Radiobiological effects of docetaxel (Taxotere): a potential radiation sensitizer.
OBJECTIVE
To investigate the ability of docetaxel (Taxotere) to radiosensitize human cell lines of differing malignant status, intrinsic radiosensitivity and p53 status.


METHODS
Cell survival following treatment with drug and/or radiation was determined by colony-forming assay on two malignant human colon cell lines of widely different radiosensitivity (HT29 and SW48). An immortal human keratinocyte line (HaCaT), which does not form tumours in nude mice, was used to assess the effect on non-malignant human epithelium.


RESULTS
The experiments indicate that docetaxel had the greatest cytotoxic and radiosensitizing effect on the SW48 (p53wt) cell line. The degree of radiosensitization was not improved by increasing the drug concentration, although the overall cytotoxicity was increased with increasing concentrations of the two agents. Both p53mut lines were less sensitive to the drug, irrespective of their malignant potential.


CONCLUSIONS
The results support a role for Taxotere as a weak radiosensitizer of the three cell lines tested. The p53 status and intrinsic radiosensitivity may be relevant to the mechanism.
Creane
M
M
Radiation Science Centre, Dublin Institute of Technology, Ireland.
Seymour
C B
CB
Colucci
S
S
Mothersill
C
C
D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects; D000077143:Docetaxel; D016158:Genes, p53; D006801:Humans; D017239:Paclitaxel / Q000031:analogs & derivatives* / Q000494:pharmacology; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D043823:Taxoids; D014407:Tumor Cells, Cultured
D011838:Radiation-Sensitizing Agents; D043823:Taxoids; D000077143:Docetaxel; D017239:Paclitaxel