In search of underlying stress mechanisms using RNAi and gene expression profiling

Abstract
In recent years, much progress has been made in the characterization of cellular parameters during heavy metal stress. However, a better understanding of underlying molecular mechanisms is highly necessary, especially concerning their carcinogenic effects. As innovative model organisms in stem cell research, and their experimental ease to perform RNAi screening, the flatworm species Schmidtea mediterranea and Macrostomum lignano were used to investigate cellular processes after exposure to the carcinogenic metal cadmium. The underlying mechanisms of these effects involve oxidative stress related processes resulting in altered gene expression profiles in function of (stem) cell proliferation. As heat shock proteins (HSP) appeared to play a significant role herein, they were subsequently knocked down using RNAi. Both RNAi experiments as well as gene expression profiling are highlighted in this study, and an overview of activated stress mechanisms and their interactions is given.