Inhibition of integrin alpha5beta1 function with a small peptide (ATN-161) plus continuous 5-FU infusion reduces colorectal liver metastases and improves survival in mice

Int J Cancer. 2003 Apr 20;104(4):496-503. doi: 10.1002/ijc.10958.


Integrin alpha(5)beta(1) is expressed on activated endothelial cells and plays a critical role in tumor angiogenesis. We hypothesized that a novel integrin alpha(5)beta(1) antagonist, ATN-161, would inhibit angiogenesis and growth of liver metastases in a murine model. We further hypothesized that combining ATN-161 with 5-fluorouracil (5-FU) chemotherapy would enhance the antineoplastic effect. Murine colon cancer cells (CT26) were injected into spleens of BALB/c mice to produce liver metastases. Four days thereafter, mice were given either ATN-161 (100 mg/kg, every 3rd day) or saline by intraperitoneal injection, with or without combination of continuous-infusion 5-FU (100 mg/kg/2 weeks), which was started on day 7. On day 20 after tumor cell inoculation, mice were killed and liver weights and number of liver metastases were determined. A follow-up study on survival was also conducted in which mice were randomized to receive ATN-161, 5-FU or ATN-161+5-FU. Combination therapy with ATN-161+5-FU significantly reduced tumor burden (liver weight) and number of liver metastases (p<0.02). Liver tumors in the ATN-161 and ATN-161+5-FU groups had significantly fewer microvessels (p<0.05) than tumors in the control or 5-FU-treated groups. Unlike treatment with either agent alone, ATN-161+5-FU significantly increased tumor cell apoptosis and decreased tumor cell proliferation (p<0.03) and improved overall survival (p<0.03, log-rank test). Targeting integrin alpha(5)beta(1) in combination with 5-FU infusion reduced liver metastases formation and improved survival in this colon cancer model. The enhancement of antineoplastic activity from the combination of anti-angiogenic therapy and chemotherapy may be a promising approach for treating metastatic colorectal cancer.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Angiogenesis Inhibitors / administration & dosage*
  • Animals
  • Apoptosis / drug effects
  • Cell Division / drug effects
  • Cell Survival / drug effects
  • Colorectal Neoplasms / drug therapy*
  • Colorectal Neoplasms / pathology
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects
  • Fluorouracil / administration & dosage*
  • Integrin alpha5beta1 / antagonists & inhibitors*
  • Integrin alpha5beta1 / physiology
  • Liver Neoplasms / blood supply
  • Liver Neoplasms / prevention & control
  • Liver Neoplasms / secondary*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Oligopeptides / administration & dosage*


  • Angiogenesis Inhibitors
  • Integrin alpha5beta1
  • Oligopeptides
  • Fluorouracil
  • acetyl-prolyl-histidyl-seryl-cysteinyl-asparaginamide