The human Matrix MetalloProtease-9 (hMMP-9) is overexpressed in tumors where it promotes the release of cancer cells thus contributing to tumor metastasis. We raised aptamers against hMMP-9, which constitutes a validated marker of malignant tumors, in order to design probes for imaging tumors in human beings.
A chemically modified RNA aptamer (F3B), fully resistant to nucleases was previously described. This compound was subsequently used for the preparation of F3B-Cy5, F3B-S-acetylmercaptoacetyltriglycine (MAG) and F3B-DOTA. The binding properties of these derivatives were determined by surface plasmon resonance and electrophoretic mobility shift assay. Optical fluorescence imaging confirmed the binding to hMMP-9 in A375 melanoma bearing mice. Quantitative biodistribution studies were performed at 30 min, 1h and 2 h post injection of 99mTc-MAG-aptamer and 111In-DOTA-F3B. 99mTc radiolabeled aptamer specifically detected hMMP-9 in A375 melanoma tumors but accumulation in digestive tract was very high. Following i.v. injection of 111In-DOTA-F3B, high level of radioactivity was observed in kidneys and bladder but digestive tract uptake was very limited. Tumor uptake was significantly (student t test, p<0.05) higher for 111In-DOTA-F3B with 2.0%ID/g than for the 111In-DOTA-control oligonucleotide (0.7%ID/g) with tumor to muscle ratio of 4.0. Such difference in tumor accumulation has been confirmed by ex vivo scintigraphic images performed at 1h post injection and by autoradiography, which revealed the overexpression of hMMP-9 in sections of human melanomas. These results demonstrate that F3B aptamer is of interest for detecting hMMP-9 in melanoma tumor.
PloS one. 2016 Feb 22*** epublish ***
David Kryza, Frédéric Debordeaux, Laurent Azéma, Aref Hassan, Olivier Paurelle, Jürgen Schulz, Catherine Savona-Baron, Elsa Charignon, Pauline Bonazza, Jacqueline Taleb, Philippe Fernandez, Marc Janier, Jean Jacques Toulmé
UNIV Lyon, Université Claude Bernard Lyon 1, LAGEP UMR 5007 CNRS, Villeurbanne, France., Université de Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France., Inserm U1212, Bordeaux, France., Inserm U1212, Bordeaux, France., Inserm U1212, Bordeaux, France., Université de Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France., Université de Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France., Hospices Civils de Lyon, Imthernat plateform, Lyon, France., Hospices Civils de Lyon, Imthernat plateform, Lyon, France., UNIV Lyon, Université Claude Bernard Lyon 1, LAGEP UMR 5007 CNRS, Villeurbanne, France., Université de Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France., UNIV Lyon, Université Claude Bernard Lyon 1, LAGEP UMR 5007 CNRS, Villeurbanne, France., Inserm U1212, Bordeaux, France.