DNA replication time accounts for tumor growth variation induced by dietary fat in a breast carcinoma model.
Female Fischer rats were pair-fed on diets containing either safflower oil (SO) or fish oil (FO) for 6 weeks. Implanted breast 13762 MAT tumors had a doubling times of 35.4 and 55.5 h in SO and FO rats, respectively (P < 0.001). Proliferation kinetics were measured in vivo by bromedeoxyuridine (BrdUrd) labeling and bivariate DNA/BrdUrd analysis by flow cytometry. After 1 h of pulsing, the labeling index was similar in both groups. However, 6 h later, tumor cells from FO rats had significantly lower relative movement of BrdUrd-labeled cells (0.78 vs. 0.91, P < 0.001). These results reflected a significantly longer S phase duration (15.0 vs. 9.1 h, P < 0.001) in FO rats and accounted for all the difference in tumor growth rates. This mechanism, which has not previously been reported, implies a significant role for fatty acids in DNA replication.
Istfan
N W
NW
Department of Medicine, New England Deaconess Hospital, Harvard Medical School, Boston, MA.
Wan
J M
JM
Bistrian
B R
BR
Chen
Z Y
ZY
D000818:Animals; D001835:Body Weight; D002455:Cell Division; D004261:DNA Replication; D004041:Dietary Fats / Q000494:pharmacology*; D005260:Female; D005395:Fish Oils; D005434:Flow Cytometry; D008325:Mammary Neoplasms, Experimental / Q000473:pathology*; D008954:Models, Biological; D009368:Neoplasm Transplantation; D051381:Rats; D011916:Rats, Inbred F344; D016196:S Phase; D012450:Safflower Oil; D013997:Time Factors
D004041:Dietary Fats; D005395:Fish Oils; D012450:Safflower Oil