title: 5-Fluorouracil combined with apigenin enhances anticancer activity through induction of apoptosis in human breast cancer MDA-MB-453 cells.
abstract: We investigated the effects of combined treatment with 5-fluorouracil and apigenin on proliferation and apoptosis, as well as the underlying mechanism, in human breast cancer MDA-MB-453 cells. The MDA-MB-453 cells, which have been shown to overexpress ErbB2, were resistant to 5-fluorouracil; 5-fluorouracil exhibited a small dose-dependent anti-proliferative effect, with an IC50 of 90 microM. Interestingly, combined treatment with apigenin significantly decreased the resistance. Cellular proliferation was significantly inhibited in cells exposed to 5-fluorouracil at its IC50 and apigenin (5, 10, 50 and 100 microM), compared with proliferation in cells exposed to 5-fluorouracil alone. This inhibition in turn led to apoptosis, as evidenced by an increased number of apoptotic cells and the activation of caspase-3. To investigate the mechanism by which the combination of 5-fluorouracil and apigenin induces apoptosis, ErbB2 expression was analyzed. The level of ErbB2 was unchanged by 5-fluorouracil alone but was drastically reduced in cells treated with 5-fluorouracil plus apigenin. Moreover, compared with 5-fluorouracil alone, 5-fluorouracil in combination with apigenin at concentrations >10 microM exerted a pro-apoptotic effect via the inhibition of Akt expression. Taken together, our results suggest that 5-fluorouracil acts synergistically with apigenin inhibiting cell growth and inducing apoptosis via the down-regulation of ErbB2 expression and Akt signaling.
authors.affiliation: Plant Resources Research Institute, Duksung Women's University, Seoul, Korea. ejchoi@duksung.ac.kr
authors.forename: Eun J
authors.initials: EJ
authors.lastname: Choi
authors.forename: Gun-Hee
authors.initials: GH
authors.lastname: Kim
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D047310:Apigenin / Q000008:administration & dosage*; D017209:Apoptosis; D001943:Breast Neoplasms / Q000188:drug therapy*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015536:Down-Regulation; D004354:Drug Screening Assays, Antitumor; D004357:Drug Synergism; D005472:Fluorouracil / Q000008:administration & dosage*; D006801:Humans; D020128:Inhibitory Concentration 50; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism
chemical_list: D047310:Apigenin; D053148:Caspase 3; D005472:Fluorouracil; D051057:Proto-Oncogene Proteins c-akt; D018719:Erb-b2 Receptor Tyrosine Kinases