유방암에서 KAI-1 단백의 발현 양상: 액와부 림프절전이를 포함한 다른 예후인자와의 상관관계

Abstract

Background : KAI-1 is a metastasis suppressor gene. We have evaluated the correlation between KAI-1 protein expression in ductal carcinomas of the breast and axillary lymph node metastasis. Methods : The expression of KAI-1 protein was confirmed by immunohistochemistry to examine breast tissues of ductal carcinomas from 50 patients with nodal metastasis and from 53 patients without metastasis. Western blot analysis was performed on fresh frozen breast tissues from 17 cases with nodal metastasis and from 19 cases without metastasis. Results : Immunohistochemical KAI-1 protein expression was decreased or negative in 39 out of 50 cases with metastasis (78%), compared with 8 out of 53 cases with no metastasis (15.1%). The difference was statistically significant (p<0.05). Immunohistochemical KAI-1 protein expression was significantly decreased in cases with higher modified Black’s nuclear grade (p=0.027) and larger tumor size (p=0.039). Western blot analysis showed positive bands at 29.5 kDa in 8 out of 19 cases without metastasis (42.1%), and none of the 17 cases with metastasis showed positive bands (p=0.0024). Conclusion : These results suggest the possibility that KAl-1 might play a major role of a metastasis suppressor gene in addition to the part it plays in the growth and progression of human breast ductal carcinoma. In addition, the decreased expression of KAI-1 protein in breast ductal carcinomas could be used as a factor suggesting poor prognosis.