Transcriptional responses to nanoparticulate matter in human colon cancer cells.. Homo sapiens

This study evaluated transcriptional effects of particles smaller than 100 nm of carbon black, SiO2, Al2O3, TiO2, ZnO and Fe203. Since there is concern that inflammation may increase the uptake and/or toxicity of ultrafine particles, we evaluated the transcriptional responses without or with a TNFα pretreatment to mimic an inflammatory state. The most pronounced transcriptional response resulted from ZnO treatement, another response was to TNFα pre-treatment. We identified stress responses, responses to Zn ions, but did not observe a consistent proinflammatory response as evaluated by Gene Ontology of the genes that altered expression most as identified by significance analysis. Keywords: colon cancer cells - response to distinct nanoparticulate Overall design: Two colon cancer cell types (RKO and CaCo-2) were pretreated with 100 ng/ml BSA or TNFα for 1 hr, the media was exchanged and with media containing the nanoparticulate, and RNA was collected after 4 hrs. Generally, the RNA from 4 independent samples were combined for one sample on the microarray, the exceptions were the TNFα treated controls where 6 independent samples were combined in 2 sets of 3 for the microarray labeling and hybridizations.