Use of amantadine as substrate for SSAT-1 activity as a reliable clinical diagnostic assay for breast and lung cancer

Aim: Spermidine/spermine N1-acetyltransferase (SSAT-1) plays a critical role in cell growth, proliferation and death, and is known to be activated in human cancer cells. Amantadine, a US FDA-approved antiviral drug, is a substrate for SSAT-1 and can be used to indirectly measure SSAT-1 activity because of its conversion to acetylamantadine (AA). This study was undertaken to further validate SSAT-1 activity in breast and lung cancer patients. Results: An increase in the urinary concentration of AA in lung and breast cancer patients was observed. The 0–2 h collection time point was determined to be optimal in revealing significant differences in urinary AA concentration between healthy controls and cancer patients. Conclusion: The high urine concentration of AA could be used as a simple and useful test for the detection of breast and lung cancer.