Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

In vivo RNAi screening identifies regulators of actin dynamics as key determinants of lymphoma progression

Abstract

Mouse models have markedly improved our understanding of cancer development and tumor biology. However, these models have shown limited efficacy as tractable systems for unbiased genetic experimentation. Here, we report the adaptation of loss-of-function screening to mouse models of cancer. Specifically, we have been able to introduce a library of shRNAs into individual mice using transplantable Eμ-myc lymphoma cells. This approach has allowed us to screen nearly 1,000 genetic alterations in the context of a single tumor-bearing mouse. These experiments have identified a central role for regulators of actin dynamics and cell motility in lymphoma cell homeostasis in vivo. Validation experiments confirmed that these proteins represent bona fide lymphoma drug targets. Additionally, suppression of two of these targets, Rac2 and twinfilin, potentiated the action of the front-line chemotherapeutic vincristine, suggesting a critical relationship between cell motility and tumor relapse in hematopoietic malignancies.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: In vivo RNAi screening strategy.
Figure 2: Functional validation of shRNAs targeting putative cell-motility genes.
Figure 3: Rac2 suppression impairs lymphoma cell migration and extends animal survival.
Figure 4: Suppression of Rac activity delays disease progression and potentiates the action of the chemotherapeutic vincristine.

Similar content being viewed by others

Accession codes

Accessions

Gene Expression Omnibus

References

  1. van Lohuizen, M. et al. Identification of cooperating oncogenes in E mu-myc transgenic mice by provirus tagging. Cell 65, 737–752 (1991).

    Article  CAS  PubMed  Google Scholar 

  2. Jonkers, J. & Berns, A. Retroviral insertional mutagenesis as a strategy to identify cancer genes. Biochim. Biophys. Acta 1287, 29–57 (1996).

    PubMed  Google Scholar 

  3. Uren, A.G. et al. Large-scale mutagenesis in p19ARF- and p53-deficient mice identifies cancer genes and their collaborative networks. Cell 133, 727–741 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Dupuy, A.J., Akagi, K., Largaespada, D.A., Copeland, N.G. & Jenkins, N.A. Mammalian mutagenesis using a highly mobile somatic Sleeping Beauty transposon system. Nature 436, 221–226 (2005).

    Article  CAS  PubMed  Google Scholar 

  5. Collier, L.S., Carlson, C.M., Ravimohan, S., Dupuy, A.J. & Largaespada, D.A. Cancer gene discovery in solid tumours using transposon-based somatic mutagenesis in the mouse. Nature 436, 272–276 (2005).

    Article  CAS  PubMed  Google Scholar 

  6. Suzuki, T., Minehata, K., Akagi, K., Jenkins, N.A. & Copeland, N.G. Tumor suppressor gene identification using retroviral insertional mutagenesis in Blm-deficient mice. EMBO J. 25, 3422–3431 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Adams, J.M. et al. The c-myc oncogene driven by immunoglobulin enhancers induces lymphoid malignancy in transgenic mice. Nature 318, 533–538 (1985).

    Article  CAS  PubMed  Google Scholar 

  8. Hemann, M.T. et al. An epi-allelic series of p53 hypomorphs created by stable RNAi produces distinct tumor phenotypes in vivo. Nat. Genet. 33, 396–400 (2003).

    Article  CAS  PubMed  Google Scholar 

  9. Dickins, R.A. et al. Probing tumor phenotypes using stable and regulated synthetic microRNA precursors. Nat. Genet. 37, 1289–1295 (2005).

    Article  CAS  PubMed  Google Scholar 

  10. Zender, L. et al. An oncogenomics-based in vivo RNAi screen identifies tumor suppressors in liver cancer. Cell 135, 852–864 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Westbrook, T.F. et al. A genetic screen for candidate tumor suppressors identifies REST. Cell 121, 837–848 (2005).

    Article  CAS  PubMed  Google Scholar 

  12. Schlabach, M.R. et al. Cancer proliferation gene discovery through functional genomics. Science 319, 620–624 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  13. Grueneberg, D.A. et al. Kinase requirements in human cells: IV. Differential kinase requirements in cervical and renal human tumor cell lines. Proc. Natl. Acad. Sci. USA 105, 16490–16495 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Firestein, R. et al. CDK8 is a colorectal cancer oncogene that regulates β-catenin activity. Nature 455, 547–551 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Luo, B. et al. Highly parallel identification of essential genes in cancer cells. Proc. Natl. Acad. Sci. USA 105, 20380–20385 (2008).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Ngo, V.N. et al. A loss-of-function RNA interference screen for molecular targets in cancer. Nature 441, 106–110 (2006).

    Article  CAS  PubMed  Google Scholar 

  17. Berns, K. et al. A large-scale RNAi screen in human cells identifies new components of the p53 pathway. Nature 428, 431–437 (2004).

    Article  CAS  PubMed  Google Scholar 

  18. Kelly, P.N., Dakic, A., Adams, J.M., Nutt, S.L. & Strasser, A. Tumor growth need not be driven by rare cancer stem cells. Science 317, 337 (2007).

    Article  CAS  PubMed  Google Scholar 

  19. Burgess, D.J. et al. Topoisomerase levels determine chemotherapy response in vitro and in vivo. Proc. Natl. Acad. Sci. USA 105, 9053–9058 (2008).

