Fluorescence Assays for Serine Proteases

Reference Number: 07-27

Inventors: Stephan H. Bossmann; Deryl L. Troyer; Matthew T. Basel


Proteases are markers for the ability of many cancers to grow and to form metastases. Several proteases are over-expressed by numerous cancer cell lines. Elevated expression levels of proteases and several other components of the plasminogen activation system are found to be correlated with tumor malignancy. Proteases used for cancer prognosis are serine proteases, aspartate proteases, cathepsins A-F, and matrix metallo-proteinases (MMPs) (zinc-dependent endopeptidases).

This invention is comprised of a protease cleavage sequence(s), which is used as a linker between two fluorophores (quantum dots and/or organic or inorganic dyes). Depending on the nanoparticles used, optical (fluorescence), magnetic (MRI), and x-ray imaging of the tumor location and extension, together with quantitative determination of the protease activity, can be performed. This assay method is useful for the quantitative determination of any enzyme that can cleave a specific linker between two fluorophores.


Advantages of this IP over previous methods:

  • Assays are
    • A replacement for invasive biopsies
    • Faster
    • Much less time demanding
    • Easier to use
    • Less costly
  • Assays can be performed
    • In vivo
    • In vitro
  • Permit a new area of accurate cancer prognosis leading to a more individual treatment of cancer patients
  • Assay can determine the stage of cancer in patient.

This innovative technology can be used to:

  • Quantitative determination of the protease-activity of all cancers that over-express urokinase, MMPs, aspartate proteases, and cathepsins A-F.).
  • Coupling of optical (fluorescence), magnetical (MRI), and x-ray imaging of the tumor location and extension, together with a quantitative determination of the protease activity.
  • Method is suitable to be applied within the brain tissue (intercranial infiltration).
  • Extension of this method to potentially all cleaving enzymes.
Patent Status
  • International Patent Protection filed in Australia, Canada, EPO, India, Japan, and USA in September 2010.

Kansas State University Research Foundation seeks to have discussions with companies that are interested in licensing and/or research collaborations.

Interested parties should contact:

Kansas State University Institute for Commercialization (KSU-IC)
2005 Research Park Circle Manhattan, KS 66502
Tel: 785-532-3900 Fax: 785-532-3909
E-Mail: ic@k-state.edu