Effects Of KAI1 Gene Transfection On The Growth And Metastasis Of Human Gastric Cancer Xenograft In Nude Mice

Objective:By establishing a nude mouse model of human gastric carcinoma transplantation,analyze the influence of KAI1 gene in different human gastric carcinoma cell lines on the growth and metastasis of transplanted tumor in nude mice.Methods:1.36 female BALB/c-nu nude mice were randomly divided into 6 groups,each group 6.Low differentiated human gastric carcinoma BGC823 cells were divided into experimental group(BGC823-OE group)infected with KAI1 gene overexpression lentiviral vector,negative control group(BGC823-NC group)infected with empty virus vector and blank control group(BGC823-Ctrl group).Highly differentiated human gastric carcinoma MKN28 cells were divided into experimental group infected with KAI1 gene lentiviral RNA interference vector experimental group(MKN28-si RNA group),negative control group(MKN28-NC group)infected with empty virus vector and blank control group(MKN28-Ctrl group).To establish a nude mice gastric carcinoma transplant tumor model through abdominal injection.The number of cells was 1×10~7cells/ml.Daily observation of nude mice diet,mental state and activity.Every 3 days to measure abdominal circumference changes and the application of small animal color ultrasound detector to detect the growth and metastasis of nude mice intraperitoneal transplant tumor.2.After 4 weeks of continuous observation,the nude mice were de-necked and the transplant tumor was removed.And the number of transplanted tumors disseminated of nude mice organs were observed,and the number and weight of the nude mice intestinal membrane transplant tumor were counted.As well as the HE staining of the nude mice organs in each group.3.IHC,Western blot and RT-PCR were used to detect the expression of KAI1 protein and KAI1m RNA in the transplanted tumor tissue of nude mice.Results:1.Two weeks after inoculation,the diet,spirit and activity of nude mice in BGC823-OE group were better than those in BGC823-NC group and BGC823-Ctrl group,while MKN28-si RNA group had poor diet,low spirit and decreased activity compared with MKN28-NC group and MKN28-Ctrl group.According to the increase of abdominal circumference of nude mice,the increase of abdominal circumference of nude mice in BGC823-OE group was the smallest,there was significant difference compared with BGC823-NC group and BGC823-Ctrl group(P<0.05).But he increase of abdominal circumference of nude mice compared with the MKN28-si RNA group MKN28-NC group and MKN28-Ctrl group had no significant difference(P>0.05).The growth and metastasis of abdominal transplanted tumor in nude mice were observed by small animal color ultrasound detector.2.The number of transplanted tumors disseminated of nude mice organs and mesenteric transplanted tumors in BGC823-OE group was significantly less than those in BGC823-NC and BGC823-Ctrl groups(P<0.05),and the weight of mesenteric transplanted tumors in BGC823-OE group was significantly lower than those in BGC823-NC and BGC823-Ctrl groups(P<0.05).In MKN28-si RNA group,the number of transplanted tumors disseminated of nude mice organs and mesenteric transplanted tumors were significantly higher than those in MKN28-NC group and MKN28-Ctrl group(P<0.05),and the weight of mesenteric transplanted tumors in MKN28-si RNA group was significantly higher than that in MKN28-NC group and MKN28-Ctrl group(P<0.05).There was no significant difference between NC group and Ctrl group in BGC823 and MKN28nude mice(P>0.05).3.By using IHC,Western blot and RT-PCR,we found that the relative expression of KAI1 protein and m RNA in BGC823-OE group was significantly higher than that in BGC823-NC group and BGC823-Ctrl group(P<0.05).The relative expression of KAI1 protein and m RNA in MKN823-si RNA group was significantly lower than that in MKN28-NC group and MKN28-Ctrl group(P<0.05).There was no significant difference in KAI1 protein and m RNA expression between NC group and Ctrl group in BGC823 and MKN28 nude mice(P>0.05).Conclusion:1.The transplanted tumor model of human gastric carcinoma in nude mice was successfully constructed.2.The growth and metastasis of BGC823 and MKN28 transplanted tumors in nude mice may be regulated by KAI1 gene.3.Overexpression of KAI1 protein may inhibite the growth and metastasis of human gastric carcinoma xenografts in nude mice.Low expression of KAI1 protein may promote the growth and metastasis of human gastric carcinoma transplanted tumor in nude mice;4.The expression of KAI1 protein and m RNA may negatively regulate the growth and metastasis of intraperitoneal tumor in nude mice.