ABSTRACT
Objective To investigate the characteristics of growth and angiogenesis of colon cancer xenograft in nude mice with metabolic syndrome induced by high fat diet.Methods Female BALB/C nude mice were fed with high fat diet (45.0％ from fat,HFD group) or common diet (13.8％ from fat,CD group) for 12 weeks (n=15,respectively).Colon cancer cell line SW480 was marked with green fluorescent protein (GFP) and subcutaneous xenograft model was established.The tumor growth was observed by the in vivo imaging system in small animal at the 4th week.By the end of the experiment,serum glucose and lipid level of the two groups were measured,visceral subcutaneous and visceral adipose tissue,liver and xenograft tumor were dissociated and weighted.The differences of proliferating cell nuclear antigen (PCNA) and CD31 expression in the tumors between groups were analyzed.The t-test or x2 test were performed for group comparison.Results Compared with CD group,the body weight,blood serum glucose level,triglyceride and cholesterol level,adipose content of subcutaneous and visceral of the HFD group significantly increased (t=2.91,4.12,4.43,3.92,3.77 and 4.02,all P＜0.05).Averagedaily energy intake of HFD group was significantly higher than that of CD group (t=2.34,P＜0.05).There was no significant difference between the two groups in liver weight (t=1.02,P＞0.05).However,by HE staining lipid vacuoles in the liver tissue was obvious in HFD group.Average bioluminescent index,tumor volume and weight of xenografts of HFD group were remarkably higher than those of CD group (t=8.84,2.48 and 2.86,all P＜0.05).The immunohistochemical staining results indicated that the strong positive rate of PCNA in xenografts of HFD group was 80.00％ and the microvessel density (MVD) was (25.75±0.96)/per high power field,both of which were higher than those of CD group (14.29％ and (13.33±1.53)/per high power field respectively,x2 =12.52,t=13.35,both P＜0.01).Conclusions The colon cancer xenograft in nude mice with metabolic syndrome induced by high fat diet had a high MVD and grew fast.