Mapping pH at Cancer Cell Surfaces
Document Type
Article
Date of Original Version
12-1-2019
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.
Publication Title, e.g., Journal
Molecular Imaging and Biology
Volume
21
Issue
6
Citation/Publisher Attribution
Wei, Da, Donald M. Engelman, Yana K. Reshetnyak, and Oleg A. Andreev. "Mapping pH at Cancer Cell Surfaces." Molecular Imaging and Biology 21, 6 (2019): 1020-1025. doi: 10.1007/s11307-019-01335-4.