Effect of down-regulation of nuclear factor NF-κB p65 on protein kinase R to induce cellular proliferation and invasion of cervical cancer HeLa cells

Objective: To investigate the effect of down-regulation of nuclear factor-κB (NF-κB)p65 on protein kinase R (PKR) to induce cellular proliferation and invasion of cervical cancer HeLa cells, and to explore their possible mechanism. Methods: Recombinant plasmid vector which contained short hairpin RNA (shRNA) interfering sequence aiming at the target of NF-κB p65 gene was constructed and transfected into HeLa cells. The expression levels of NF-κB p65 and PKR mRNAs were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay. The expression levels of NF-κB p65, PKR, phospho-PKR (p-PKR) and phospho-eukaryotic initiation factor 2α (p-eIF2α) were detected by Western blotting. The proliferative ability of HeLa cells after NF-κB p65 gene silencing was detected by MTT assay. The invasive ability of HeLa cells after NF-κB p65 gene silencing was detected by Transwell invasion assay. Results: The recombinant plasmid vector pSilencer-NF-κB p65-shRNA was successfully constructed. Based on interfering the expressions of NF-κB p65 mRNA and protein, the relative expressions of PKR mRNA and protein (including p-PKR) of pSilencer-NF-κB p65-shRNA transfection group were significantly higher as compared with those of the pSilencer-negative control (NC)-shRNA transfection group and the blank control group (only transfection reagent was added) (all P < 0.05), and the relative expression of p-eIF2α protein of pSilencer-NF-κB p65-shRNA transfection group was also significantly higher (P < 0.05); but the proliferative and invasive abilities of HeLa cells of pSilencer-NF-κB p65-shRNA transfection group were significantly decreased (both P < 0.05 ). Conclusion:NF-κB p65 can down-regulate the expression and activity of PKR to restrain the activation of PKR/eIF2α signal transduction pathway, and promote the proliferation and invasion of cervical cancer HeLa cells. Therefore, NF-κB p65 may play an important role in the generation and development of cervical cancer. DOI:10.3781/j.issn.1000-7431.2014.07.004