Molecular mechanisms of hyperplasia induction by human papillomavirus E7.
Infections of human papillomavirus (HPV) induce a variety of benign tumors, such as warts and condylomas. During the process of aberrant cell proliferation, genetic mutations are accumulated in the cells, from which malignant tumor cells arise. The viral oncoproteins E6 and E7 are known to help disrupt the cell cycle checkpoint machinery and accelerate chromosomal instability, events which are critical in malignant conversion. However, the mechanisms involved in the hyperplasia caused by HPV infection have remained unknown. We analysed the effects of regulatory genes of HPV18, a typical high-risk-type HPV, on the formation of the epithelial organ by using an organotypic culture system, and found that E7 had potent activity to induce hyperplasia, to which the disruption of the pRb pathway was well correlated. However, analysis with the E7 variants indicated that other pocket proteins are also involved in the activity.
Ueno
T
T
Laboratory of Gene Analysis, Department of Viral Oncology, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto, Japan.
Sasaki
K
K
Yoshida
S
S
Kajitani
N
N
Satsuka
A
A
Nakamura
H
H
Sakai
H
H
D049109:Cell Proliferation; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000502:physiology*; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D052161:Human papillomavirus 18 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D006965:Hyperplasia; D015603:Keratinocytes / Q000473:pathology* / Q000821:virology*; D021962:Membrane Microdomains / Q000473:pathology / Q000821:virology; D009856:Oncogene Proteins, Viral / Q000502:physiology*; D009924:Organ Culture Techniques; D016160:Retinoblastoma Protein / Q000037:antagonists & inhibitors / Q000378:metabolism
D004268:DNA-Binding Proteins; C052633:E7 protein, Human papillomavirus type 18; D009856:Oncogene Proteins, Viral; D016160:Retinoblastoma Protein