Upregulated Tie2 expression in plasma: a potential non-invasive biomarker for the diagnosis of breast cancer

Breast cancer is by far the most common malignancy found in women and causes a significant public health problem around the world. Early diagnosis of cancer plays an important role in successful treatment and survival of patients. This study aims to investigate the possibility of plasma Tie2 to be used as a biomarker for diagnosis of breast cancer. In total, 20 healthy volunteers and 33 breast cancer patients were considered for this study. The level of Tie2 in plasma was detected using the ELISA technique and immunohistochemistry was performed to measure the expression of Tie2 in normal and breast cancer tissues. Plasma concentrations of Tie2 were significantly higher among breast cancer patients compared to healthy subjects, and both mRNA and protein expression of Tie2 were higher in breast cancer tissue than in normal tissue. Plasma concentrations of Tie2 were positively correlated with the grade of breast cancer. Finally, in vitro knockdown of Tie2 expression in a breast adenocarcinoma cell line inhibited the proliferation of these cells. It is concluded from the results that Tie2 might be a useful plasma biomarker for the early detection of breast cancer and could be developed to be a target for novel drug discovery.