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

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

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.

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).

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.