ObjectiveTo investigate the effect of octreotide on inhibition of growth of subcutaneously implanted tumor with human gall bladder cancer cells in nude mice, and to explore the mechanisms.
MethodsWe established subcutaneous implanted tumor model in nude mice by using human gallbladder carcinoma cell line GBC-SD. A total of 18 male nude mice bearing xenografts of the cell line were randomly divided into therapy and control groups, with 9 in each group. Octreotide was administered intraperitoneally at a dose of 100 μg/(kg·d) to the therapy group and isovolumic normal saline was administered to the control group for 6 weeks. All mice were put to death, and the weight and volume of the tumors were assayed. Flow cytometry was used to examine apoptosis of tumor cells. Immunohistochemical staining was used to examin the expression of p53, bcl-2, and Ki-67.
ResultsThe weight of implanted tumors in nude mice in the therapy group［(0.99±0.54)g］ was lower than that in control group ［(1.58±0.51)g, P<0.05］. Tumor inhibitory rate was 37.3% in therapy group.The apoptotic rate of implanted tumor cells in the therapy group was significantly higher than that in the control group ［(7.76±2.62)% vs. (4.27±1.50)%, P<0.01］. In the therapy group, the percentage of p53, bcl-2, and Ki-67 positive cells was (79.48±5.22)%, (46.72±6.40)%,and (37.56±6.67)% respectively, while in the control group the percentage of p53, bcl-2, and Ki-67 positive cells was (87.13±8.26)%,(53.85±7.72)%,( 45.45±8.73)% respectively. There was a significant difference between the two groups (P<0.05).
ConclusionsOctreotide can inhibit the growth of human gallbladder carcinoma cells implanted tumor in the nude mice model. The mechanisms may involve inhibition of proliferation and induction of apoptosis.