A cancer vaccine containing plasmid DNA encoding human prostatic acid phosphatase (PAP) (pTVG-HP) with potential immunostimulatory and antineoplastic activities. Upon administration, pTVG-HP plasmid DNA vaccine may stimulate the host immune system to generate a cytotoxic T lymphocyte (CTL) response against PAP-expressing prostate cancer cells. PAP or prostatic specific acid phosphatase (PSAP) is a tumor associated antigen (TAA) that may be overexpressed in prostate cancer.