Lactate measurement

The metabolic behavior of the cells under the different treatment conditions was determined by analyzing extracellular lactate. The 786-O cells and HUVECs were plated in 24-well transwell plates in the manner as described above and cultured for 96 h. Lactate was quantified using the l-Lactic Acid (l-Lactate) Assay Kit (Megazyme, Ireland) following the manufacturer’s instructions. Briefly, samples were collected after centrifugation of the culture medium. The lactic acid concentration calibration reagent was added to the supernatant samples, and samples were incubated for 5 min at 37 °C. The OD values at 340 nm were obtained from a plate reader and the concentration of lactate was calculated following the formula specified in the manual.