Pancreatic Neuroendocrine Tumors and EMT Behavior Are Driven by the CSC Marker DCLK1.
Doublecortin-like kinase 1 (DCLK1), a marker for intestinal and pancreatic cancer stem cells, is highly expressed in neuroblastomas. This study was conducted to assess DCLK1 expression levels in pancreatic neuroendocrine tumor (PNET) tissues and to explore the roles of this molecule in clinical tissue from multiple PNET patients, cells (BON1, QGP1, and CM) and tumor xenografts. Immunohistochemically, all PNET tissues highly and diffusely expressed DCLK1 as a full-length isoform, identical to that detected in primary liver NETs. A DCLK1-overexpressing PNET cell line (QGP1-DCLK1) exhibited epithelial-mesenchymal transition (EMT)-related gene signatures, and robust upregulation of Slug (SNAI2), N-Cadherin (CDH2), and Vimentin (VIM) was validated by real-time PCR and immunoblotting. QGP1-DCLK1 cells had increased cell migration in a wound-healing assay and formed significantly larger xenograft tumors in nude mice. The factors involved in the formation of the fast-growing tumors included p-FAK (on Tyr925), p-ERK1/2, p-AKT, Paxillin, and Cyclin D1, which upon knockdown or pharmacologic inhibition of DCLK1 abolished the expression of these molecules. In conclusion, robust and ubiquitous expression of DCLK1 was first demonstrated here in human PNET tissue specimens and cells. DCLK1 characterized the PNET cell behavior, inducing p-FAK/SLUG-mediated EMT. These findings suggest the possibility of developing novel therapeutic strategies against PNETs by targeting DCLK1.Implications:Evidence here reveals that human PNETs diffusely and robustly express the cancer stem cell marker DCLK1, which drives SLUG-mediated EMT, and suggests that NETs share biological features for druggable targets with other tumors, including neuroblastoma that also highly expresses DCLK1.Mol Cancer Res; 15(6); 744-52. ©2017 AACR.
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Yu
Y
Ikezono
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan. hirokoga@med.kurume-u.ac.jp.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Hironori
H
Koga
Department of Pathology, Kurume University School of Medicine, Kurume, Japan.
Jun
J
Akiba
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Mitsuhiko
M
Abe
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Takafumi
T
Yoshida
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Fumitaka
F
Wada
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Toru
T
Nakamura
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Hideki
H
Iwamoto
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Atsutaka
A
Masuda
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Takahiko
T
Sakaue
Department of Pathology, Kurume University School of Medicine, Kurume, Japan.
Hirohisa
H
Yano
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.
Osamu
O
Tsuruta
Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan.|Liver Cancer Research Division, Research Center for Innovative Cancer Therapy, Kurume University, Kurume, Japan.
Takuji
T
Torimura
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics; D045744:Cell Line, Tumor; D000089742:Doublecortin-Like Kinases; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D005260:Female; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology; D018358:Neuroendocrine Tumors / Q000235:genetics / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
D014408:Biomarkers, Tumor; D047908:Intracellular Signaling Peptides and Proteins; D014443:Tyrosine; C117347:DCLK1 protein, human; D000089742:Doublecortin-Like Kinases; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; D017346:Protein Serine-Threonine Kinases