Inflammatory factors promote oral squamous cell carcinoma cells metastasis, via nuclear factor kappa B signal pathway in vitro

Abstract

To investigate the roles of inflammatory factors and nuclear factor kappa B (NF-kappaB) signal pathway in metastasis of oral squamous cell carcinoma. The oral squamous cell carcinoma cell lines with highly metastasis potential (Tb) and lower metastasis potential (Tca8113) were used in this study. The levels of NF-kappaB activity in oral squamous cell carcinoma cell lines were determined by Western blotting and luciferase reporter assay. pBalphabe-IkappaBalpha-SR expression vector or NF-kappaB inhibitor pyrolidinedithiocarbamate (PDTC) was used to inhibit NF-kappaB, and cell migration was examined by transwell assay. The secretion of tumor necrosis factor-alpha (TNF-alpha), IL-1alpha, IL-6, IL-8 and GM-CSF proinflammatory cytokines was determined by ELISA when Tb cells were transfected with pBalphabe-SR-IkappaBalpha or treated with PDTC. Western blotting showed that the levels of phosphorIkappaBalpha and phosphor-p65 were highly expressed in Tb cells. Tb cells had high level of constitutive NF-kappaB activity and were more sensitive to TNF-alpha. The migration of highly metastatic Tb cells, either transfected with dominant-negative mutant inhibitor pBalphabe-SR-IkappaBalpha or treated with PDTC, was suppressed when determined by transwell assay. The secretion of proinflammatory cytokines, including TNF-alpha, IL-1alpha, IL-6, IL-8 and granulocyte-macrophage colony stimulating factor (GM-CSF), was inhibited by pBalphabe-SR-IkappaBalpha transfection or PDTC treatment. The inflammatory factors such as TNF-alpha could promote oral squamous cell carcinoma cell metastasis via NF-kappaB signal pathway.