We have developed a mouse colon adenocarcinoma cell line that produces tumors in a dose-dependent manner when injected subcutaneously. Our previous work has demonstrated its sequential pattern of tumor area and weight under 12L:12D (12 hours light, 12 hours darkness) photoperiod. This study investigated whether shorter (6L:18D) or longer (18L:6D) photoperiods alter tumor growth. Significantly greater tumor area, weight, and group mortality were found in mice exposed to 12L:12D photoperiods as compared to either 6L:18D or 18L:6D photoperiods, and difluoromethylornithine (DFMO) was a more effective inhibitor of tumor growth under the if6L:18D photoperiod compared to 12L:12D. These results demonstrate an important role of photoperiod on tumor growth.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)