LI-COR Introduces 2-DG Optical Agent for Cancer Research
April 3, 2008, Lincoln, NE: LI-COR Biosciences introduces a new optical probe for use in research pertaining to tumor biology, tumor metastases, and diabetes. IRDye® 800CW 2-DG is a fluorescent optical imaging agent that has been shown to be reactive with implanted tumors derived from a number of cell lines including A431, SW620, 3T3-L1, and PC3LMN4. The optical agent exhibits the expected dose response with increasing concentrations of the agent in both cell based and animal experiments.
Additional information is contained in the following abstract:
Joy L Kovar, William Volcheck, D Michael Olive, and Melanie A Simpson
IRDye 800CW 2-deoxyglucose, a near infrared metabolic optical imaging agent?
Abstract: Cancer cells are often characterized by a high metabolic rate exemplified in dramatically elevated glucose uptake. This biological activity has been exploited for noninvasive imaging by positron emission tomography using glucose analogues such as 18F-2-deoxy-D-glucose to generate a tumor-localized signal. In this work, our goal was to adapt a similar methodology for optical imaging of tumors in mice. We selected a fluorophore with maximal excitation and emission wavelengths in the near infrared (NIR) spectral range (700-900 nm), where low absorption coefficients of tissues allow greater optical sensitivity, deeper tissue penetration, and low autofluorescence. The NIR fluorophore, IRDye 800CW (excitation/emission of 778 nm/794 nm), was covalently coupled to 2-deoxyglucose (2DG). The resultant conjugate was evaluated first for specificity and sensitivity in vitro. Specificity of the agent was assessed using an In-Cell Western assay, in which concentration dependence of label uptake was established by fluorescence changes in a high throughput microplate format. Uptake of the labeled agent was specifically blocked in a dose dependent manner by addition of unlabeled 2-deoxyglucose. Subsequent in vivo studies were conducted to optimize dosing, clearance, and the optimal time post-injection for signal capture in nude mice. A research prototype imager, optimized to detect IRDye 800CW signal, was used to characterize the IRDye 800CW 2DG optical agent in subcutaneous tumors derived from either an epithelial carcinoma (A431 cells), colorectal carcinoma (SW620 cells), or prostate carcinomas (PC3M-LN4 and 22Rv1). In all cases, the tumors were clearly imaged with good signal to noise characteristics. This pilot demonstration suggests IRDye 800CW 2DG will be an excellent general optical imaging tool for studying tumor biology in mice.