Differential expression of Gab2 and BMI 1 in primary osteosarcoma and matched lung metastasis and its clinical significance

Objective To investigate the significance of differential expression of Gab2 and BMI 1 in primary lesions of osteosarcoma and corresponding lung metastasis specimens. Methods We collected 24 patients with osteosarcoma in our hospital. All patients underwent neoadjuvant chemotherapy after definite diagnosis. The specimens of 24 patients with osteosarcoma were selected as the primary group and their corresponding pulmonary metastases. The specimens were used as the metastasis group. The primary lesions of 32 patients with osteosarcoma who did not metastasize were selected as the control group. The immunohistochemical method was used to detect Gab2 protein, BMI 1 protein and proliferation cell nuclear antigen (Ki-67) protein in the primary group and lung metastasis group. The expression of the control group was positive (+ ) with a positive cell ratio greater than 25%, 5% to 25% was weakly positive (+ ), and less than 5% was negative (-). Results The positive rate of Gab2 in the primary group (37.5%) was significantly lower than that in the metastatic group (75%), and higher than that in the control group (16.7%). The difference was statistically significant (P 0.05); the positive rate of Ki-67 in the primary group (45.8%) was significantly lower than that in the metastatic group (79.2%), which was also higher than that in the control group (25%). The differences were statistically significant (P<0.05). In addition, the Gab2 gene was positively correlated with Ki-67 (r=0.752, P<0.01), but negatively correlated with BMI-1 expression (r=-0.655, P<0.05). Conclusion The high expression of Gab2 gene is associated with lung metastasis of osteosarcoma and negatively correlated with the expression of BMI 1 gene, However, high expression of the BMI 1 gene is also associated with lung metastasis in osteosarcoma. Key words: Osteosarcoma lung metastasis; Gab2; BMI 1; Paired specimen; immunochemistry