Rapamycin effect on Wild Type and TSC deficient Mouse Embryonic Fibroblasts : Time Course

Aberrant activation of the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) is a common molecular event in a large variety of pathological settings, including genetic tumor syndromes, cancer, and obesity. However, the cell intrinsic consequences of mTORC1 activation remain poorly defined. Here, we identify global trancriptional changes in TSC1 and TSC2 null MEFs, which exhibit constitutive activation of mTORC1, compared to wild-type littermate control lines. A rapamycin time course is included to determine those changes that are dependent on mTORC1 signaling, revealing mTORC1 induced and repressed transcripts. In order to identify mTORC1-dependent transcriptional changes, we compared wild-type MEFs to both Tsc1-/- and Tsc2-/- MEFs following serum starvation, where mTORC1 signaling is off in wild-type cells and fully active in TSC-deficient cells. All cell lines were serum-starved for 24 h, and the Tsc1-/- and Tsc2-/- cells were treated with a time course of rapamycin prior to the isolation of mRNA for microarray analysis.