【Animal Modeling】-E-cad in the nude mouse model of low rectal cancer lymph node metastasis

  Objective: To investigate the expression of E-cadherin (E-cadherin) in the lymph node metastasis model of low rectal cancer in nude mice, and analyze its role in the process of lymph node metastasis of rectal cancer.

  Method: A nude mouse model with low rectal cancer lymph node metastasis was established by inoculating the rectal mucosa of nude mice with the logarithmic growth phase of the human colorectal cancer cell line SW480. 120 nude mice were randomly divided into 3 groups, 40 in each group. Group A (rectal cancer model group) was injected with dimethylhydrazine injection + SW480, group B (dimethylhydrazine control group) was injected with dimethylhydrazine. Group C (blank control group) was not given treatment. ELISA was used to detect serum E-cad content, and Western blot and RT-PCR were used to detect the mRNA expression level of E-cad protein in transplanted tumor tissues.

  Result: The serum E-Cad content of nude mice in group A was (19.48±1.25) mg/L, which was significantly higher than the serum E-Cad content of nude mice in groups B and C (2.36±0.18). mg/L and 2.15±0.12 mg/L) (t = 8.28, 9.01, P\u003c0.05). The serum E-Cad content of nude mice with lateral lymph node metastasis was significantly higher than that of nude mice without lateral lymph node metastasis, and the difference was statistically significant (t = 10.28, P\u003c0.05). The expression intensity of E-Cad protein in the transplanted tumor tissue of nude mice in group A was weaker than that in groups B and C (t = 9.81, 7.69, P\u003c0.05). In group A, the expression intensity of E-Cad protein in transplanted tumor tissues of nude mice with lateral lymph node metastasis was significantly weaker than that of nude mice without lateral lymph node metastasis, and the difference was significant. (T = 9.36, P\u003c0.05). The expression of E-CadmNA in the transplanted tumor tissue of nude mice in group A was significantly down-regulated, which was significantly different from the expression in groups B and C (P\u003c0.05). In group A, the expression intensity of E-CadmNA in the transplanted tumor tissues of nude mice with lateral lymph node metastasis was significantly down-regulated. Compared with nude mice without lateral lymph node metastasis, the difference was significant (t = 7.85, P\u003c0.05).

  Conclusion: The expression level of serum E-cad may be closely related to the lymphatic metastasis of rectal cancer. At the same time, the expression of E-Cad protein and mRNA in rectal cancer tissues decreased or disappeared.