The invention provides the identification of the presence of
mutant ROS
protein in
human cancer. In some embodiments, the
mutant ROS are FIG-ROS fusion proteins comprising part of the FIG
protein fused to the
kinase domain of the ROS
kinase. In some embodiments, the
mutant ROS is the overexpression of wild-type ROS in cancerous tissues (or tissues suspected of being cancerous) where, in
normal tissue of that same
tissue type, ROS is not expressed or is expressed at lower levels. The mutant ROS proteins of the invention are anticipated to drive the proliferation and survival of a subgroup of human cancers, particularly in cancers of the liver (including
bile duct),
pancreas,
kidney, and testes. The invention therefore provides, in part, isolated polynucleotides and vectors encoding the disclosed mutant ROS polypeptides (e.g., a FIG-ROS(S) fusion polypeptide), probes for detecting it, isolated mutant polypeptides, recombinant polypeptides, and reagents for detecting the fusion and truncated polypeptides. The identification of the mutant ROS polypeptides enables new methods for determining the presence of these mutant ROS polypeptides in a biological sample, methods for screening for compounds that inhibit the proteins, and methods for inhibiting the progression of a
cancer characterized by the mutant polynucleotides or polypeptides, which are also provided by the invention.