Expression of hepatocyte growth factor in human hepatocellular carcinoma

We have shown that hepatocyte growth factor, secreted by human liver myofibroblasts, promoted in vitro invasion of human hepatocellular carcinoma cell lines. The aim of this work was to measure hepatocyte growth factor expression in 29 human hepatocellular carcinomas and the corresponding peri-tumoral livers.

We used reverse transcription-polymerase chain reaction, in situ hybridization, ELISA and Western blot.

Sixty-two of tested hepatocellular carcinomas were positive by reverse transcription-polymerase chain reaction. With in situ hybridization, a signal was found in every sample. In many cases, the signal was localized in cells labeled with an anti-smooth muscle alpka-actin antibody, while hepatocytes were mostly non-labeled. ELISA, performed in 15 pairs of hepatocellular carcinomas and surrounding livers, detected hepatocyte growth factor in every sample with wide variations. Hepatocellular carcinomas that had developed in non-cirrhotic livers contained essentially the same amount of hepatocyte growth factor as the matching non-tumoral liver. In cirrhotic livers, the hepatocyte growth factor content of the tumors was significantly lower than that of the surrounding cirrhotic livers.

These data indicate that hepatocyte growth factor is expressed at significant levels in every hepatocellular carcinoma tested and that its expression takes place in the stromal myofibroblasts.