Author contributions M.G., K.Y., and C.B-D. conceived the project. F.B. led CRISPR-Cas9 screening, codeveloped Project Score webportal, performed analyses, verified WRN dependency. F.I. led computational analyses and figure preparation, contributed to the Project Score webportal. G.P. performed experiments to verify WRN dependency, carried out analyses, contributed to in vivo studies. E.G. contributed to computational analysis and figures. D.vdM. contributed to developing the Project Score webportal. G.

The MET tyrosine kinase receptor (also known as the HGF receptor) promotes tissue remodelling, which underlies developmental morphogenesis, wound repair, organ homeostasis and cancer metastasis, by integrating growth, survival and migration cues in response to environmental stimuli or cell-autonomous perturbations. The versatility of MET-mediated biological responses is sustained by qualitative and quantitative signal modulation. Qualitative mechanisms include the engagement of dedicated signal transducers and the subcellular compartmentalization of MET signalling pathways, whereas quantitative regulation involves MET partnering with adaptor amplifiers or being degraded through the shedding of its extracellular domain or through intracellular ubiquitylation. Controlled activation of MET signalling can be exploited in regenerative medicine, whereas MET inhibition might slow down tumour progression.Throughout embryogenesis, cells bud off from developing tissues and move outwards to shape and pattern the complex architecture of prospective organs 1 . A similar process occurs in adult life during wound healing and tissue repair, when lingering cells migrate into injury sites to recreate the pre-existing structures 2 . The acquisition of cell motility is necessary, but not sufficient, for this event. Cells that detach from their neighbours must elude anoikis, a form of apoptotic cell death that occurs when cells lose adhesion with the extracellular matrix 3 . Moreover, migratory cells undergo extensive mitotic divisions to produce 'founder populations', which settle in newly forming organs during development or colonize worn tissues during repair 4,5 . The normal phases of embryogenesis and organ regeneration strongly resemble the pathological process of tumour invasiveness: similarly to cells at the wound edge, cells at the tumour's leading front disrupt intercellular contacts and infiltrate the adjacent surroundings, where they resist anoikis and grow before lodging in the blood vessels for systemic dissemination 6 . This resemblance is not simply a biological correlate, it has a common mechanistic basis: cancer cells resurrect the latent schemes of cellular reorganization, which are usually confined to embryonic development and damaged adult organs, and leverage them to become competent for metastasization 7 . The activities -motility, survival and proliferation -that occur in developing, injured and neoplastic tissues embody a biological programme that is defined as 'invasive growth' 8 . This is triggered by extracellular stimuli that regulate the activity of several transcription factors that, in turn, modulate the expression of a number of proteins, ranging from cytoskeletal and cell-cell junctional components to cell cycle regulators and anti-apoptotic effectors 9, 10 . One major environmental inducer of invasive growth is hepatocyte growth factor (HGF, also known as scatter factor), the ligand for the MET tyrosine kinase receptor (also known as the HGF receptor) 11,12,13,14,15,16,17,18,19,20 (Box 1). ...

As for other types of malignancy, colorectal cancer is not a homogeneous disease but actually comprises multiple entities that vary in natural history and molecular pathogenesis. This heterogeneity explains why molecular cancer therapeutics against individual disease driver targets have proven to be effective in only a fraction of cases. One prototypical example is provided by the anti-epidermal growth factor receptor (EGFR) monoclonal antibodies cetuximab and panitumumab, which are approved for the treatment of metastatic colorectal cancer. In unselected patients, the extent of clinical benefit from monotherapy with either drug hovers near the threshold for statistical significance, with response rates of approximately 10% ( 3-5 ).The population of potential responders has been recently enriched thanks to a biomarker-development strategy that is driven by the plausible biological rationale that constitutive activation of signaling pathways parallel to or downstream from EGFR, such as the RAS-RAF axis, should circumvent EGFR inhibition and therefore preclude sensitivity to EGFRtargeted agents ( 6 ). Indeed, the authors of both retrospective and prospective trials have convincingly demonstrated the inefficacy of EGFR-neutralizing antibodies in metastatic colorectal cancer patients with common (codons 12 and 13) KRAS mutations ( 7-12 ).Along this line, in a number of retrospective studies investigators have provided initial evidence that rare KRAS mutations as well as NRAS , BRAF , and (possibly) PIK3CA mutations also are significantly associated with low response rates ( 13-16 ). When considering the cumulative incidence of Only a fraction of patients with metastatic colorectal cancer receive clinical benefit from therapy with anti-epidermal growth factor receptor (EGFR) antibodies, which calls for the identification of novel biomarkers for better personalized medicine. We produced large xenograft cohorts from 85 patient-derived, genetically characterized metastatic colorectal cancer samples ("xenopatients") to discover novel determinants of therapeutic response and new oncoprotein targets. Serially passaged tumors retained the morphologic and genomic features of their original counterparts. A validation trial confirmed the robustness of this approach: xenopatients responded to the anti-EGFR antibody cetuximab with rates and extents analogous to those observed in the clinic and could be prospectively stratified as responders or nonresponders on the basis of several predictive biomarkers. Genotype-response correlations indicated HER2 amplification specifically in a subset of cetuximab-resistant, KRAS/NRAS/BRAF/PIK3CA wild-type cases. Importantly, HER2 amplification was also enriched in clinically nonresponsive KRAS wild-type patients. A proof-of-concept, multiarm study in HER2-amplified xenopatients revealed that the combined inhibition of HER2 and EGFR induced overt, long-lasting tumor regression. Our results suggest promising therapeutic opportunities in cetuximab-resistant patients with metastatic colorectal ca...

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