Fig. 1.

CPT1A is indispensable for tumor progression and LCSCs maintenance in lung cancer. a–c Relevance of CPT1A expression with the tumor progression in NSCLC patients. Representative IHC staining for CPT1A in the normal or cancerous lung tissues from NSCLC patients (left) and IHC score of CPT1A were depicted on the right. Scale bars, 500 μm (up); 50 μm (down) (insets) (a). Correlation of CPT1A level with the clinical stages of NSCLC patients (b) and overall survival (OS) of NSCLC patients with lung cancer stratified according to the expression of CPT1A in the tumor (c). d–i Effects of Cpt1a on tumor progression in the transgenic mouse. Construction strategy for the transgenic SKC (Sftpc-CreER^T2; Kras^G12D; Cpt1a^flox/flox) mice and the experimental scheme (d). Representative micro-CT image (left) and H&E staining (right) of the lung tissue from SKC or control mice. Scale bars, 2 mm (micro-CT); 1 mm (H&E, left); 5 mm (H&E, right) (insets) (e). Overall survival of SKC or control mice (f). Percentages of distinct types of immune cells (g) and IFNγ⁺ cells gated on CD45⁺ cells in the lung tissues from SKC or control mice (h). Representative images of C11-BODIPY staining in the lung tissue from SKC or control mice. Scale bars, 50 μm (insets) (i). j Spare respiratory capacity in adherent or spheroid cells of LLC-shNC/shCPT1A cells measured by using Seahorse XF Pro analyzer with mitochondrial stress test. Data represent the mean ± s.d.; n = 3-6 samples. k Representative tumor-sphere images of H1299-shNC/shCPT1A cells cultured with sphere-forming medium. Scale bars, 200 μm (insets)；zoomed images (left bottom, 2.5 times amplification). l Percentages of ALDH⁺ cells in H1299-shNC/shCPT1A cells determined by flow cytometry. m, Representative western blot for CPT1A, SOX2, OCT4 and NANOG in adherent, spheroid or shNC/shCPT1A cells of H1299 cells. *P < 0.05, **P < 0.01, ***P < 0.001; ns: not significant. The statistical analysis was performed using a two-tailed Student’s t-test or Pearson’s correlation test