2-(n-(7-nitrobenz-2-oxa-1-3-diazol-4-yl)amino)-2-deoxyglucose and Mouth-Neoplasms

The demanding metabolic needs of cancer cells are met by aerobic glycolysis. While whole-body PET imaging methods exist for evaluating this metabolic response, these are not ideal for local, more detailed regions such as mucosal surfaces. Fluorescence imaging of glucose analogs with similarities to radiolabeled deoxyglucose used in PET, namely, fluorescent 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG), offers such an alternative, particularly as this glucose analog may be delivered by local topical delivery. In this chapter, methods for in vivo epithelial imaging in a preclinical hamster model for oral cancer and oral epithelial dysplasia are described. Outlined are methods for preparation and in vivo delivery of 2-NBDG by topical application to the oral mucosa followed by fluorescence imaging to compare fluorescence responses between neoplasia and control mucosa or to monitor changes in fluorescence signal with time in both groups.

Topics: 4-Chloro-7-nitrobenzofurazan; Administration, Topical; Animals; Carcinoma, Squamous Cell; Deoxyglucose; Fluorescent Dyes; Glucose; Intravital Microscopy; Mesocricetus; Mouth Neoplasms; Neoplasms, Experimental

The overall objective of this study was to develop an optical imaging approach to simultaneously measure altered cell metabolism and changes in tissue extracellular pH with the progression of cancer using clinically isolated biopsies. In this study, 19 pairs of clinically normal and abnormal biopsies were obtained from consenting patients with head and neck cancer at University of California, Davis Medical Center. Fluorescence intensity of tissue biopsies before and after topical delivery of 2-NBDG (2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose) and Alexa 647-pHLIP [pH (low) insertion peptide] was measured noninvasively by widefield imaging, and correlated with pathologic diagnosis. The results of widefield imaging of clinical biopsies demonstrated that 2-NBDG and pHLIP peptide can accurately distinguish the pathologically normal and abnormal biopsies. The results also demonstrated the potential of this approach to detect subepithelial lesions. Topical application of the contrast agents generated a significant increase in fluorescence contrast (3- to 4-fold) in the cancer biopsies as compared with the normal biopsies, irrespective of the patient and location of the biopsy within a head and neck cavity. This unpaired comparison across all the patients with cancer in this study highlights the specificity of the imaging approach. Furthermore, the results of this study indicated that changes in intracellular glucose metabolism and cancer acidosis are initiated in the early stages of cancer, and these changes are correlated with the progression of the disease. In conclusion, this novel optical molecular imaging approach to measure multiple biomarkers in cancer has a significant potential to be a useful tool for improving early detection and prognostic evaluation of oral neoplasia.

Topics: 4-Chloro-7-nitrobenzofurazan; Acidosis; Aged; Aged, 80 and over; Biomarkers, Tumor; Biopsy; Carbocyanines; Contrast Media; Deoxyglucose; Disease Progression; Female; Glucose; Head and Neck Neoplasms; Humans; Hydrogen-Ion Concentration; Male; Microscopy, Fluorescence; Middle Aged; Mouth Neoplasms; Optical Imaging; Optics and Photonics; Prognosis

The clinical value of assessing tumor glucose metabolism via F-18 fluorodeoxyglucose (FDG) PET imaging in oncology is well established; however, the poor spatial resolution of PET is a significant limitation especially for early stage lesions. An alternative technology is optical molecular imaging, which allows for subcellular spatial resolution and can be effectively used with topical contrast agents for imaging epithelial derived cancers. The goal of this study was to evaluate the potential of optical molecular imaging of glucose metabolism to aid in early detection of oral neoplasia. Fluorescently labeled deoxyglucose (2-NBDG (2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-D-glucose)) was applied topically to tissue phantoms, fresh oral biopsies (n = 32) and resected tumors specimens (n = 2). High-resolution imaging results show that 2-NBDG can be rapidly delivered to oral epithelium using topical application. In normal epithelium, the uptake of 2-NBDG is limited to basal epithelial cells. In contrast, high-grade dysplasia and cancers show uptake of 2-NBDG in neoplastic cells throughout the lesion. Following 2-NBDG labeling, the mean fluorescence intensity of neoplastic tissue averages 3.7 times higher than that of matched nonneoplastic oral biopsies in samples from 20 patients. Widefield fluorescence images of 8-paired oral specimens were obtained pre and postlabeling with 2-NBDG. Prior to labeling, neoplastic samples showed significantly lower autofluorescence than nonneoplastic samples. The fluorescence of neoplastic samples increased dramatically after labeling; the differential increase in fluorescence was on average 30 times higher in neoplastic samples than in normal samples. Topical application of 2-NBDG can therefore provide image contrast in both widefield and high-resolution fluorescence imaging modalities, highlighting its potential in early detection of oral neoplasia.

Topics: 4-Chloro-7-nitrobenzofurazan; Administration, Topical; Cell Line, Tumor; Deoxyglucose; Glucose; Humans; Microscopy, Fluorescence; Mouth Neoplasms