Target-specific fluorochrome for in vivo imaging of endothelin receptors
Endothelins (ET) play an important role in numerous diseases, like atherosclerosis, congestive heart failure and cancer. Particularly, ET-1 is an important factor in the pathophysiology of certain human cancers, e.g. prostatic, or breast carcinoma. The ETA-receptor is closely involved in tumor angiogenesis and has been identified as poor prognostic marker e.g. for breast cancer.
Molecular optical imaging is a new emerging imaging tool for various diseases with many advantages, e.g. high sensitivity for label detection, capability for multi-wavelengths imaging and the absence of radioisotopes or other ionizing radiation. Imaging techniques like fluorescence reflectance imaging (FRI) or fluorescence mediated tomography (FMT) are interesting alternatives to the use of nuclear imaging techniques like SPECT or PET. Therefore, an optical method for the visualization of ETA-receptor density in affected tissues would be invaluable for clinical diagnosis and the evaluation of therapy.
The present invention relates to the use of special compounds for the preparation of a diagnostic composition for the diagnosis of cancer, the evaluation of cancer biology and/or monitoring of anti-cancer therapy.
The results of numerous experiments (e.g. in vitro binding assays with the breast adenocarcinoma cell line MCF-7 and in vivo FMT studies) indicate that the modified photoprobes tightly bind to ETA-receptors and thus qualify as a potent candidate for the in vivo imaging of ETA-overexpressing tissues.
The diagnostic compositions of the invention are preferably employed for fluorescence mediated tomography (FMT) or fluorescence reflectance imaging methods.
Specifically, the detection of ETA-receptor expressing breast cancer cells should be greatly facilitated.
Commercial use and advantages of the invention
The new imaging agents can be used for non-invasive detection of molecular targets (i.e. cells or tissues expressing endothelin receptors) which promote or are associated with tumor progression.
Advantages of the invention:
The fluorescent photoprobes enhance the ability for
- early diagnosis of cancer
- the evaluation of cancer biology (i.e. “grading”) leading to specific treatment protocols
- monitoring of molecular targeted anti-cancer therapy
The compounds represent biocompatible, targeted fluorochromes, with a high binding potency for endothelin A receptor.
The molecule has a low molecular weight so that the tracer can be rapidly eliminated from the organism.
Patent applications filed in Europe