Regorafenib Effects on Human Colon Carcinoma Xenografts Monitored by Dynamic Contrast-enhanced Computed Tomography with Immunohistochemical Validation
Overview
Authors
Affiliations
Objective: To investigate dynamic contrast-enhanced computed tomography for monitoring the effects of regorafenib on experimental colon carcinomas in rats by quantitative assessments of tumor microcirculation parameters with immunohistochemical validation.
Materials And Methods: Colon carcinoma xenografts (HT-29) implanted subcutaneously in female athymic rats (n = 15) were imaged at baseline and after a one-week treatment with regorafenib by dynamic contrast-enhanced computed tomography (128-slice dual-source computed tomography). The therapy group (n = 7) received regorafenib daily (10 mg/kg bodyweight). Quantitative parameters of tumor microcirculation (plasma flow, mL/100 mL/min), endothelial permeability (PS, mL/100 mL/min), and tumor vascularity (plasma volume, %) were calculated using a 2-compartment uptake model. Dynamic contrast-enhanced computed tomography parameters were validated with immunohistochemical assessments of tumor microvascular density (CD-31), tumor cell apoptosis (TUNEL), and proliferation (Ki-67).
Results: Regorafenib suppressed tumor vascularity (15.7±5.3 to 5.5±3.5%; p<0.05) and tumor perfusion (12.8±2.3 to 8.8±2.9 mL/100 mL/min; p = 0.063). Significantly lower microvascular density was observed in the therapy group (CD-31; 48±10 vs. 113±25, p<0.05). In regorafenib-treated tumors, significantly more apoptotic cells (TUNEL; 11844±2927 vs. 5097±3463, p<0.05) were observed. Dynamic contrast-enhanced computed tomography tumor perfusion and tumor vascularity correlated significantly (p<0.05) with microvascular density (CD-31; r = 0.84 and 0.66) and inversely with apoptosis (TUNEL; r = -0.66 and -0.71).
Conclusions: Regorafenib significantly suppressed tumor vascularity (plasma volume) quantified by dynamic contrast-enhanced computed tomography in experimental colon carcinomas in rats with good-to-moderate correlations to an immunohistochemical gold standard. Tumor response biomarkers assessed by dynamic contrast-enhanced computed tomography may be a promising future approach to a more personalized and targeted cancer therapy.
Enhancing Colorectal Cancer Treatment Through VEGF/VEGFR Inhibitors and Immunotherapy.
Jiao J, Wu Y, Wu S, Jiang J Curr Treat Options Oncol. 2025; .
PMID: 40045029 DOI: 10.1007/s11864-025-01306-8.
Multikinase Treatment of Glioblastoma: Evaluating the Rationale for Regorafenib.
Munoz-Marmol A, Melendez B, Hernandez A, Sanz C, Domenech M, Arpi-Llucia O Cancers (Basel). 2025; 17(3).
PMID: 39941744 PMC: 11816343. DOI: 10.3390/cancers17030375.
Han K, Kang R, Jeon H, Lee H, Lee J, Park H Cells. 2020; 9(7).
PMID: 32660121 PMC: 7408082. DOI: 10.3390/cells9071655.
Takeuchi N, Koike K, Yoshida S, Fujiwara M Oncol Lett. 2019; 18(6):6469-6474.
PMID: 31807169 PMC: 6876333. DOI: 10.3892/ol.2019.11043.
Fondevila F, Mendez-Blanco C, Fernandez-Palanca P, Gonzalez-Gallego J, Mauriz J Exp Mol Med. 2019; 51(9):1-15.
PMID: 31551425 PMC: 6802659. DOI: 10.1038/s12276-019-0308-1.