title: Characterization of a pituitary-tumor-derived cell line, TtT/GF, that expresses Hoechst efflux ABC transporter subfamily G2 and stem cell antigen 1.
abstract: The anterior lobe of the pituitary gland is composed of five types of endocrine cells and of non-endocrine folliculo-stellate cells that produce various local signaling molecules. The TtT/GF cell line is derived from pituitary tumors, produces no hormones and has folliculo-stellate cell-like characteristics. The biological function of TtT/GF cells remains elusive but several properties have been postulated (support of endocrine cells, control of cell proliferation, scavenger function). Recently, we observed that TtT/GF cells have high resistance to the antibiotic G418 and low influx for Hoechst 33342, indicating the presence of ATP-binding cassette (ABC) transporters that efflux multiple drugs, i.e., a property similar to that of stem/progenitor cells. Therefore, we examine TtT/GF cells for the presence of ABC transporters, for the efflux ability of Hoechst 33342 and for those genes characteristic of TtT/GF cells. Real-time polymerase chain reaction (PCR) for ABC transporters demonstrated that Abcb1a, Abcb1b and Abcg2, regarded as stem cell markers, were characteristically expressed in TtT/GF cells but not in Tpit/F1 and LβT2 cells. Furthermore, the remarkable low-efflux ability of Hoechst 33342 from TtT/GF cells was confirmed by using inhibitors and contrasted with the abilities of Tpit/F1 and LβT2 cells. The high and specific expression of stem cell antigen 1 (Sca1) in TtT/GF cells was confirmed by real-time PCR. We also demonstrated those genes that are expressed abundantly and characteristically in TtT/GF, suggesting that TtT/GF cells have unique characteristics similar to those of stem/progenitor cells of endothelial or mesenchymal origin. Thus, the present study has revealed an intriguing property of TtT/GF cells, providing a new clue for an understanding of the function of this cell line.
authors.affiliation: Division of Life Science, Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-mita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Mitsuishi
authors.forename: Takako
authors.initials: T
authors.lastname: Kato
authors.forename: Mo
authors.initials: M
authors.lastname: Chen
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Cai
authors.forename: Hideji
authors.initials: H
authors.lastname: Yako
authors.forename: Masashi
authors.initials: M
authors.lastname: Higuchi
authors.forename: Saishu
authors.initials: S
authors.lastname: Yoshida
authors.forename: Naoko
authors.initials: N
authors.lastname: Kanno
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueharu
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kato
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000032:analysis / Q000235:genetics*; D000818:Animals; D000950:Antigens, Ly / Q000032:analysis / Q000235:genetics*; D000954:Antigens, Surface / Q000032:analysis / Q000378:metabolism*; D045744:Cell Line, Tumor; D002470:Cell Survival; D015972:Gene Expression Regulation, Neoplastic; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics*; D051379:Mice; D010902:Pituitary Gland / Q000378:metabolism / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000235:genetics* / Q000473:pathology; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C501412:Abcg2 protein, mouse; D000950:Antigens, Ly; D000954:Antigens, Surface; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; C540400:W8B2 protein, human