Upregulation of SOX4 antagonizes cellular senescence in esophageal squamous cell carcinoma.

Senescence, a terminal cell proliferation arrest that is caused by a variety of cellular stresses such as telomere erosion, DNA damage and oncogenic signaling, is classically considered a tumor defense barrier. However, the mechanism by which cancer cells overcome senescence is undetermined. In this study, the gene expression array data of esophageal squamous cell carcinoma (ESCC) was compared with paired normal tissues and showed that a cohort of genes, including proteinases, chemokines and inflammation factors, are upregulated in ESCC, which exhibits the senescence-associated secretory phenotype. In addition, reverse transcription-quantitative polymerase chain reaction was used to demonstrate that gender determining region Y-box 4 (SOX4) is upregulated in ESCC, and that its expression is inversely correlated with senescence markers. In addition, the knockdown of SOX4 expression by short hairpin RNA decreases ESCC cell proliferation and enhances doxorubicin-induced cell senescence. These results reveal the presence of a senescent microenvironment in ESCC, and suggest an important antisenescence role of SOX4 in ESCC progression.