Effect Of Dexamethasone On Microcirculation Function Of Liver Cancer And Its Mechanism

Part OneThe effect of microcirculation in hepatocellular carcinoma mice by dexamethasone Objective:To investigate the effect of microcirculation in hepatocellular carcinoma (HCC) mice by dexamethasone.Methods:The murine hepatocellular carcinoma model in situ with green fluorescent protein markers (HepG2-GFP) was constructed, and the dynamic microscope observation system for living was used to determine the effect of tumor growth and microvascular angiogenesis in liver surface of mice. The malignant cells H22 were inoculated in check pouch of golden hamster to construct the transplantation tumor model, and the device of microcirculation observation was used to detect the microvascular tortuosity, microvascular density and angiogenesis after treatment by Dex.Results:(1) Hepatocellular carcinoma mice in situ:murine hepatoma model with green fluorescent markers (HepG2-GFP) was constructed to explore the effect of microcirculation function after treated by Dex (n=10). After treatment for 16 days, the body weight of two groups was respectively increased by 21%,1%; the tumor mass of Dex group was smaller than the control group. Both the density and total length of microvessel in Dex group were smaller than control group. The average length of tumor blood vessel in Dex group was about 22% of the control group (1159±1227 pixel vs 5177±2840 pixel, P< 0.01). The tumor weight in Dex group was significantly lower than the control group (0.0161±0.0083g vs 0.0297±0.0085g, P< 0.05), and the rate of tumor inhibition was approximately 45.8%. These results indicated that Dex had inhibition effect on tumor growth and angiogenesis in murine hepatoma model in situ. (2) The tumor model of golden hamster cheek pouch:the H22 were inoculated into the surface of golden hamster cheek pouch to construct the transplantation tumor model. The animals were treated with Dex after inoculated for three days. On the five days and seventh days after inoculation, the results showed that tumor volume in Dex groups were smaller than control groups (P< 0.05, P< 0.05). The microvascular tortuosity, the density of microvascular and the flux of blood in microvascular were declined in Dex group than control groups.Conclusion:The dexamethasone showed inhibition efficacy to tumor growth and angiogenesis in mice hepatoma model with green fluorescent protein markers (HepG2-GFP). The microvascular tortuosity, microvascular density and tumor surface flux of blood in golden hamster cheek pouch tumor model were reduced by dexamethasone after treatment.Part TwoThe effect of angiogenesis and gluconeogenesis pathway in murine hepatocellular carcinoma by dexamethasoneObjective:To explore the effect of angiogenesis and gluconeogenesis in HCC murine after treated by Dex and attempt to reveal the potential mechanism.Methods:The malignant cells H22 and murine normal cell NCTC-1469 were respectively cultured, and western blot was used to explore the expression of proteins PEPCK and G6Pase which were the two key enzymes that regulated gluconeogenesis. The H22 cells were treated with different concentration of Dex (0,0.1,1,10 μM) for 7 days, and western blot was used to explore the expression of proteins PEPCK and G6Pase. The supernatant fluid from cultured H22 treated by Dex was collected and co-cultured with HUVECs. In vitro, migration assays, Transwell assays, and tube formation assays were performed to assess the migration, proliferation and tube formation abilities in HUVECs, respectively. H22 were inoculated to murine hepatoma model with green fluorescent protein markers (HepG2-GFP) was constructed to explore angiogenesis after treatment by Dex.Results:The results showed that the two key enzymes of gluconeogenesis, PEPCK and G6Pase were almost deficient in malignant cells H22 compared with mice normal liver cells NCTC-1469 (P< 0.01). After treatment by Dex (0,0.1,1,10 μM) for 7 days, the expression of PEPCK and G6Pase were upregulated which showed that gluconeogenesis pathway can be restored (P< 0.01) in malignant cells H22. The HUVECs were cultured to confluence in 6-well plates and co-cultured with the supernatant fluid of H22. The results showed that the supernatant fluid of H22 treated by Dex can attenuate the abilities of migration, tube formation in HUVECs (P< 0.05, P< 0.05) and affect the endothelial permeability of HUVECs (P< 0.05). In mouse tissue, the PEPCK and G6Pase were higher expressed in Dex group than HCC groups (P<0.01). 11β-HSD1 and 11β-HSD2 were abnormally expressed in tumor which can also be restored by Dex. Meanwhile, the microvessel density and total length of microvessels in Dex treated group were less than HCC groups(P<0.05).Conclusions:This study explored the therapeutic efficacy in HCC murine by Dex and found that Dex might inhibit tumor growth and angiogenesis by augmenting the gluconeogenesis pathway.