Abstract
UVB is a well-known environmental carcinogen, triggering cell cycle arrest and regulating metabolic activities. To investigate the transcriptional time course responses to UVB radiation, we performed loop-designed cDNA microarray experiments with D-optimal Algorithm analysis to evaluate the relative gene expressions of normal human fibroblasts. Functional classification implied the regulation of suggested biological responses to UVB radiation at the cellular level. The suggested biological responses revealed that transcriptional and translational activities were regulated without bias to activation or repression, inflammatory responses were induced, transient cell cycle arrest occurred in early stage, DNA replication was gradually elevated, and energy production was promoted. In general, common gene regulations altered by UVB were obviously shown in this study. Interestingly, our data showed that cells irradiated by UVB exhibited prolonged transcriptional activation of mitochondrial respiratory chain. The increase of ratio of relative mitochondrail activity also manifested that relative mitochondrial activity was induced by UVB irradiation. Here, our data demonstrates that UVB provokes the prolonged transcriptional activation of mitochondrial respiratory chain.