[Expression of toll-like receptor 4 in colorectal cancer].

Toll-like receptors (TLRs) play an essential role in innate immunity by recognizing various pathogens and by activating acquired immunity. Based on the hypothesis that abnormalities of innate immune responses are involved in carcinogenesis, we examined the presence or absence of the expression of Toll-like receptor 4 (TLR4), comprising one of the TLR families, in colorectal cancer tissues. TLR4 expression in cancerous and non-cancerous colorectal tissue specimens obtained at surgery was investigated by reverse-transcription polymerase chain reaction (RT-PCR). Then, TLR4 expression levels were quantified by real-time PCR and compared between the 2 groups. TLR4 expression was significantly higher in non-cancerous tissues than in cancerous tissues. Interestingly, these results suggested that TLR4 expression was up-regulated in non-cancerous tissues or down-regulated in cancerous tissues in patients with colorectal cancer.