ObjectiveTo investigate the effect of X-linked inhibitor of apoptosis protein(XIAP) gene on the tumor necrosis factor-α(TNF-α)-induced apoptosis, and expression of vascular endothelial growth factor(VEGF) and cyclooxygenase-2(COX-2) in nasopharyngeal carcinoma cells.
MethodsHuman nasopharyngeal carcinoma 5-8F cells were divided into blank group, TNF-α group(cells treated with 10 ng/mL exogenous TNF-α for 12 h), si-XIAP group(cells transfected with si-XIAP for 48 h) and TNF-α+si-XIAP(cells transfected with si-XIAP for 48 h, then treated with 10 ng/mL exogenous TNF-α for 12 h).Western blotting was used to detect the protein expression of XIAP, VEGF, COX-2, Cleaved caspase3, Bax, NF-κB p65 and Ikkβ.MTT assay and flow cytometry were used to detect cell viability and apoptosis rate.
ResultsThe expression of XIAP in 5-8F cells transfected with si-XIAP was significantly lower than that in blank group(P < 0.01).The cell viability in TNF-α group and si-XIAP group was lower than that in blank group(P < 0.05), and the apoptosis rate and the expression of Cleaved caspase3 and Bax were higher than those in blank group(P < 0.05).The expressions of VEGF, COX-2, NF-κB p65 and Ikkβ in TNF-α group were higher than those in blank group(P < 0.05).The expressions of VEGF, COX-2, NF-κB p65 and Ikkβ in si-XIAP group were lower than those in blank group(P < 0.05).The cell viability in TNF-α+si-XIAP group was lower than that in TNF-α group and si-XIAP group(P < 0.05);the expressions of VEGF, COX-2, NF-κB p65 and Ikkβ were lower than those in TNF-α group and higher than those in si-XIAP group(P < 0.05);the apoptosis rate and the expression of Cleaved caspase3 and Bax were higher than those in TNF-α group and si-XIAP group(P < 0.05).
ConclusionsDown-regulating the expression of XIAP gene enhances TNF-α-induced apoptosis and reduces the expression of VEGF and COX-2 in nasopharyngeal carcinoma 5-8F cells, which is related to the inhibition of NF-κB signaling pathway.
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