Advertisement

Mapping pH at Cancer Cell Surfaces

  • Da Wei
  • Donald M. Engelman
  • Yana K. Reshetnyak
  • Oleg A. AndreevEmail author
Brief Article
  • 22 Downloads

Abstract

Purpose

To develop a tool to measure the pH at the surfaces of individual cells.

Procedures

The SNARF pH-sensitive dye was conjugated to a pHLIP® peptide (pH-Low Insertion Peptide) that binds cellular membranes in tumor spheroids. A beam splitter allows simultaneous recording of two images (580 and 640 nm) by a CCD camera. The ratio of the two images is converted into a pH map resolving single spheroid cells. An average pH for each cell is calculated and a pH histogram is derived.

Results

Surface pH depends on cellular glycolytic activity, which was varied by adding glucose or deoxy-glucose. Glucose was found to decrease the surface pH relative to the pH of the bulk solution. The surface pH of metastatic cancer cells was lower than that of non-metastatic cells indicating a higher glycolytic activity.

Conclusions

Our method allows cell surface pH measurement and its correlation with cellular glycolytic activity.

Key Words

pHLIP Warburg effect Tumor acidity pH measurements SNARF fluorescence 

Notes

Acknowledgments

We would like to thank our colleagues Anna Moshnikova and Michael Anderson for useful discussions and suggestions.

Funding Information

Financial support was received from NIH RO1 GM073857 grant to DME, OAA, and YKR.

Compliance with Ethical Standards

Conflict of Interest

D.M.E., O.A.A., and Y.K.R. are founders of pHLIP, Inc. They have shares in the company, but the company did not fund any part of the work reported in the paper, which was done in their academic laboratories.

