The Involvement of WNT Signaling Pathway in Human Colon Cancer Metastasis

Abstract

Colon cancer is one of the most common cancers. Mortality from colon cancer mainly derives from its metastases. The mechanisms for colon metastasis are not clear. Aberrant WNT signals have been commonly observed in human colon cancer. Therefore, we hypothesize that WNT signaling pathway participates in the metastasis of colon cancer. To test this hypothesis, we used the cell line models SW480 and SW620, which are poorly and highly metastatic colon cancer cell lines, respectively. SW480 was established from a primary human colon cancer, while SW620 was from a lymph node metastasis in the same patient a year later. mRNA expression of genes involved in WNT pathway were detected in SW480 and SW620 by real‐time PCR. WNT5a decreased 1000 times in SW620 compared to SW480. N‐Myc downstream‐regulated gene 1 (NDRG1), which was reported to inhibit WNT pathway by interacting with WNT co‐receptors, decreased 10 times. On the other hand, secreted frizzled‐related protein 1(sFRP1), another WNT signaling antagonist, increased 3 times in SW620. The significant difference of WNT signaling observed between SW480 and SW620 showed strong correlation between the WNT signaling pathway and the invasive ability of colon cancer cells. Mechanisms of this interaction between WNT signaling pathway and colon cancer metastasis are under future investigation. This research was supported by the University of Illinois at Urbana‐Champaign.