Effects of silencing Id-1 in cell culture of human adenoid cystic carcinoma

SummaryAdenoid cystic carcinoma (ACC) is a slow growing but highly invasive cancer with a high recurrence rate. Id (inhibitor of DNA binding) proteins are dominant regulators of basic helix–loop–helix transcription factors that control malignant cell behavior in many different tissues. This study aimed to identify the potential role of inhibiting DNA binding-1 (Id-1) in human salivary adenoid cystic carcinoma (SACC) progression. First, we compared the Id-1 protein expression in a human salivary adenoid cystic carcinoma cell line (ACCM) against three other cell lines and found that Id-1 protein expression in ACCM to be significantly higher. Then we measured Id-1 mRNA and protein expression in ACCM before and after RNA interference (RNAi), which showed successful inhibition of Id-1. Further studies then demonstrated that the proliferation and invasiveness of ACCM cells were dramatically down-regulated, and increased numbers of apoptotic cells were detected after Id-1 silencing. Consequently, our data suggest that Id-1 is a potential target in the treatment of human salivary adenoid cystic carcinoma.