Fig. 5
mTOR and MEK inhibition significantly blocks hepatocarcinogenesis and lung metastasis triggered by Fbxl6 elevation and Kras mutation. a Nude mice bearing KLC orthotopic HCC tumors were randomized into three groups: the negative control (NC) group, everolimus (E) group and everolimus combined with trametinib (E + T) group. The NC group was treated with vehicle, the E group was treated with everolimus (diluted in DMSO and coil oil, 4 mg/kg, intraperitoneal injection) twice per week for six rounds, and the E + T group was treated with both everolimus (the everolimus dose was as in the E group) and trametinib (diluted in DMSO and coil oil, 0.5 mg/kg, intraperitoneal injection) twice per week for six rounds. The mice were sacrificed after the last injection, and representative images showing tumorigenesis are presented. n = 7. b Tumor weight, the tumor/liver weight ratio, and tumor volume were analyzed (n = 7). c Representative images showing the effect of mTOR and MEK/ERK inhibitors on lung metastases. The lung metastasis rate (d) and number of lung distant lung metastatic foci (e) were quantified. f Representative HE and IHC staining images for lipase C (LIPC) showing distinct lung metastatic foci expressing LIPC. Scale bars = 200 or 50 μm. g Representative images of HE and IHC staining for Prelid2, p-mTOR, p-4EBP1, and p-ERK in the NC, E and E + T groups. Representative consecutive IHC staining images are presented. Scale bars = 200 or 50 μm. One-way ANOVA with Tukey’s multiple comparisons test was used in (b, e). *P < 0.05; **P < 0.01; ***P < 0.001. KLC LSL-KrasG12D/+;LSL-Fbxl6KI/+;Alb-Cre, mTOR mammalian target of rapamycin, MEK mitogen-activated protein kinase kinase, Fbxl6 F-box and leucine-rich repeat 6, Kras kirsten rat sarcoma, NC negative control, E everolimus, T trametinib, DMSO dimethyl sulfoxide, ERK extracellular signal-regulated kinase, IHC immunohistochemistry