Fig. 6: Targeting PCK/CPT1A axis slows down tumor growth of 18F-FDG-PET/CT-negative gastric cancer.

A Analysis of the Effects of PCK2 and CPT1A on Cell Proliferation. Cell proliferation curves of MKN-45 and MKN-1 cell lines treated with 3-MPA (alone or in combination with ETO) were demonstrated. Data are presented as mean ± SD (n = 3). Statistical analysis was performed using two-way ANOVA: ^****P < 0.0001; ns, not significant. B–D Assay for Tumor Formation. MKN-45 and MKN-1 cell lines were injected into athymic nude mice. The mice were intraperitoneally injected with PBS (10 mg/kg), 3-MPA (5 mg/kg), ETO (10 mg/kg), or a combination of 3-MPA and ETO every other day. After 22 days, the xenograft tumors were excised, and representative images are shown (B). Tumor volume (C) and mass (D) were quantified. Data are presented as mean ± SD (n = 5). Statistical analysis was performed using two-way ANOVA: ^**P < 0.01; ^***P < 0.001; ^****P < 0.0001; ns, not significant. E Immunohistochemistry (IHC) Analysis of Cell Proliferation. Five pairs of mice injected with MKN-45 and MKN-1 cell lines were co-stained with Ki-67. Representative images of tumor tissues are shown (scale bars, 50 μm) (left panel), and the quantification of Ki-67 staining is presented (right panel). Data are presented as mean ± SD (n = 5). Statistical analysis was performed using two-way ANOVA: ^*P < 0.05; ^****P < 0.0001; ns, not significant. F, H Establishment and characterization of patient-derived xenograft (PDX) models of gastric cancer. Fresh tumor tissue from a gastric cancer patient was surgically implanted into the subcutaneous pocket of an immunodeficient mouse. Upon day 14, the mice were intraperitoneally injected with PBS (10 mg/kg), 3-MPA (5 mg/kg), ETO (10 mg/kg), or a combination of 3-MPA and ETO every other day. After 14 days, the xenograft tumors were excised, and representative images are shown (F). Tumor volume (G) and mass (H) were quantified. Data are presented as mean ± SD (n = 3). Statistical analysis was performed using two-way ANOVA: ^****P < 0.0001; ns, not significant. I Immunohistochemistry (IHC) Analysis of Cell Proliferation. The mice injected with gastric cancer tissues were co-stained with Ki-67. Representative images of tumor tissues are shown (scale bars, 50 μm) (left panel), and the quantification of Ki-67 staining is presented (right panel). Data is presented as mean ± SD (three fields from each analyzed mouse). Statistical analysis was performed using two-way ANOVA: ^****P < 0.0001; ns, not significant.