Fig. 4.

Ibuprofen impairs mammary prostaglandin production, tumor promotion and immature myeloid cell frequency during involution. a INV group mice were generated by breeding, and pups nursed for 10 days (10 D). Pups were removed to initiate synchronous mammary gland involution at which time ibuprofen containing (IBU) chow (300 mg/kg chow) or normal chow was administered to INV mice. Control NP mice received normal chow only. Two days later (INV D2 for INV group mice) mammary glands were harvested and b assessed by lipid mass spectroscopy for absolute quantification of the indicated prostaglandin (blue) and leukotriene (red) family members. c The above breeding schema was repeated. Mice received the indicated dose of ibuprofen starting at initiation of involution and in age-matched NP mice. One day later, mice received an orthotopic fat pad implantation of 20,000 syngeneic D2A1 mammary epithelial tumor cells. At ~ 3 weeks post injection d tumor sizes were recorded. The tumor data are an aggregate of three independent experiments. Data were normalized between experiments by utilizing the time point where the mean tumor volume of the NP group tumors was the same for all three studies. Tumors were digested into single cell suspensions for determination of e immature monocyte and f mature macrophage content by flow cytometry. Determination of statistically significant differences were based upon two-tailed Student’s t-test between the indicated groups with p < 0.05 (*), p < 0.01 (**), p < .001 (***), p < .0001 (****)