イタノ ナオキ   ITANO NAOKI
  板野 直樹
   所属   京都産業大学  生命科学部 先端生命科学科
   職種   教授
言語種別 英語
発行・発表の年月 1993/12
形態種別 研究論文
査読 査読あり
標題 MEMBRANE-INTERCALATED PROTEOGLYCAN OF A STROMA-INDUCING CLONE FROM LEWIS LUNG-CARCINOMA BINDS TO FIBRONECTIN VIA ITS HEPARAN-SULFATE CHAINS
執筆形態 その他
掲載誌名 JOURNAL OF BIOCHEMISTRY
出版社・発行元 OXFORD UNIV PRESS
巻・号・頁 114(6),pp.862-873
著者・共著者 N ITANO,K OGURI,H NAKANISHI,M OKAYAMA
概要 A Lewis lung carcinoma-derived low metastatic clone, P29, with a capacity to induce a fibrotic stromal response of host tissue, exhibits tumorigenesis depending on an interstitial matrix formed by the induced stromal cells. Using this clone, in the present study we isolated and characterized a membrane-intercalated proteoglycan that mediates interaction between the tumor cells and interstitial matrix. The tumor cells were cultured in the presence of [H-3]glucosamine and [S-35]sulfate or [S-35]methionine, and hydrophobic proteoglycans were isolated by chromatography on DEAE-Sephacel and then Octyl-Sepharose CL-4B. Proteoglycans with high affinity to the octylresidue were obtained from the cell layer but not to any significant extent from the medium. By CsCl density gradient centrifugation, they were separated into bottom, middle, and top subfractions, which were shown to consist of homogeneous species with estimated M(r) values of 270,000 (named CPGIIIB), 200,000 (CPGIIIM), and 195,000 (CPGIIIT), respectively, by gel filtration on Sepharose CL-4B. These proteoglycans were intercalated into phosphatidylcholine liposomes, suggesting that they are all membrane-intercalated proteoglycans. Analyses of their glycosaminoglycans with chondroitinase ABC and heparitinase I plus II demonstrated that they all contain heparan sulfate as a major glycosaminoglycan (58-85%) and chondroitin 4-sulfate as a minor one (15-42%). Of these three proteoglycans, only CPGIIIB proteoglycan bound specifically to fibronectin-Sepharose 4B under physiological conditions. Molecular analyses of this proteoglycan by Sepharose CL-4B or SDS-PAGE before and after treatments with glycosaminoglycan degradation enzymes or trifluoromethanesulfonic acid demonstrated that CPGIIIB proteoglycan is a hybrid proteoglycan having heparan sulfate and chondroitin 4-sulfate chains on the same core protein with an M(r) of 40,000. Affinity chromatographies of the CPGIIIB proteoglycan on fibronectin-Sepharose 4B after treatments with these enzymes demonstrated that it bound to fibronectin via its heparan sulfate chains. On the basis of the above results, we propose that the CPGIIIB proteoglycan mediates the interaction between the tumor cells and interstitial matrix.
ISSN 0021-924X/1756-2651