Inhibitory effects of prostaglandin D2 against the proliferation of human colon cancer cell lines and hepatic metastasis from colorectal cancer

The inhibitory action of prostaglandin D₂ (PGD₂) and its effect on the cell cycle were examined in cell lines SW480 and LS174T of human colon cancer. The growth of the cell lines were assessed 24h and 48h after the addition of 1.0μg/ml and 10.0μg/ml PGD₂. The growth of SW480 cells and 24h and 48h after the addition of 10.0μ/ml, while that of LS174T was inhibited by both doses after 24h and 48h. S-Phase DNA synthesis in the SW480 cells was significantly blocked 24h after the addition of 10.0μg/ml PGD₂. The cell cycle of LS174T cells was arrested at the G₀+G₁ phase 24h after the addition of 1.0μg/ml and 10.0μg/ml PGD₂. The correlation between hepatic metastasis and PGD₂ concentration in human cancer tissue was examined. The mean value of PGD₂ concentrations in the primary cancer tissue was significantly lower in the hepatic metastasis group than that in the group without hepatic metastasis. These findings suggest that measuring the PGD₂ in cancer tissue may be useful for detecting and predicting the hepatic metastasis from human colorectal cancer.