JARID1B modulates breast cancer cell apoptosis by regulating p53 expression

Jumonji AT-rich interactive domain 1B (JARID1B) has been implicated in breast cancer progression, but its role in apoptosis has not been explored. The present study was designed to investigate the effect of JARID1B on breast cancer cell apoptosis. Apoptosis was assessed by TUNEL, flow cytometry and caspase-3 activity. JARID1B and p53 expression were examined by Western blot. Cell viability was measured by an MTT assay. We found that JARID1B is overexpressed in the breast cancer cell line and in breast cancer tissues. Upregulated expression of JARID1B in breast cancer tissues correlates with poor patient prognosis. The apoptosis of breast cancer cells is significantly increased by RNA interference targeting JARID1B. Moreover, the expression of p53 is modulated by JARID1B; the silencing of JARID1B exhibits greatly increased p53 expression at the protein level. The inhibition of p53 by small interfering RNA (siRNA) reverses the JARID1B siRNA-induced increase of apoptosis. Our results collectively suggest that JARID1B plays a key role in breast cancer cell apoptosis, and it may partially achieve this role through p53.