STOCKHOLM, Sweden—New legislations on the registration and use of chemicals within the cosmetic industry have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization such as allergic contact dermatitis—an inflammatory skin disease that affects a significant proportion of the population, commonly caused by immunological responses toward chemical haptens. Current test of sensitizing chemicals rely on animal experimentation; therefore, there is a need to replace animal experiments with in vitro tests displaying a higher predictive power.
Researchers developed a novel cell-based assay for the prediction of sensitizing chemicals (BMC Genomics. 2011, 12:399). By analyzing the transcriptome of the human cell line MUTZ-3 after 24-hour stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, a biomarker signature of 200 genes with potent discriminatory ability was identified. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization.
A gene signature predicting sensitization, using a human cell line in vitro, was identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests.
