Article

KRAS and YAP1 converge to regulate EMT and tumor survival

Cell (Impact Factor: 32.24). 06/2014; 158(1). DOI: 10.1016/j.cell.2014.06.004
Source: PubMed

ABSTRACT

Cancer cells that express oncogenic alleles of RAS typically require sustained expression of the mutant allele for survival, but the molecular basis of this oncogene dependency remains incompletely understood. To identify genes that can functionally substitute for oncogenic RAS, we systematically expressed 15,294 open reading frames in a human KRAS-dependent colon cancer cell line engineered to express an inducible KRAS-specific shRNA. We found 147 genes that promoted survival upon KRAS suppression. In particular, the transcriptional coactivator YAP1 rescued cell viability in KRAS-dependent cells upon suppression of KRAS and was required for KRAS-induced cell transformation. Acquired resistance to Kras suppression in a Kras-driven murine lung cancer model also involved increased YAP1 signaling. KRAS and YAP1 converge on the transcription factor FOS and activate a transcriptional program involved in regulating the epithelial-mesenchymal transition (EMT). Together, these findings implicate transcriptional regulation of EMT by YAP1 as a significant component of oncogenic RAS signaling.

1 Follower
 · 
99 Reads
  • Source
    • "Elevated expression of YAP has also been identified in various human cancers (Dong et al., 2007; Harvey et al., 2013; Mo et al., 2014). Notably, recent studies demonstrated that YAP overexpression promoted resistance to KRAS-, RAF-, and MEK-targeted cancer therapies (Kapoor et al., 2014; Lin et al., 2015; Shao et al., 2014), highlighting the need to target YAP for cancer treatment. Efforts have been devoted to search for druggable targets within the Hippo-YAP pathway in order to develop pharmacological compounds that could inhibit YAP oncogenic activities. "
    [Show abstract] [Hide abstract]
    ABSTRACT: As the key effector in the Hippo pathway, YAP was identified as an oncoprotein whose expression is elevated in various human cancers. However, the development of potentially therapeutic compounds targeting YAP has been slow and limited. Here, we find that tankyrase inhibitors suppress YAP activity. This effect is mediated by anigomotin (AMOT) family proteins. Tankyrases associate with AMOT family proteins and promote their degradation through E3 ligase RNF146. By antagonizing tankyrase activity, tankyrase inhibitors stabilize AMOT family proteins, thereby suppressing YAP oncogenic functions. Together, our studies not only demonstrate the tankyrase-RNF146-AMOT axis as an upstream pathway regulating YAP but also reveal a therapeutic opportunity in targeting YAP for cancer treatment.
    Full-text · Article · Oct 2015 · Cell Reports
  • Source
    • "nuclear enrichment in Er/Er keratinocytes led to elevated expression of its target genes, we performed qPCR to assay the mRNA levels of the genes Cyr61, Ctgf, Zeb1, and Snai2, which were previously shown to be Yap1 transcriptional targets (Heallen et al., 2011; Shao et al., 2014). They exhibited reduced expression in differentiating WT keratinocytes (Fig. 3a), which was correlated with the Yap1 cytoplasmic retention pattern shown above. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The homozygous repeated epilation (Er/Er) mouse mutant of the gene encoding 14-3-3σ displays an epidermal phenotype characterized by hyperproliferative keratinocytes and undifferentiated epidermis. Heterozygous Er/+ mice develop spontaneous skin tumors and are highly sensitive to tumor-promoting DMBA/TPA induction. The molecular mechanisms underlying 14-3-3σ regulation of epidermal proliferation, differentiation, and tumor formation have not been well elucidated. In the present study, we found that Er/Er keratinocytes failed to sequester Yap1 in the cytoplasm, leading to its nuclear localization during epidermal development in vivo and under differentiation-inducing culture conditions in vitro. In addition, enhanced Yap1 nuclear localization was also evident in DMBA/TPA-induced tumors from Er/+ skin. Furthermore, shRNA knockdown of Yap1 expression in Er/Er keratinocytes inhibited their proliferation, suggesting that YAP1 functions as a downstream effector of 14-3-3σ controlling epidermal proliferation. We then demonstrated that keratinocytes express all seven 14-3-3 protein isoforms, some of which form heterodimers with 14-3-3σ, either full-length WT or the mutant form found in Er/Er mice. However Er 14-3-3σ does not interact with Yap1, as demonstrated by co-immunoprecipitation. We conclude that Er 14-3-3σ disrupts the interaction between 14-3-3 and Yap1, thus fails to block Yap1 nuclear transcriptional function, causing continued progenitor expansion and inhibition of differentiation in Er/Er epidermis.Journal of Investigative Dermatology accepted article preview online, 10 February 2015. doi:10.1038/jid.2015.42.
    Full-text · Article · Feb 2015 · Journal of Investigative Dermatology
  • Source
    • "In this issue of The EMBO Journal, Hong et al (2014) propose a new mechanism to explain the role of YAP1 in RAS-mediated cellular transformation. In agreement with the aforementioned studies, Hong and colleagues confirm that YAP1 is required for efficient RAS-induced cellular transformation and tumor formations in vivo (Nguyen et al, 2014; Shao et al, 2014). They furthermore show that oncogenic RAS is able to stabilize endogenous YAP1 protein by downregulating the mRNA levels of the SOCS box proteins SOCS5 and 6, thereby preventing YAP1 ubiquitination. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The Hippo-signaling effector YAP1 was recently found to compensate for oncogenic RAS in certain neoplasms, suggesting so far unanticipated molecular interplays between these major signaling routes. A new study in this issue of The EMBO Journal details KRAS-dependent control of YAP1 stability as well as positive feedback regulation via the RAS/YAP1/EGFR-ligand axis as novel molecular mechanisms that could become exploitable for therapeutic strategies.
    Full-text · Article · Sep 2014 · The EMBO Journal
Show more

