Fig. 5

ALDOA enhanced H520 cell proliferation and cyclin D1 expression in an epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) pathway-dependent manner. a Cyclin D1 expression was tested by western blotting after treatment with mitogen-activated kinase kinase 1/2 (MEK1/2) inhibitor U0126-EtOH or DMSO control treatment. Cyclin D1 protein was quantified by western blotting. Data are shown as mean ± SD in (b). β-actin was used as loading control. *P < 0.05 versus shNC. c Colony formation assays after MEK1/2 activity blockade with U0126-EtOH. The colony numbers were counted, and the rate of decrease in each group was calculated using the following formula: decrease rate = (colony number of DMSO treatment − colony number of actinomycin D treatment)/colony number of DMSO treatment. The results indicated that rate of decrease in the colony number was higher in the shNC than shAL-1 or shAL-2 group. Data are shown as mean ± SD in (d). *P < 0.05 versus shNC. e Cells were serum-starved for 24 h or supplemented with 50 ng/mL epidermal growth factor (EGF) for 0.5 or 1 h, respectively. Cyclin D1 and relevant proteins that are engaged in the EGFR/MAPK pathway were measured by western blotting. The results showed that cyclin D1 protein was almost the same in the shAL and shNC group cells with EGF treatment for 0.5 h. Data are shown as mean ± SD in (f). β-actin was used as loading control