Introduction: Human epidermal growth factor 2 (HER2) gene overexpression in breast carcinoma cell lines has been shown to drive mammary carcinogenesis and tumor growth and invasion through its effects on mammary stem cells. Objective: Therefore, we investigated the mechanism by which HER2 regulates cancer stem cell (CSC) activity in gastric cancer cells. Methods:HER2 was transfected into MKN28 gastric cancer cells, and its role in regulating CSC activity was determined by characterizing the HER2-overexpressing cells. Results: The sphere formation assay revealed that the sphere sizes and frequency of sphere formation were significantly greater for the HER2-overexpressing cells than for the MKN28 control cells. The CSC markers Oct-4 and BMI1 were more highly expressed in the HER2-overexpressing cells, as were the EMT markers. This was accompanied by a significant enhancement in cellular invasion of the Matrigel and migration. The E-cadherin level was significantly downregulated, and the mesenchymal marker Snail upregulated, in the HER2-transfected cells. HER2 overexpression activated the well-characterized CSC-associated Wnt/β-catenin signaling pathway, as shown by the luciferase assay. After treatment of these cells with the Wnt signal inhibitor PRI-724, the BMI1 and Oct-4 levels were decreased for 24 h and Snail was also downregulated. Immunofluorescence staining revealed the significant restoration of E-cadherin levels in the HER2-transfected cells after PRI-724 treatment. Conclusions: These results established a role for HER2 in regulating gastric CSC activity, with Wnt/β-catenin signaling being mediated via a HER2-dependent pathway. In summary, HER2-overexpressing gastric cancer cells exhibited increased stemness and invasiveness and were regulated by Wnt/β-catenin signaling.

1.
Bray
F
,
Ferlay
J
,
Soerjomataram
I
,
Siegel
RL
,
Torre
LA
,
Jemal
A
.
Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries
.
CA Cancer J Clin
.
2018
Nov
;
68
(
6
):
394
424
.
[PubMed]
0007-9235
2.
Wagner
AD
,
Grothe
W
,
Haerting
J
,
Kleber
G
,
Grothey
A
,
Fleig
WE
.
Chemotherapy in advanced gastric cancer: a systematic review and meta-analysis based on aggregate data
.
J Clin Oncol
.
2006
Jun
;
24
(
18
):
2903
9
.
[PubMed]
0732-183X
3.
Bang
YJ
,
Van Cutsem
E
,
Feyereislova
A
,
Chung
HC
,
Shen
L
,
Sawaki
A
, et al;
ToGA Trial Investigators
.
Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial
.
Lancet
.
2010
Aug
;
376
(
9742
):
687
97
.
[PubMed]
0140-6736
4.
Yano
T
,
Doi
T
,
Ohtsu
A
,
Boku
N
,
Hashizume
K
,
Nakanishi
M
, et al
Comparison of HER2 gene amplification assessed by fluorescence in situ hybridization and HER2 protein expression assessed by immunohistochemistry in gastric cancer
.
Oncol Rep
.
2006
Jan
;
15
(
1
):
65
71
.
[PubMed]
1021-335X
5.
Fassan
M
,
Mastracci
L
,
Grillo
F
,
Zagonel
V
,
Bruno
S
,
Battaglia
G
, et al
Early HER2 dysregulation in gastric and oesophageal carcinogenesis
.
Histopathology
.
2012
Nov
;
61
(
5
):
769
76
.
[PubMed]
0309-0167
6.
Fassan
M
,
Pizzi
M
,
Realdon
S
,
Balistreri
M
,
Guzzardo
V
,
Zagonel
V
, et al
The HER2-miR125a5p/miR125b loop in gastric and esophageal carcinogenesis
.
Hum Pathol
.
2013
Sep
;
44
(
9
):
1804
10
.
[PubMed]
0046-8177
7.
Kim
MA
,
Lee
HJ
,
Yang
HK
,
Bang
YJ
,
Kim
WH
.
Heterogeneous amplification of ERBB2 in primary lesions is responsible for the discordant ERBB2 status of primary and metastatic lesions in gastric carcinoma
.
Histopathology
.
2011
Nov
;
59
(
5
):
822
31
.
[PubMed]
0309-0167
8.
Marx
AH
,
Tharun
L
,
Muth
J
,
Dancau
AM
,
Simon
R
,
Yekebas
E
, et al
HER-2 amplification is highly homogenous in gastric cancer
.
Hum Pathol
.
2009
Jun
;
40
(
6
):
769
77
.
[PubMed]
0046-8177
9.
Jørgensen
JT
,
Hersom
M
.
Her2 as a prognostic marker in gastric cancer - a systematic analysis of data from the literature
.
J Cancer
.
2012
;
3
:
137
44
.
[PubMed]
0378-2360
10.
Lei
YY
,
Huang
JY
,
Zhao
QR
,
Jiang
N
,
Xu
HM
,
Wang
ZN
, et al
The clinicopathological parameters and prognostic significance of HER2 expression in gastric cancer patients: a meta-analysis of literature
.
