Development of mice models of orthotopic pancreatic cancer

AsPC1 cells (ATCC, Manassas, VA, USA; a 62-year-old Caucasian female with pancreatic adenocarcinoma) were grown in RPMI 1640 medium supplemented with 10% Fetal Bovine Serum and 1% penicillin and streptomycin (Life Technologies, Grand Island, NY, US). Cells were incubated in humidified atmosphere at 37 °C and 5% CO₂, with the culture media changed every 3 days. Initially, pancreatic cancer xenograft models were created using 1.5 M AsPC1 cells which were placed in 100 µl of matrigel and then subcutaneously injected into the flank of 6-week-old nude mice⁵⁰. After three weeks, xenograft tumors reached 10 mm in size at which point they were removed from each animal and cut into small blocks (2 × 2 × 2 mm³). Each tumor block was then implanted into the pancreas of a new group of nude mice, as previously described⁵⁰. In brief, a 10 mm vertical skin incision was made on the left side of the upper abdomen of a recipient nude mouse. The peritoneum was then carefully opened, and the pancreas exposed. A single block of tumor was then carefully implanted into the body of the pancreas. The pancreas was then placed back into the abdominal cavity and abdominal wall closed using a 5–0 absorbable suture and surgical staples⁵¹. Following the surgery, animals (n = 6 for each treatment group) were observed on heat pad for 30 minutes before returning to their cage. The surgical wound was monitored daily for any signs of wound infection, bleeding or wound dehiscence or other post-procedure complications (i.e. changes in their weight, behavior, feeding patterns, posture and activity level). Staples were removed on postoperative day 7–10 with sterile surgical staple removal.