Effect And Mechanism Research Of Cold Atmospheric Plasma On Different Breast Cancer Subtype Cells

Breast cancer is divided into multiple subtypes due to its high heterogeneity.Among the subtypes of breast cancer,triple-negative breast cancer has a high degree of malignancy,lacks effective targeted therapy,and has poor prognosis.Chemotherapies have been canonically used for triple-negative breast cancer treatment,which have severe side effects and make patients suffer a lot from the treatment.It is very important for researchers to develop effective and low-toxic targeted therapies and novel therapeutic methods for triple-negative breast cancer.The emerging role of cold atmospheric plasma as an anti-tumor approach has been recognized in recent years,and the efficacy of plasma as an oncotherapy has been demonstrated in over twenty types of cancers.Further,cold atmospheric plasma has shown great synergies with many existing anti-tumor drugs.Most studies have focused on exploring the sensitivity of cancer and normal cells to cold atmospheric plasma.Very few has laid focus on the difference of sensitivity in different subtypes to cold atmospheric plasma.Using one normal breast epithelial cell line MCF10A as the control,we investigated whether different subtypes of breast cancer cells have different sensitivity to cold atmospheric plasma by using two luminal breast cancer cell lines MCF7 and BT474 and four triple-negative breast cancer cell lines SUM149,SUM159,MDAMB231 and MDAMB468.The main results are listed follows:(1)The stability of the results obtained by direct plasma treatment and plasma-activated medium(PAM)was compared and PAM was chosen for subsequent experiments.The effect of PAM prepared by different mediums with the same serum ratio on the cell viability of different cells were compared,and the difference of medium causes negligible influence on the results.(2)The effect of PAM on the cell viability,apoptosis and migration ability of seven cell lines was measured.It was found that PAM could induce cell apoptosis,inhibit cell viability and migration ability of triple-negative breast cancer cells,while causing little effect on normal breast cells and the luminal subtype.The phosphorylation level of MAPK signaling pathway-related protein was measured,which demonstrated that PAM could inhibit the cell viability of MDAMB231 via suppressing the phosphorylation level of JNK.(3)The proportion of ALDH1~+cells in SUM149 and SUM159 was more than that of MCF10A and MCF7.PAM could significantly reduce the proportion of ALDH1~+cells and inhibit the self-renewal ability of SUM149 and SUM159,while causing little effect on MCF10A and MCF7.PAM did not affect the mRNA and protein expression of ALDH1,and it was speculated that PAM reduced the proportion of ALDH1~+cells in SUM149 and SUM159 by affecting the post-translational modification of ALDH1 protein or killing more ALDH1~+cells.(4)Atorvastatin could inhibit cell viability of triple-negative breast cancer cells,and it had negligible effect on its migration;PAM had synergistic effect with atorvastatin to further inhibit the viability of triple negative breast cancer cells.