Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Uroplakins (UPs) Ia, Ib, II, and III, transmembrane proteins constituting the asymmetrical unit membrane of urothelial umbrella cells, are the first specific urothelial differentiation markers described. We investigated the presence and localization patterns of UPs in various human carcinomas by applying immunohistochemistry (avidin-biotin-peroxidase complex method), using rabbit antibodies against UPs II and III, to paraffin sections. Positive reactions for UP III (sometimes very focal) were noted in 14 of the 16 papillary noninvasive transitional cell carcinomas (TCCs) (88%), 29 of the 55 invasive TCCs (53%), and 23 of the 35 TCC metastases (66%). Different localization patterns of UPs could be distinguished, including superficial membrane staining like that found in normal umbrella cells (in papillary carcinoma), luminal (microluminal) membrane staining (in papillary and invasive carcinoma), and, against expectations, peripheral membrane staining (in invasive carcinoma). Non-TCC carcinomas of various origins (n = 177) were consistently negative for UPs. The presence of UPs in metastatic TCCs represents a prime example of even advanced tumor progression being compatible with the (focal) expression of highly specialized differentiation repertoires. Although of only medium-grade sensitivity, UPs do seem to be highly specific urothelial lineage markers, thus operating up interesting histodiagnostic possibilities in cases of carcinoma metastases of uncertain origin.
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PMID:Uroplakins, specific membrane proteins of urothelial umbrella cells, as histological markers of metastatic transitional cell carcinomas. 748 1

We have investigated, by immunohistochemical staining of various paraffin-embedded carcinoma sections, the tissue-specific expression of uroplakin III--a recently characterized constituent glycoprotein (47 kD) of the asymmetrical unit membrane which forms plaques on apical surface of urothelial umbrella cells. The apical membrane pattern of normal urothelial umbrella cells was in part maintained in papillary transitional cell carcinomas (TCCs). In addition, in both papillary and invasive TCCs, variously sized lumina exhibited positive membrane staining of uroplakin III. In some cases, basal cell membrane staining was seen. Positive reactions (which sometimes were very focal) were noted in 16/18 papillary non-invasive TCCs (89%), 21/37 invasive TCCs (57%) and 12/15 TCC metastases (80%). Non-TCC carcinomas of different origin (n = 63) were consistently negative. These results show that uroplakin III may serve as a useful marker for TCCs, revealing specific urothelial differentiation features to be expressed in such tumors even after metastasis. This marker, while of only intermediate sensitivity, is highly specific, thus opening interesting histodiagnostic possibilities in the case of unclear carcinoma metastases.
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PMID:[Uroplakin III, a specific membrane protein of urothelial umbrella cells, as a histological markers for metastatic transitional cell carcinomas]. 751 Dec 94

A cohort of 300 ACI rats was kept under standard laboratory conditions. After 30 months or upon natural death, complete autopsy was performed. In the genitourinary tract four kidney and five bladder tumors were found. Two of these bladder tumors, RBT323 and RBT157, are serially transplantable. In the fifth transplant generation the RBT323 tumor becomes metastatic to the lungs in more than 90% of animals. The metastatic ability of the RBT157 tumor changes from low to intermediate (50% of the rats have lung metastases) in the fourth passage. Histologically, the initial passages of the RBT323 and 157 tumors are grade II transitional cell carcinoma (TCC). The histological pattern of the RBT157 tumor remains essentially unchanged, whereas the RBT323 tumor progresses to a grade III tumor in the third passage. Electron microscopical studies reveal oblong elliptical and round vesicles lined by an asymmetrical unit membrane in the tumor cells, which stresses the urothelial origin of the tumors. Immunohistochemically both tumors show expression of cytokeratin 5, 7, 8 and 18. The progression of the tumors to a metastatic phenotype, however, is not associated with a specific change in the morphological characteristics. Cytogenetic analysis shows that both tumors are peridiploid with few marker chromosomes. Interestingly, both of these independently arising tumors exhibit a loss of chromosome 5. Rat chromosome 5 is syntenic to the major portion of human chromosome 9 (p23-qter). Loss of chromosome 9 is a cytogenetic trait of human superficial TCC, hence the RBT model is also in cytogenetic respect similar to human TCC.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The rat bladder tumor model system RBT resembles phenotypically and cytogenetically human superficial transitional cell carcinoma. 817 64