Skip to main content

Thank you for visiting 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:

Macropinocytosis of protein is an amino acid supply route in Ras-transformed cells

This article has been updated


Macropinocytosis is a highly conserved endocytic process by which extracellular fluid and its contents are internalized into cells through large, heterogeneous vesicles known as macropinosomes. Oncogenic Ras proteins have been shown to stimulate macropinocytosis but the functional contribution of this uptake mechanism to the transformed phenotype remains unknown1,2,3. Here we show that Ras-transformed cells use macropinocytosis to transport extracellular protein into the cell. The internalized protein undergoes proteolytic degradation, yielding amino acids including glutamine that can enter central carbon metabolism. Accordingly, the dependence of Ras-transformed cells on free extracellular glutamine for growth can be suppressed by the macropinocytic uptake of protein. Consistent with macropinocytosis representing an important route of nutrient uptake in tumours, its pharmacological inhibition compromises the growth of Ras-transformed pancreatic tumour xenografts. These results identify macropinocytosis as a mechanism by which cancer cells support their unique metabolic needs and point to the possible exploitation of this process in the design of anticancer therapies.

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: Oncogenic KRAS-expressing pancreatic cancer cells display increased levels of macropinocytosis both in culture and in vivo.
Figure 2: Oncogenic Kras-induced macropinocytosis in mouse NIH 3T3 cells mediates the internalization of extracellular albumin, which is subsequently targeted for proteolytic degradation.
Figure 3: Macropinocytic uptake of extracellular protein drives the accumulation of catabolic intermediates and entry of protein-derived amino acids into central carbon metabolism.
Figure 4: Macropinocytosis is required for albumin-dependent cancer cell proliferation in vitro and for tumour growth in vivo.

Similar content being viewed by others

Change history

  • 29 May 2013

    Minor changes were made to the Methods Summary in the PDF.


  1. Bar-Sagi, D. & Feramisco, J. R. Induction of membrane ruffling and fluid-phase pinocytosis in quiescent fibroblasts by ras proteins. Science 233, 1061–1068 (1986)

    Article  ADS  CAS  Google Scholar 

  2. Porat-Shliom, N., Kloog, Y. & Donaldson, J. G. A unique platform for H-Ras signaling involving clathrin-independent endocytosis. Mol. Biol. Cell 19, 765–775 (2008)

    Article  CAS  Google Scholar 

  3. Walsh, A. B. & Bar-Sagi, D. Differential activation of the Rac pathway by Ha-Ras and K-Ras. J. Biol. Chem. 276, 15609–15615 (2001)

    Article  CAS  Google Scholar 

  4. Lopez-Crapez, E., Chypre, C., Saavedra, J., Marchand, J. & Grenier, J. Rapid and large-scale method to detect K-ras gene mutations in tumor samples. Clin. Chem. 43, 936–942 (1997)

    CAS  PubMed  Google Scholar 

  5. Aoki, K., Yoshida, T., Sugimura, T. & Terada, M. Liposome-mediated in vivo gene transfer of antisense K-ras construct inhibits pancreatic tumor dissemination in the murine peritoneal cavity. Cancer Res. 55, 3810–3816 (1995)

    CAS  PubMed  Google Scholar 

  6. Ivanov, A. I. Pharmacological inhibition of endocytic pathways: is it specific enough to be useful? Methods Mol. Biol. 440, 15–33 (2008)

    Article  CAS  Google Scholar 

  7. West, M. A., Bretscher, M. S. & Watts, C. Distinct endocytotic pathways in epidermal growth factor-stimulated human carcinoma A431 cells. J. Cell Biol. 109, 2731–2739 (1989)

    Article  CAS  Google Scholar 

  8. Capon, D. J., Chen, E. Y., Levinson, A. D., Seeburg, P. H. & Goeddel, D. V. Complete nucleotide sequences of the T24 human bladder carcinoma oncogene and its normal homologue. Nature 302, 33–37 (1983)

