Fig. 6

Upregulation of the IL-6R/STAT3 pathway in colorectal cancer cells in the tumor budding area by IL-6 derived from neighboring macrophages. A–D The representative double immunofluorescence of CD68 and IL-6. A A low magnification of double immunofluorescence was shown at depth 4 and depth 5. Nuclear staining was performed with DAPI. B In a high-power field at depth 4, CD68-positive and IL-6-negative macrophages were labeled with TRITC red (arrows). The dashed-line rectangle at depth 5 is magnified in C–E. C CD68-positive macrophages were labeled with TRITC red. D IL-6-positive cells were labeled with FITC green. E The merged yellow was observed at depth 5. F–H The representative double immunofluorescence of AE1/AE3 and phospho-STAT3 (pSTAT3). F A low magnification of double immunofluorescence was shown at depth 4 and depth 5. Nuclear staining was performed with DAPI. The solid line rectangle at depth 4 is magnified in (G). G In a high-power field at depth 4, AE1/AE3-positive and IL-6-negative colorectal cancer cells were labeled with TRITC red. The dashed-line rectangle at depth 5 is magnified in (H). H AE1/AE3-positive cytoplasm of colorectal cancer cells were labeled with TRITC red. pSTAT3-positive nuclear of the cell was labeled with FITC green. The AE1/AE3-positive and pSTAT3-positive cell was observed at depth 5. These double immunofluorescences were performed on four samples. Bars, 10 μm