Fluorophore-NanoLuc BRET Reporters Enable Sensitive In Vivo Optical Imaging and Flow Cytometry for Monitoring Tumorigenesis

Cancer Res. 2015 Dec 1;75(23):5023-33. doi: 10.1158/0008-5472.CAN-14-3538. Epub 2015 Sep 30.


Fluorescent proteins are widely used to study molecular and cellular events, yet this traditionally relies on delivery of excitation light, which can trigger autofluorescence, photoxicity, and photobleaching, impairing their use in vivo. Accordingly, chemiluminescent light sources such as those generated by luciferases have emerged, as they do not require excitation light. However, current luciferase reporters lack the brightness needed to visualize events in deep tissues. We report the creation of chimeric eGFP-NanoLuc (GpNLuc) and LSSmOrange-NanoLuc (OgNLuc) fusion reporter proteins coined LumiFluors, which combine the benefits of eGFP or LSSmOrange fluorescent proteins with the bright, glow-type bioluminescent light generated by an enhanced small luciferase subunit (NanoLuc) of the deep-sea shrimp Oplophorus gracilirostris. The intramolecular bioluminescence resonance energy transfer that occurs between NanoLuc and the fused fluorophore generates the brightest bioluminescent signal known to date, including improved intensity, sensitivity, and durable spectral properties, thereby dramatically reducing image acquisition times and permitting highly sensitive in vivo imaging. Notably, the self-illuminating and bifunctional nature of these LumiFluor reporters enables greatly improved spatiotemporal monitoring of very small numbers of tumor cells via in vivo optical imaging and also allows the isolation and analyses of single cells by flow cytometry. Thus, LumiFluor reporters are inexpensive, robust, noninvasive tools that allow for markedly improved in vivo optical imaging of tumorigenic processes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Burkitt Lymphoma / chemistry
  • Burkitt Lymphoma / pathology
  • Carcinogenesis / chemistry*
  • Carcinogenesis / pathology
  • Carcinoma, Non-Small-Cell Lung / chemistry
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Decapoda / enzymology
  • Flow Cytometry / methods*
  • Green Fluorescent Proteins / chemistry*
  • Green Fluorescent Proteins / genetics
  • HEK293 Cells
  • Heterografts
  • Humans
  • Luciferases / chemistry*
  • Luciferases / genetics
  • Luminescent Agents / chemistry*
  • Lung Neoplasms / chemistry
  • Lung Neoplasms / pathology
  • Mice, Inbred NOD
  • Mice, SCID
  • Optical Imaging / methods*
  • Recombinant Fusion Proteins / chemical synthesis
  • Recombinant Fusion Proteins / chemistry*
  • Recombinant Fusion Proteins / genetics


  • Luminescent Agents
  • Recombinant Fusion Proteins
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Luciferases