Uptake of a fluorescent l-glucose derivative 2-NBDLG into three-dimensionally accumulating insulinoma cells in a phloretin-sensitive mannerReport as inadecuate

Uptake of a fluorescent l-glucose derivative 2-NBDLG into three-dimensionally accumulating insulinoma cells in a phloretin-sensitive manner - Download this document for free, or read online. Document in PDF available to download.

Human Cell

, Volume 29, Issue 1, pp 37–45

First Online: 09 November 2015Received: 29 September 2015Accepted: 10 October 2015DOI: 10.1007-s13577-015-0125-3

Cite this article as: Sasaki, A., Nagatomo, K., Ono, K. et al. Human Cell 2016 29: 37. doi:10.1007-s13577-015-0125-3


Of two stereoisomers of glucose, only d- and not l-glucose is abundantly found in nature, being utilized as an essential fuel by most organisms. The uptake of d-glucose into mammalian cells occurs through glucose transporters such as GLUTs, and this process has been effectively monitored by a fluorescent d-glucose derivative 2-N-7-Nitrobenz-2-oxa-1,3-diazol-4-ylamino-2-deoxy-d-glucose 2-NBDG at the single cell level. However, since fluorescence is an arbitrary measure, we have developed a fluorescent analog of l-glucose 2-N-7-Nitrobenz-2-oxa-1,3-diazol-4-ylamino-2-deoxy-l-glucose 2-NBDLG, as a negative control substrate for more accurately identifying the stereoselectivity of the uptake. Interestingly, a small portion of mouse insulinoma cells MIN6 abundantly took up 2-NBDLG at a late culture stage ≳10 days in vitro, DIV when multi-cellular spheroids exhibiting heterogeneous nuclei were formed, whereas no such uptake was detected at an early culture stage ≲6 DIV. The 2-NBDLG uptake was persistently observed in the presence of a GLUT inhibitor cytochalasin B. Neither d- nor l-glucose in 50 mM abolished the uptake. No significant inhibition was detected by inactivating sodium-glucose cotransporters SGLTs with Na-free condition. To our surprise, the 2-NBDLG uptake was totally inhibited by phloretin, a broad spectrum inhibitor against transporters-channels including GLUTs and aquaporins. From these, a question might be raised if non-GLUT-non-SGLT pathways participate in the 2-NBDLG uptake into spheroid-forming MIN6 insulinoma. It might also be worthwhile investigating whether 2-NBDLG can be used as a functional probe for detecting cancer, since the nuclear heterogeneity is among critical features of malignancy.

Keywordsl-Glucose Tumor Spheroid Cancer Biomarker Electronic supplementary materialThe online version of this article doi:10.1007-s13577-015-0125-3 contains supplementary material, which is available to authorized users.

An erratum to this article can be found at http:-dx.doi.org-10.1007-s13577-016-0135-9.

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Author: Ayako Sasaki - Katsuhiro Nagatomo - Koki Ono - Toshihiro Yamamoto - Yuji Otsuka - Tadashi Teshima - Katsuya Yamada

Source: https://link.springer.com/

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