Development of an optimized activatable MMP-14 targeted SPECT imaging probe

Watkins, Gregory; Jones, Ella F.; Shell, M. Scott; VanBrocklin, Henry F.; Pan, Michael; Hanrahan, Stephen M.; Feng, Jin Jin; He, Jiang; Sounni, Nor Eddine; Dill, Ken A.; Contag, Christopher H.; Coussens, Lisa M.; Franc, Benjamin L.

doi:10.1016/j.bmc.2008.11.078

Cited by 58 publications

(36 citation statements)

References 48 publications

(46 reference statements)

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“…Interestingly, the development of an activatable, MMP-14 targeted SPECT imaging probe was reported recently 92. Only a modest two-fold reduction of cellular radioactivity was observed in the presence of a broad-spectrum MMPI.…”

Section: Spect Imaging Of Mmpsmentioning

confidence: 99%

Molecular Imaging of Proteases in Cancer

Yang

Hong

Zhang

et al. 2009

Cancer�Growth�Metastasis

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Proteases play important roles during tumor angiogenesis, invasion, and metastasis. Various molecular imaging techniques have been employed for protease imaging: optical (both fluorescence and bioluminescence), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT), and positron emission tomography (PET). In this review, we will summarize the current status of imaging proteases in cancer with these techniques. Optical imaging of proteases, in particular with fluorescence, is the most intensively validated and many of the imaging probes are already commercially available. It is generally agreed that the use of activatable probes is the most accurate and appropriate means for measuring protease activity. Molecular imaging of proteases with other techniques (i.e. MRI, SPECT, and PET) has not been well-documented in the literature which certainly deserves much future effort. Optical imaging and molecular MRI of protease activity has very limited potential for clinical investigation. PET/SPECT imaging is suitable for clinical investigation; however the optimal probes for PET/SPECT imaging of proteases in cancer have yet to be developed. Successful development of protease imaging probes with optimal in vivo stability, tumor targeting efficacy, and desirable pharmacokinetics for clinical translation will eventually improve cancer patient management. Not limited to cancer, these protease-targeted imaging probes will also have broad applications in other diseases such as arthritis, atherosclerosis, and myocardial infarction.

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Section: Spect Imaging Of Mmpsmentioning

confidence: 99%

Molecular Imaging of Proteases in Cancer

Yang

Hong

Zhang

et al. 2009

Cancer�Growth�Metastasis

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“…Although ACPPs were successfully used for optical imaging and MRI of MMP-2/9 (21-25), the use of this concept in nuclear imaging or therapy has remained largely unexplored. Recently Watkins et al investigated an MMP-14-activatable analog for SPECT (26). Although in vitro activation was observed in cell cultures expressing MMP-14, a control cell line lacking MMP-14 expression also activated the probe, and therefore MMP-14 selectivity could not be demonstrated.…”

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confidence: 99%

Tumor Targeting of MMP-2/9 Activatable Cell-Penetrating Imaging Probes Is Caused by Tumor-Independent Activation

Duijnhoven¹,

Robillard²,

Nicolay³

et al. 2011

J Nucl Med

106

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Activatable cell-penetrating peptides (ACPPs) are a new class of promising molecular imaging probes for the visualization of enzymes in vivo. The cell-penetrating function of a polycationic peptide is efficiently blocked by intramolecular electrostatic interactions with a polyanionic peptide. Proteolysis of a cleavable linker present between the polycationic cell-penetrating peptide and polyanionic peptide affords dissociation of both domains and enables the activated cell-penetrating peptide to enter cells. Here, we aimed to develop an ACPP sensitive to matrix metalloproteinase-2 and -9 (MMP-2/9) for nuclear imaging purposes. Methods: MMP-2/9 ACPPs and nonactivatable cell-penetrating peptides (non-ACPP) were prepared by 9-fluorenylmethyloxycarbonyl solid-phase peptide synthesis and labeled with 177 Lu or 177 Lu/ 125 I for dual-isotope studies. The in vivo biodistribution of these probes was assessed in MMP-2/9-positive tumor-bearing mice (n 5 6) and healthy mice (n 5 4) using g-counting. Furthermore, a radiolabeled cell-penetrating peptide serving as a positive control was evaluated in tumorbearing mice (n 5 6). Results: Biodistribution studies showed a 5-fold-higher retention of ACPP in tumor than in muscle (P , 0.01) and a 6-fold-higher tumor retention relative to non-ACPP (P , 0.01), supporting earlier studies on fluorescently labeled ACPPs proposing activation by tumor-associated MMP-2/9. Surprisingly, however, the uptake of ACPP was significantly higher than that of non-ACPP in almost all tissues (P , 0.01). To unravel the activation process of ACPP in vivo, we developed dual-isotope ACPP analogs (dACPPs) that allowed us to discriminate between uncleaved dACPP and activated dACPP. In vivo biodistribution of dACPP indicated that the tissue-associated counts originated from activated dACPP. Interestingly, dACPP administration to healthy mice, compared with MMP-2/9-positive tumor-bearing mice, resulted in a similar dACPP biodistribution. Furthermore, a radiolabeled cell-penetrating peptide showed tumor-to-tissue ratios equal to those found for ACPP (P . 0.05). Conclusion: This study demonstrates that the tumor targeting of radiolabeled MMP-2/9 ACPPs is most likely caused by the activation in the vascular compartment rather than tumor-specific activation, as suggested earlier.The results in the present paper indicate that different and more tissue-specific enzyme-ACPP combinations are needed to unleash the full potential of the elegant ACPP concept in living animals.

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“…The present study presents encouraging results for cell-based screening of MMP activity. Of particular note is that the present approach may ultimately be fine-tuned to accommodate selective MMP substrates, both in linear and triple-helical form [14; 62; 63; 64; 65; 66; 67]. …”

Section: Discussionmentioning

confidence: 99%

Comparison of metalloproteinase protein and activity profiling

Giricz

Lauer

Fields

2011

Analytical Biochemistry

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Proteolytic enzymes play fundamental roles in many biological processes. Members of the matrix metalloproteinase (MMP) family have been shown to take part in processes crucial in disease progression. The present study used the ExcelArray Human MMP/TIMP Array to quantify MMP and tissue inhibitor of metalloproteinase (TIMP) production in the lysates and media of 14 cancer and one normal cell line. The overall patterns were very similar in terms of which MMPs and TIMPs were secreted in the media versus associated with the cells in the individual samples. However, more MMP was found in the media, both in amount and in variety. TIMP-1 was produced in all cell lines. MMP activity assays with three different FRET substrates were then utilized to determine if protein production correlated with function for the WM-266-4 and BJ cell lines. Metalloproteinase activity was observed for both cell lines with a general MMP substrate (Knight SSP), consistent with protein production data. However, although both cell lines promoted the hydrolysis of a more selective MMP substrate (NFF-3), metalloproteinase activity was only confirmed in the BJ cell line. The use of inhibitors to confirm metalloproteinase activities pointed to the strengths and weaknesses of in situ FRET substrate assays.

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Development of an optimized activatable MMP-14 targeted SPECT imaging probe

Cited by 58 publications

References 48 publications

Molecular Imaging of Proteases in Cancer

Molecular Imaging of Proteases in Cancer

Tumor Targeting of MMP-2/9 Activatable Cell-Penetrating Imaging Probes Is Caused by Tumor-Independent Activation

Comparison of metalloproteinase protein and activity profiling

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