Abstract: ObjectiveTo study the expressions of DLL4（deltalike ligand 4）， COX-2（Cyclooxygenase-2） and MMP-2（matrix metalloproteinase-2） in different molecular subtypes of breast cancer and analyze their correlation.
MethodsThe expressions of DLL4， COX-2 and MMP-2 were determined by SP immunohistochemistry in 100 cases of breast carcinoma （41 luminal A， 18 lumianl B， 22 HER-2 overexpression and 19 basallike subtypes） and 40 cases of adjacent normal breast tissues. Then the correlation of DLL4， COX-2 and MMP2 expression with lymph node metastasis was analyzed.
ResultsThe positive expression rates of DLL4，COX-2 and MMP-2 in breast cancer were 73.0％， 81.0％ and 93.0％， significantly higher than those in adjacent normal breast tissues（P＜0.05）. The positive rates of DLL4， COX-2 and MMP-2 were 95.5％， 100.0％ and 100.0％ in HER-2 overexpression type， and 89.5％， 94.7％ and 100.0％ in basal-like subtype. They were significantly higher than those in luminal A and luminal B subtypes（P＜0.05）. The expression of DLL4，COX-2 and MMP-2 in lymph node metastasis group were 88.7％， 92.5％ and 96.2％ respectively， higher than those without lymph node metastasis group（P＜0.05）. Positive correlation could be found between DLL4 and COX-2, MMP2 expression（r=0.215， P＜0.05； r=0.435， P＜0.05）. Conclusion DLL4， COX-2 and MMP-2 are highly expressed in HER2 overexpression and basallike subtypes of breast cancer. These results suggest that they might be important factors in breast carcinogenesis， development and metastasis. These proteins are indicators of metastasis of breast cancer.