References

  1. 1.
    Warburg O (1956) On the origin of cancer cells. Science 123:309–314CrossRefGoogle Scholar
  2. 2.
    Griffiths JR (1991) Are cancer cells acidic? Br J Cancer 64:425–427CrossRefGoogle Scholar
  3. 3.
    Griffiths JR, Stevens AN, Iles RA et al (1981) D (1981) 31P-NMR investigation of solid tumours in the living rat. Biosci Rep 1:319–325CrossRefGoogle Scholar
  4. 4.
    Wike-Hooley JL, Haveman J, Reinhold HS (1984) The relevance of tumour pH to the treatment of malignant disease. Radiother Oncol 2:343–366CrossRefGoogle Scholar
  5. 5.
    Zhang X, Lin Y, Gillies RJ (2010) Tumor pH and its measurement. J Nucl Med 51:1167–1170CrossRefGoogle Scholar
  6. 6.
    Kroemer G, Pouyssegur J (2008) Tumor cell metabolism: cancer’s Achilles’ heel. Cancer Cell 13:472–482CrossRefGoogle Scholar
  7. 7.
    Damaghi M, Wojtkowiak JW, Gillies RJ (2013) pH sensing and regulation in cancer. Front Physiol 4:370CrossRefGoogle Scholar
  8. 8.
    Chiche J, Brahimi-Horn MC, Pouyssegur J (2010) Tumour hypoxia induces a metabolic shift causing acidosis: a common feature in cancer. J Cell Mol Med 14:771–794CrossRefGoogle Scholar
  9. 9.
    Anderson M, Moshnikova A, Engelman DM, Reshetnyak YK, Andreev OA (2016) Probe for the measurement of cell surface pH in vivo and ex vivo. Proc Natl Acad Sci U S A 113:8177–8181CrossRefGoogle Scholar
  10. 10.
    Andreev OA, Dupuy AD, Segala M, Sandugu S, Serra DA, Chichester CO, Engelman DM, Reshetnyak YK (2007) Mechanism and uses of a membrane peptide that targets tumors and other acidic tissues in vivo. Proc Natl Acad Sci U S A 104:7893–7898CrossRefGoogle Scholar
  11. 11.
    Andreev OA, Engelman DM, Reshetnyak YK (2010) pH-sensitive membrane peptides (pHLIPs) as a novel class of delivery agents. Mol Membr Biol 27:341–352CrossRefGoogle Scholar
  12. 12.
    Reshetnyak YK, Yao L, Zheng S, Kuznetsov S, Engelman DM, Andreev OA (2011) Measuring tumor aggressiveness and targeting metastatic lesions with fluorescent pHLIP. Mol Imaging Biol 13:1146–1156CrossRefGoogle Scholar
  13. 13.
    Weerakkody D, Moshnikova A, Thakur MS, Moshnikova V, Daniels J, Engelman DM, Andreev OA, Reshetnyak YK (2013) Family of pH (low) insertion peptides for tumor targeting. Proc Natl Acad Sci U S A 110:5834–5839CrossRefGoogle Scholar
  14. 14.
    Andreev OA, Engelman DM, Reshetnyak YK (2014) Targeting diseased tissues by pHLIP insertion at low cell surface pH. Front Physiol 5:97CrossRefGoogle Scholar
  15. 15.
    Wyatt LC, Lewis JS, Andreev OA et al (2017) Applications of pHLIP Technology for Cancer Imaging and Therapy: (trends in biotechnology 35, 653-664, 2017). Trends Biotechnol 36(12):1300CrossRefGoogle Scholar
  16. 16.
    Hashim AI, Zhang X, Wojtkowiak JW, Martinez GV, Gillies RJ (2011) Imaging pH and metastasis. NMR Biomed 24:582–591Google Scholar
  17. 17.
    Moon RB, Richards JH (1973) Determination of intracellular pH by 31P magnetic resonance. J Biol Chem 248:7276–7278Google Scholar
  18. 18.
    Gillies RJ, Liu Z, Bhujwalla Z (1994) 31P-MRS measurements of extracellular pH of tumors using 3-aminopropylphosphonate. Am J Phys 267:C195–C203CrossRefGoogle Scholar
  19. 19.
    Ojugo AS, McSheehy PM, McIntyre DJ et al (1999) Measurement of the extracellular pH of solid tumours in mice by magnetic resonance spectroscopy: a comparison of exogenous (19)F and (31)P probes. NMR Biomed 12:495–504CrossRefGoogle Scholar
  20. 20.
    Garcia-Martin ML, Herigault G, Remy C et al (2001) Mapping extracellular pH in rat brain gliomas in vivo by 1H magnetic resonance spectroscopic imaging: comparison with maps of metabolites. Cancer Res 61:6524–6531Google Scholar
  21. 21.
    Rata M, Giles SL, deSouza NM et al (2014) Comparison of three reference methods for the measurement of intracellular pH using 31P MRS in healthy volunteers and patients with lymphoma. NMR Biomed 27:158–162CrossRefGoogle Scholar
  22. 22.
    Wykoff CC, Beasley NJ, Watson PH et al (2000) Hypoxia-inducible expression of tumor-associated carbonic anhydrases. Cancer Res 60:7075–7083Google Scholar
  23. 23.
    Griffiths JR, McIntyre DJ, Howe FA, Stubbs M (2001) Why are cancers acidic? A carrier-mediated diffusion model for H+ transport in the interstitial fluid. Novartis Found Symp 240:46–62 discussion 62–47, 152–153Google Scholar
  24. 24.
    Ivanov S, Liao SY, Ivanova A, Danilkovitch-Miagkova A, Tarasova N, Weirich G, Merrill MJ, Proescholdt MA, Oldfield EH, Lee J, Zavada J, Waheed A, Sly W, Lerman MI, Stanbridge EJ (2001) Expression of hypoxia-inducible cell-surface transmembrane carbonic anhydrases in human cancer. Am J Pathol 158:905–919CrossRefGoogle Scholar

Copyright information

© World Molecular Imaging Society 2019

Authors and Affiliations

  1. 1.Physics DepartmentUniversity of Rhode IslandKingstonUSA
  2. 2.Department of Molecular Biophysics and Biochemistry, YaleNew HavenUSA

Personalised recommendations