Together, our present observations strongly suggest that the CD133-PTPRK axis plays a pivotal role in the regulation of colon cancer progression as well as drug resistance.
Using three independent primary spheroidal colon cancer cultures that expressed a Wnt reporter construct we observed high Wnt activity was associated with the cell surface markers CD133, CD166, and CD29, but not CD24 and CD44, while the original study found all five markers were correlated with high Wnt activity (Figure 2F; Vermeulen et al., 2010).
CD133-containing MVs induced the development of chemoresistance by abolishing the inhibitory effects of anti-epidermal growth factor receptor (EGFR) drugs on cell proliferation and motility in colon cancer.
We found that RAC3 overexpression was mainly associated to CD133+ side-population of colon cancer cells and also to early and advanced stages of colon cancer, involving increased expression of mesenchymal and stem markers.
Although the <i>TP53</i> gene is frequently mutated in colon cancer, it remains not fully understood whether and how tumor protein p53 (p53) is associated with CD133 expression in colon cancer cells.
In conclusion, p-STAT3 may participate in the progression of the early stage of colon cancer through the up-regulation of CD133, which in turn induces survivin expression.
However, sorted CD133+ colon cancer cells exhibit no increased resistance to 5-FU, and CD133 levels exhibit no correlation with colon cancer patient survival or cancer recurrence.
Here, using a human colon carcinoma HT-29 model, we demonstrated that the intratumoral (64)Cu-ATSM high-uptake regions exhibited malignant characteristics, such as upregulated DNA repair and elevated %CD133(+) cancer stem-like cells.
To elucidate the role of CD133 expression in chemoresistance, we silenced the CD133 expression in a colon cancer cell line and determined its effect on the biological characteristics downstream.
CD66c was absent in CD133-positive cells that were isolated from normal colon, whereas its expression was brightest (CD66c(bright) ) in CD133-positive cells from colon cancer samples.
Recent studies suggest CD133, a surface protein widely used for isolation of colon cancer stem cells, to be associated with tumor angiogenesis and recurrence.