[Expression of PAK4 in breast cancer and benign breast pathological changes].

OBJECTIVE: To study the role of p21-activated kinase-4 (PAK4) in the occurrence, progression and metastasis of breast cancer. METHOD: PAK4 expression was detected in 35 cases of normal breast, 22 breast cystic hyperplasia, 28 breast adenofibroma, 37 breast cancer (including 7 non-invasive cancer, 9 early invasive cancer and 21 invasive cancer) and 13 metastatic breast cancer tissues using immunohistochemistry for a comparison of PAK4 expression and distribution. RESULTS: PAK4 was expressed mainly in the cytoplasm of the cancer cells, occasionally in the cell nuclei, and virtually not expressed in the matrix surrounding the breast cells. PAK4 positivity rates increased in the order of normal breast tissues, benign changes (including breast cystic hyperplasea and breast adenoma), breast cancer and metastatic cancer tissues; in the cancer tissues, the positivity rates increased in the order of non-invasive breast tumor, early invasive tumor and invasive tumor tissues. CONCLUSION: PAK4 is closely correlated to the progression and metastasis of breast cancer and may become a new diagnostic and therapeutic target of breast cancer.