Silencing of nuclear factor kappa b 1 gene expression inhibits colony formation, cell migration and invasion via the downregulation of interleukin 1 beta and matrix metallopeptidase 9 in renal cell carcinoma

Abstract

Renal cell carcinoma (RCC) is a highly deadly urological tumor due to its high metastatic incidence and its notorious chemoresistance. The nuclear transcription factor kappa B (NF-κB) family has been associated with apoptosis resistance and cellular invasion in RCC. The purpose of this study was to evaluate the impact of NF-κB1 gene silencing on the colony formation, cell migration and invasion abilities of the RCC cell line. Renca-mock and Renca-shRNA-NF-κB1 cells were used in this work. NF-κB1 downregulation was assessed by western blotting. The mRNA expression levels of interleukin-1 beta (IL-1β) and MMP-9 were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). The IL-1β levels in the culture media were determined by a commercial ELISA kit. The MMP-9 protein expression and gelatinolytic activity were evaluated by western blotting and zymography, respectively, and the migration and invasion abilities were analysed. The expression levels of p105 and p50 in Renca-shRNA-NF-κBmoc1 cells were significantly reduced compared with those in the Renca-mock cells. The colony numbers of shRNA-NF-кB1 cells were lower than the colony numbers of the Renca-mock cells. NF-κB1 knockdown inhibited the cell migration and invasion of Renca-shRNA-NF-κB1 cells. These cells also exhibited reduced levels of IL-1β. The MMP-9 expression and activity levels were significantly reduced in Renca-shRNA-NF-κB1 cells. Taken together, these results indicate that the downregulation of NF-κB1 suppresses the tumourigenicity of RCC by reducing MMP-9 expression and activity; thus, NF-κB1 could be a molecular target for RCC treatment.

Keywords: Colony formation; IL-1β; Invasion; MMP-9; Migration; NF-κB1; Renal cell carcinoma; shRNA.