ICG-001 suppresses growth of gastric cancer cells and reduces chemoresistance of cancer stem cell-like population
Liu et al. Journal of Experimental & Clinical Cancer Research
ICG-001 suppresses growth of gastric cancer cells and reduces chemoresistance of cancer stem cell-like population
Yi Liu 0
Hui Chen 0
Peiming Zheng
Yingxia Zheng
Qin Luo
Guohua Xie
Yanhui Ma
Lisong Shen
0 Equal contributors Department of Clinical Laboratory, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine , Shanghai 200092 , China
Background: ICG-001, a small molecule, binds CREB-binding protein (CBP) to disrupt its interaction with β-catenin and inhibits CBP function as a co-activator of Wnt/β-catenin-mediated transcription. Given its ability to inhibit Wnt/ β-catenin signaling pathway, ICG-001 has been used in some tumor types to exert its anticarcinogenic effect. Here, we examined ICG-001 and its potential role as a therapeutic in gastric cancer (GC). Methods: The gastric cancer cell lines SGC-7901, MGC-803, BGC-823 and MKN-45 were used in vitro and in vivo. The abilities of cell proliferation, tumor sphere formation, metastasis, tumorgenesis and chemoresistance to chemotherapy drugs in vitro were evaluated by MTT assay, colony formation assay, flow cytometry, migration and invasion assay, and tumor spheres culture. The in vivo experiments were performed using a subcutaneous transplantation tumor model in athymic nude mice. Alterations at RNA and protein levels were followed by qRT-PCR, western blot, coimmunoprecipitations and immunofluorescence assay. Results: In this study, we showed that ICG-001 significantly inhibited growth and metastasis of multiple GC cell lines, induced cell apoptosis, and augmented in vitro tumor spheres suppression when used in combination with chemotherapy drugs probably through robustly blocking association of β-catenin with CBP and N-cadherin, but promoting association of β-catenin with P300 and E-cadherin, instead of altering the distribution and expression of β-catenin. Conclusions: Our findings suggest that ICG-001 suppresses GC cell line growth, metastasis and reduces its stem cell-like properties and chemoresistance, indicating that ICG-001 is a potentially useful small molecule therapeutic for GC.
ICG-001; Gastric cancer; Wnt/β-catenin signaling pathway; Growth; Stem cell-like
Background
Gastric cancer (GC) is currently the fourth most
common malignancy and the third leading cause of
cancerrelated deaths worldwide [
1
]. The incidence and
mortality of gastric cancer are the highest in East Asia
(particularly in Korea, Mongolia, Japan, and China), and it has
become the second most lethal cancer in China [
2
]. GC
is difficult to treat because it frequently presents at an
advanced, non-operative stage and is highly resistant to
cytotoxic or targeted molecular therapy. While our
understanding of the molecular and cellular basis of GC
continues to expand, present therapeutic options remain
limited and offer only modest survival benefits for most
patients.
Wnt/β-catenin signaling pathway is a critical
developmental signaling pathway whose deregulation is strongly
implicated in the pathogenesis of many types of cancer
[
3
]. Perturbations of Wnt/β-catenin signaling pathway can
promote the initiation and progression of GC and has
been linked to aggressive tumor behavior [
4
]. Although
plagued by poor pharmacokinetics in vivo, several novel
Wnt/β-catenin inhibitors have been demonstrable in vivo
activity and are now in various stages of preclinical or
early clinical development. ICG-001 was first identified in
a screen of small molecules that inhibited Wnt/β-catenin
transcriptional activity in a colorectal cancer cell line [
5
].
ICG-001 selectively blocks the interaction of β-catenin
with its transcriptional co-activator
cyclic-AMP-responseelement-binding protein (CBP). Recent studies have
provided convincing evidence of the inhibitory effects of
ICG-001 on Wnt-driven disease models including
pulmonary fibrosis [
6
], renal interstitial fibrosis [
7
], acute
lymphoblastic leukemia [
8
], chronic myocardial infarction
[
9
], dermal fibrosis [
10
], salivary tumorigenesis [
11
] and
pancreatic ductal adenocarcinoma [
12
]. However,
ICG001 has not been explored in gastric cancer. Further, the
mechanisms of ICG-001 in cancer inhibition and in
chemoresistance of cancer stem cells to chemotherapy drugs
are not yet fully discovered.
Given the importance of Wnt/β-catenin signaling
pathway in GC, we have now explored therapeutic
potential and related mechanism of ICG-001 in GC cell
lines and stem-like cells. ICG-001 significantly inhibited
in vitro and in vivo GC cell lines growth by inducing
G0/G1 cell cycle arrest and reduced chemoresistance of
stem-like cells to chemotherapy drugs. Mechanically,
ICG-001 disrupted the association between β-catenin
with CBP, P300, E-cadherin and N-cadherin, instead of
perturbing the expression and distribution of β-catenin.
Methods
Cell culture and treatment
The gastric cancer cell lines SGC-7901, MGC-803,
BGC-823 and MKN-45 were purcha (...truncated)