Fig. 6.

Mutation of serine 314 to alanine in the endogenous GLS gene in A549 cells induces lung cancer differentiation. a Appearance of HBE, parental A549, and A549-GAC (S314A) cells after being cultured in Airway epithelial cell basal medium and RPMI 1640 with 10% FBS medium separately. Scale bars: 100 μm. b The expression of indicated proteins in parental A549 and A549-GAC (S314A) was determined by western blotting using the indicated antibodies. c–e Parental A549 cells and A549-GAC (S314A) mutant cells (1 × 10⁷) were subcutaneously injected into the flanks of nude mice. Four weeks later, tumors were dissected out, photographed (c), and their weights and volumes measured. The p value was calculated by paired t test (d, e). f, g Photomicrographs of hematoxylin-eosin (HE) staining for tumors induced by parental A549 cells (f) and A549-GAC (S314A) cells (g). Magnification of upper figures is ×40, Scale bars: 200 μm. The magnification of lower figures is ×200, Scale bars: 20 μm. h, i Immunohistochemical staining in tumors induced by parental A549 cells and A549-GAC(S314A) cells for Ki67 (h) and TTF1 (i). Magnification is ×200, Scale bars: 50 μm