Combination therapy of interferon-alpha and 5-fluorouracil inhibits tumor angiogenesis in human hepatocellular carcinoma cells by regulating vascular endothelial growth factor and angiopoietins.

Abstract

We recently reported that interferon-alpha (IFN-alpha) and 5-fluorouracil (5-FU) combination therapy in advanced hepatocellular carcinoma (HCC) achieved excellent clinical results. However, the mechanism underlying this combination therapy remains to be elucidated. In this study, we examined the anti-tumor effects of IFN-alpha and 5-FU combination therapy in vivo and aimed to reveal its anti-angiogenic effects by investigating the expression of vascular endothelial growth factor (VEGF) and angiopoietins (Ang-1 and Ang-2). Human HCC cells, HuH7, were subcutaneously injected in nude mice. Ten days later, groups of mice received treatment with IFN-alpha alone, 5-FU alone, or with a combination of IFN-alpha and 5-FU for four weeks. Immunohistochemical examinations of proliferating cell nuclear antigen (PCNA), cell differentiation antigen 34 (CD34), Ang-1, -2 and VEGF, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and quantification of VEGF, Ang-1 and-2 mRNA using real-time RT-PCR were performed. Results showed that IFN-alpha and 5-FU combination therapy significantly inhibited the growth of human HCC cells compared with the control group or single agent treatment. The combination therapy decreased PCNA-positive cells as well as microvessel density (MVD) and induced apoptosis of (TUNEL-positive cells) more than other treatment groups. Immunohistochemical analysis revealed that the combination therapy significantly decreased the expression of VEGF and Ang-2 and increased that of Ang-1. The ANG2/ANG1 mRNA expression ratio was significantly lower in the combination therapy group. In conclusion, our results suggested that IFN-alpha and 5-FU combination therapy has anti-proliferative and anti-angiogenic effects and can induce apoptosis in vivo. The synergistic and anti-angiogenic effects may in part be attributable to the regulation of Ang-1, -2 and VEGF.

• Authors: Hiroshi Wada, Hiroaki Nagano, Hirofumi Yamamoto, Isao Arai, Hideo Ota, Masato Nakamura, Bazarragchaa Damdinsuren, Takehiro Noda, Shigeru Marubashi, Atsushi Miyamoto, Yutaka Takeda, Koji Umeshita, Yuichiro Doki, Keizo Dono, Shoji Nakamori, Masato Sakon, Morito Monden
• Journal: Oncology reports (Oncol Rep) Vol. 18 Issue 4 Pg. 801-9 (Oct 2007) ISSN: 1021-335X [Print] Greece
• PMID: 17786339 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Angiopoietins
• Interferon-alpha
• RNA, Messenger
• RNA, Neoplasm
• VEGFA protein, human
• Vascular Endothelial Growth Factor A
• Fluorouracil

Topics

• Angiopoietins (genetics, metabolism)
• Animals
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Apoptosis (drug effects)
• Carcinoma, Hepatocellular (blood supply)
• Drug Synergism
• Female
• Fluorouracil (administration & dosage)
• Humans
• Immunoenzyme Techniques
• Interferon-alpha (administration & dosage)
• Liver Neoplasms (blood supply)
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Neovascularization, Pathologic (drug therapy)
• RNA, Messenger (genetics, metabolism)
• RNA, Neoplasm (genetics, metabolism)
• Reverse Transcriptase Polymerase Chain Reaction
• Vascular Endothelial Growth Factor A (genetics, metabolism)