The compound AST-003 could effectively promote apoptosis of renal cell carcinoma cells in vitro

The toxicity of Sunitinib limits its clinical application. A new compound AST-003 was designed and synthesized based on the structure of Sunitinib, and previous study has confirmed that AST-003 has the same efficacy and less toxicity as Sunitinib. We conducted this study to further verify the effect of AST-003 on renal cell carcinoma (RCC) cells in vitro and its mechanism.Five RCC cell lines, A498, 786-0, SW-13, Caki-1 and ACHN, were used. Cells were treated with different concentrations of AST-003, and the effect of AST-003 on cell viability was detected by MTT assay and IC50 was determined. Blank control group and AST-003 group were set to evaluate the effect of AST-003 on cell apoptosis and cell cycle. The effect of AST-003 on cell protein expression was detected by western blot.After treatment with AST-003, the viability of the above five RCC cells was significantly inhibited. The IC50 of AST-003 on A498, 786-0, SW-13, Caki-1 and ACHN were 7.396, 6.592, 3.803, 12.05 and 3.422 µmol/L, respectively. Compared with the blank control group, the apoptotic rates were 52.37% and 13.34% in A498 cells (P<0.001), 59.23% and 6.66% in 786-0 cells (P<0.001), 45.67% and 4.19% in SW13 cells (P<0.001), 51.67% and 2.33% in Caki-1 cells (P<0.001), 55.40% and 5.50% in ACHN cells (P<0.001). Flow cytometry revealed that the proportion of cells in G0/G1 phase was significantly increased and the proportion of cells in S phase was significantly decreased in AST-003 group compared with blank control group, suggesting that AST-003 could block cells in G0/G1 phase. Western blot indicated that AST-003 could induce the up-regulation of the protein expression levels of apoptotic genes Caspase3, Caspase8, Caspase9, Bax and tumor suppressor p53, and inhibit the phosphorylation of STAT3, mTOR, AMPK and ERK, as well as the expression of Bcl-2, MKK, MKKK, c-jun and Ras proteins.We found that AST-003 could effectively promote the apoptosis of RCC cells in vitro and block the cells in the intercellular phase, and its mechanism was similar to that of Sunitinib, suggesting that AST-003 has the value for further research.