ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of metronomic chemotherapy of S-1 on angiogenesis of hepatocellular carcinoma in animal model.</p><p><b>METHOD</b>S-1 was dissolved in a 0.5% (w/v) HPMC solution. 30 LCI-D20 were randomly devided into five groups: control group(O), 10 mg * kg(-1) * d(-1) S-1 group (A), 1 mg * kg(-1) * d(-1) S-1 group (B), 0.5 mg * kg(-1) * d(-1) S-1 group (C) and 0.25 mg * kg(-1) * d S-1 group (D). 28 days after the treatment with 0.5% (w/v) HPMC solution, tumors in LCI-D20 mice were moved out. Tumor mass was measured and microvessel density (MVD) was used to evaluate angiogenesis in tumor. The cellular apoptosis was determined using flow cytometry. The expression of VEGF, bFGF and TSP-1 was measured by RT-PCR.</p><p><b>RESULTS</b>The mean tumor mass was 2.01, 0.38, 1.12, 1.38, 2.27 g in O, A, B, C, D group, respectively. The mean MVD was 39.57, 19.90, 5.93, 17.10, 29.53 in O, A, B, C, D respectively. The mean tumor cellular apoptosis rate was 4.08%, 44.37%, 31.73%, 19.83%, and 8.25% in O, A, B, C, D respectively. The expression of VEGF and bFGF in O group was highest, and A was slightly low, and C and D taked the third place, and B was the lowst; The expression of TSP-1 in B was highest, and C and D were slightly low, and A taked the third place, and O was the lowst.</p><p><b>CONCLUSION</b>Metronomic chemotherapy of S-1 destabilizes pre-existing tumor vasculature and inhibits ongoing angiogenesis.</p>