Researchers heal prostate cancer with novel cancer immune therapy
Leeds –UK researchers have cured mice xenografted with human prostate tumours with a new immune therapy approach. Until now, immune therapy approaches have been highly unsuccessful as each tumour has specific proteins and identifying the right antigens has been a huge challenge. However, researchers headed by Alan Melcher from University of Leeds and US researchers from Mayo Clinic in Rochester have solved this problem by expressing a virally expressed epitope library (VEEL) from normal human prostate. In mice, the researchers detected no autoimmunity. Furthermore, tumours that escaped immune selection adopted a new phenotype and could be treated with a second-line therapy. Most importantly, the DNA library which was expressed in the highly immunogenic vesicular stomatitis virus (VSV), made the immune system 'self-select' the cancer antigens to which to respond and did not react against other healthy parts of the body. Also, the process of self-selection was triggered when the vaccine was injected into the bloodstream, an approach to vaccination that is far more practical than injecting directly into tumours. According to the researchers, use of the cDNA library led to presentation of a broad repertoire of undefined tumour-associated antigens, which reduced emergence of treatment-resistant variants and will permit rational, combined-modality approaches in the clinic.