In vitro investigation on the mechanism of spleen tyrosine kinase-nuclear factor kappa B signalling inducing cyclooxygenase-2 up-regulation in cancer pain caused by oral cancer associated macrophage

Abstract

Background: The mechanism of oral cancer related pain is still unclear. Objectives: To explore the mechanism of cyclooxygenase-2 (COX-2) up-regulation in oral cancers associated macrophage via molecular biology techniques and primary culture of murine macrophage; and find a new way for cancer pain control. Methods: Murine macrophage was induced by M-CSF and Cal27 conditional medium. Purity of the macrophage was detected by CD68 immunofluorescence staining. Inhibitors of spleen tyrosine kinase (Syk) and nuclear factor kappa B (NFκB) were adopted to inhibit these pathways. Real-time polymerase chain reaction and western blot was adopted to detect the alterations on COX-2 and pathway related proteins. Findings and Conclusion: All the induced cells specifically express CD68. Cal27 conditional medium could significantly induce COX-2 expression (P < 0.001). Inhibition of Syk pathway attenuated the phosphorylation of NFκB-P65 and reduce COX-2 expression (P < 0.01); and inhibition of NFκB pathway had no effects on Syk phosphorylation but significantly inhibit COX-2 up-regulation (P < 0.01). Syk-NFκB is responsible for COX-2 overexpression in oral cancer associated macrophages. Targeting this pathway might be a new way for oral cancer related cancer pain control.