MicroRNA-374b inhibits liver cancer progression via down regulating programmed cell death-1 expression on cytokine-induced killer cells
- Fen Huang
- Bo Wang
- Jiangzheng Zeng
- Shenggang Sang
- Junhua Lei
- Yanda Lu
Published online on: February 5, 2018
Copyright: © Huang et al.
This is an open access article distributed under the terms of Creative Commons Attribution License.
Programmed cell death‑1 (PD‑1) is an oncogene associated with suppressing proliferation and cytokine production of T cells in the progression of liver cancer. microRNAs (miRs) regulate gene expression via specific binding to the target 3'untranslated region of mRNA. In the present study, miR‑374b was indicated to interact with PD‑1 and affect the tumor‑targeting capacity of cytokine‑induced killer (CIK) cells. miR‑374b inhibitor significantly increased PD‑1 expression in CIK cells. A synthetic small interfering (si)RNA targeting PD‑1 was employed to silence the expression level of PD‑1 in CIK cells. Then, the antitumor effect of siPD‑1 in CIK cells was investigated. In vitro study demonstrated that IFN‑γ secretion and the concentration of lactate dehydrogenase were significantly increased in the PD‑1 knockdown group; however, the viability of HepG2 cells in the PD‑1 knockdown group had significantly decreased, compared with the HepG2 cells in the negative control group. In vivo study indicated that mice inoculated with HepG2 cells and CIK cells with PD‑1 knocked down had a significantly smaller tumor volume, compared with the control group. To conclude, human CIK cells transfected with siPD‑1 can target liver cancer cells and enhance immunotherapy efficacy, and therefore they have potential in the immunotherapy of liver cancer.