Photoperiod influences the growth of colon cancer in mice.
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 6L:18D photoperiod compared to 12L:12D. These results demonstrate an important role of photoperiod on tumor growth.
Waldrop
R D
RD
Dept. of Surgery, University of Texas Medical Branch, Galveston.
Saydjari
R
R
Rubin
N H
NH
Rayford
P L
PL
Townsend
C M
CM
Thompson
J C
JC
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology*; D000818:Animals; D001835:Body Weight; D002940:Circadian Rhythm; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology*; D000518:Eflornithine / Q000627:therapeutic use; D008027:Light; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009929:Organ Size; D011897:Random Allocation; D013154:Spleen / Q000473:pathology; D013737:Testis / Q000473:pathology; D014407:Tumor Cells, Cultured
D000518:Eflornithine