title: p53 dependence and apoptosis in response to FP treatment with p53-transfected colon cancer cell lines by use of thin layer collagen gel.
abstract: The combination of 5-fluorouracil (5-FU) plus Cisplatin (CDDP) (FP treatment) possesses synergistic cytotoxicity against colon cancer. The molecular mechanisms by which chemotherapeutic agents induce apoptosis have been clarified by identifying apoptosis-related genes such p53 and bcl-2. We previously established a new experimental technique in which cancer cells are distributed in thin collagen gel as 1 or 2 cell layers. additionally, we evaluated the efficacy and toxicity of FP treatment in the gastric and colon cancer cell lines, and examined the relationship between the response to FP treatment and apoptosis. In these results we reported transfection of normal p53 gene into p53 mutant and analyzed the impact of the p53 gene in a sensitivity test. In this study, we examined induced apoptosis in colon cancer cell lines and the status of p53 expression in response to treatment of HCT116, COLO320, SW480 and DLD1 with 5-FU alone, CDDP alone and FP treatment under flow cytometric analysis. Transfection of SW480 and DLD1 cells was performed to compare the chemosensitivity of naturally occurring mutant-type p53 SW480 and DLD1 cells with neo-transfected SW480 and DLD1 cells and transfected SW480 and DLD1 cells. Appreciable apoptosis was induced in HCT116 and COLO320 (p53 wild-type) but not in SW480 and DLD1 cells (p53 mutant-type). Transfected SW480 and DLD1 cells underwent significantly more apoptosis (p<lt;0.001) than naturally occurring mutant-type p53 SW480 and DLD1 cells. p53 expression may further induce apoptosis in FP treatment. Patients with p53 wild-type may be better candidates for FP therapy than patients with p53 mutant-type in colon cancer. Therefore, we think that p53 may be also effective against colon cancer in FP therapy.
authors.affiliation: Department of Surgical Oncology, Gifu University, Gifu City 501-1194, Japan. nobuhisa517@hotmail.com
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Matsuhashi
authors.forename: Masanao
authors.initials: M
authors.lastname: Saio
authors.forename: Atsushi
authors.initials: A
authors.lastname: Matsuo
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Shigetoyo
authors.initials: S
authors.lastname: Saji
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D002945:Cisplatin / Q000008:administration & dosage; D003094:Collagen / Q000737:chemistry*; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D018076:DNA, Complementary / Q000378:metabolism; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D005434:Flow Cytometry; D005472:Fluorouracil / Q000008:administration & dosage; D005782:Gels; D016158:Genes, p53; D006801:Humans; D008856:Microscopy, Fluorescence; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D014162:Transfection; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
chemical_list: D018076:DNA, Complementary; D005782:Gels; D016159:Tumor Suppressor Protein p53; D003094:Collagen; D002945:Cisplatin; D005472:Fluorouracil