title: Altered growth response of oral mucosal keratinocytes in p53-deficient mice.
abstract: P53 has important regulatory functions in cell growth, differentiation and apoptosis. Here we analyzed the effects of p53 on the growth response of oral mucosal keratinocytes (OMKCs) using p53-deficient (p53-/-) mice. No morphological difference was found between p53-/- and wild-type (p53+/+) oral mucosa. In a long-term culture, p53-/- OMKCs continued to proliferate past the point at which p53+/+ became senescent. The percentage of p53-/- OMKCs in the G0/G1 phase was lower than that of p53+/+ OMKCs. Proliferation of cultured OMKCs induced by epidermal growth factor (EGF) and interleukin-(IL)-1alpha was more strongly enhanced in p53-/- than in p53+/+ mice. Such an enhanced response was not due to increased mRNA expression of growth factor receptors. These data suggest that p53 acts as a modulator of G1 arrest in OMKCs and is also involved in the regulation of responses to EGF and IL-1alpha without affecting the expression of their receptors.
authors.affiliation: Second Department of Oral and Maxillofacial Surgery, School of Dentistry, Showa University, Tokyo, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Ito
authors.forename: R
authors.initials: R
authors.lastname: Kamijo
authors.forename: Y
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: T
authors.initials: T
authors.lastname: Toyoshima
authors.forename: K
authors.initials: K
authors.lastname: Takizawa
authors.forename: K
authors.initials: K
authors.lastname: Sumitani
authors.forename: M
authors.initials: M
authors.lastname: Nagumo
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002453:Cell Cycle; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009061:Mouth Mucosa / Q000002:abnormalities / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017472:Receptors, Interleukin-1 / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000235:genetics / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D017472:Receptors, Interleukin-1; D016159:Tumor Suppressor Protein p53; D004815:Epidermal Growth Factor; D066246:ErbB Receptors