Methods for introducing heterologous cells into fish to determine if the heterologous cells contain cancer cells or a pathogen

Patent Number: 7,408,095

In general it is quickly forgotten that the biggest contribution of embryonic stem cell technology to medicine has not been in the area of actually generating therapeutics, but in development of model systems for studying diseases. It was only through the generation of knockout and transgenic animals that we as biologists were able to start deciphering the in vivo relevance of the genome.

That being said, the current patent covers an interesting new model system. Fish. The patent teaches the use of pre-immune zebrafish for administration of human tissue and assessment of its function. In the area of stem cells, we are more familar with immune compromised strains such as the nude mouse (lacks thymus, and therefore T cells), or the SCID mouse (lacks T and B cells), or the NOD-SCID (lacks T and B cells and has poor NK/monocyte function, therefore easily accepts human tissue).

The first independent claim of the patent covers "A method of analyzing a sample for presence of a cancer cell or pathogen, comprising: (a) obtaining a sample from a patient containing a cell or population of cells; (b) introducing the cell or the population of cells into a zebrafish embryo that has not yet developed an immune system that would subject the cell or population of cells to immune rejection; and (c) detecting a property of the cell or the population of cells to indicate whether the cell or the population of cells comprises a cancer cell or pathogen."

Apparent advantages of this system in comparison to more conventional approaches include cost and ease of manipulation. This will be a very interesting patent to watch !!

View this patent on the USPTO website.