Specific magnetic resonance imaging of vascular endothelial growth factor-C targeted molecular probe and its clinical significance in a rat model of hepatocellular carcinoma

Objective To investigate the magnetic resonance ( MR) imaging features of the targeted molecular probe with vascular endothelial growth factor-C ( VEGF-C) antibody and superparamagnetic iron oxide ( USPIO) , VEGF-C-USPIO, in a rat model of hepatocellular carcinoma ( HCC) and its clinical significance. Methods The induction method was used to establish a rat model of in situ HCC, and30 Sprague-Dawley rats were randomly divided into experimental group with 20 rats and control group with 10 rats. The rats in the experimental group were treated with tail vein injection of the targeted molecular probe VEGF-C-USPIO, and those in the control group were treated with tail vein injection of the non-targeted probe USPIO. MR scanning was performed before injection and at 1 hour after injection;the intensity of T2 WI signal in liver tumor and adjacent liver tissue was measured; contrast-to-noise ratio ( CNR) was calculated, and the two groups were compared in terms of CNR before and after enhancement. Liver tissue was collected after scanning, and HE staining was performed to clarify the pathological type of liver cancer in rats; Prussian blue staining was performed to analyze the content of iron in tumor cells; immunohistochemical staining was performed to investigate the expression of VEGF-C in liver cancer tissue. The independent samples t-test was used for comparison between the experimental group and the control group, and the paired samples t-test was used for comparison within each group after the injection of contrast agent. Results Cancer was successfully induced in all 30 rats; the pathological diagnosis was HCC, and the tumor formation rate was 100%. The experimental group had a significant change in CNR at 1 hour after the injection of the targeted contrast agent VEGF-C-USPIO ( 2. 11 ± 0. 23 vs 3. 47 ± 0. 45, t =-13. 15, P < 0. 001) , while the control group had no significant change in CNR at 1 hour after the injection of the non-targeted contrast agent USPIO ( 3. 51 ± 0. 14 vs 3. 82 ± 0. 61, t =-1. 40, P = 0. 192) ; there was a significant difference in CNR between the two groups after injection ( t = 17. 60, P < 0. 001) . HE staining performed for liver tissue samples showed a pathological type of HCC; immunohistochemical staining showed that VEGF-C was mainly expressed in the membrane and cytoplasm of hepatoma cells; Prussian blue staining showed that compared with the control group, the experimental group had a significant increase in iron particles in tumor tissue. Conclusion The synthesized targeted molecular probe VEGF-C-USPIO has a good active targeting effect on a rat model of HCC and can realize the specific imaging of HCC through the change in MR signal intensity. Therefore, it provides an imaging basis for the early diagnosis of HCC.