Biomedica Life Sciences SA

In the initial stages of tumor formation, overexpression of integrins identifying the RGD sequence (Arg-Gly-Asp) is observed. The aim of the present study was the synthesis and labeling of two novel RGD derivatives, via the precursor [99mTc(H2O)3(CO)3]+, as well as the radiochemical and radiopharmacological evaluation of the labeled products. The labeling led to the formation of a single product in each case (>98%), with noteworthy in vitro stability, fast blood clearance and elimination by the hepatobiliary and the urinary systems.

Cell adhesion molecules, such as integrins, play a vital role in angiogenesis, a key pathway for tumor growth, invasion and metastasis. The integrin alpha(v)beta(3), which recognizes the RGD sequence (Arg-Gly-Asp), may provide a target for in vivo tumor imaging. A linear and a cyclic RGD peptide derivative (RGDfK-His and cRGDfK-His, respectively), labelled via the precursor [99mTc(H2O)3(CO)3]+, were comparatively evaluated and their radiobiological properties were assessed in normal and tumor-bearing mice. Biodistribution studies showed non-specific uptake in all organs, rapid blood clearance and elimination via the hepatobiliary and urinary systems. Tumor uptake was higher for the cyclic radiolabelled derivative, as the both biodistribution and imaging studies suggested. The cRGDfK-His, labelled via the fac-[99mTc(CO)3]-core, may prove to be a useful tool for early tumor detection.

Cell adhesion mols., such as integrins, play a vital role in angiogenesis, a key pathway for tumor growth, invasion and metastasis.The integrin α_vβ₃, which recognizes the RGD sequence (Arg-Gly-Asp), may provide a target for in vivo tumor imaging.A linear and a cyclic RGD peptide derivative (RGDfK-His and cRGDfK-His, resp.), labeled via the precursor [^99mTc(H₂O)₃(CO)₃]⁺, were comparatively evaluated and their radiobiol. properties were assessed in normal and tumor-bearing mice.Biodistribution studies showed non-specific uptake in all organs, rapid blood clearance and elimination via the hepatobiliary and urinary systems.Tumor uptake was higher for the cyclic radiolabeled derivative, as both biodistribution and imaging studies suggested.The cRGDfK-His, labeled via the fac-[^99mTc(CO)₃]-core, may prove to be a useful tool for early tumor detection.