Cloning and sequencing of the cynomolgus monkey prostate specific antigen cDNA.

Background Prostate-specific antigen (PSA) is an invaluable tumor marker for the detection of early prostate cancer, and can be a target for active immunotherapy of prostate cancer. We wanted to assess the usefulness of the cynomolgus monkey (Macaca fascicularis) as a relevant animal model to evaluate PSA-specific therapies. Methods RNA was isolated from the prostate of cynomolgus monkeys, and PSA gene products were amplified by reverse transcriptase-polymerase chain reaction using primers from conserved regions of human and rhesus monkey (Macaca mulatta) PSA genes. These amplified products were then sequenced. Results The cynomolgus PSA amino acid sequence is 89.7% identical to the human PSA gene, and 99.2% identical to the rhesus PSA amino acid sequence. Like the human and rhesus PSA genes, an open-reading frame of 261 amino acids was identified for the cynomolgus gene. Expression of the cynomolgus PSA gene appears to be restricted to the prostate, as it is in humans. Conclusions The high identity between human and cynomolgus PSA sequences suggests that the cynomolgus monkey should be studied further for its potential as a large animal model to evaluate PSA-specific therapies.