Mass Spectrometric Imaging of Red Fluorescent Protein in Breast Tumor Xenografts
- 498 Downloads
Mass spectrometric imaging (MSI) in combination with electrospray mass spectrometry (ESI-MS) is a powerful technique for visualization and identification of a variety of different biomolecules directly from thin tissue sections. As commonly used tools for molecular reporting, fluorescent proteins are molecular reporter tools that have enabled the elucidation of a multitude of biological pathways and processes. To combine these two approaches, we have performed targeted MS analysis and MALDI-MSI visualization of a tandem dimer (td)Tomato red fluorescent protein, which was expressed exclusively in the hypoxic regions of a breast tumor xenograft model. For the first time, a fluorescent protein has been visualized by both optical microscopy and MALDI-MSI. Visualization of tdTomato by MALDI-MSI directly from breast tumor tissue sections will allow us to simultaneously detect and subsequently identify novel molecules present in hypoxic regions of the tumor. MS and MALDI-MSI of fluorescent proteins, as exemplified in our study, is useful for studies in which the advantages of MS and MSI will benefit from the combination with molecular approaches that use fluorescent proteins as reporters.
Key wordsMALDI Tryptic-peptides Breast cancer
This work is part of the research program of the “Foundation for Fundamental Research on Matter (FOM),” which is financially supported by the “The Netherlands Organization for Scientific Research (NWO).” The authors gratefully acknowledge financial support from NIH grant R01 CA134695. They also gratefully acknowledge continued support from The Netherlands Proteomics Centre (NPC). The authors are indebted to A.F. Maarten Altelaar and Albert J.R. Heck for enabling LC-ESI-MS/MS experiments in the NPC facility.
- 10.Raman, V., Artemov, D., Pathak, A.P., Winnard Jr., P.T., McNutt, S., Yudina, A., Bogdanov Jr., A., Bhujwalla, Z.M.: Characterizing vascular parameters in hypoxic regions: a combined magnetic resonance and optical imaging study of a human prostate cancer model. Cancer Res. 66, 9929–9936 (2006)CrossRefGoogle Scholar
- 11.Krishnamachary, B., Penet, M.F., Nimmagadda, S., Mironchik, Y., Raman, V., Solaiyappan, M., Semenza, G.L., Pomper, M.G., Bhujwalla, Z.M.: Hypoxia regulates CD44 and its variant isoforms through HIF-1α in triple negative breast cancer. PLoS ONE 7(8): e44078 (2012)Google Scholar
- 13.Jiang, L., Greenwood, T.R., Artemov, D., Raman, V., Winnard, Jr., P.T., Heeren, R.M., Bhujwalla, Z.M., Glunde, K.: Localized hypoxia results in spatially heterogeneous metabolic signatures in breast tumor models. Neoplasia 14, 732–741 (2012)Google Scholar
- 14.Jiang, L., Greenwood, T.R., Amstalden van Hove, E.R., Chughtai, K., Raman, V., Winnard, Jr., P.T., Heeren, R.M.A., Artemov, D., Glunde, K.: Combined magnetic resonance, fluorescence, and histology imaging strategy in a human breast tumor xenograft model. NMR Biomed. doi: 10.1002/nbm.2846(2012)