Carbon nanotubes induce autophagy, apoptosis, and S-phase cell cycle arrest in HeLa cells

Carbon nanotubes (CNTs) are ubiquitous in the environment and are widely used in industry and medicine, but their unspecified safety has raised concerns. This study aims to explore the potential hazards of carbon nanotubes. This study exposed different concentrations of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) to HeLa cells. The results showed that exposure to SWCNTs and MWCNTs resulted in slow growth and decreased survival of HeLa cells. The oxidative stress and autophagy of the cells were intensified, the cell division was abnormal, and the number of S-phase cells was reduced. After 100 μg/ml MWCNTs exposure, the proportion of apoptotic cells increased, and the transcript levels of apoptosis-related genes like <i>Caspase-3</i> and <i>Bcl-2</i> were upregulated. In addition, each group’s differentially expressed proteins (DEPs) were mainly related to the regulation of protein catabolic process, glycogen metabolic process, nucleotide synthesis and processing, response to reactive oxygen species, and regulation of cell division and apoptosis. These findings suggest that CNTs induce toxic effects through oxidative stress, exacerbating autophagy and apoptosis, and reducing cell viability. Therefore, the harmful effects of CNTs on organisms should be comprehensively considered in their production and utilization.