The effects of mainstream cigarettes smoke components on gene expression in NCI-H292 cells.
Cigarette smoke is a complex mixture of more than 4,000 components, and many different in vitro tests are currently used to assess the biological effects of cigarette smoke. The present study was carried out to determine the mainstream cigarette smoke component(s) associated with the expression of four genes: interleukin-8 (IL-8), heme oxygenase-1 (HO-1), matrix metalloprotease-1 (MMP-1) and the airway mucin MUC5AC.
First, the correlation factor was calculated using the correlative analyses between each value of gene expression relative to the vehicle control induced by 9 different kinds of sample cigarettes and the amount of each component in the smoke. Benzene, benzopyrene and catechol in PP and carbonyl components in GVP had a high correlation with the induction of the four genes. Next, we estimated the contribution of particulate phase (PP) and gas vapor phase (GVP). GVP induced IL-8, HO-1 and MMP-1 gene expressions more than PP. By contrast, MUC5AC was more strongly induced by PP than GVP.
When additional experiments were carried out on each individual chemical component by treating with each candidate component in the amount equivalent to that in test solution, the 3 candidate chemicals in PP didn't induce any of the four genes. In contrast, the mixture of carbonyls and acrolein alone induced each of the four genes
In summary, although we suggested that carbonyls are one component of cigarette smoke associated with the gene expression, they were only part of the effects of cigarette smoke. Furthermore, as there were differences in the contribution of PP and GVP in regards to the expression of each gene, it suggests the presence of the specific components that contribute to the expression of each gene.