Amino acid transporter ASCT2 was previously demonstrated to be essential for human hepatoma cell growth and survival, as its silencing via inducible antisense RNA expression results in complete apoptosis within 48 h by a mechanism that transcends its role in amino acid delivery. To gain mechanistic insights into the reliance of cancerous liver cells on ASCT2, the aim of this study was to determine the early consequences of its silencing on growth and survival signaling that presage apoptosis. Induced antisense ASCT2 RNA in SK-Hep1 cells led to >90% suppression of ASCT2 mRNA by 6 h and inhibition of mTOR/Raptor (mTOR complex 1 (mTORC1)) signaling by 8 h, as manifested by diminished S6K1 and 4EBP1 phosphorylation, while protein synthesis rates declined by nearly 50% despite no measurable decreases in the cap-binding protein eIF4G or cellular ribosomal protein content. Depressed mTORC1 signaling occurred prior to detectable reduction in ASCT2 activity, but coincided with a 30% decline in total cellular ASCT2 protein. By 12 h after ASCT2 silencing, further decrements were observed in protein synthesis rates and ASCT2 protein and activity, each by approximately 50%, while signaling from mTOR/Rictor (mTOR complex 2 (mTORC2)) was stimulated as indexed by enhanced phosphorylation of the Akt/PKB kinase on serine 473, and of its pro-apoptotic substrate Bad on serine 136. These results suggest that ASCT2 silencing inhibits mTORC1 signaling to the translational machinery followed by an mTORC2-initiated survival response, establishing a link between amino acid transporter expression and mTOR function.