Echinococcus granulosus protoscoleces promotes proliferation and invasion of hepatocellular carcinoma cells

There may exist a connection between Echinococcus granulosus infection and cancer development. Here, it is aimed to investigate specific effects of E. granulosus protoscoleces (PSCs) on the proliferation and invasion capacities of hepatocellular carcinoma (HCC) cells in vitro and ex vitro. HepG2 cells were cultured with different quantities of E. granulosus PSCs in vitro. MTT analysis was used to evaluate effects of E. granulosus PSCs on the proliferation of HepG2 cells. Besides, scratch and transwell assays were respectively used for the detection of HepG2 cells migration and invasion capacities after co-culture with E. granulosus PSCs. Then, HepG2 cells were subcutaneously transplanted into nude mice with or without E. granulosus PSCs. From the 25th day of transplantation, the volume of subcutaneous lesions was measured every four days. At the 37th day, subcutaneous lesions were removed and their weight was evaluated. H&E staining was used for detecting basic pathological changes. HepG2 cells grew well without obvious morphological changes. Proliferation rate and migration capacity of HepG2 cells were higher in the co-culture group than the control group, which was closely associated with quantities of E. granulosus PSCs and co-culture time length. Moreover, HepG2 cells co-cultured with E. granulosus PSCs had stronger invasion ability than the control HepG2 cells. Importantly, there existed significant differences in the volume and weight of subcutaneous lesions after transplanting HepG2 cells with E. granulosus PSCs than the control group. HepG2 cells were also more pathologically heterogeneous in morphology after transplantation with E. granulosus PSCs. Thus, E. granulosus PSCs may promote proliferation and invasion of HCC cells.