High level of BRD4 promotes non-small cell lung cancer progression.

Bromodomain containing protein 4 (BRD4), a member of the bromodomain and extra terminal domain (BET) protein family, has been shown to play important roles in tumor progression. However, its role in non-small cell lung cancer (NSCLC) is still largely unknown. Here, we found that BRD4 expression was significantly upregulated in NSCLC tissues and NSCLC cell lines with higher invasion and metastasis potentials. Suppression of BRD4 expression in NSCLC cell lines impaired cell invasion, inhibited cell proliferation, and accelerated cell apoptosis. Clinically, we observed that the BRD4 level was significantly related to histological type, lymph node metastasis, tumor stage and differentiation. More importantly, high level of BRD4 was closely correlated with the poor prognosis of NSCLC patients. Therefore, our study suggests that BRD4 is one of the major contributors to the invasion-prone phenotype of NSCLC, and a potential therapeutic target of NSCLC.