Mycobacteria-Derived Agents for the Treatment of Urological and Renal Cancers

Mycobacteria are the unique group of bacteria that are currently used in antitumoral immunotherapy. Specifically, intravesical instillation of viable cells of Mycobacterium bovis Bacillus Calmette-Guérin (BCG), after transurethral resection of non-muscle invasive bladder cancer, is the most efficacious treatment for avoiding recurrence and progression of the disease. BCG has been used for the last 35 years for bladder cancer treatment, but other mycobacteria or mycobacteria components are currently under pre- clinical and clinical studies for the immunotherapeutic treatment of non-invasive bladder cancer and also of other types of tumors located at the urinary system. Those are, for instance, cell wall extracts or heat-killed forms from BCG or other mycobacteria such as Mycobacterium phlei or Mycobacterium indicus pranii (MIP) or even viable cells from non-pathogenic mycobacteria such us Mycobacterium brumae . A review of the literature in which mycobacteria components, non-viable mycobacteria, and viable mycobacteria have been used for these different cancers will be performed. In this chapter, the func-tion of mycobacteria as antitumor agents will be then analyzed, awarding the audience a broad knowledge of one of the beneficial applications of mycobacteria, which are usually introduced as dangerous microorganisms. bacterial cell wall components are responsible for the antitumor effect but other fractions also triggered the production of Th1 cytokines and stimulated the cytotoxic activity against T24 BC cells by peripheral blood cells. Antigens from different cell fractions are recognized by surface-located receptors present in antigen-presenting cells.