title: p53 inhibits adriamycin-induced down-regulation of cyclin D1 expression in human cancer cells.
abstract: The tumor suppressor p53 gene product is an essential component of the cytotoxic pathway triggered by DNA-damaging stimuli such as chemotherapeutic agents and ionizing radiation. We previously demonstrated that adenovirus-mediated wild-type p53 gene transfer could enhance the cytotoxic actions of chemotherapeutic drugs both in vitro and in vivo; however, the molecular mechanism of this chemosensitization is still unclear. Cyclin D1 is a major regulator of the progression of cells into the proliferative stage of the cell cycle. Here we show that infection with an adenovirus vector expressing the wild-type p53 gene (Ad-p53) caused an increase in cyclin D1 protein levels in human colorectal cancer cell lines DLD-1 and SW620; treatment with the anti-cancer drug adriamycin, however, down-regulated their cyclin D1 protein expression in a dose-dependent manner. The suppression of cyclin D1 expression following adriamycin treatment could be blocked by simultaneous Ad-p53 infection. Furthermore, DLD-1 and SW620 cells transfected with the cyclin D1 expression construct displayed increased sensitivity to adriamycin compared to that of the vector-transfected control. Our results suggest that ectopic wild-type p53 gene transfer results in increased cyclin D1 expression and, consequently, sensitizes human colorectal cancer cells to chemotherapeutic agents.
authors.affiliation: Division of Surgical Oncology, Okayama University Graduate School of Medicine and Dentistry, Okayama, 700-8558, Japan.
authors.forename: Jianghua
authors.initials: J
authors.lastname: Shao
authors.forename: Fuminori
authors.initials: F
authors.lastname: Teraishi
authors.forename: Koh
authors.initials: K
authors.lastname: Katsuda
authors.forename: Noriaki
authors.initials: N
authors.lastname: Tanaka
authors.forename: Toshiyoshi
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism*; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004317:Doxorubicin / Q000494:pharmacology*; D005822:Genetic Vectors; D006801:Humans; D012334:RNA, Neoplasm / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000502:physiology*
chemical_list: D000970:Antineoplastic Agents; D012334:RNA, Neoplasm; D016159:Tumor Suppressor Protein p53; D019938:Cyclin D1; D004317:Doxorubicin