MiR-30c facilitates natural killer cell cytotoxicity to lung cancer through targeting GALNT7.

BACKGROUND

MicroRNAs (miRNAs) have been reported to play important roles in regulating natural killer (NK) cell cytotoxicity to cancer cells.

OBJECTIVE

This study aimed to investigate the effects and potential mechanism of miR-30c in regulating NK cell cytotoxicity to lung cancer cells.

METHODS

Primary NK cells were derived from the peripheral blood of lung cancer and normal participants. Exosomes were isolated and validated via transmission electron microscopy and nanoparticle tracking analysis. The levels of miR-30c, polypeptide N-acetylgalactosaminyltransferase 7 (GALNT7) and proteins in PI3K/AKT pathway were determined using quantitative real-time polymerase chain reaction or western blot. Tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) levels and the cytotoxicity of effector NK cells to target lung cancer cells were measured via enzyme linked immunosorbent assay, cell apoptosis or xenograft experiments. The relationship between miR-30c and GALNT7 was analyzed by luciferase activity, RNA pull-down and RNA immunoprecipitation assays. And a xenograft mice model was established to verify the effect of miR-30c in regulating NK cell cytotoxicity to lung cancer cells in vivo.

RESULTS

NK cell-derived exosomes carrying miR-30c, and miR-30c level was significantly downregulated in primary NK cells of lung cancer patients. MiR-30c overexpression promoted TNF-α and IFN-γ secretion and enhanced the cytotoxicity of interleukin 2 (IL-2)-treated NK cells to lung cancer cells, while knockdown of miR-30c played an opposite effect in regulating the cytotoxicity of NK cells to lung cancer cells. GALNT7 was a target of miR-30c and was negatively regulated by miR-30c. Besides, miR-30c targeted GALNT7 to exert its function in regulating NK cell cytotoxicity. Furthermore, GALNT7 prompted the activation of PI3K/AKT pathway in NK cells. Additionally, miR-30c overexpression enhanced NK cell cytotoxicity to lung cancer cells and inhibited tumor growth in vivo.

CONCLUSION

miR-30c enhanced NK cell cytotoxicity to lung cancer cells via decreasing GALNT7 and inactivating the PI3K/AKT pathway, suggesting that regulating miR-30c expression maybe a promising approach for enhancing NK cell-based antitumor therapies.