Cytotoxicity and cytokinetic effects of mitomycin C and/or photochemotherapy in a human colon adenocarcinoma cell line.
1. The cytotoxicity and cytokinetic effects of Mitomycin C (MC) and/or photochemotherapy (PCT) in cultured human colon adenocarcinoma (WiDr) cells were investigated using colony formation to determine cell survival and DNA flow cytometry to analyze cell kinetics. 2. A low concentration of MC (0.01 micrograms/ml) caused accumulation of cells in late S and early G2 phase; higher concentrations (0.05-0.5 micrograms/ml) induced accumulation of the cells in mid and early S phase. 3. The effects of the lowest concentration of MC (0.01 micrograms/ml) were reversible upon removal of the drug, whereas a higher concentration of MC (0.1 micrograms/ml) resulted in a permanent inhibition of cell cycle progression. 4. The sensitivity of Photofrin II-loaded cells to PCT can be enhanced significantly by the addition of MC. 5. The MC-induced accumulation of the cells in S phase may be one reason for the increased cytotoxicity of PCT combined with MC. 6. The data suggest that MC may also inhibit repair of PCT-induced DNA damage.
Ma
L W
LW
Department of Biophysics, Institute for Cancer Research, Montebello, Oslo, Norway.
Steen
H B
HB
Moan
J
J
Berg
K
K
Peng
Q
Q
Saether
H
H
Rimington
C
C
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D002470:Cell Survival; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D016685:Mitomycin / Q000627:therapeutic use*; D010778:Photochemotherapy; D014407:Tumor Cells, Cultured
D016685:Mitomycin