Apatinib combined with Keytruda treatment induces apoptosis of gastric carcinoma cells through CES4/miR-616-5p/DUSP2 axis

Gastric carcinoma (GC) is a highly malignant and heterogeneous tumour. Long non-coding RNA CES4 is down-regulated in GC. However, whether CES4 can participate in GC remains unclear; we have carried out research on this topic. GC cells (HGC-27 and MKN-7) were treated with anti-tumour drugs: apatinib combined with Keytruda. Cell viability and apoptosis were detected by CCK-8 assay and flow cytometry. Gene and protein expression were examined by quantitative real-time PCR and western blot. Luciferase reporter assay was performed to verify the relationship among CES4, miR-616-5p and dual-specificity phosphatase-2 (DUSP2). CES4 was highly expressed in the apatinib combined with Keytruda-treated HGC-27 and MKN-7 cells. Apatinib combined with Keytruda treatment repressed cell viability and promoted apoptosis of HGC-27 and MKN-7 cells, which was abrogated by CES4 knockdown. Furthermore, CES4 promoted DUSP2 expression by sponging miR-616-5p in HGC-27 and MKN-7 cells. CES4 knockdown promoted cell viability and inhibited apoptosis of drug-treated HGC-27 and MKN-7 cells by regulating miR-616-5p/DUSP2 axis. In conclusion, these data demonstrate that apatinib combined with Keytruda treatment induces apoptosis of GC cells through CES4/miR-616-5p/DUSP2 axis. Thus, this work provides the experimental basis for the combination of apatinib and Keytruda as a treatment for GC.