Abstract
OBJECTIVE: The purpose of this research was to investigate the anti-angiogenic inhibitory effect of KR-31831, a newly developed anti-angiogenic agent, on an in vivo human ovarian carcinoma model using dynamic contrast-enhanced (DCE) MRI. MATERIALS AND METHODS: Xenografted ovarian tumors were established by subcutaneous injection of SKOV3 cells into mice. The mice were treated daily with KR-31831 at 50 mg/kg for 21 days. Tumor tissues were excised corresponding to the DCE-MRI sections for evaluation of MVD with CD31 immunohistochemistry. All in vivo MRIs were performed on a 7.0 Tesla micro-MRI System. DCE-MRI was acquired prior to initiating treatment with KR-31831 and again on days 3 and 21 after treatment. The permeability parameters (K(trans), v(e), and v(p)) were estimated using a pharmacokinetic model. RESULTS: Qualitatively, the K(trans) parametric mapping showed different changes before and after treatment with KR-31831 in the treatment group. For quantification of this change, the median of K(trans) values were compared before and after treatments in the control and KR-31831-treated groups. A non-parametric statistical test (Wilcoxon signed-rank test) showed decreasing K(trans) values on day 21 compared to days 0 and 3 in the KR-31831-treated group (p < 0.05), whereas there was no significant difference in the control group (p = 0.84). CONCLUSION: Our results suggest that DCE-MRI can be a useful tool by which to evaluate the anti-angiogenic effect of KR-31831 on a xenografted human ovarian carcinoma model.