Toll-like receptors (TLRs) not only form an important part of the innate immune system but also serve to activate the adaptive immune system in response to cancer. Real-time PCR; immunohistochemical stain and Western blotting analyses were performed to clarify molecular alterations in colorectal cancer (CRC) patients. We identified Toll-like receptor 1 (
TLR1),
TLR2,
TLR4 and
TLR8 gene expression levels and downstream gene,
i.e.,
interleukin-6 (
IL-6),
IL-8,
interferon-α (
IFN-α) and myeloid differentiation primary-response protein-88 (
MyD88), expression levels in CRC patients and in cancer cell lines. CRC tissues have higher
TLR1,
TLR2,
TLR4,
TLR8,
IL-6 and
IL-8 gene expression levels than do the normal colon mucosa (
p < 0.05). TLR2 expression varied in different cell types (mucosa and lymphocytes). There was no difference in the
MyD88 and
IFN-α gene expression levels between cancerous and normal colon mucosa. CRC patients had higher levels of IL-6 (
p = 0.002) and IL-8 (
p = 0.038) expression than healthy volunteers did; and higher IL-6 and IL-8 expression was also found to signify a higher risk of recurrence. CL075 (3M002) treatments can reduce the production of IL-8 in different cancer cell lines. The signaling pathway of TLRs in cancer tissue is different from that in normal cells; and is MyD88-independent. Higher expression levels of TLR1, TLR2, TLR 4 and TLR 8 mRNA were related to upregulation inflammatory cytokines
IL-6 and
IL-8 gene expression in tissue and to the upregulation of IL-6 in blood. The concentration of IL-6 in serum can be used as an indicator of the possibility of CRC recurrence. Treatment with 3M002 can reduce IL-6 production
in vitro and may prevent CRC recurrence. Our findings provide evidence that
TLR1,
TLR2,
TLR4 and
TLR8 gene expression induce downstream
IL-6 and
IL-8 gene expression; detection of these expression levels can serve as a CRC marker.
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