title: Gene expression deregulation by KRAS G12D and G12V in a BRAF V600E context.
abstract: BACKGROUND
  KRAS and BRAF mutations appear of relevance in the genesis and progression of several solid tumor types but the co-occurrence and interaction of these mutations have not yet been fully elucidated. Using a microsatellite stable (MSS) colorectal cancer (CRC) cell line (Colo741) having mutated BRAF and KRASWT, we also aimed to investigate the KRAS-BRAF interaction. Gene expression profiles for control KRASWT, KRAS G12V and KRAS G12D transfected cells were obtained after cell clone selection and RT-PCR screening. Extensive qPCR was performed to confirm microarray data.
  
  
  RESULTS
  We found that the KRAS G12V state deregulated several genes associated to cell cycle, apoptosis and nitrogen metabolism. These findings indicated a reduced survival and proliferation with respect to the KRASWT state. The KRAS G12D state was, instead, characterized by several other distinct functional changes as for example those related to chromatin organization and cell-cell adhesion without affecting apoptosis related genes.
  
  
  CONCLUSIONS
  These data predict that the G12D mutation may be more likely selected in a BRAF mutated context. At the same time, the presence of the KRAS G12V mutation in the cells escaping apoptosis and inducing angiogenesis via IL8 may confer a more aggressive phenotype. The present results get along with the observations that CRCs with G12V are associated with a worse prognosis with respect to the WT and G12D states and may help identifying novel CRC pathways and biomarkers of clinical relevance.
authors.affiliation: Centro Biotecnologie Avanzate, Genova, Italy. massimiliano.monticone@cba-biotecnologie.it
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Monticone
authors.forename: Emanuela
authors.initials: E
authors.lastname: Biollo
authors.forename: Massimo
authors.initials: M
authors.lastname: Maffei
authors.forename: Alessandra
authors.initials: A
authors.lastname: Donadini
authors.forename: Francesco
authors.initials: F
authors.lastname: Romeo
authors.forename: Clelia Tiziana
authors.initials: CT
authors.lastname: Storlazzi
authors.forename: Walter
authors.initials: W
authors.lastname: Giaretti
authors.forename: Patrizio
authors.initials: P
authors.lastname: Castagnola
mesh_terms: D045744:Cell Line, Tumor; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D009154:Mutation / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics* / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras); D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018631:ras Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins