title: Down regulation of a novel protein, PSP, in rat hepatoma cdRLh 84-beared tumor.
abstract: Perchloric acid-soluble protein (PSP) is a members of a new hypothetical family (YER057c/YJGF family) of small proteins with presently unknown function. The high degree of evolutionary conservation of these proteins reflect an involvement in basic cellular regulation. The expression of PSP was examined in rat hepatoma cell dRLh 84-beared rats. The tumor weight increased to 4.24 g at 3 weeks after the transplantation of hepatoma cells and hepatoma which has less differentiated characteristics were observed in rat liver. The expression of PSP in rat hepatoma was down regulated as compared with intact tissue. Thus the expression of PSP seems to be associated with the differentiation process in these transformed cells. On the other hand, some positive cells against the PSP-antibody were observed in the central region of tumor tissue by immunohistochemistry. These cells were shown to be the lymphocytes and the macrophages. The involvement of PSP to cellular growth and differentiation is discussed.
authors.affiliation: Department of Veterinary Internal Medicine, Faculty of Agriculture, Kagoshima University, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kaneki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanouchi
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kawasaki
authors.forename: Masao
authors.initials: M
authors.lastname: Akuzawa
authors.forename: Tatsuzo
authors.initials: T
authors.lastname: Oka
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002460:Cell Line; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012260:Ribonucleases / Q000378:metabolism*
chemical_list: D006360:Heat-Shock Proteins; C097211:Rida protein, rat; D012260:Ribonucleases