Tumor tissue
The snap-frozen liver and kidney tissues were lyophilized and homogenized into powder. Approximately 10 mg of homogenized tissue was transferred to a 2 mL Eppendorf tube, and 400 µL of methanol was added. The mixture was then sonicated for 2 min and 1 mL of MTBE (methyl tert-butyl ether) was added followed by 1 h of shaking in a shaking water bath at room temperature. Separation was induced by the addition of 250 µL of water followed by room temperature incubation for 10 min. After 15 min of centrifugation at 14,000 rpm at 4 °C, the supernatant was separated (upper organic layer and lower polar layer). For the metabolomics study, 200 µL of supernatant was taken and evaporated to dryness under a nitrogen stream at 37 °C. The dried residue was then reconstituted in 100 µL of 80% methanol, and 50 µL was loaded into the UHPLC-Orbitrap-MS system for analysis. For the tissue lipidomics study, the same volume of supernatant was taken, processed following the same method and finally reconstituted in 100 µL of chloroform/methanol (2:1). In order to normalize tissue metabolomics and lipidomics data, the protein concentration of each sample was quantified. Each sample was diluted with distilled water, and the protein concentration was measured by Nano-MD (SINCO, Korea) using 10 µL of sample. For both the tissue metabolomics and lipidomics analyses, QC samples were made by taking identical volumes from each sample and running the samples following a sequence similar to that of plasma analysis.