Questions & Answers about this publication

  • Andrei Nikonov added an answer in Cell Signaling:
    Does anyone has tried a good antibody for YAP in mouse cell lines samples?

    I have tried the YAP antibody from Cell Signaling, but I am using it 1:500 and I get a very weak signal. 

    Andrei Nikonov

    According to the recent paper on YAP1 and KRAS pathways convergence, the antibody you mentioned is used either at a dilution 1:50 to 1:10 (in co-immunoprecipitation). So if you are doing IP, just increase the Ab concentration.

    In the same paper ChIP is also performed but with antibody from Santa.

    If you are doing western blot, then simply increase the concentration of primary-YAP Ab and after incubation save it and conserve by adding sodium azide to 0.04% storing it at +4C. It should be stable for more than a month. I typically performed some 7-12 westerns with such a solution (add azide only once, after first incubation).

    Increasing the concentration of Ab often also means decreasing the volume of your solution. You can easily do a western in 5-10 ml final volume on orbital shaker inside a 50-ml falcon (hence avoiding evaporation). However, to avoid background perform blocking and all washes in ordinary vessels with plenty on solution.

    Best,

    AN

    • [Show abstract] [Hide abstract]
      ABSTRACT: Cancer cells that express oncogenic alleles of RAS typically require sustained expression of the mutant allele for survival, but the molecular basis of this oncogene dependency remains incompletely understood. To identify genes that can functionally substitute for oncogenic RAS, we systematically expressed 15,294 open reading frames in a human KRAS-dependent colon cancer cell line engineered to express an inducible KRAS-specific shRNA. We found 147 genes that promoted survival upon KRAS suppression. In particular, the transcriptional coactivator YAP1 rescued cell viability in KRAS-dependent cells upon suppression of KRAS and was required for KRAS-induced cell transformation. Acquired resistance to Kras suppression in a Kras-driven murine lung cancer model also involved increased YAP1 signaling. KRAS and YAP1 converge on the transcription factor FOS and activate a transcriptional program involved in regulating the epithelial-mesenchymal transition (EMT). Together, these findings implicate transcriptional regulation of EMT by YAP1 as a significant component of oncogenic RAS signaling.
      No preview · Article · Jun 2014 · Cell