The Mechanistic Study Of BCLAF1 In The Regulation Of Breast Cancer Ferroptosis

In the worldwide,the incidence rate and mortality of breast cancer are at the forefront,posing a serious threat to women’s health.Although surgery,radiotherapy,chemotherapy,endocrine therapy,immunotherapy and targeted therapy can reduce the death risk of breast cancer patients.However,the mortality of breast cancer is still soaring due to cancer progression,metastasis and secondary infection caused by treatment failure.Breast cancer cells can escape the cell death induced by treatment,which is one of the reasons for treatment failure.Ferroptosis is an iron-dependent cell death mode,which is different from cell apoptosis,but also a process highly regulated by genes.Since it is still unclear how breast cancer cells regulate ferroptosis during the occurrence and development of tumors,studying its specific mechanism can provide a new direction for the treatment of breast cancer.We mainly studied the function and mechanism of BCL2 related transcription factor 1(BCLAF1)protein in ferroptosis of breast cancer.First of all,we found that BCLAF1 protein is relatively high expression in breast cancer patients by reviewing data and literature,and its increased expression is related to the shortened survival period of patients.Through in vitro experiments,we found that BCLAF1 depletion in breast cancer cells can impair the proliferation,migration and invasion of breast cancer cells,but the mechanism of the protein is still unclear.Previous studies have found that changes in the expression of BCLAF1 protein in hepatocellular carcinoma cells are related to fatty acid metabolism,oxidative phosphorylation and ROS pathway.According to other studies,lung cancer cells with BCLAF1 depletion are extremely sensitive to the ferroptosis inducer Erastin,and this sensitivity can be inhibited by the ferroptosis protector Ferr-1.so we speculate that the BCLAF1 protein may be related to the ferroptosis.After depleting BCLAF1 in breast cancer cells,we measured cell ROS level and conducted the killing experiment of ferroptosis inducer.The results showed that BCLAF1 depletion can promote ROS level and increase the sensitivity to ferroptosis inducer.Then we found that BCLAF1 depletion in breast cancer cells can reduce the expression of GPX4 protein by immunoblotting.In addition,when we depleting BCLAF1 in breast cancer cell,the resistance of cells to ferroptosis can be partially restored after increasing GPX4 expression.Then we overexpressed the plasmid containing the full length sequence of BCLAF1 protein in breast cancer cells,and found that the proliferation of breast cancer cells was significantly accelerated,and the resistance of cells to ferroptosis was also significantly increased.These results suggest that BCLAF1 protein is associated with ferroptosis.Later,through website analysis,we found that BCLAF1 protein was associated with the signal pathway containing NFE2L2 protein in breast cancer patients,and the level of NFE2L2 mRNA was positively correlated with the level of BCLAF1 mRNA.When depleting NFE2L2,we found that the mRNA and protein levels of BCLAF1 were also down-regulated.Finally,through the prediction of the website,we found that there are two NFE2L2 protein binding sites in the promoter region of BCLAF1 gene.In summary,we clarified that BCLAF1 protein can target and promote the expression of GPX4 protein to protect breast cancer cells from the impact of ferroptosis process through in vitro experiments.Moreover,under oxidative stress,NFE2L2 protein can promote the expression of BCLAF1 protein,thereby inhibiting the occurrence of ferroptosis.Therefore,we found that BCLAF1 protein is a key ferroptosis regulator,which can provide a potential target for the treatment of breast cancer.