Silica nanoparticles effects on gene expression of A549 cells

Expansion of nanotechnology will bring many potential benefits as adversely effects on human health. Protection of the human respiratory system from exposure of volatile nanoparticles has become an emerging health concern. The understanding of the biological processes involved in the development and maintenance of a variety of pathologies is improved by genome-wide approaches. Technical feasibility of this type of experiment has perfected in recent years, but data analysis remains challenging. In this context, gene set analysis has emerged as a fundamental tool for the interpretation of the results. We demonstrate how the use of a combination of gene-by-gene and gene set analyses can enhance the interpretation of results. Gene set analyses are able to distinguish responses due to nanoparticle size also discriminating between long and short time recovery after exposure. Transcription regulation and cell proliferation modulation appear to be an early response while oxidative stress and mitochondrial perturbation are late response. Moreover, smaller the particle higher the effect on inflammatory response and DNA damage activation. By integrating the two approaches, we evidenced the importance of MMP1, MMP9, MMP7 and MMP14 genes in response to Ludox® silica nanoparticles and the involvement apoptosis process in cell viability. This study is based on the treatment of A549 cells with two different silica nanoparticles (SM30, 9 nm of diameter, and AS30, 18 nm of diameter). Treatment with nanoparticles were performed independently. We performed three biological replicates for each condition.