Xenograft Mouse Model for Cancer Research

All animal experiments were performed in accordance with E.U. directive 2010/63 (regional Gothenburg animal ethics committee approval #287/289–12 and #36–2014). For cell line xenografts, cells were suspended in RPMI, mixed 1:1 with Matrigel (BD Biosciences), and 2 × 10⁵ cells transplanted subcutaneously into the flanks of immunocompromised, non-obese severe combined immune deficient interleukin-2 chain receptor γ knockout mice (NOG mice; Taconic, Denmark). For transcriptome analyses, all CDX tumors were harvested once they reached 100 −200 mm³ in size. To assess effects of trametinib, xenografts whose growth were increased on two consecutive measurements, were randomized to two treatment groups: vehicle or trametinib (4 mg compound/kg food = 1 mg/kg/day) (Selleckchem, Houston, TX) mixed in the fodder (ResearchDiets Inc., New Brunswick, NJ). Mice were weighed and tumors measured using calipers twice a week. Mice were euthanized when tumors were larger than 10 × 10 mm² as per ethical regulations [55 (link)].