World J Surg Oncol
.
2017
Mar
;
15
(
1
):
68
.
[PubMed]
1477-7819
11.
Slamon
DJ
,
Clark
GM
,
Wong
SG
,
Levin
WJ
,
Ullrich
A
,
McGuire
WL
.
Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene
.
Science
.
1987
Jan
;
235
(
4785
):
177
82
.
[PubMed]
0036-8075
12.
Slamon
DJ
,
Godolphin
W
,
Jones
LA
,
Holt
JA
,
Wong
SG
,
Keith
DE
, et al
Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer
.
Science
.
1989
May
;
244
(
4905
):
707
12
.
[PubMed]
0036-8075
13.
Korkaya
H
,
Paulson
A
,
Iovino
F
,
Wicha
MS
.
HER2 regulates the mammary stem/progenitor cell population driving tumorigenesis and invasion
.
Oncogene
.
2008
Oct
;
27
(
47
):
6120
30
.
[PubMed]
0950-9232
14.
Magnifico
A
,
Albano
L
,
Campaner
S
,
Delia
D
,
Castiglioni
F
,
Gasparini
P
, et al
Tumor-initiating cells of HER2-positive carcinoma cell lines express the highest oncoprotein levels and are sensitive to trastuzumab
.
Clin Cancer Res
.
2009
Mar
;
15
(
6
):
2010
21
.
[PubMed]
1078-0432
15.
Qi
W
,
Li
X
,
Zhang
Y
,
Yao
R
,
Qiu
W
,
Tang
D
, et al
Overexpression of Her-2 upregulates FoxM1 in gastric cancer
.
Int J Mol Med
.
2014
Jun
;
33
(
6
):
1531
8
.
[PubMed]
1107-3756
16.
Takebe
N
,
Miele
L
,
Harris
PJ
,
Jeong
W
,
Bando
H
,
Kahn
M
, et al
Targeting Notch, Hedgehog, and Wnt pathways in cancer stem cells: clinical update
.
Nat Rev Clin Oncol
.
2015
Aug
;
12
(
8
):
445
64
.
[PubMed]
1759-4774
17.
Begnami
MD
,
Fukuda
E
,
Fregnani
JH
,
Nonogaki
S
,
Montagnini
AL
,
da Costa
WL
 Jr
, et al
Prognostic implications of altered human epidermal growth factor receptors (HERs) in gastric carcinomas: HER2 and HER3 are predictors of poor outcome
.
J Clin Oncol
.
2011
Aug
;
29
(
22
):
3030
6
.
[PubMed]
0732-183X
18.
Shan
YQ
,
Ying
RC
,
Zhou
CH
,
Zhu
AK
,
Ye
J
,
Zhu
W
, et al
MMP-9 is increased in the pathogenesis of gastric cancer by the mediation of HER2
.
Cancer Gene Ther
.
2015
Apr
;
22
(
3
):
101
7
.
[PubMed]
0929-1903
19.
Yang
Z
,
Guo
L
,
Liu
D
,
Sun
L
,
Chen
H
,
Deng
Q
, et al
Acquisition of resistance to trastuzumab in gastric cancer cells is associated with activation of IL-6/STAT3/Jagged-1/Notch positive feedback loop
.
Oncotarget
.
2015
Mar
;
6
(
7
):
5072
87
.
[PubMed]
1949-2553
20.
Li
G
,
Zhao
L
,
Li
W
,
Fan
K
,
Qian
W
,
Hou
S
, et al
Feedback activation of STAT3 mediates trastuzumab resistance via upregulation of MUC1 and MUC4 expression
.
Oncotarget
.
2014
Sep
;
5
(
18
):
8317
29
.
[PubMed]
1949-2553
21.
Stewart
J
,
James
J
,
McCluggage
GW
,
McQuaid
S
,
Arthur
K
,
Boyle
D
, et al
Analysis of wntless (WLS) expression in gastric, ovarian, and breast cancers reveals a strong association with HER2 overexpression
.
Mod Pathol
.
2015
Mar
;
28
(
3
):
428
36
.
[PubMed]
0893-3952
22.
Zhi
QM
,
Chen
XH
,
Ji
J
,
Zhang
JN
,
Li
JF
,
Cai
Q
, et al
Salinomycin can effectively kill ALDH(high) stem-like cells on gastric cancer
.
Biomed Pharmacother
.
2011
Oct
;
65
(
7
):
509
15
.
[PubMed]
0753-3322
23.
Lu
D
,
Choi
MY
,
Yu
J
,
Castro
JE
,
Kipps
TJ
,
Carson
DA
.
Salinomycin inhibits Wnt signaling and selectively induces apoptosis in chronic lymphocytic leukemia cells
.
Proc Natl Acad Sci USA
.
2011
Aug
;
108
(
32
):
13253
7
.
[PubMed]
0027-8424
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.