Abstract
BackgroundOptical imaging is one of the most common, low-cost imaging tools used for investigating the tumor biological behavior in vivo. This study explores the feasibility and sensitivity of a near infrared fluorescent protein mKate2 for a long-term non-invasive tumor imaging in BALB/c nude mice, by using a low-power optical imaging system.MethodsIn this study, breast cancer cell line MDA-MB-435s expressing mKate2 and MDA-MB-231 expressing a dual reporter gene firefly luciferase (fLuc)-GFP were used as cell models. Tumor cells were implanted in different animal body compartments including subcutaneous, abdominal and deep tissue area and closely monitored in real-time. A simple and low-power optical imaging system was set up to image both fluorescence and bioluminescence in live animals.ResultsThe presence of malignant tissue was further confirmed by histopathological assay. Considering its lower exposure time and no need of substrate injection, mKate2 is considered a superior choice for subcutaneous imaging compared with fLuc. On the contrary, fLuc has shown to be a better option when monitoring the tumor in a diffusive area such as abdominal cavity. Furthermore, both reporter genes have shown good stability and sensitivity for deep tissue imaging, i.e. tumor within the liver. In addition, fLuc has shown to be an excellent method for detecting tumor cells in the lung.ConclusionsThe combination of mKate2 and fLuc offers a superior choice for long-term non-invasive real-time investigation of tumor biological behavior in vivo.
Highlights
Optical imaging is one of the most common, low-cost imaging tools used for investigating the tumor biological behavior in vivo
Based on our preliminary test of mice (n = 6) bearing an MDA-MB-435s-mKate2 tumor, the intensity of autofluorescence excited by 588 nm light was around 1000 counts
Subcutaneous imaging In order to investigate tumor development, as well as the report gene sensitivity in the subcutaneous compartment, mKate2 expressing tumor and a dual reporter gene LucGFP expressing tumor injected in the right and left flank of a single mice, respectively
Summary
Optical imaging is one of the most common, low-cost imaging tools used for investigating the tumor biological behavior in vivo. This study explores the feasibility and sensitivity of a near infrared fluorescent protein mKate for a long-term non-invasive tumor imaging in BALB/c nude mice, by using a low-power optical imaging system. Among fluorescent proteins, red-shifted proteins are considered a superior choice for in vivo imaging because of their reduced autofluorescence, less diffusion and deeper penetration of light in the far-red and near-infrared region (NIR). Compared with other commercial fluorescent proteins, both excitation and emission spectra of mKate are relatively non-absorbed and less scattered by the surrounding tissues and proteins (largely by hemoglobin) [13, 14]. Besides to the high-brightness and far-red emission spectrum, its excellent pH resistance and photostability make mKate a superior candidate for oncological study in live animals such as mice [15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
