Gene expression profiling of PPARα has been used in several
studies, but fewer studies went further to identify the
tissue-specific pathways or genes involved in PPARα activation
in genome-wide. Here, we employed and applied gene set enrichment
analysis to two microarray datasets both PPARα related
respectively in mouse liver and intestine. We suggested that the
regulatory mechanism of PPARα activation by WY14643 in mouse
small intestine is more complicated than in liver due to more involved
pathways. Several pathways were cancer-related such as pancreatic
cancer and small cell lung cancer, which indicated that PPARα
may have an important role in prevention of cancer development. 12
PPARα dependent pathways and 4 PPARα independent
pathways were identified highly common in both liver and intestine of
mice. Most of them were metabolism related, such as fatty acid
metabolism, tryptophan metabolism, pyruvate metabolism with regard to
PPARα regulation but gluconeogenesis and propanoate metabolism
independent of PPARα regulation. Keratan sulfate biosynthesis,
the pathway of regulation of actin cytoskeleton, the pathways
associated with prostate cancer and small cell lung cancer were not
identified as hepatic PPARα independent but as WY14643
dependent ones in intestinal study. We also provided some novel
hepatic tissue-specific marker genes