Quantitatively evaluating the evolution of the tumor perfusion in A549 lung adenocarcinoma transplantation model induced by antiangiogenic treatment

To quantitatively evaluate the evolution of the tumor perfusion in A549 lung adenocarcinoma transplantation model induced by antiangiogenic treatment.To establish the preclinical transplantation model of lung adenocarcinoma, 60 BALB/c nu/nu mice was inoculated with A549 cell lines via axilla. Sixty mice were randomly divided into 2 groups. The treatment group was treated with intravenous Bevacizumab (10 mg/kg weight, in a single injection), and the control group received saline only in the same dose. Five times of volume perfusion CT (VPCT) scan was performed before treatment, and on the second, forth, sixth and tenth days of treatment, respectively. The values of blood flow (BF) in the A549 tumors were measured after scanning. The microvessel density (MVD), vessel maturity index (VMI) in the tumors were determined using multiplexed QDs-based immunohistochemical staining.Comparing the values of BF, VMI and MVD between the two groups on the same day before treatment, the values of BF, VMI and MVD of the treatment group were (13.5±1.5) ml·(100 ml)(-1)·min(-1,) 0.14±0.04, (45.7±16.5)/HPF, respectively, and those in the control group were (13.4±1.6) ml·(100 ml)(-1)·min(-1) , 0.14±0.05, (48.0±7.0) /HPF , respectively. There was no significant difference between the two groups (all P>0.05). And on the second, forth, sixth, tenth days of treatment, the values of BF of the treatment group were (17.9±7.3), (32.2±6.9), (18.5±2.4) and (13.8±1.8) ml·(100 ml)(-1)·min(-1,) respectively, and those in the control group were (10.5±0.6), (9.6±0.8), (5.7±1.2) and (1.9±1.0) ml·(100 ml)(-1)·min(-1,) respectively. The values of VMI of the treatment group were 1.17±0.22, 3.25±0.23, 2.94±0.31 and 1.07±0.18, respectively, and those in the control group were 0.12±0.03, 0.13±0.03, 0.15±0.03, and 0.13±0.03, respectively. The values of MVD of the treatment group were (38.0±6.3), (24.3±5.4), (15.2±3.4) and (13.5±4.7)/HPF, respectively, and those in the control group were (44.8±5.9), (48.0±12.8), (41.8±5.7) and (45.7±20.3)/HPF, respectively. In treated mice, BF and VMI were significantly higher than those in the control group (all P<0.01). BF and VMI increased from day2, and reached the peak at day4 (P<0.01), then decreased at day6, however the value of BF at day6 was still higher than that in the baseline (P<0.01) and decreased to the baseline level at day10; while the value of VMI was still higher than that in the baseline at day10. And on the forth, sixth, tenth days of treatment, in treated mice, the values of MVD were significantly lower than those in the control group and the baseline level before treatment (all P<0.01). In control mice, BF decreased (all P<0.01) with the time, while MVD and VMI had no changes.The tumor perfusion and vessel maturity are transiently increased in A549 lung adenocarcinoma transplantation model induced by antiangiogenic treatment. VPCT is helpful to quantify the evolution of the tumor perfusion and then evaluate the functional changes of tumor vessel maturity.