BACKGROUNDMetastasis is the main cause of the death of lung cancer patients. Much attention has been pain to the research of lung cancer metastasis. Metastasis-associated protein 1 (MTA1) is one member of metastasis associated protein family. Its overexpression is correlated with metastasis of esophageal carcinoma and breast cancer, but the generality of its expression in cancer and the significance for judging biological behaviors of tumor and evaluating prognosis of patients is to be investigated. The aim of the study is to study the relationship between MTA1 expression and clinicopathological factor regarding metastasis and prognosis of human non-small cell lung cancer (NSCLC).

METHODSThe expression of MTA1 was detected in 101 parafin-embedded specimens by immunohistochemistry method, as well as in 35 freshly-taken NSCLC tissues by Western blot.

RESULTSThere were 56 cases (55.4%) of NSCLC with yellow or even brown particles in nucleus of tumor cell among 101 cases, and MTA1 protein showed negative expression in epithelia of bronchi or alveoli in neighboring noncancerous tissue. Western blot analysis showed the level of MTA1 in NSCLC tissues was remarkably higher than that in normal tissues (t=3.953, P=0.000). Expression of MTA1 was remarkably higher in tumor with metastasis than that in tumor without metastasis (t=4.057, P=0.000). Expression of MTA1 significantly correlated with differentiation (Chi-square=10.131, P=0.006), lymphatic metastasis (Chi-square=8.535, P=0.003) and p-TNM stage (Chi-square=17.419, P=0.000). The survival time of pa-tients with negative MTA1 expression was (44.866±12.946) months, which was significantly higher than that of patients with positive MTA1 expression [(23.714±7.498) months] (Chi-square=10.006, P=0.002). In multivariate analysis, only lymphatic metastasis and TNM stage could be considered as independent prognostic factors.

CONCLUSIONSMTA1 might play an important role in the development and metastasis of NSCLC. Patients with MTA1 expression have a greater chance of metastasis and a poorer prognosis. However, MTA1 expression is not an independent prognosis factor.