Comparative study on DOTA-derivatized bombesin analog labeled with 90Y and 177Lu: in vitro and in vivo evaluation.

Introduction: The aim of the study was to compare in vitro and in vivo a novel DOTA-chelated bombesin (BN) analog of the amino acid sequence, QRLGNQWAVGHLM-CONH(2) (BN[2-14]NH(2)), labeled with (90)Y and (177)Lu, for its potential use in targeted radiotherapy of tumors expressing gastrin releasing peptide (GRP) receptors. The same amino acid sequence, but with different chelator, referred as BN1.1 (Gly-Gly-Cys-Aca-QRLGNQWAVGHLM-CONH(2)), has already been studied and reported; however, the DOTA-chelated one, suitable for labeling with M(+3) type radiometals, was not yet described.

Spacer site modifications for the improvement of the in vitro and in vivo binding properties of (99m)Tc-N(3)S-X-bombesin[2-14] derivatives.

It has been shown that gastrin releasing peptide receptors (GRPRs) are overexpressed in various types of cancer cells. Bombesin is an analogue of the mammalian GRP that binds with high specificity and affinity to GRPRs. Significant research efforts have been lately devoted to the design of radiolabeled 8 or 14 aminoacid bombesin (BN) peptides for the detection (either with gamma or positron emitting radionuclides) and therapy (with beta(-) emitting radionuclides) of cancer.

Evaluation of a series of new 99mTc-labeled bombesin-like peptides for early cancer detection.

Bombesin (BN) is a peptide exhibiting a high affinity for the gastrin-releasing peptide (GRP) receptor, which is overexpressed by a variety of tumors, including breast or prostate cancer. The aim of the present study was the investigation of the complexes formed between a series of BN-like peptides and the nuclides (185/187)Re and 99mTc. The (185/187)Re complexes were formed via the precursor Regluconate.

Structural study by NMR of an oxorhenium-RGD decapeptide complex for application in radiotherapy.

The decapeptide Arg-Gly-Asp-Ser-Cys-Arg-Gly-Asp-Ser-Tyr, which contains two Arg-Gly-Asp (RGD) moieties in its sequence, has been successfully labeled with radioactive rhenium (Re-188) yielding a single, stable oxorhenium complex. This complex is being evaluated for possible application in oncology as a target-specific radiotherapeutic agent, because its radioactive technetium-99m analogue has already been applied for the scintigraphic detection of malignant melanoma in humans. For structural characterization purposes, the complex of the decapeptide was synthesized at the macroscopic level using nonradioactive rhenium (Re-185/Re-187).

Biodistribution and scintigraphic studies of 153Sm-labeled anti-CEA monoclonal antibody for radioimmunoscintigraphy and radioimmunotherapy.

The anti-CEA monoclonal antibody, which selectively localizes in colon cancer, was labeled with Samarium-153 (153Sm). 153Sm is mainly a beta-emitter which can be used for therapeutic purposes, while its gamma-ray facilitates imaging studies. Labeling was achieved using the bicyclic anhydride of DTPA as chelator for Sm-153 tagging onto the antibody.