Growth characteristics of alpha-foetoprotein-secreting human hepatocellular carcinoma in athymic (nude) mice.

1. The growth characteristics of a human hepatocellular carcinoma, derived from the PLC/PRF/5 cell-line ('Alexander'), transplanted into sub-lethally irradiated athymic (nu/nu) mice have been examined. The xenograft re-expresses alpha-foetoprotein production although this tumour marker was not detected during cell culture in vitro. 2. There is a positive correlation between serum alpha-foetoprotein concentration and tumour mass (r = 0.978), validating the use of this tumour marker to assess growth. 3. In mice with progressively growing xenografts there is a linear correlation between log serum alpha-foetoprotein concentration and time, compatible with exponential tumour growth. Growth of the human hepatocellular carcinoma xenograft is rapid, with an alpha-foetoprotein doubling time of 6.1 +/- 2.1 days (+/- standard deviation) and a mass doubling time of 3.6 +/- 1.2 days (+/- standard deviation). 4. The tumour cell birth or production rate, determined by a stathmokinetic (metaphase arrest) technique using vincristine, is 15.7 +/- 3.8 (95% confidence limits) cells per 1000 cells per hour. The tumour cell loss factor (49%) is low and may contribute to the rapid growth of this human hepatocellular carcinoma xenograft.