Comparison of KrasG12D/WT;p53Fx/Fx and KrasG12D/G12D;p53Fx/Fx MEFs

Microarray expression data generated to compare the biological impact of KrasG12D allelic duplication in p53null mouse embryonic fibroblasts (MEFs). The RAS/MAPK-signalling pathway is frequently deregulated in non-small cell lung cancer (NSCLC), often through activating mutations in KRAS. Mouse models demonstrated that activation of a single endogenous mutant Kras allele is sufficient to promote lung tumour formation, but acquisition of other genetic alterations is required for malignant progression. Using a well-established lung cancer mouse model we recently demonstrated that advanced KrasG12D-driven spontaneous tumours frequently exhibit enhanced MAPK signalling and KrasG12D allelic enrichment (KrasG12D/Kraswild-type>1), implying that mutant Kras copy gains are positively selected during lung cancer progression. To compare the oncogenic impact of a single mutant allele versus additional mutant Kras copy gain, we carried out a comprehensive analysis of mutant Kras homozygous and heterozygous MEFs and lung cancer cells and show that these genotypes are phenotypically distinct. Title: Mutant Kras copy number defines metabolic reprogramming and therapeutic susceptibilities Authors: Emma M Kerr, Edoardo Gaude, Frances K Turrell, Christian Frezza and Carla P Martins For MEF generation, KrasLSL-G12D/+ ;p53Fx/Fx mixed background (C57Bl/6/129/Sv) animals were interbred and embryos collected at day E12.5 to overcome KrasLSL-G12D/G12D embryonic lethality and Cre-mediated recombination performed immediately after MEF generation. Cells were cultured in DMEM supplemented with 10% FBS, 2 mM L-Glutamine for one passage and then infected with adenovirus-Cre (5 × 107 plaque-forming units/1 x 106 cells). Recombination of LoxP sites was confirmed by PCR analysis. Three independent embryos per genotype were analysed using GPL6887 Illumina MouseWG-6 v2.0 expression beadchip.