The participation of stem cells (and/or cancer stem cells) in tumor cell invasion and metastasis is considered in numerous studies a key step in tumorigenesis. Our search for genes specifically induced by changes in colon cancer cell adhesion during tumor progression, revealed a number of genes previously defined as intestinal stem cell signature genes (see the figure below for one such gene). We are studying the function of these genes in colon cancer cells and their metastasis to the liver, expecting to also uncover hints on their role in normal intestinal stem cell homeostasis.
The localization of SMOC-2 in cultured CRC cells overexpressing L1 and in CRC tissue. (A) SMOC-2 is localized outside the cells at the tip of cellular protrusions (white arrowheads) in L1-expressing CRC cells; (B) CRC tissue was strongly stained for SMOC-2 (black arrowheads) at the more invasive areas of the tumor, while normal colonic epithelium displayed SMOC-2 staining exclusively at the bottom of colonic crypts (black arrows), where colonic stem cells are localized.