    Article  ADS  CAS  Google Scholar 

  9. Knowles, M. A. & Williamson, M. Mutation of H-ras is infrequent in bladder cancer: confirmation by single-strand conformation polymorphism analysis, designed restriction fragment length polymorphisms, and direct sequencing. Cancer Res. 53, 133–139 (1993)

    CAS  PubMed  Google Scholar 

  10. Wagner, M. et al. A murine tumor progression model for pancreatic cancer recapitulating the genetic alterations of the human disease. Genes Dev. 15, 286–293 (2001)

    Article  CAS  Google Scholar 

  11. Hingorani, S. R. et al. Trp53R172H and KrasG12D cooperate to promote chromosomal instability and widely metastatic pancreatic ductal adenocarcinoma in mice. Cancer Cell 7, 469–483 (2005)

    Article  CAS  Google Scholar 

  12. Nolan-Stevaux, O. et al. GLI1 is regulated through Smoothened-independent mechanisms in neoplastic pancreatic ducts and mediates PDAC cell survival and transformation. Genes Dev. 23, 24–36 (2009)

    Article  CAS  Google Scholar 

  13. Stehle, G. et al. Plasma protein (albumin) catabolism by the tumor itself–implications for tumor metabolism and the genesis of cachexia. Crit. Rev. Oncol. Hematol. 26, 77–100 (1997)

    Article  CAS  Google Scholar 

  14. Gaglio, D., Soldati, C., Vanoni, M., Alberghina, L. & Chiaradonna, F. Glutamine deprivation induces abortive s-phase rescued by deoxyribonucleotides in k-ras transformed fibroblasts. PLoS ONE 4, e4715 (2009)

    Article  ADS  Google Scholar 

  15. Matés, J. M. et al. Glutamine homeostasis and mitochondrial dynamics. Int. J. Biochem. Cell Biol. 41, 2051–2061 (2009)

    Article  Google Scholar 

  16. Reis, R. C., Sorgine, M. H. & Coelho-Sampaio, T. A novel methodology for the investigation of intracellular proteolytic processing in intact cells. Eur. J. Cell Biol. 75, 192–197 (1998)

    Article  CAS  Google Scholar 

  17. Newsholme, E. A., Crabtree, B. & Ardawi, M. S. Glutamine metabolism in lymphocytes: its biochemical, physiological and clinical importance. Q. J. Exp. Physiol. 70, 473–489 (1985)

    Article  CAS  Google Scholar 

  18. Wu, M. C., Arimura, G. K. & Yunis, A. A. Mechanism of sensitivity of cultured pancreatic carcinoma to asparaginase. Int. J. Cancer 22, 728–733 (1978)

    Article  CAS  Google Scholar 

  19. Gaglio, D. et al. Oncogenic K-Ras decouples glucose and glutamine metabolism to support cancer cell growth. Mol. Syst. Biol. 7, 523 (2011)

    Article  Google Scholar 

  20. Metallo, C. M. et al. Reductive glutamine metabolism by IDH1 mediates lipogenesis under hypoxia. Nature 481, 380–384 (2012)

    Article  ADS  CAS  Google Scholar 

  21. Hirai, H. & Varmus, H. E. SH2 mutants of c-src that are host-dependent for transformation are transdominant inhibitors of mouse-cell transformation by activated c-src. Genes Dev. 4, 2342–2352 (1990)

    Article  CAS  Google Scholar 

  22. Kasahara, K. et al. Role of Src-family kinases in formation and trafficking of macropinosomes. J. Cell. Physiol. 211, 220–232 (2007)

    Article  CAS  Google Scholar 

  23. Mettlen, M. et al. Src triggers circular ruffling and macropinocytosis at the apical surface of polarized MDCK cells. Traffic 7, 589–603 (2006)

    Article  CAS  Google Scholar 

  24. Veithen, A., Cupers, P., Baudhuin, P. & Courtoy, P. J. v-Src induces constitutive macropinocytosis in rat fibroblasts. J. Cell Sci. 109, 2005–2012 (1996)

