HUMAN PANCREATIC PHOSPHOLIPASE A(2) STIMULATES THE GROWTH OF HUMAN PANCREATIC-CANCER CELL-LINE

Phospholipase A(2) (PLA(2)) from human pancreas, designated hPLA(2)-I, functions as a digestive enzyme, Interestingly, the present study demonstrated that the mature form of hPLA(2)-I stimulated the growth of a human pancreatic cancer cell line MIAPaCa-2, rvhereas the pro-form was ineffective. PLA(2)s from Laticauda semifasciata fraction I, Crotalus adamanteus venom, Streptomyces violaceoruber and bee venom, showed no proliferative effect to the growth of MIAPaCa-2. The Scatchard plot analysis revealed that the MIAPaCa-2 cell had a specific binding site for the mature hPLA(2)-I. The equilibrium binding constant (K-d) and the maximum binding capacity (B-max) were 2.6 nM and 0.4 fmol/10(6) cells, respectively. These results suggest that the mature hPLA(2)-I, but not the pro-form, may function as a growth factor of pancreas carcinoma via the specific binding site.