Insulin-like growth factor-binding protein 3 expression increases during immortalization of cervical keratinocytes by human papillomavirus type 16 E6 and E7 proteins.
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.
Berger
Allison J
AJ
Millennium Pharmaceuticals, Incorporated, Cambridge, Massachusetts 02139, USA. aberger@mpi.com
Baege
Astrid
A
Guillemette
Tracy
T
Deeds
James
J
Meyer
Ron
R
Disbrow
Gary
G
Schlegel
Richard
R
Schlegel
Robert
R
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
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