The inhibitory effect of PS on: A, p-Raf/p-MEK/p-ERK; B, p-ErbB3 and p-PI3K/p-Akt/p-PS6K/p-4E-PB-1; and C, p-mTOR (S2481 and S2448)/Rictor/Raptor expression in A549 cells (1.5xIC50) in vitro. Densitometry results are shown as numbers (italics) below the immunoblots. D, PS increased conversion of LC3-I to LC3-II as indicated by the increased LC3-II/LC3-I ratios (italics). E, Inhalation PS treatment significantly reduced phosphorylation of signaling components of Raf/MEK/ERK and PI3K/Akt pathways in orthotopic A549 tumors. F, Inhalation PS treatment significantly induced autophagy in the orthotopic tumors as indicated by the increased LC3-II/LC3-I ratios and reduced expression of p-mTOR. *p<0.05.