Digital gene expression profiling analysis of A549 cells cultured with PM10 in moxa smoke

Moxibustion is a traditional Chinese medicine therapy to cure diseases by fumigating meridians or affected parts via burning of moxa floss. Moxa smoke (MS) is one of the key factors in moxibustion. In this study, we adopted digital gene expression profiling, a next-generation gene sequencing technology, to investigate the effect of MS, inhalable particulate matter (PM10), on human lung adenocarcinoma A549 cells. The effects of MS PM10 on A549 cells, over different treatment durations were investigated in different groups: the 4-h group (4-h MS group and 4-h control group) and the 20-h group (20-h MS group and 20-h control group). Samples collected from the four groups were stored at −80 °C for subsequent digital gene expression analysis. The differentially expressed genes (DEGs), identified after PM10 treatment, were screened, and their expression patterns analyzed by cluster analysis, Gene Ontology term enrichment, and Kyoto Encyclopedia of Genes and Genomes pathway analysis. Compared with two control groups, 1109 DEGs were identified after 4 h of MS intervention and 3565 DEGs were found after 20 h of MS intervention, respectively. Compared with that after 4-h intervention, 2149 DEGs were identified after 20-h intervention. Cluster analysis demonstrated that PM10 can significantly inhibit cell cycle process with the prolongation of intervention time. Significant pathway enrichment analysis showed that MS PM10 can inhibit A549 cell cycle process at all phases. When MS PM10 exposure time prolongs, the inhibitory effect on cell cycle process becomes more obvious. MS PM10 has many biological activities, and may cause differential expression of genes involved in various biological processes. Nevertheless, further research on MS is warranted for better understanding of the mechanistic details.