Objectives: Recent studies suggest that the interaction between interleukin (IL)-1β and IL-6 in the microenvironment might be involved in the development and progression of human colorectal cancer (CRC). However, the expression of IL-1β/IL-6 network within the CRC microenvironment is not fully understood.
Materials and methods: The level of IL-1β/IL-6 network expression in 40 biopsies of sporadic CRC and 15 biopsies of controls was assessed using quantitative real-time polymerase chain reaction (PCR) assay, immunohistochemistry (IHC) and double immunofluorescence staining.
Results: Quantitative results obtained by real-time PCR revealed that both IL-1β and IL-6 mRNA expressions were increased in CRC tissues compared with expressions in controls. In which, IL-6 mRNA expression in primary CRC tissues showed a statistically significant relationship with tumor invasion depth. IHC observations confirmed that increased expression of IL-1β and IL-6 immunoreactivities was located in both the CRC epithelium and stroma. Furthermore, IHC results also revealed that increased expression of IL-1β receptor type 1 (IL-1R1) and IL-6 receptor (IL-6R) were observed in both CRC epithelial and stromal cells. IHCs in serial CRC sections and double immunofluorescence staining revealed a highly co-expression of IL-1R1 immunoreactivity with IL-6 immunoreactivity in the same cells, which confirmed a histological fundament of IL-1β/IL-6 network.
Conclusion: The IL-1β/IL-6 network is highly expressed in the CRC microenvironment, indicating that this network is important in the progression of CRC.
Keywords: Carcinogenesis; Colorectum; Interleukin-1β; Interlukin-6.
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