Cancer Research
Research Toward a Cure
Tissue Invasion and Metastasis
The third hallmark of cancer cells is tissue invasion and metastasis (spreading) which is a major source of mortality in cancer patients. Cancer spreads when gene mutations allow transformed cells to break free from the primary tumor and travel through the bloodstream to establish a new colony of cells at another location.
Tumor Imaging with IRDye® 800CW
Figure 1. Nude mouse bearing subcutaneous tumors, U87 (left hip) and A431(right hip), were imaged 24 hours post
intravenous injection of IRDye 800CW RGD (1 nmole).
Integrins are heterodimeric cell surface glycoproteins involved in cell-to-cell and cell-to-matrix interactions involved in cancer cell invasion and metastatsis. The recognition motif, a tripeptide sequence RGD (Arg-Gly-Asp) binds integrin receptors including αvβ3. Labeled RGD peptide has been employed to monitor cells in which the αvβ3 receptor is over-expressed. Several groups have labeled RGD with fluorescent dyes for in vitro and in vivo imaging.
A nude mouse bearing two subcutaneously implanted tumors on the hips illustrate IRDye 800CW RGD localized to tumor tissue (Figure 1). U87 cells (Left hip) expresses high levels of αvβ3 integrins while A431 cells express lower levels. The imaging data are consistent with this observation as demonstrated by the higher signal in the U87 tumor.
