Amino acid response by Halofuginone in Cancer cells triggers autophagy through proteasome degradation of mTOR

Halofuginone induces the amino acid starvation response (AAR) pathway. Thyroid cancer WRO cells, breast cancer MCF-7 cells, and ovarian cancer OAW-42 cells were exposed to 100？nM halofuginone (HF) for 4, 8 and 24？h. Total and phosphorylated (Ser 51) eIF2α protein levels were assessed by immunoblotting. As loading control, filters were stripped and probed with anti β-Tubulin as loading control. Representative immunoblots from three independent experiments are shown along with P-eIF2α/eIF2α band intensity ratios as index of AA