Dclk1, a tumor stem cell marker, regulates pro-survival signaling and self-renewal of intestinal tumor cells.
More than 80% of intestinal neoplasia is associated with the adenomatous polyposis coli (APC) mutation. Doublecortin-like kinase 1 (Dclk1), a kinase protein, is overexpressed in colorectal cancer and specifically marks tumor stem cells (TSCs) that self-renew and increased the tumor progeny in ApcMin/+mice. However, the role of Dclk1 expression and its contribution to regulating pro-survival signaling for tumor progression in Apc mutant cancer is poorly understood.



We analyzed DCLK1 and pro-survival signaling gene expression datasets of 329 specimens from TCGA Colon Adenocarcinoma Cancer Data. The network of DCLK1 and pro-survival signaling was analyzed utilizing the GeneMANIA database. We examined the expression levels of Dclk1 and other stem cell-associated markers, pro-survival signaling pathways, cell self-renewal in the isolated intestinal epithelial cells of ApcMin/+mice with high-grade dysplasia and adenocarcinoma. To determine the functional role of Dclk1 for tumor progression, we knocked down Dclk1 and determined the pro-survival signaling pathways and stemness. We used siRNA technology to gene silence pro-survival signaling in colon cancer cells in vitro. We utilized FACS, IHC, western blot, RT-PCR, and clonogenic (self-renewal) assays.



We found a correlation between DCLK1 and pro-survival signaling expression. The expression of Dclk1 and stem cell-associated markers Lgr5, Bmi1, and Musashi1 were significantly higher in the intestinal epithelial cells of ApcMin/+mice than in wild-type controls. Intestinal epithelial cells of ApcMin/+mice showed increased expression of pro-survival signaling, pluripotency and self-renewal ability. Furthermore, the enteroids formed from the intestinal Dclk1+cells of ApcMin/+mice display higher pluripotency and pro-survival signaling. Dclk1 knockdown in ApcMin/+mice attenuates intestinal adenomas and adenocarcinoma, and decreases pro-survival signaling and self-renewal. Knocking down RELA and NOTCH1 pro-survival signaling and DCLK1 in HT29 and DLD1 colon cancer cells in vitro reduced the tumor cells' ability to self-renew and survive.



Our results indicate that Dclk1 is essential in advancing intestinal tumorigenesis. Knocking down Dclk1 decreases tumor stemness and progression and is thus predicted to regulate pro-survival signaling and tumor cell pluripotency. This study provides a strong rationale to target Dclk1 as a treatment strategy for colorectal cancer.
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA. parthasarathy-chandrakesan@ouhsc.edu.|OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. parthasarathy-chandrakesan@ouhsc.edu.|Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA. parthasarathy-chandrakesan@ouhsc.edu.
Parthasarathy
0000-0002-7587-9553
P
Chandrakesan
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
Jiannan
J
Yao
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.|Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA.
Dongfeng
D
Qu
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA.
Randal
R
May
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
Nathaniel
N
Weygant
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|Beijing Chao-Yang Hospital Department of Oncology, Capital Medical University, Beijing, China.
Yang
Y
Ge
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA.
Naushad
N
Ali
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA.
Sripathi M
SM
Sureban
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|Access Endocrine, Diabetes and Thyroid center, Oklahoma City, OK, USA.
Modhi
M
Gude
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.|Department of Medicine, National Jewish Health, Denver, CO, USA.
Kenneth
K
Vega
COARE Biotechnology, Oklahoma City, OK, USA.
Eddie
E
Bannerman-Menson
Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.
Lijun
L
Xia
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
Michael
M
Bronze
Beijing Chao-Yang Hospital Department of Oncology, Capital Medical University, Beijing, China. anguangyu@hotmail.com.
Guangyu
G
An
Division of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA. Courtney-houchen@ouhsc.edu.|OU Cancer Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. Courtney-houchen@ouhsc.edu.|Department of Veterans Affairs Medical Center, Oklahoma City, OK, USA. Courtney-houchen@ouhsc.edu.|COARE Biotechnology, Oklahoma City, OK, USA. Courtney-houchen@ouhsc.edu.
Courtney W
CW
Houchen
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000066673:Cell Self Renewal / Q000235:genetics*; D002470:Cell Survival / Q000235:genetics*; D016000:Cluster Analysis; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D000089742:Doublecortin-Like Kinases; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D055785:Gene Knockdown Techniques; D017491:Genes, APC; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D051881:Receptor, Notch1 / Q000378:metabolism; D015398:Signal Transduction
D047908:Intracellular Signaling Peptides and Proteins; D051881:Receptor, Notch1; C117347:DCLK1 protein, human; D000089742:Doublecortin-Like Kinases; D017346:Protein Serine-Threonine Kinases
APC mutation; Cancer stem cells; Colorectal cancer; Dclk1; Intestinal epithelial cells; Nanoparticles; Pro-survival signaling; Self-renewal