RESUMO
BACKGROUND: By identifying the molecular mechanisms underlying sodium selenite (Na2SeO3) cytotoxicity during exposure in non-tumor cells (HaCaT cells), we will improve the current understanding of its antiproliferative effects and modulation of gene expression in the main pathways related to the cell cycle, cell death, oxidative stress, and DNA damage and repair. METHODS: Non-tumor HaCaT cells were treated with Na2SeO3 to induce cytotoxicity, and the effects were investigated using an MTT assay (cell viability), real-time cell analysis (profiling the cell index), flow cytometry (membrane integrity, cell cycle disruption, and apoptosis), a comet assay (genotoxicity, i.e., DNA damage), and RT-qPCR (mRNA expression of genes). RESULTS: Treatment with Na2SeO3 was cytotoxic at 10 µM, producing morphological changes in cells (cytoplasmic granulations); however, it did not have a genotoxic effect. Na2SeO3 induced cell membrane damage, cell death, and cell cycle arrest in HaCaT cells. It also altered the mRNA expression levels of PUMA, ATR, and mTOR genes. However, it had no effect on the mRNA expression of caspases or PARP1, BIRC5, BECN1, and c-MYC genes, suggesting that Na2SeO3 causes PUMA-dependent apoptosis in HaCaT cells. The mRNA expression of specific genes related to oxidative stress, DNA damage and repair, and cell cycle control were unchanged by Na2SeO3. CONCLUSIONS: We demonstrated the cytotoxic effect of Na2SeO3 in HaCaT cells by analyzing mRNA expression patterns, changes in cell morphology, and proliferation kinetics.
