Atorvastatin suppresses KRAS^G12D-induced lung myeloid pathology. (A) Effects of in vitro atorvastatin treatment on BrdU incorporation in CD45⁺ cells developing in AdCre/KRAS^G12D whole-lung cell cultures. Mixed-lineage cultures established from whole-lung cells during the first week were treated for 96 hours with dimethyl sulfoxide (DMSO) or 3.3 μM atorvastatin (statin) in serum-free media, and labeled with BrdU for 18 hours. BrdU incorporation in developed CD45⁺ cells was measured by flow cytometry. Representative contour plots are indicated on the left, and the percentage of BrdU⁺ in the CD45⁺ cells is summarized in the right bar graph (n = 3, mean + SD). (B) Effects of in vitro atorvastatin treatment on CD11c and F4/80 expression on CD45⁺ cells developing in AdCre/KRAS^G12D whole-lung cell cultures. Cells developed and treated as in panel A were analyzed by flow cytometry. Representative contour plots are indicated in the top, and mean fluorescence intensity (MFI) values of CD11c and F4/80 staining are summarized in the bottom bar graph (n = 3, mean + SD). (C) Immunoblot analysis of ERK/AKT phosphorylation and PARP-1 cleavage in AdCre/KRAS^G12D lung-derived CD11c⁺ cells treated with atorvastatin. Freshly harvested/enriched CD11c⁺ cells were cultured for 24 hours with 3.3 μM atorvastatin or DMSO in serum-free media for protein harvest. (D) H&E staining of lung sections from AdCre/KRAS^WT and AdCre KRAS^G12D mice treated with either vehicle or atorvastatin (10 mg/kg, daily for 5 weeks). Scale bar, 0.5 mm. (E) Lung hematopoietic-lineage cell numbers were quantitated in AdCre/KRAS^G12D mice treated with vehicle or atorvastatin (G12D vehicle/statin, n = 5 each), and control AdCre/KRAS^WT mice were similarly treated (WT vehicle/statin, n = 2 each). The bar graph summarizes each hematopoietic-lineage cell number per left lobe (mean + SD), and P values by Student t test between G12D vehicle/statin mice are indicated. Representative contour plots for CD11c-F4/80 staining of whole-lung cells obtained from G12D vehicle/statin mice are indicated on the right. FSC, forward scatter; NS, not significant; p-AKT, phosphorylated AKT; p-ERK, phosphorylated ERK.