Expression of Prostate Specific Molecules in Bacille Calmette‐Guerin: An Immunotherapeutic Approach to Prostate Cancer

Objective: The objective is to develop an immunotherapeutic vaccine for the treatment of metastatic prostate cancer. Results: Bacille Calmette Guerin (BCG) were engineered to express prostate specific antigen (PSA) or prostate specific membrane antigen (PSMA). Western blotting techniques indicate that recombinant BCG (rBCG) express approximately 25 ng PSA or 112 pg PSMA per 1 μg microgram of protein in rBCG bacterial lysates. Discussion: BCG, the vaccine for tuberculosis, is a potent immunologic adjuvant stimulating both the humoral and cell-mediated immune systems. Prostate cancer patients can generate cytotoxic lymphocytes against specific peptides from normal, self-molecules such as PSA and PSMA. Therefore, a rBCG vaccine that expresses prostate specific proteins may stimulate an immune response to recognize and destroy prostate cancer cells. Conclusion: BCG can be engineered to express prostate specific molecules and may be useful as an immunotherapeutic vaccine against prostate cancer.