[In vivo and in vitro studies on PGE2 production and function in human hepatocellular carcinoma]

In order to investigate the production of PGE2 and its' function in human hepatocellular carcinoma, the effects of indomethacin and PGE2 on tumor growth were examined using in vivo and in vitro techniques. HH2-6 cells produced PGE2 in the culture media, and the inverse relationship was observed in between the cell proliferation and the culture supernatant PGE2 levels. While in vivo, plasma and tumor tissue PGE2 levels of tumor bearing nude mice were significantly increased for 1 or 2 weeks after tumor inoculation. In the case of which indomethacin was injected daily into the abdominal cavity (4 mg/kg body weight), the elevation of plasma and tissue PGE2 levels was remarkably suppressed, and the latent time of tumor growth was also prolonged. On the other hand, another case of which PGE2 was injected (10 micrograms or 0.1 microgram i.p.) at first 10 days revealed shortened latent time. These results indicate the intimate relation between PGE2 and latent time on tumor growth. Furthermore, histological findings suggest that tumor derived PGE2 might play an important role in tumor angiogenesis.