Egfrfl/fl and EgfrΔmye mice were utilized as described18 (link). C57BL/6 Egfrfl/fl mice were crossed with C57BL/6 LysMcre/cre mice to generate myeloid-specific, Egfr deletion (EgfrΔmye). C57BL/6 Egfrfl/fl mice were crossed to CD-1/DBA Foxa3cre/+ mice obtained from Timothy Wang (Columbia University Medical Center)60 (link), to generate EgrfΔGIepi mice. As EgrfΔGIepi mice contain one Cre allele, littermates were utilized for all experiments. Animals were used under protocol M/10/155, approved by the Institutional Animal Care and Use Committee at Vanderbilt University.
Male mice, aged 6-12 weeks, were utilized for all studies. Samples sizes were based on previous AOM-DSS studies from our laboratory. Mice were not removed from the cages into which they were weaned. No other criteria were utilized for selection or randomization. Mice were subjected to the azoxymethane (AOM)-dextran sodium sulfate (DSS) colon tumorigenesis model27 (link),61 . Mice received one intraperitoneal AOM injection (12.5 mg/kg) on Day 0, and three doses of 4% DSS in their drinking water on Days 5, 26, and 47. The first two cycles of DSS lasted for 5 days, and the third for 4 days. Mice were weighed every 7 days from the start of the first DSS cycle and on Day 0 to determine the AOM dosage. Mice were sacrificed on Day 77.
Rarely, EgfrΔmye mice developed an enlarged spleen that was not attributable to AOM-DSS treatment. These mice were excluded from further analysis.
Tumor multiplicity was determined by visual inspection via dissecting microscope. Tumor burden was determined by the summation of tumor area, assessed by electronic caliper. Histologic colitis and dysplasia were determined by a gastrointestinal pathologist, M.K.W., in a blinded manner.
Male mice, aged 6-12 weeks, were utilized for all studies. Samples sizes were based on previous AOM-DSS studies from our laboratory. Mice were not removed from the cages into which they were weaned. No other criteria were utilized for selection or randomization. Mice were subjected to the azoxymethane (AOM)-dextran sodium sulfate (DSS) colon tumorigenesis model27 (link),61 . Mice received one intraperitoneal AOM injection (12.5 mg/kg) on Day 0, and three doses of 4% DSS in their drinking water on Days 5, 26, and 47. The first two cycles of DSS lasted for 5 days, and the third for 4 days. Mice were weighed every 7 days from the start of the first DSS cycle and on Day 0 to determine the AOM dosage. Mice were sacrificed on Day 77.
Rarely, EgfrΔmye mice developed an enlarged spleen that was not attributable to AOM-DSS treatment. These mice were excluded from further analysis.
Tumor multiplicity was determined by visual inspection via dissecting microscope. Tumor burden was determined by the summation of tumor area, assessed by electronic caliper. Histologic colitis and dysplasia were determined by a gastrointestinal pathologist, M.K.W., in a blinded manner.
