Kinetics of carcinoembryonic antigen and carbohydrate antigen 19-9 production in a human pancreatic cancer cell line (SUIT-2)

Summary

Kinetics of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) production in a human pancreatic cancer cell line (SUTT-2) were investigated. Production of CEA reached a maximum, 31.0 ng/1 X 10⁶ cells, in the late stationary phase with transient decline during the early exponential phase and 15.5% of the produced CEA was released into the medium, while production of CA19-9 reached a maximum, 421 U/l X 10⁶ cells, in the early stationary phase and 68.8% of the produced CA19-9 was released into the medium. Accordingly, the kinetics of CEA and CA19-9 production of SUIT-2 in vitro might be independent. CEA was stained immunohistochemically in the cytoplasm of the cells forming small buds above the monolayer cell sheet. On the contrary, CA19-9 positive cells were observed scattered in the monolayer cell sheet and CA19-9 was stained in the cytoplasm, predominantly at the projections of the cell surface. CEA and CA19-9 were also detected in the sera of nude mice bearing SUIT-2 tumors and their concentrations correlated well with tumor volume. Correlation coefficients between tumor markers and tumor volume were 0.79 (p<0.01) for CEA and 0.90 (p<0.01) for CA19-9.