Correlation between CA19‐9 production in vitro and histological grades of differentiation in vivo in clones isolated from a human pancreatic cancer cell line (SUIT‐2)

Abstract

The production of carcino-embryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) were investigated in 28 clones isolated from a human pancreatic cancer cell line (SUIT-2) and related to in vitro morphology of the clones and in vivo tumorigenicity. Clones of fusiform and polygonal cells could be morphologically distinguished in confluent cultures. There was no significant difference in CEA production between fusiform-cell clones (2.10 ± 2.70 ng/L x 10⁶ per 24 h) and polygonal-cell clones (6.01 ± 7.30 ng/L x 10⁶ per 24 h), but polygonal-cell clones had higher production of CA19-9 (1176.1 ± 1628.4 U/L x 10⁶ per 24 h) than fusiform (6.0 ± 7.3 U/L x 10⁶ per 24 h; P < 0.01). Production of CA19-9 in vitro correlated with the histological grade of differentiation in vivo in nude mice (r= 0.73, P < 0.001), but CEA production did not. The polygonal-cell clones developed well-differentiated carcinomas in vivo and produced significantly more CA19-9 (P < 0.001) than fusiform-cell clones, which generally developed into poorly differentiated tubular adenocarcinomas in vivo. This cell line may provide an appropriate system for further studies of the biology and therapy of pancreatic cancer.