Anti-tumor potential of high salt in breast Cancer cell lines

Recent ²³Na-MRI reports show higher salt deposition in malignant breast tissue than in surrounding normal tissue. The effect of high salt on cancer progression remains controversial. Here, we investigated the direct effect of high salt on breast cancer progression in vitro.

Here, the impact of high salt on apoptosis, proliferation, cell cycle, adhesion, and migration of MDA-MB-231 and MCF-7 cells was studied using MTT, scratch, and clonogenic assays, as well as RT-PCR and flow cytometry. Gene expression was analyzed using Real-Time PCR and western blotting. The effect of high salt on global transcriptomics changes in MDA MB-231 cells was studied using RNA-sequencing analysis.

Flow cytometry with Annexin V and CFSE revealed that high salt-induced dose-dependent apoptosis and inhibited proliferation. High salt-induced cell cycle arrest at the G1/S phase of the cell cycle. p-MDM2 is known to suppress p53, which plays a crucial role in regulating apoptosis and cell cycle arrest under cellular stress conditions. High salt treatment led to decreased p-MDM2 and increased p53 expression, suggesting that high salt induces apoptosis through p53 stabilization. decreased p-MDM2 and increased p53 expression. High salt also reduced migration and adhesion of cells in a dose-dependent manner suggesting its inhibitory effect on metastatic properties as evident from wound healing assay. RNA sequencing analysis revealed overexpression of tumor suppressor genes and genes associated with anti-tumor activity (PCDHGA11, EIF3CL, RAVER1, TNFSF15, RANBP3L) and under-expression of genes involved in cancer-promoting activity (MT1X, CLDN14, CSF-2).

Our results unequivocally demonstrate the anti-tumor efficacy of high salt against breast cancer cells, suggesting its potential as a therapeutic strategy in cancer treatment.