C3 shows reactivity with human, porcine and chicken villin.
References
•Bacchi CE, Gown AM 1991. Distribution and pattern of expression of villin, a gastrointestinal-associated cytoskeletal protein, in human carcinomas: a study employing paraffin-embedded tissue. Laboratory Investigation 64: 418-424.
•Droz D, Rousseau-Merck MF, Jaubert F, et al 1990. Cell differentiation in Wilm's tumor (nephroblastoma): an immunohistochemical study. Human Pathology 21: 536-544.
•Grone HJ, Weber K, Helmchen U, Osborn M 1986. Villin - a marker of brush border differentiation and cellular origin in human renal cell carcinoma. American Journal of Pathology 124: 294-302.
•Moll R, Robine S, Dudouet B, Louvard D 1987. Villin: a cytoskeletal protein and a differentiation marker expressed in some human adenocarcinomas. Virchows Archives B Cell Pathology and Molecular Pathology 54: 155-169.
•Robine S, Huet C, Moll R et al 1985. Can villin be used to identify malignant and undifferentiated normal digestive epithelial cells? Proceedings of the National Academy of Sciences USA 82: 8488-8492.
•West AB, Isaac CA, Carboni JM et al 1988 Localization of villin, a cytoskeletal protein specific to microvilli, in human ileum and colon neoplasms. Gastroenterology 94: 343-352.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Accurate, Biodesign (ID2C3), Biogenesis (20/24), Chemicon (15E2), Immunotech (ID2C3) and Serotec (ID2C3).
Fixation/Preparation
HIER is required for fixed paraffin-embedded sections. Fixation in Carnoy's solution or methacarn preserves immunoreactivity. The antibody is also immunoreactive in fresh cell preparations and frozen sections.
Background
Microvilli increase the absorptive surface of epithelial cells by as much as 20 times. They comprise a highly specialized plasma membrane of a thick extracellular coat of polysaccharide and digestive enzymes and a core comprising a central rigid bundle of 20-30 parallel actin filaments that extend from the tip of the microvillus down to the cell cortex. The actin filaments are all oriented with their plus ends pointing away from the cell body and are held together at regular intervals by actin-bundling proteins. Besides fimbrin, which occurs in microspikes and philopodia, the most important bundling protein is villin, which is found only in microvilli. Like fimbrin, villin crosslinks actin filaments into tight parallel bundles, but in a different actin-binding sequence and is capable of stimulating the formation of long microvilli in cultured fibroblasts which do not normally contain villin and have only a few small microvilli.
Villin, a 95 kD, Ca2+ -regulated actin-binding protein, is found in absorptive cells of the small and large intestines, in ductal cells of the pancreas and biliary system and in the cells of the proximal renal tubules. Villin is also found in undifferentiated normal and tumoral cells of intestinal origin in vivo and in cell culture so that its expression is seen in cells that do not necessarily display microvilli-lined brush borders (Robine et al, 1985).
Applications
Villin has been employed as a marker of gastrointestinal tumors, particularly those from the colon, stomach and pancreas, all such tumors staining positive in one study (Bacchi & Gown, 1991). Gallbladder and hepatocellular carcinomas were also shown to express villin (Moll et al, 1987). A subset of non-gastrointestinal tumors, including some adenocarcinomas of the ovary, endometrium and kidney, were also positive (Moll et al, 1987; Bacchi & Gown, 1991). Lung adenocarcinomas were rarely positive and no staining was observed in breast carcinoma or mesothelioma. The presence of villin in renal carcinomas is variable and is frequently seen in clear cell and chromophilic tumors but not in chromophobe cell tumors (Moll et al, 1987). Villin also appears to be expressed in the tubular and glandular areas of better differentiated tumors and is not observed in sarcomatoid renal carcinoma, leading to the suggestion that it may be a potential grading marker (Grone et al, 1986). Its expression in renal carcinomas suggests that they display proximal rather than distal tubular differentiation. It is also observed in the glandular areas of Wilm's tumor (Droz et al, 1990).
Comments
Villin shows apical localization but may also be seen in the basement membrane area surrounding tumor nests (West et al, 1988). Clone ID2C3 shows reactivity with human, porcine and chicken villin.
References
•Bacchi CE, Gown AM 1991. Distribution and pattern of expression of villin, a gastrointestinal-associated cytoskeletal protein, in human carcinomas: a study employing paraffin-embedded tissue. Laboratory Investigation 64: 418-424.
•Droz D, Rousseau-Merck MF, Jaubert F, et al 1990. Cell differentiation in Wilm's tumor (nephroblastoma): an immunohistochemical study. Human Pathology 21: 536-544.
•Grone HJ, Weber K, Helmchen U, Osborn M 1986. Villin - a marker of brush border differentiation and cellular origin in human renal cell carcinoma. American Journal of Pathology 124: 294-302.
•Moll R, Robine S, Dudouet B, Louvard D 1987. Villin: a cytoskeletal protein and a differentiation marker expressed in some human adenocarcinomas. Virchows Archives B Cell Pathology and Molecular Pathology 54: 155-169.
•Robine S, Huet C, Moll R et al 1985. Can villin be used to identify malignant and undifferentiated normal digestive epithelial cells? Proceedings of the National Academy of Sciences USA 82: 8488-8492.
•West AB, Isaac CA, Carboni JM et al 1988 Localization of villin, a cytoskeletal protein specific to microvilli, in human ileum and colon neoplasms. Gastroenterology 94: 343-352.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
