siRNA inhibits esophageal squamous cell carcinoma cell lines growth via NF-κB signaling pathway

摘要

More and more evidences have shown that the activation of nuclear transcription factor (NF)-kappaB/Rel plays a critical role in the initiation and progression of carcinogenesis. In the present study, NF-κB pathway, in the two ESCC cell lines Eca109 and EC9706, and one control cell line HeLa229, was respectively investigated with immunocytochemistry, Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR). RNA interference (RNAi) was employed to specific inhibition the expression of p65. Cell growths were evaluated by 3-(4,5-Dimethylthiazol-2-y)-2,5-diphenyltetrazolium bromide (MTT). Immunocytochemical and Western blot analysis showed that p50 and p65, IκBα and p-IκBα were mainly expressed and localized in the cytoplasm. RT-PCR displayed constitutively expressed NF-κB p50, p65 and IκBα mRNA in the two ESCC cell lines. Finally, p65 siRNA decreased the expression of p65 and compared to the untransfected cells, viability of the two ESCC cells was significantly suppressed at the same concentration of 5-FU (P < 0.05). The results of the present study showed that there was the constitutively activated NF-κB signaling pathway in the ESCC cell lines, in which the gene overexpression of p50, p65 and IκBα or the phosphorylation and degradation of IκBα may be the main cause to maintain the activity of NF-κB. Thus, RNAi targeting p65 increased the sensitivity to 5-FU, suggesting that NF-κB might be a good target for cancer treatment.