title: Restricted expression of calcium-binding protein S100A5 in human kidney.
abstract: Reverse transcription--polymerase chain reaction (RT-PCR) identified the expression of calcium-binding protein S100A5 in the noncancerous parts of resected samples from renal cell carcinoma (RCC) patients (n = 7) but not in the carcinoma lesions. Rabbit anti-S100A5 antibody immunohistochemically detected the antigen in the thick ascending limb of Henle, distal convoluted tubule, and collecting duct system. No apparent immunopositivity was observed in the glomerulus, proximal tubules, interstitial cells, or RCC cells. Thus, it was suggested that S100A5 protein plays an inherent functional role to the post-thick ascending limb of Henle portion in the nephron. Further, the carcinomas tested were originated probably not in the S100A5-positive distal epithelium but in the -negative epithelium of proximal tubules. Then, total RNA was extracted by phenol/chloroform from 1 ml urine of healthy volunteers, and S100A5 was amplified by RT-PCR from all samples (n = 12), indicating that the transcript of S100A5 is detectable even in the cells released into urine.
authors.affiliation: Laboratory of Host Defenses, University of Shizuoka, Shizuoka, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Teratani
authors.forename: Takumi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Kaori
authors.initials: K
authors.lastname: Yamahara
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Kumagai
authors.forename: Akira
authors.initials: A
authors.lastname: Ishikawa
authors.forename: Kazumori
authors.initials: K
authors.lastname: Arai
authors.forename: Ryushi
authors.initials: R
authors.lastname: Nozawa
mesh_terms: D002135:Calcium-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000652:urine; D002292:Carcinoma, Renal Cell / Q000235:genetics / Q000378:metabolism* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism*; D007680:Kidney Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000601:surgery; D007684:Kidney Tubules / Q000378:metabolism; D009928:Organ Specificity; D012333:RNA, Messenger / Q000096:biosynthesis; D009418:S100 Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000652:urine
chemical_list: D002135:Calcium-Binding Proteins; D012333:RNA, Messenger; D009418:S100 Proteins; C082355:S100A5 protein, human