title: Alteration of integrin expression relates to malignant progression of human papillomavirus-immortalized esophageal keratinocytes.
abstract: To investigate cellular changes related to the malignant progression of keratinocytes, we studied the serum-resistant clones from CHEK-1, a human papillomavirus type 16 E6/E7-immortalized esophageal cell line cultured in a serum-free medium. Established clones exhibited morphologic variety. Slow growing clones presented in cuboidal shapes with tight cellular adhesion and highly expressed alpha2 and alpha6beta4 integrins. Moderately proliferating clones showed loose intercellular adhesion and reduced expression of alpha2 integrin. Spindle-shaped, rapidly proliferating clones with prominent actin stress fibers demonstrated reduced alpha6 and alpha4 integrin expression in addition to alpha2 integrin and showed anchorage-independent growth. Reduced expression of alpha2 integrin was observed between 50 and 100 population doubling lengths (PDLs) during the immortalization of CHEK-1. These results suggest that the reductions of alpha2 and alpha6beta4 integrins are related to changes seen during immortalization and malignant progression.
authors.affiliation: Department of Molecular Virology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sashiyama
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shino
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Sakao
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shimada
authors.forename: Susumu
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Takenori
authors.initials: T
authors.lastname: Ochiai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shirasawa
mesh_terms: D000199:Actins / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism*; D000954:Antigens, Surface / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002455:Cell Division; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000378:metabolism* / Q000473:pathology; D003114:Colony-Forming Units Assay; D015536:Down-Regulation; D004847:Epithelial Cells / Q000378:metabolism / Q000821:virology; D004947:Esophagus / Q000378:metabolism / Q000821:virology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D039421:Integrin alpha2; D039161:Integrin alpha6beta4; D016023:Integrins / Q000378:metabolism*; D015603:Keratinocytes / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D018613:Microscopy, Confocal; D009856:Oncogene Proteins, Viral / Q000235:genetics; D027383:Papillomaviridae / Q000502:physiology*
chemical_list: D000199:Actins; D015703:Antigens, CD; D000954:Antigens, Surface; D039421:Integrin alpha2; D039161:Integrin alpha6beta4; D016023:Integrins; D009856:Oncogene Proteins, Viral