Correlation between blood circulation grading and angiogenesis using ultrasonic contrast of rabbit VX2 hepatic carcinoma

Objective: To build the rabbit model of VX2 hepatic carcinoma, examine the tumor body using the ultrasonic contrast and study the correlation between the blood circulation grading and angiogenesis.

Methods: The VX2 tumor strain was prepared in the lateral muscle of the hind legs of 40 male New Zealand rabbits (which were purchased from Nanjing Senbao Biotech Co., Ltd.). The tumor block was embedded in the center of left liver lobe directly to build the rabbit model of VX2 hepatic carcinoma. The ultrasonic contrast was performed 14 d after implanting the tumor body. The semi-quantitative classification (0-IV level) was taken according to the blood flow of tumor vessel. Animals were executed using the air embolism method. The liver was separated to extract RNA and total protein respectively. The real-time PCR and western blotting method were employed to detect the expression of angiogenesis-related factors of VEGF, bFGF and TNF-α, while the ultrasonic contrast to detect the correlation with blood circulation grading. The Pearson product moment correlation coefficient was used to measure the linear relationship between these two variables and analyze the correlation between the blood circulation grading and angiogenesis using the ultrasonic contrast.

Results: Thirty-three rabbits had the successful model of VX2 hepatic carcinoma. The blood circulation grading by ultrasonic contrast was: 2 cases at level 0 (6.60%), 5 cases at level I (16.7%), 12 cases at level II (40.0%), 6 cases at level III (20.0%) (local dense or clustered blood flow) and 5 cases at level IV (16.7%). The results showed that there was positive correlation between three angiogenesis-related factors and the blood circulation grading. The correlation coefficient between three angiogenesis-related factors and the blood circulation grading was over 0.9, which indicated the relatively high correlation.

Conclusions: The ultrasound blood circulation grading for the hepatic carcinoma can clearly reflect the changes of blood vessel, which will be of critical significance for the early diagnosis of hepatic carcinoma and clinical evaluation of angiogenesis indicators.