Induction of DNA damage and growth arrest by citalopram in breast cancer cells mediated via activation of Gadd45a and apoptotic genes

Breast cancer patients experience more severe emotional distress and depression compared to those with other cancers. Selective serotonin reuptake inhibitors (SSRIs), like citalopram, are commonly used to treat depression. However, the link between SSRI use and breast cancer progression is debated. This study examined the cytotoxic effects of citalopram on triple-negative (MDA-MB231) and ER-positive (MCF-7) breast cancer cells. Results showed a significant decrease in cell viability in both cell lines following citalopram treatment. Interestingly, flow cytometry analysis revealed increased apoptotic cells and induction of cell cycle arrest upon treatment of the cells with citalopram. MCF-7 cells were arrested in the sub-G0-G1 phase, while MDA-MB231 cells accumulated in the S phase. Gene expression analysis demonstrated increased Bax expression and decreased Bcl2 levels. Moreover, cytochrome c and NF-κB were upregulated upon treatment with citalopram. Furthermore, transmission electron microscopy (TEM) analysis of treated cells showed apoptotic morphological changes including shrunken nuclei, membrane blebbing, and chromatin condensation with prominent appearance of autophagosomes and autolysosomes. Additionally, GADD45a and p21, involved in growth arrest and DNA damage, were significantly upregulated. In conclusion, citalopram's ability to induce apoptosis and alter cell cycle suggests its potential in breast cancer treatment.