Expression of interleukin-17 in human colorectal cancer

The proinflammatory cytokine IL-17 plays a potential role in T-cell mediated angiogenesis and promotes tumourigenicity of human cervical cancer. The objective of this study was to determine whether IL-17 protein level is altered in colorectal tumours (n=74) compared with paired normal mucosa and in plasma from patients (n=61) with colorectal cancer (CRC) compared with a healthy group (n=78). Analyses by ELISA showed that IL-17 protein was undetectable in 48.6% of the patients with cancer, as well as corresponding normal tissue which may in part reflect an individual difference. No significant difference was observed regarding IL-17 protein levels between cancer and matched normal tissue or in plasma between patients and the healthy group. Immunohistochemistry (n=20) revealed heterogenous immunoreactivity in 65% of the cases. The results of this study suggest that IL-17 plays a minor or partial role in CRC.