Figure 6.

FASN inhibition attenuates SCLC lipogenesis, self-renewal properties, chemotherapy resistance and USP13-dependent tumorigenesis. (A) Triglyceride (left) and cholesterol (right) levels were measured in H1048 cells treated with the FASN inhibitor TVB-2640 at the indicated doses for 72 hours. DMSO was used as the vehicle control. Data represent the means ± SD of triplicate samples. Two-tailed student’s t-test was used. **p < 0.01, ***p < 0.001. (B) Triglyceride (left) and cholesterol (right) levels were measured in H1048 cells after 50 μM FASN inhibitor TVB-2640 treatment for the indicated periods of time. Data represent the means ± SD of triplicate samples. Two-tailed student’s t-test was used. **p < 0.01, ***p < 0.001. (C, D) Left: ELDA was performed in H1048 (C) and H69 (D) cells with or without FASN inhibitor TVB-2640 treatment at the indicated dose. Representative sphere images (top right) and stemness frequency illustration of the cells with the upper and lower 95% confidence intervals (bottom right) are shown. Scale bars, 50 μm. Data represent the means ± SD of wells. Two-tailed student’s t-test was used. *p < 0.05, **p < 0.01, ***p < 0.001. (E) Nude mice were subcutaneously injected with H69AR cells and intraperitoneally injected with indicated drugs when the size of the tumor reached approximately 100 mm³. Tumor sizes and volumes were measured and calculated (n=5 per group). Data represent the means ± SD of five mice per group. Two-tailed student’s t-test was used. *p < 0.05, **p < 0.01, ***p < 0.001. (F) H1048 cells with or without USP13 depletion, or shUSP13 cells combined with reconstituted expression of WT HA-rUSP13 were subcutaneously injected into nude mice and then with or without TVB-2640 treatment. Tumor sizes and volumes were measured and calculated (n=5 per group). Data represent the means ± SD of five mice per group. Two-tailed student’s t-test was used. ns, not significant. ***p < 0.001.