Differences in AR, ERα and EGFR, PI3k, AKT protein expression levels after gene silencing and sex hormones intervention in A549 cells
After Small interfering RNA (siRNA) specifically targeting AR and ERα in A549 cells for 48 h, according to the western blotting analysis, AR and ERα protein expression levels were significantly knocked down (Fig.1 A, B). We then examined the protein expression of EGFR and its downstream PI3K/AKT axis and found that the EGFR, PI3K, AKT protein expression levels were down-regulated (Fig.1 A, B). After testosterone (T) and estradiol (E2) at concentrations of 0, 10, 50 and 100μM interfered with A549 cells for 48 hours, according to the western blotting analysis, we found that 10μM T and 10μM E2 interventions could up-regulate AR and ERα expression and increase protein expression on EGFR/PI3K/AKT axis, while 50μM T and 50μM E2 interventions inhibited the expression of AR and ERα and inhibited the expression of EGFR/PI3K/AKT axis compared to the Control group. However, compared with the 50μM T and 50μM E2 groups, 100μM concentration of T and E2 intervention increased the expression of AR and ERα again, and correspondingly increased the expression of EGFR/PI3K/AKT axis (Fig.1 C, D).
Difference in AR, ERα and EGFR, PI3k, AKT mRNA expression levels after gene silencing and sex hormones intervention in A549 cells
Total RNA was extracted from cells, and the relative AR, ERα and EGFR, PI3k, AKT mRNA expression levels were shown in Fig.2. After gene silencing in A549 cells for 48 h, compared with the control group, Lipo group and NC-siRNA group respectively, AR and ERα mRNA expression levels in the AR-siRNA group and ERα-siRNA group were significantly knocked down [AR: (0.96 ± 0.03),(0.99 ± 0.02),(1.02 ± 0.03) vs (0.08 ± 0.01) and ERα: (1.07 ± 0.06),(1.01 ± 0.04),(1.05 ± 0.07) vs (0.14 ± 0.02); P<0.001; Fig.2 A,B]. In addition, the expression levels of EGFR, PI3k, and AKT in the AR-siRNA group and the ERα-siRNA group were significantly lower than those in control, Lipo, and NC-siRNA groupS[EGFR: (0.42 ± 0.04) vs (1.03 ± 0.02), (0.98 ± 0.04), (1.01 ± 0.02); PI3k: (0.27 ± 0.02) vs (1.01 ± 0.01), (1.04 ± 0.04), (1.08 ± 0.02); AKT: (0.38 ± 0.06) vs (1.01 ± 0.02), (1.07 ± 0.04), (1.04 ± 0.04);P<0.001,Fig.2 A and EGFR: (0.39 ± 0.05) vs (1.05 ± 0.07), (0.98 ± 0.04), (0.96 ± 0.06); PI3k: (0.31 ± 0.02) vs (1.09 ± 0.09), (1.04 ± 0.02), (0.96 ± 0.02); AKT: (0.34 ± 0.05) vs (1.08 ± 0.07), (0.99 ± 0.04), (0.96 ± 0.03); P<0.001,Fig2 B].
After sex hormones intervened in A549 cells for 48 h, compared with the control group, 10 µM T and 10μM E2 groups could promote the expression levels of AR and ERα[(1.05 ± 0.05) vs (1.32 ± 0.05), P<0.01, Fig.2 C ; (1.06 ± 0.04) vs (1.18 ± 0.04), P<0.05, Fig.2 D], while 50μM T and 50μM E2 groups inhibited the expression levels of AR and ERα [(1.05 ± 0.05) vs (0.31 ± 0.04), P<0.001, Fig.2 C ; (1.06 ± 0.04) vs (0.34 ± 0.05), P<0.001, Fig2 D]. When the concentrations of T and E2 increased to 100μM, the expression levels of AR and ERα were enhanced again compared to 50μM T and 50μM E2 groups[(0.67 ± 0.02) vs (0.31 ± 0.04), P<0.001, Fig.2 C; (0.87 ± 0.03) vs (0.34 ± 0.05), P<0.001, Fig.2 D ]. Changes in expression levels of EGFR, PI3k, and AKT are consistent with changes in AR and ERα expression levels (Fig.2 C, D).
Changes of cell proliferation and apoptosis after gene silencing and sex hormones intervention in A549 cells
After knocked down of AR and ERα expression, proliferation of A549 cells was inhibited compared with control, Lipo, and NC groups[(0.99 ± 0.05) vs (1.55 ± 0.01), (1.52 ± 0.02), (1.51 ± 0.02), P<0.001; (1.05 ± 0.03) vs (1.53 ± 0.02), (1.53 ± 0.01), (1.51± 0.05), P<0.001; Fig.3 A]. After sex hormones intervened in A549 cells for 48 h, compared with the control group, 10μM T and 10μM E2 groups promoted cell proliferation[(1.66 ± 0.03) vs (1.36 ± 0.01), P<0.001; (1.63 ± 0.04) vs (1.44 ± 0.03), P<0.01; Fig.3 B], while 50μM T and 50μM E2 groups inhibited cell proliferation[(0.67 ± 0.04) vs (1.36 ± 0.01), P<0.001; (0.70 ± 0.02) vs (1.44 ± 0.03), P<0.01; Fig.3 B]. When the concentrations of T and E2 increased to 100μM, the proliferation of A549 cells was enhanced compared to 50μM T and 50μM E2 groups[(1.01 ± 0.04) vs (0.67 ± 0.04), P<0.01; (1.06 0.04) vs (0.70 ± 0.02), P<0.001; Fig.3 B].
Compared with Control group, Lipo group and NC group, knocked down of AR and ERa expression increased the apoptosis of A549 cells[(42.11 ± 1.26) vs (5.52 ± 0.22),(5.96 ± 0.65),(6.06 ± 0.54), P<0.001; (39.92 ± 0.62) vs (5.52 ± 0.22),(5.96 ± 0.65),(6.06 ± 0.54), P<0.001; Fig.3 C]. In the sex hormone intervention experiment, 10μM T and 10μM E2 intervention groups showed decreased apoptosis of A549 cells compared to the control group[(1.58 ± 0.30) vs (5.52 ± 0.22), P<0.01; (3.27 ± 0.24) vs (5.52 ± 0.22), P<0.05; Fig.3 C]. While 50μM T and 50μM E2 intervention groups promoted apoptosis of A549 cells compared with the control group[(36.41 ± 1.79) vs (5.52 ± 0.22), P<0.001; (37.46 ± 1.04) vs (5.52 ± 0.22), P<0.001; Fig.3 C]. When the concentrations of T and E2 increased to 100μM, the apoptosis of A549 cells also showed decreased compared to 50μM T and 50μM E2 groups[(8.79 ± 0.61) vs (36.41 ± 1.79) , P<0.001; (9.46 ± 0.5) vs (37.46 ± 1.04), P<0.001; Fig.3 C].
Changes of cell migration and invasion after gene silencing and sex hormone intervention in A549 cells
Knocked down of AR and ERα expression result in the poor migration and invasion compared to control, Lipo, and NC groups (Fig.4 A, B; P<0.001). In the sex hormone intervention experiments, compared with the control group, 10 μM T and 10 μM E2 intervention might promote cell migration and invasion, while 50 μM T and 50 μM E2 intervention inhibited cell migration and invasion (Fig.4 A,B; (Fig.4 A, B; P<0.05, P<0.001). When the concentrations of T and E2 increased to 100 μM, the migration and invasion of the cells were enhanced compared with the concentration of 50 μM (Fig.4 A, B; P<0.001).