Elevated Phospholipase A(2) Activities in Plasma Samples from Multiple Cancers

Only in recent years have phospholipase A(2) enzymes (PLA(2)s) emerged as cancer targets. In this work, we report the first detection of elevated PLA(2) activities in plasma from patients with colorectal, lung, pancreatic, and bladder cancers as compared to healthy controls. Independent sets of clinical plasma samples were obtained from two different sites. The first set was from patients with colorectal cancer (CRC; n = 38) and healthy controls (n = 77). The second set was from patients with lung (n = 95), bladder (n = 31), or pancreatic cancers (n = 38), and healthy controls (n = 79). PLA(2) activities were analyzed by a validated quantitative fluorescent assay method and subtype PLA(2) activities were defined in the presence of selective inhibitors. The natural PLA(2) activity, as well as each subtype of PLA(2) activity was elevated in each cancer group as compared to healthy controls. PLA(2) activities were increased in late stage vs. early stage cases in CRC. PLA(2) activities were not influenced by sex, smoking, alcohol consumption, or body-mass index (BMI). Samples from the two independent sites confirmed the results. Plasma PLA(2) activities had approximately 70% specificity and sensitivity to detect cancer. The marker and targeting values of PLA(2) activity have been suggested.