Cathepsin E as a Marker of Colon Cancer

Elevated levels of cathepsin E (catE) are demonstrated to be diagnostic of intestinal forms of cancer, such as colorectal cancer. Elevated levels of cathepsin E (catE, monomeric forms) are demonstrated to be detectable in the urine of animals having colorectal cancer, and a diagnostic/screening method for identifying and/or detecting colorectal cancer in an animal from a urine sample is provided. Specific tissue immunohistochemcial staining for catE (monomeric forms) in dysplastic tissue is also disclosed, and is shown to correlate with the level of dysplastic lesion severity. Hence, a method for identifying and determining the level of dysplastic lesion severity is provided. Cathepsin E mRNA transcription and expression levels are also demonstrated to be upregulated in dysplastic tissue, relative to non-dysplastic tissue. Hence, a method for transcriptionally profiling an animal to monitor the progression of colorectal disease is provided.