title: Expression of integrin subunits in normal and malignant human salivary gland cell clones and its regulation by transforming growth factor-beta 1.
abstract: In this study, we have examined the expression of integrin subunits in normal and malignant human salivary gland cell clones as well as its regulation by transforming growth factor-beta 1 (TGF-beta 1). By the analysis using immunofluorescence staining, an SV40 immortalized normal human salivary gland duct cell clone (NS-SVDC) with no tumorigenic ability by s.c. implantation into nude mice was identified to express the integrin beta 1, alpha 2, alpha 3 and alpha 6 subunits on the cell surface, while the expression of these subunits, except for beta 1 subunit, was reduced or completely diminished in a neoplastic human salivary gland duct cell clone (HSGc) with tumorigenic but not metastatic potential in nude mice and metastatic cell clones derived after in vitro exposure of HSGc to N-methyl-N-nitrosourea. In addition, immunoblot analysis also exhibited the same results as those obtained with immunofluorescence staining. The alpha 1 subunit was not demonstrable in any of the cell clones by both techniques. TGF-beta 1 augmented the expression of the beta 1 subunit in NS-SV-DC, while HSGc and metastatic cell clones demonstrated no changes in the expression of the beta 1 subunit in response to TGF-beta 1. These findings, therefore, suggest that there is an inverse relationship between the malignancy and the expression mode of integrin subunits, especially alpha 2 subunit, in human salivary gland cell clones with varying degrees of malignant potential, and that TGF-beta 1 is a positive regulatory factor in the expression of the beta 1 subunit in normal but not malignant cell clones.
authors.affiliation: Second Department of Oral and Maxillofacial Surgery, Tokushima University School of Dentistry, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Azuma
authors.forename: K
authors.initials: K
authors.lastname: Fukui
authors.forename: T
authors.initials: T
authors.lastname: Yuki
authors.forename: T
authors.initials: T
authors.lastname: Tamatani
authors.forename: K
authors.initials: K
authors.lastname: Motegi
authors.forename: M O
authors.initials: MO
authors.lastname: Hoque
authors.forename: H
authors.initials: H
authors.lastname: Yoshida
authors.forename: M
authors.initials: M
authors.lastname: Sato
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D002999:Clone Cells / Q000378:metabolism; D006801:Humans; D039423:Integrin alpha1; D039421:Integrin alpha2; D039422:Integrin alpha3; D039503:Integrin alpha6; D019012:Integrin beta1 / Q000378:metabolism*; D016023:Integrins / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D012469:Salivary Glands / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
chemical_list: D015703:Antigens, CD; D039423:Integrin alpha1; D039421:Integrin alpha2; D039422:Integrin alpha3; D039503:Integrin alpha6; D019012:Integrin beta1; D016023:Integrins; D016212:Transforming Growth Factor beta