Fig. 1

Overview of profiling free amino acids in cells. a Treatment of inhibitors to cells. The three types of isogenic MCF-10A cells including WT, K-Ras, and K-Ras/PI3K were treated for 24 or 48 h with three different kinase inhibitors: multiple kinase inhibitor (REGO), PI3K inhibitor (PI3K-i), and MEK inhibitor (MEK-i). Non-treated (NT) cells were used as controls. b Quantification of amino aicd levels. The IFAAs were extracted, chemically labeled, and separated to generate the amino acid profile in triplicate for 24 different conditions. The qunatified AA levels from each profile were represented into a 19-by-1 vector for the subsequent analysis. Note that unassigned peaks in an HPLC chromatogram were marked with *