Figure 1.

(A) Endostatin (rh-E) therapy is most efficacious when started prior to tumour cell seeding. All mice were inoculated with tumour cells on t₀. Recombinant human endostatin or control citrate buffer was given in different time schemes as indicated and the intrahepatic tumour load (HRA) for all different treatment groups was assessed on day 12. Data are plotted as means±s.e.m. (B) Reduced therapeutic efficacy of rh-E treatment on established tumours. (a) Haematoxylin- and eosin-stained sections from a liver 7 days after intrasplenic injection of tumour cells just prior to the start of treatment, showing three small intrahepatic tumour lesions (dark nodules). (b) Tumour-bearing liver 19 days after tumour cell injection treated with citrate buffer. (c) Tumour-bearing liver 19 days after tumour cell injection treated with rh-E. The tumours continued to grow under rh-E treatment. For quantification, see (A).