Figure 6
The interleukin (IL)-1/IL-6 axis is involved in the development of ulcerative colitis (UC)–associated colorectal cancer. (a) Immunohistochemical staining for neutrophils (human neutrophil peptide (HNP)1–3-positive) and IL-1β (brown) was performed on formalin-fixed serial sections of surgical colon samples from 18 patients with colitis-associated cancer (CAC). Representative results for one sample are shown. Scale bar=100 μm (left), 50 μm (right). (b) Neutrophils (CD66b+) infiltrating the lesions of patients with CAC or from the peripheral blood of healthy volunteers were sorted by fluorescence-activated cell sorting (FACS) and IL-1β mRNA levels were measured by quantitative reverse-transcriptase–polymerase chain reaction (RT–PCR). Each group consisted of 5–6 specimens. (c) Surgical colon samples from 15 patients with CAC were collected and intestinal mononuclear phagocytes (MPs; CD68-positive) or IL-6 (brown) detected by immunohistochemistry. Representative results for one sample are shown. Scale bar=100 μm (left), 50 μm (right). (d) MPs (CD68+CD11b+) were isolated from the colon lamina propria (LP) of patients with CAC or from the normal mucosa and IL-6 mRNA levels were measured by quantitative RT–PCR. Each group consisted of 5–6 specimens. (e) Neutrophils isolated from the LP of the colon of patients with CAC or from the peripheral blood of healthy volunteers were cocultured with control MPs for 24 h in the presence or absence of IL-1Ra (2 μg ml−1) and then IL-6 protein levels were measured by enzyme-linked immunosorbent assay (ELISA). The data are pooled from three independent experiments. (f) MPs were isolated from the LP of the normal mucosa of patients with CAC and incubated for 24 h with or without (unstimulated (US)) IL-1β (1 μg ml−1), and then IL-6 expression was measured by quantitative RT–PCR. The data are pooled from three independent experiments. **P<0.01; ***P<0.001.
