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

Aim: Spermidine/spermine N-1-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. [GRAPHICS] Lay abstract: This study describes a novel noninvasive urine test for detecting and screening of breast and lung cancer using a safe and approved drug called amantadine. Higher concentration of the acetylated form of amantadine in the urine are detectable in the urine of both breast and lung cancer patients as compared with healthy adult volunteers. This test is simple and may serve as a useful tool for determining the presence of breast and lung cancer.