MRP3 was the predominant MRP isoform in gallbladder carcinomas (93%) and cholangiocellular carcinomas (57%), whereas MRP2 expression was detected in only 29% of gallbladder carcinomas and was undetectable in cholangiocellular carcinomas.
Furthermore, strong MRP expression (> or = 50%) was detected in 13 (93%) of the 14 G1 carcinomas, but in only 4 (44%) of the 9 G2/G3 carcinomas (p<0.05).
Furthermore, MRP expression in 4 squamous-cell carcinomas (L13, 18, 19 and 20) was more than 3.6 times higher than in KB-3-1 cells, and the average MRP mRNA expression level of all squamous-cell carcinomas was significantly higher than that of adenocarcinoma of the lung and of colorectal and gastric carcinomas.
In conclusion, the expression of DF3, To and sialosyl-Tn antigens is an effective histopathological indicator for carcinomas in the area of the ampulla of Vater, and the expression of DF3 and intestinal-MRP antigens is a useful indicator of the prognosis of the patients.