Expression of interleukin (IL)-11 and IL-11 receptor in human colorectal adenocarcinoma: IL-11 up-regulation of the invasive and proliferative activity of human colorectal carcinoma cells

Previous investigations have shown that interleukin (IL)-11/IL-11 receptor alpha-chain (IL-11R alpha), a member of the PI3K, MAPK and JAK-STAT activating family of cytokines/ receptors, correlates with the regulation of tumor progression. In this study, we established the IL-11/IL-11R alpha expression profile in human colorectal adenocarcinoma (CRC) and clarified its signaling pathway and role in the invasion activity of CRC cell lines. To elucidate the role of IL-11/IL-11R alpha, we examined 103 cases of CRC and 24 cases of colorectal adenoma by immunohistochemistry. In addition, we investigated the invasive activity of cell signaling pathway of CRC cell lines. The IL-11R alpha expression was correlated with tumor invasion and lymphatic infiltration (p < 0.01, respectively). Recombinant human IL-11 (rhIL-11) promoted the migration and proliferation of HT-29 cells and activated the PI3K and p44/p42 MAPK pathways. Wortmannin, a PI3K inhibitor, and PD98059, a p44/p42 MAPK inhibitor, significantly reduced the promotion of invasion and proliferation activity by rhIL-11, respectively. In summary, the IL-11R alpha expression was correlated with clinicopathological features and IL-11 promoted the invasion via the PI3K and up-regulated the proliferation via the p44/p42 MAPK in CRC cells. These findings suggested that the IL-11/IL-11R pathway plays an important role in the progression of CRC.