Apoptosis-inducing factor (AIF) nuclear translocation mediated caspase-independent mechanism involves in X-ray-induced MCF-7 cell death

Abstract

Purpose: Breast cancer is the most common cancer among women and radiotherapy is a conventional therapy following surgery. Previous studies have demonstrated that except the caspase-dependent pathway, caspase-independent pathway is also involved in the cell death responding to irradiation, despite the unclear mechanism. The purpose of the present study was to observe the role of apoptosis-inducing factor (AIF), the first identified caspase-independent molecule, in X-ray-induced breast cancer cell (MCF-7) cell death.Materials and methods: In this study, WST-1 assay, DAPI nuclear staining and clonogenic survival assay were used to test the cell response to different treatments; Western blot was used to detect the protein expression; RT-PCR and plasmid transfection were used to observe the role of AIF.Results: X-ray-induced AIF transferred from the mitochondrion to the nucleus. Inhibition of AIF expression reduced X-ray-induced MCF-7 cell death. Further, AIF nuclear translocation is in a caspase-independent manner in this process, but not caspase-dependent manner.Conclusions: The present study revealed that AIF nuclear translocation proceeded in X-ray-induced MCF-7 cell death in a caspase-independent manner.