    CAS  PubMed  Google Scholar 

  25. Bos, J. L. ras oncogenes in human cancer: a review. Cancer Res. 49, 4682–4689 (1989)

    CAS  PubMed  Google Scholar 

  26. Jones, S. et al. Core signaling pathways in human pancreatic cancers revealed by global genomic analyses. Science 321, 1801–1806 (2008)

    Article  ADS  CAS  Google Scholar 

  27. Holm, E. et al. Substrate balances across colonic carcinomas in humans. Cancer Res. 55, 1373–1378 (1995)

    CAS  PubMed  Google Scholar 

  28. Tsakraklides, V. & Bell, S. P. Dynamics of pre-replicative complex assembly. J. Biol. Chem. 285, 9437–9443 (2010)

    Article  CAS  Google Scholar 

  29. Wise, D. R. et al. Myc regulates a transcriptional program that stimulates mitochondrial glutaminolysis and leads to glutamine addiction. Proc. Natl Acad. Sci. USA 105, 18782–18787 (2008)

    Article  ADS  CAS  Google Scholar 

  30. Antoniewicz, M. R., Kelleher, J. K. & Stephanopoulos, G. Accurate assessment of amino acid mass isotopomer distributions for metabolic flux analysis. Anal. Chem. 79, 7554–7559 (2007)

    Article  CAS  Google Scholar 

  31. Fernandez, C. A., Des Rosiers, C., Previs, S. F., David, F. & Brunengraber, H. Correction of 13C mass isotopomer distributions for natural stable isotope abundance. J. Mass Spectrom. 31, 255–262 (1996)

    Article  ADS  CAS  Google Scholar 

Download references


We are grateful to members of the Bar-Sagi laboratory for their comments and discussions, and N. Fehrenbacher and M. Philips for sharing cell lines. This work was supported National Institutes of Health (NIH) grant R01CA055360 to D.B.-S. C.C. was supported by a Canadian Institutes of Health Research postdoctoral fellowship and an AACR postdoctoral fellowship provided by the Pancreatic Cancer Action Network. M.G.V.H. acknowledges support from the Burroughs Wellcome Fund, the Damon Runyon Cancer Research Foundation, the Smith Family, the Stern family, the Broad Institute and the National Cancer Institute (P01-CA117969 and P30-CA14051-39). J.J.K. was supported by a Hope Funds for Cancer Research Fellowship (HFCR-11-03-01). C.B.T., J.A.D. and J.D.R. acknowledge support by the Stand Up To Cancer (SU2C) Pancreatic Cancer Dream Team Award. All animal care and procedures were approved by the Institutional Animal Care and Use Committee at NYU School of Medicine. The Histopathology Core of NYU School of Medicine is partially supported by the National Institutes of Health (grant 5 P30CA016087-32). Troma I, an antibody that recognizes CK8, was contributed by P. Brulet and R. Kemler and made available by the Developmental Studies Hybridoma Bank under the auspices of the NICHD.

Author information

Authors and Affiliations



C.C. and D.B.-S. conceived the cell biological and cell-growth experiments. C.C. carried out the macropinocytic assays, microscopy and proliferation assays. C.C. and R.G.S.-A. carried out the xenograft experiments. C.C. and E.G. carried out the KRAS knockdown experiments. S.M.D., S.J.P., C.M.M. and M.G.V.H. conceived and carried out the 13C-labelling experiments. J.J.K., S.H., M.N., J.A.D., C.B.T. and J.D.R. conceived and carried out the human metabolomics analysis.

Corresponding author

Correspondence to Dafna Bar-Sagi.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures 1-13 and Supplementary Table 1. (PDF 1103 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Commisso, C., Davidson, S., Soydaner-Azeloglu, R. et al. Macropinocytosis of protein is an amino acid supply route in Ras-transformed cells. Nature 497, 633–637 (2013).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing: Cancer

Sign up for the Nature Briefing: Cancer newsletter — what matters in cancer research, free to your inbox weekly.

Get what matters in cancer research, free to your inbox weekly. Sign up for Nature Briefing: Cancer