Reduced expression of ADAM8 and its role in breast cancer

Objective To investigate the expression of a disintegrin-like and metalloproteinase 8 ( ADAM8 ) in breast cancer and in normal breast tissues and its negative regulation role in tumorigenesis and progress of breast cancer.Methods The expression of ADAM8 in breast cancer and normal breast tissues was detected by immunohistochemistry (IHC),qRT-PCR,and Western blot.The relation between ADAM8 expression and the clinicopathological parameters of breast cancer patients was analyzed.Results ADAM8 was expressed in breast cancer and normal breast tissues.The expression of ADAM8 mRNA and protein was significantly lower in breast cancer than in normal breast tissues (qRT-PCR:P =0.015,IHC:P =0.044,Western blot:P =0.000).The expression rate of ADAM8 was related to lymph node metastasis,tumor stage and tumor size,although the difference had no statistical significance.IHC results showed that ADAM8 expression level was lower in stage Ⅲ + Ⅳthan in stage Ⅰ + Ⅱ ( P =0.574 ).qRT-PCR showed ADAM8 mRNA expression was lower in stage Ⅱb + Ⅲ than in stage Ⅰ + Ⅱ a ( P =0.247).ADAM8 expression was lower in the breast cancer tissues with lymph node metastasis than in those without lymph node metastasis (P =0.560 by IHC and P =0.592 by qRT-PCR).ADAM8 expression was lower in tumors whose size ＞ 2 cm than in tumors whose size ≤ 2 cm,however,the difference had no statistical significance ( P ＞ 0.05 ).Conclusions ADAM8 is significantly lower-expressed in breast cancer than in normal breast tissues,which is associated with clinical stages and lymph node metastasis.The reduced expression of ADAM8 may play a role in the pathogenesis and progress of breast cancer. Key words: Breast cancer; ADAM8; Real-time fluorescent quantitative polymerase chain reaction; Western blot; Immunohistochemistry