Toll-Interleukin 1 Receptor Domain Containing Adaptor Protein (Tirap) Positively Regulates The Progression Of Nsclc Via Promoting Cell Proliferation

Toll-Interleukin 1 Receptor Domain Containing Adaptor Protein (TIRAP) is an adaptor protein for Toll-like receptors-2 and-4 (TLR2/4) which are engaged in transducing the signal to downstream molecules. Toll-like receptors (TLR) are overexpressed in many types of cancer cells. However, the detailed role of TIRAP in non-small cell lung cancer (NSCLC) has not been elucidated. In this study, Western blot and immunohistochemistry (IHC) staining showed that TIRAP was up-regulated in NSCLC tissues compared with adjacent non-tumor tissues. IHC analysis indicated that TIRAP was significantly associated with clinical pathologic variables. Kaplan-Meier analysis showed that high expression of TIRAP was related to poor prognosis of lung cancer patients. And TIRAP along with other clinicopathological variables was an independent prognostic indicator for patients' overall survival by multivariate analysis. In vitro studies using serum starvation-refeeding experiment, TIRAP-siRNA transfection assay, and flow cytometry analysis demonstrated that TIRAP expression promoted proliferation of NSCLC cells, while TIRAP knockdown led to inhibition of cell growth. Our results indicated that TIRAP was involved in the tumorigenesis of NSCLC and might be a potential therapeutic target of NSCLC.