[Expression and significance of N-cadherin and β-catenin protein in osteosarcoma].

Objective: To evaluate the expression of N-cadherin and β-catenin protein and their relationship with clinicopathological characteristics of osteosarcoma.

Methods: The expressions of N-cadherin and β-catenin at protein level were detected by immunohistochemical staining in 54 cases of osteosarcoma, 11 cases of osteoid osteoma, 7 cases of osteoblastoma and 8 cases of newly formed bone in nonmalignant bone diseases. The relationship between the two indexes and clinicopathological characteristics of osteosarcoma was analyzed.

Results: In newly formed bone, osteoblastoma, osteoid osteoma and osteosarcoma, the positive expression rate of N-cadherin protein was 75.0%, 71.4%, 63.6% and 35.2%, respectively. The positive expression rate of N-cadherin protein in osteosarcoma was significantly lower than that in osteoid osteoma, osteoblastoma and newly formed bone in nonmalignant bone diseases (P = 0.035). The positive expression rate of N-cadherin protein in osteosarcoma cases with pulmonary metastasis was lower than that in cases without (21.7% vs. 56.3%, P = 0.027). The positive expression rate of N-cadherin protein in osteosarcoma cases died in two years was lower than that in cases lived for more than two years (18.2% vs. 50.0%, P = 0.024). In newly formed bone, osteoblastoma, osteoid osteoma and osteosarcoma, the aberrant expression rate of β-catenin protein was 12.5%, 28.6%, 27.3% and 66.7%, respectively. The aberrant expression rate of β-catenin protein in osteosarcoma was significantly higher than that in osteoid osteoma, osteoblastoma and newly formed bone (P = 0.002). Aberrant expression rate of β-catenin in osteosarcoma cases with pulmonary metastasis was higher than that without (82.6% vs. 43.8%, P = 0.011). An inverse correlation was found between the aberrant expression of β-catenin and N-cadherin expression in osteosarcoma(r = -0.302, P = 0.027).

Conclusion: The positive expression rate of N-cadherin is decreased in osteosarcoma while aberrant expression rate of β-catenin increased. The expression of N-cadherin protein is closely correlated with the metastasis and prognosis of osteosarcoma, but the expression of β-catenin protein is merely correlated with the metastasis of osteosarcoma.