JQ1, a small molecule inhibitor of BRD4, suppresses cell growth and invasion in oral squamous cell carcinoma

The present study aimed to evaluate whether bromodomain 4 (BRD4) is expressed in Cal27 cells and to assess the effect of JQ1 on cell proliferation, apoptosis, invasion and BRD4, C-Myc and Twist expression in Cal27 cells. Immunofluorescence staining was used to determine whether BRD4 was expressed in Cal27 cells. Cell viability and proliferation were evaluated using CCK-8 assay. Flow cytometry was used to determine the apoptosis and cell cycle distribution. The cell invasion was evaluated using Transwell plate. The expression levels of BRD4, C-Myc and Twist were determined by quantitative RT-PCR (qRT-PCR) and western blotting. BRD4 was highly expressed in Cal27 cells. JQ1 inhibited cell proliferation, induced cell apoptosis, induced cell cycle arrest, and inhibited cell invasion. Gene and protein expression levels of BRD4, C-Myc and Twist were downregulated in cells treated with JQ1. JQ1 inhibited Cal27 cell growth and invasion, and downregulated expression of several oncogenes. JQ1 may be a new drug for oral squamous cell carcinoma treatment.