Figure 2. High ERBB2 expression and low STING expression were observed in AR cells. (A) Cell proliferation after treatment with apatinib for different times, as assessed using an MTT assay (*P < 0.05, **P < 0.01). The successful establishment of AR HN30 cells was demonstrated by their insensitivity to apatinib. Colony formation of AR cells was enhanced compared with that of the control. (B) Venn diagram of predicted up or downregulated mRNAs for AR cells compared with PC controls. A total of 198 downregulated and 277 upregulated mRNAs were obtained for differential analysis. STING and ERBB2 were identified as having the highest fold change. (C) A correlation was determined among VEGFR2, ERBB2, and STING using TIMER correlation analysis (http://timer.cistrome.org/). (D) AR and PC cells were treated with apatinib (20 μM) for 24 hours. Then, qRT-PCR and western blotting were performed to assess expression of ERBB2 and STING in AR and PC cells. *P < 0.05, **P < 0.01, ***P < 0.001 versus the control.