Apoptosis in cultured human colon cancer cells induced by combined treatments with 5-fluorouracil, tumor necrosis factor-alpha and interferon-alpha.
Biochemical analysis using nick end-labeling was performed to investigate the effect of various combinations of 5-fluorouracil, natural human tumor necrosis factor-alpha and natural human interferon-alpha on the induction of apoptosis in RPMI 4788 human colon cancer cells. After treatment with 5-fluorouracil (1 mM) for 48 h, the number of nick end-positive cells was significantly increased in comparison to the situation without treatment. When tumor cells were treated with 1 mM 5-fluorouracil, 2.86 Japan Reference Units (JRU)/ml natural human tumor necrosis factor-alpha and 1 x 10(3) IU/ml natural human interferon-alpha in combination for 48 h, the number of nick end-positive cells was significantly higher than that after treatment with 5-fluorouracil alone. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay revealed a significant decrease of relative viability, as compared to treatment with 5-fluorouracil (1 mM), 5-fluorouracil + natural human tumor necrosis factor-alpha, or 5-fluorouracil + natural human interferon-alpha for 48 h. Pretreatment with 5-fluorouracil (1 mM) for 24 h prior to treatment with natural human tumor necrosis factor-alpha (2.86 JRU/ml) and natural human interferon-alpha (10(3) IU/ml) for 24 h resulted in a significant increase of nick end-positive cells compared to pretreatment with natural human tumor necrosis factor-alpha and natural human interferon-alpha prior to treatment with 5-fluorouracil for 24 h (p < 0.05). These results suggest that 5-fluorouracil alone can induce apoptosis in RPMI 4788 tumor cells and that this effect can be enhanced by combination with natural human tumor necrosis factor-alpha and natural human interferon-alpha.
Oka
Y
Y
First Department of Surgery, Okayama University Medical School, Japan.
Naomoto
Y
Y
Yasuoka
Y
Y
Hatano
H
H
Haisa
M
M
Tanaka
N
N
Orita
K
K
D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects*; D001399:Azure Stains; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004396:Coloring Agents; D004253:DNA Nucleotidylexotransferase; D005472:Fluorouracil / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D016898:Interferon-alpha / Q000008:administration & dosage / Q000627:therapeutic use*; D008739:Methyl Green; D013778:Tetrazolium Salts; D013844:Thiazoles; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000008:administration & dosage / Q000627:therapeutic use*
D000964:Antimetabolites, Antineoplastic; D000970:Antineoplastic Agents; D001399:Azure Stains; D004396:Coloring Agents; D016898:Interferon-alpha; D013778:Tetrazolium Salts; D013844:Thiazoles; D014409:Tumor Necrosis Factor-alpha; D008739:Methyl Green; D004253:DNA Nucleotidylexotransferase; C022616:thiazolyl blue; D005472:Fluorouracil