Fig. 1

A map of folate-mediated 1C metabolism and expression of MTHFD2 in lung cancer tissues and EGF-stimulated cells. a Folate-mediated 1C metabolism. The reaction catalyzed by MTHFD2 is depicted with purple arrows. Major amino acids and enzymes involved in 1C metabolism are written in blue and black characters in boxes, respectively. MTX methotrexate. b Time-dependent MTHFD2 mRNA levels in SAECs stimulated with or without EGF (100 ng/ml) in the presence or absence of gefitinib (1 μM) were measured by quantitative RT-PCR. The data are represented as mean ± SD, N = 3. c MTHFD2 mRNA levels in H322 cells treated with or without EGF (100 ng/ml) for 8 h were measured by quantitative RT-PCR. Experiments were performed three times and the representative results were presented. The data are represented as mean ± SD, N = 3. Statistical significance is calculated with a two-tailed unpaired t-test; **p < 0.01. d Western blot for MTHFD2 in lung cancer cell lines and normal lung epithelial cells (SAECs). β-Actin was used as loading control