DCLK1 plays an important role in colorectal cancer tumorgenesis through the regulation of miR-200c.

Doublecortin-like kinase 1 (DCLK1) is a protein kinase that is known as a specific cancer stem cell (CSC) marker in colorectal cancer (CRC). Deregulation of DCLK1 expression has been reported in various cancers. We measured the protein expression of DCLK1 in 38 CRC and normal colon samples by immunohistochemistry (IHC). HCT-116 and SW-48 cells were transfected with DCLK1 siRNA and analyzed for expression of DCLK1 and miR-200c. The effects of DCLK1 knockdown on cell migration, invasion, sphere-forming, and apoptosis were explored. It was found that DCLK1 protein expression levels were significantly higher in CRC tissue than in normal colon specimens. Silencing of DCLK1 significantly inhibited cell migration, invasion, and sphere-forming potential; it also induced apoptosis as well as increased expression of miR-200c. Furthermore, silencing of miR-200c significantly up-regulated DCLK1 expression. Overall, our data demonstrated that DCLK1 plays an important role in cancer progression and is involved in the regulation of miR-200c expression.