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Docetaxel chronopharmacology in mice
M Tampellini1, E Filipski, X H Liu
1Laboratoire Rythmes Biologiques et Chronothérapeutique (Université Paris XI), Institut du Cancer et d'Immunogénétique, Hôpital Paul Brousse, Villejuif, France.
Cancer Research
|September 10, 1998
Summary
Administering docetaxel during the light phase, when mice rest, significantly improved tolerance and antitumor efficacy. This chronotherapy approach, timed to circadian rhythms, offers a promising strategy for enhancing cancer treatment outcomes.
Area of Science:
- Chronopharmacology
- Cancer Therapeutics
- Circadian Biology
Background:
- Docetaxel efficacy and tolerance can be influenced by administration timing.
- Circadian rhythms regulate physiological processes, potentially affecting drug response.
- Optimizing docetaxel administration based on circadian cycles may improve treatment outcomes.
Purpose of the Study:
- To investigate the impact of circadian rhythm-timed docetaxel administration on its tolerance and antitumor efficacy.
- To determine optimal dosing times for docetaxel to maximize therapeutic benefit and minimize toxicity.
- To explore the underlying mechanisms of circadian rhythm-dependent docetaxel toxicity and efficacy.
Main Methods:
- Seven experiments involving 626 male B6D2F1 mice synchronized to a 12:12 light-dark cycle.
- Docetaxel administered intravenously at various doses, schedules, and circadian times (hours after light onset - HALO).
- Endpoints included survival, body weight, hematological and intestinal toxicities, tumor growth, and bone marrow cell cycle analysis.
Main Results:
- Docetaxel administered during the light phase (3, 7, 11 HALO) showed significantly lower toxicity and higher survival rates compared to administration during darkness (19, 23 HALO).
- Optimal dosing times (e.g., 7 HALO weekly) resulted in maximal increases in lifespan for tumor-bearing mice.
- Reduced toxicity correlated with circadian nadirs in S/G2-M phase and BCL-2 expression in bone marrow.
Conclusions:
- Circadian-timed docetaxel administration significantly enhances both drug tolerability and antitumor efficacy.
- Administering docetaxel during the light phase (resting period) is associated with improved therapeutic index.
- Circadian regulation of cell cycle dynamics is a key mechanism underlying docetaxel's chronomodulated effects.