miR-21 is mTOR-dependent and may be TSC2-independent.

<p><b>A</b>) Stable downregulation of tuberin in C3H-10T1/2 pre-pericytes results in increased phosphorylation of ribosomal protein S6, as expected. Treatment with Rapamycin (20 nM, 24 h) inhibits phosphorylation of S6. <b>B</b>) Downregulation of TSC2 in C3H-10T1/2 cells does not affect miR-21 expression. Inhibition of mTORC1 with Rapamycin induces ∼2-fold increase in miR-21 expression in both control shRNA and TSC2 shRNA cells. Bars represent the mean of two biologic replicates +/− SD. * p<0.05. <b>C</b>) LAM patient-derived cells (621-101), TSC2-null rat uterine leiomyoma-derived cells (ELT3), TSC2-null mouse embryonic fibroblasts (MEFs), HEK293 and lung adenocarcinoma (A549) cells were treated with Rapamycin 20 nM vs Control for 24 h. Relative MiR-21 expression was determined by qRT-PCR. Human cells were normalized to RNU44, mouse cells to snora202 and rat cells to U87, which are all small nucleolar RNA molecules. For all charts, bars represent the mean of three biologic replicates +/− standard error. * p<0.05. ** p<0.01.