title: Insulin-like growth factor-binding protein 3 expression increases during immortalization of cervical keratinocytes by human papillomavirus type 16 E6 and E7 proteins.
abstract: Human papillomaviruses (HPVs) infect cervical epithelial cells and induce both benign and precancerous lesions. High-risk HPVs promote the development of cervical cancer in vivo and can immortalize cervical epithelial cells in vitro, whereas low-risk HPVs cannot. We used cDNA microarrays and quantitative polymerase chain reaction to compare cellular gene expression in primary cervical epithelial cells during a time course after retroviral transduction with either low-risk or high-risk E6/E7 genes. At early passages, cervical cells transduced with high-risk E6/E7 genes demonstrated increased expression of the cell cycle-regulated genes CDC2 and ubiquitin carrier E2-C. At later passages, these same cells exhibited dramatic increases in insulin-like growth factor-binding protein-3 (IGFBP-3) mRNA and both secreted an intracellular protein, with mRNA levels increasing approximately 85-fold. Corroborating these in vitro studies, in situ hybridization of cervical biopsies with an IGFBP-3 riboprobe revealed high levels of expression in high-grade squamous intraepithelial neoplasia but not in normal cervical epithelium. Our in vitro results indicate that overexpression of IGFBP-3 is a late event after E6/E7 expression, and analysis of cervical lesions indicates that overexpression of this gene is also seen in vivo.
authors.affiliation: Millennium Pharmaceuticals, Incorporated, Cambridge, Massachusetts 02139, USA. aberger@mpi.com
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Berger
authors.forename: Astrid
authors.initials: A
authors.lastname: Baege
authors.forename: Tracy
authors.initials: T
authors.lastname: Guillemette
authors.forename: James
authors.initials: J
authors.lastname: Deeds
authors.forename: Ron
authors.initials: R
authors.lastname: Meyer
authors.forename: Gary
authors.initials: G
authors.lastname: Disbrow
authors.forename: Richard
authors.initials: R
authors.lastname: Schlegel
authors.forename: Robert
authors.initials: R
authors.lastname: Schlegel
mesh_terms: D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D002584:Cervix Uteri / Q000166:cytology / Q000378:metabolism; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000096:biosynthesis*; D015603:Keratinocytes / Q000378:metabolism* / Q000473:pathology*; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D018972:Insulin-Like Growth Factor Binding Protein 3; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16