    Article  PubMed  PubMed Central  Google Scholar 

  20. Burridge, K. & Wennerberg, K. Rho and Rac take center stage. Cell 116, 167–179 (2004).

    Article  CAS  PubMed  Google Scholar 

  21. Ridley, A.J., Paterson, H.F., Johnston, C.L., Diekmann, D. & Hall, A. The small GTP-binding protein rac regulates growth factor-induced membrane ruffling. Cell 70, 401–410 (1992).

    Article  CAS  PubMed  Google Scholar 

  22. Nishihara, H. et al. DOCK2 associates with CrkL and regulates Rac1 in human leukemia cell lines. Blood 100, 3968–3974 (2002).

    Article  CAS  PubMed  Google Scholar 

  23. Helfer, E. et al. Mammalian twinfilin sequesters ADP-G-actin and caps filament barbed ends: implications in motility. EMBO J. 25, 1184–1195 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Smith, L.G. & Li, R. Actin polymerization: riding the wave. Curr. Biol. 14, R109–R111 (2004).

    Article  CAS  PubMed  Google Scholar 

  25. Gao, Y., Dickerson, J.B., Guo, F., Zheng, J. & Zheng, Y. Rational design and characterization of a Rac GTPase-specific small molecule inhibitor. Proc. Natl. Acad. Sci. USA 101, 7618–7623 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Cancelas, J.A. et al. Rac GTPases differentially integrate signals regulating hematopoietic stem cell localization. Nat. Med. 11, 886–891 (2005).

    Article  CAS  PubMed  Google Scholar 

  27. Besson, A., Gurian-West, M., Schmidt, A., Hall, A. & Roberts, J.M. p27Kip1 modulates cell migration through the regulation of RhoA activation. Genes Dev. 18, 862–876 (2004).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Leask, A. & Abraham, D.J. All in the CCN family: essential matricellular signaling modulators emerge from the bunker. J. Cell Sci. 119, 4803–4810 (2006).

    Article  CAS  PubMed  Google Scholar 

  29. Nick, J.A. et al. Selective activation and functional significance of p38alpha mitogen-activated protein kinase in lipopolysaccharide-stimulated neutrophils. J. Clin. Invest. 103, 851–858 (1999).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  30. Tani, N. et al. Effects of fibronectin cleaved by neuropsin on cell adhesion and migration. Neurosci. Res. 39, 247–251 (2001).

    Article  CAS  PubMed  Google Scholar 

  31. Kleber, S. et al. Yes and PI3K bind CD95 to signal invasion of glioblastoma. Cancer Cell 13, 235–248 (2008).

    Article  CAS  PubMed  Google Scholar 

  32. Margulies, M. et al. Genome sequencing in microfabricated high-density picolitre reactors. Nature 437, 376–380 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We would like to thank E. van Veen for help with motility assays, C. Whittaker and J. Pritchard for bioinformatic processing of sequencing data, H. Thompson for expert technical assistance, and members of the Hemann laboratory for helpful advice and discussions. M.T.H. is a Rita Allen Fellow and the Latham Family Career Development Assistant Professor of Biology and is supported by US National Institutes of Health RO1 CA128803-01. C.E.M. is supported by the MIT Department of Biology training grant, and E.E.H. and E.D. were supported by MIT's UROP program. Additional funding was provided by the Integrated Cancer Biology Program grant 1-U54-CA112967 to F.B.G. and M.T.H.

Author information

Authors and Affiliations

Authors

Contributions

C.E.M. and M.T.H. designed the experiments and wrote the manuscript. C.E.M. and E.E.H. performed the screen and subsequent validation experiments. E.D. and M.T.H. performed initial GFP dilution experiments. F.B.G. designed motility experiments.

Corresponding author

Correspondence to Michael T Hemann.

Supplementary information

Supplementary Text and Figures

Supplementary Figures 1–4 and Supplementary Tables 1 and 2 (PDF 1513 kb)

Supplementary Video 1

Suppression of Rac2 causes motility defects in lymphoma cells. Lymphoma cells were infected with a vector coexpressing a Rac2 shRNA and GFP (green), or a vector control that expresses the fluorescent protein Cherry (red). These cell populations were mixed and plated on fibronectin-coated plates, stimulated with SDF (100 ng/mL), and imaged for approximately 30 minutes. Representative cells are shown. In each movie, two unstained apoptotic (black) cells are also shown. (MOV 4876 kb)

Supplementary Video 2

Suppression of Rac2 causes motility defects in lymphoma cells. Lymphoma cells were infected with a vector coexpressing a Rac2 shRNA and GFP (green), or a vector control that expresses the fluorescent protein Cherry (red). These cell populations were mixed and plated on fibronectin-coated plates, stimulated with SDF (100 ng/mL), and imaged for approximately 30 minutes. Representative cells are shown. In each movie, two unstained apoptotic (black) cells are also shown. (MOV 4876 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Meacham, C., Ho, E., Dubrovsky, E. et al. In vivo RNAi screening identifies regulators of actin dynamics as key determinants of lymphoma progression. Nat Genet 41, 1133–1137 (2009). https://doi.org/10.1038/ng.451

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ng.451

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing