Natural killer (NK) cells have been demonstrated to inhibit
tumor growth. However, the role of NK cells in the inhibition of
hepatocellular carcinoma metastasis is not well understood. The present study aimed to investigate the roles that NK cells may serve in inhibiting
hepatocellular carcinoma metastasis. The role of isolated NK cells in the inhibition, proliferation, migration and invasion of the
hepatoma cell line, MHCC97-H, was examined in vitro. Additionally, the survival rate of NK cells labeled with
carboxyfluorescein diacetate-succinimidyl ester was assessed in vivo. An orthotopic implantation model was used to evaluate the role of NK cells in suppressing MHCC97-H cells in vivo. The effect of
interleukin (IL)-2 stimulation on the
tumor-inhibitory role of the NK cells was measured indirectly by analyzing the expression of various
NK cell receptors and activated NK cell markers. It was observed that the NK cells inhibited the proliferation, migration and invasion of the MHCC97-H cells in vitro. Furthermore, the NK cells demonstrated long-term survival in the livers of the nude mice, and inhibited lung
metastasis of
hepatocellular carcinoma in vivo. However, liver
tumor growth was not inhibited by the NK cells.
IL-2 was identified to enhance the
tumor-inhibitory effect of NK cells. The present study concludes that
IL-2 may enhance the antitumor activity of the NK cells, and thereby inhibit the
metastases of
hepatocellular carcinoma in mice.