Aberrant activation of Notch signaling in extrahepatic cholangiocarcinoma: clinicopathological features and therapeutic potential for cancer stem cell-like properties.
Little is known about the roles of Notch signaling in cholangiocarcinoma (CC). The expression of hairy and enhancer of split 1 (Hes-1) has not been investigated yet in resected specimens of CC. Notch signaling has been reported to be related to cancer stem cell (CSC) like properties in some malignancies. Our aim is to investigate the participation of Notch signaling in resected specimens of extrahepatic CC (EHCC) and to evaluate the efficacy of CC cells with CSC-like properties by Notch signaling blockade.



First, the expression of Notch1, 2, 3, 4 and Hes-1 was examined by immunohistochemistry in 132 resected EHCC specimens. The clinicopathological characteristics in the expression of Notch receptors and Hes-1 were investigated. Second, GSI IX, which is a γ-secretase-inhibitor, was used for Notch signaling blockade in the following experiment. Alterations of the subpopulation of CD24+CD44+cells, which are surface markers of CSCs in EHCC, after exposure with GSI IX, gemcitabine (GEM), and the combination of GSI IX plus GEM were assessed by flow cytometry using the human CC cell lines, RBE, HuCCT1 and TFK-1. Also, anchorage-independent growth and mice tumorigenicity in the cells recovered by regular culture media after GSI IX exposure were assessed.



Notch1, 2, 3, 4 and Hes-1 in the resected EHCC specimens were expressed in 50.0, 56.1, 42.4, 6.1, and 81.8 % of the total cohort, respectively. Notch1 and 3 expressions were associated with poorer histological differentiation (P = 0.008 and 0.053). The patients with the expression of at least any one of Notch1-3 receptors, who were in 80.3 % of the total, exhibited poorer survival (P = 0.050). Similarly, the expression of Hes-1 tended to show poor survival (P = 0.093). In all of the examined CC cell lines, GSI IX treatment significantly diminished the subpopulation of CD24+CD44+cells. Although GEM monotherapy relatively increased the subpopulation of CD24+CD44+cells in all lines, GSI IX plus GEM attenuated it. Anchorage-independent growth and mice tumorigenicity were inhibited in GSI IX-pretreated cells in RBE and TFK-1 (P < 0.05).



Aberrant Notch signaling is involved with EHCC. Inhibition of Notch signaling is a novel therapeutic strategy for targeting cells with CSC-like properties.
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Shuichi
S
Aoki
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan. masamichi@surg1.med.tohoku.ac.jp.
Masamichi
M
Mizuma
Department of Pathology, Tohoku University Hospital, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Yayoi
Y
Takahashi
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Yoichi
Y
Haji
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Ryo
R
Okada
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Tomoya
T
Abe
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Hideaki
H
Karasawa
Division of Cancer Stem Cell, Miyagi Cancer Center Research Institute, 47-1 Nodayama, Medeshimashiote aza, Natori, 981-1293, Japan.
Keiichi
K
Tamai
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Takaho
T
Okada
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Takanori
T
Morikawa
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Hiroki
H
Hayashi
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Kei
K
Nakagawa
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Fuyuhiko
F
Motoi
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Takeshi
T
Naitoh
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Yu
Y
Katayose
Department of Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aobaku, Sendai, 980-8574, Japan.
Michiaki
M
Unno
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001650:Bile Duct Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000628:therapy; D015415:Biomarkers; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018281:Cholangiocarcinoma / Q000175:diagnosis / Q000378:metabolism* / Q000628:therapy; D004195:Disease Models, Animal; D005260:Female; D015870:Gene Expression; D064593:Heterografts; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D014411:Neoplastic Stem Cells / Q000378:metabolism; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D000072056:Transcription Factor HES-1 / Q000378:metabolism; D055815:Young Adult
D015415:Biomarkers; D051880:Receptors, Notch; D000072056:Transcription Factor HES-1; C078493:HES1 protein, human
Cancer stem cell; Cholangiocarcinoma; Hes-1; Notch signaling