Expression and anti-apoptotic function of TRAF4 in human breast cancer MCF-7 cells

Tumor necrosis factor (TNF) receptor‑associated factor 4 (TRAF4) was initially identified as a gene amplified and overexpressed in breast carcinoma. The present study investigated the expression and anti-apoptotic function of TRAF4 in human breast cancer MCF‑7 cells. TRAF4 was found to be localized in the cytoplasm and nuclei of MCF‑7 cells by immunofluorescence staining and western blotting. The expression of TRAF4 in normal MCF‑10A breast cells was found to be lower than in MCF‑7 and MDA‑MB‑231 breast cancer cells. Following TNF‑α treatment, TRAF4 depletion by siRNA in the MCF‑7 cells was observed to suppress cell proliferation and the nuclear expression of nuclear factor κB was significantly reduced. The percentage of early apoptotic cells in the MCF‑7 cells was augmented upon TRAF4‑knockdown, and an increase in G1 phase cells and a decrease in S phase cells was detected. These results indicate that TRAF4 has anti-apoptotic effects on apoptosis induced by TNF‑α in MCF‑7 cells.