YY1-Induced Upregulation of Long Noncoding RNA ARAP1-AS1 Promotes Cell Migration and Invasion in Colorectal Cancer Through the Wnt/β-Catenin Signaling Pathway

Abstract

Introduction:

It has been reported that long noncoding RNAs (lncRNAs) are crucial regulators in progression of human cancers, including colorectal cancer (CRC). However, the function of lncRNA ARAP1 antisense RNA 1 (ARAP1-AS1) in CRC remains unclear.

Aim:

The aim of this study was to investigate the function and molecular mechanism of lncRNA ARAP1-AS1 in CRC.

Results:

ARAP1-AS1 was highly expressed in CRC tissues and cell lines. ARAP1-AS1 knockdown suppressed cell migration, invasion, and epithelial–mesenchymal transition (EMT). YY1 transcription factor (YY1) enhanced the transcription activity of ARAP1-AS1. The YY1/ARAP1-AS1 axis promoted CRC cell migration and invasion. YY1/ARAP1-AS1 could regulate the Wnt/β-catenin signaling pathway.

Conclusions:

This study revealed that YY1-induced upregulation of ARAP1-AS1 promoted cell migration, invasion, and EMT process in CRC through the Wnt/β-catenin signaling pathway.

Introduction

Colorectal cancer (CRC) ranks third among the most common malignancies, which is the fourth leading cause of cancer-related death.^1,2 There are more than 1.2 million patients who were diagnosed with CRC each year.³ Surgical resection, chemotherapy, and radiotherapy are the most common therapeutic methods for CRC. Despite therapeutic strategies having been improved, the overall survival rate of CRC patients within 5 years is still low.^4,5 Although molecular mechanisms underlying cancer progression have been studied and reported, the efficient molecular mechanism involved in CRC progression is still largely unknown. Therefore, it is necessary to investigate the novel molecular mechanism associated with the biological processes of CRC.

Long noncoding RNAs (lncRNAs) without the ability to code proteins have been shown to be crucial regulators in the occurrence and development of various tumors.^6

–11 It has been reported that lncRNAs regulate various biological processes at multiple levels.¹² Aberrant expression of lncRNAs has been identified to be an important factor for progression and development of malignancies.^{13

–20} The aim of this study is to explore the mechanism of functional lncRNAs in CRC.

lncRNA ARAP1 antisense RNA 1 (ARAP1-AS1) has been reported to be an oncogene in bladder cancer.²¹ However, its role in CRC is still unknown. Based on The Cancer Genome Atlas (TCGA) dataset, the authors found that ARAP1-AS1 was highly expressed in colorectal adenocarcinoma samples. Furthermore, the level of ARAP1-AS1 was examined in 82 pairs of CRC tissues and normal tissues. Since the expression of ARAP1-AS1 was correlated with metastasis, the authors performed functional assays to determine the effect of ARAP1-AS1 knockdown on CRC cell migration, invasion, and epithelial–mesenchymal transition (EMT) progress. Additionally, previous studies have shown that upregulation of lncRNAs is usually caused by their upstream transcription factors.^22

–26

In this study, both bioinformatic analysis and mechanism experiments revealed the interaction between transcription factor YY1 and ARAP1-AS1. Additionally, the Wnt/β-catenin signaling pathway was found to be a downstream pathway of ARAP1-AS1. Finally, rescue assays were conducted to demonstrate the function of the YY1/ARAP1-AS1 axis in regulating CRC cell migration and the Wnt/β-catenin signaling pathway. In conclusion, the present study revealed that the YY1/ARAP1-AS1 axis promoted CRC cell migration, invasion, and EMT progress through the Wnt/β-catenin signaling pathway.

Materials and Methods

Tissues samples

All CRC tissues and adjacent nontumor tissues (n = 82) were obtained from patients who received surgical resection at The First Affiliated Hospital of Wenzhou Medical University. After collection, samples were immediately frozen in liquid nitrogen and preserved at −80°C until total RNA isolation. No local or systemic treatments were performed in these patients before surgery. This study had the approval of the Ethics Committee of The First Affiliated Hospital of Wenzhou Medical University. All patients had signed written informed consent before the study.

Cell culture

The normal human colon epithelial cell line, HCoEpiC, and five human CRC cell lines (SW620, SW480, HT29, LoVo, and HCT116) were purchased from American Type Culture Collection (ATCC, Manassas, VA). These cell lines were then incubated in Dulbecco's modified Eagle's medium (DMEM; Thermo Fisher, Grand Island, NY) supplemented with 10% fetal bovine serum (FBS; Sigma-Aldrich, St. Louis, MO), 100 U/mL penicillin, and 100 U/mL streptomycin (Invitrogen, Carlsbad, CA) in a humidified atmosphere with 5% CO₂ at 37°C. The culture medium was replaced every 3 d and cell passage was performed when the cells grew up to 80%–90% confluence.

RNA extraction and quantitative real-time polymerase chain reaction

Total RNA was extracted from tissues or cells using TRIzol reagent (Invitrogen) based on the manufacturer's protocol. NanoDrop2000c (Thermo Scientific, Waltham, MA) was used to detect the quantity and quality of isolated RNAs. Total RNA was reverse transcribed to complementary DNA (cDNA) using the PrimeScript^™ RT Master Mix (TaKaRa, Shiga, Japan). cDNA templates were amplified by real-time polymerase chain reaction (RT-PCR) using SYBR Green Master Mix (Applied Biosystems, Foster City, CA). PCR amplification was carried out as follows: 95°C for 5 min, followed by 40 cycles at 95°C for 5 s and 61°C for 30 s. GAPDH served as an internal control. The 2^−ΔΔCt method was used to calculate relative expression levels of RNAs. Primers for quantitative real-time polymerase chain reaction (qRT-PCR) are listed in Supplementary Table S1.

Plasmid construction and cell transfection

Human CRC cell lines (SW480 and HT29) were incubated in six-well plates for 24 h before transfection. The short hairpin RNAs against ARAP1-AS1 (termed sh-ARAP1-AS1#1 and sh-ARAP1-AS1#2) and negative control (termed sh-NC), the pcDNA 3.1 vector specific to YY1 (termed YY1) and negative control (termed NC), and the short hairpin RNA against transcription factor YY1 (termed sh-YY1) and negative control (termed sh-NC) were designed and synthesized by the RiboBio Company (Guangzhou, China). Transfections were conducted and finished using Lipofectamine 2000 (Invitrogen). The interference sequences are listed in Supplementary Table S1.

CCK-8 assay

The transfected SW480 and HT29 cell lines were reaped for CCK-8 assay. After diluting to 5 × 10³ cells/mL, cells were planted into 96-well plates. Cell proliferation was assessed using a Cell Counting Kit-8 kit (DOJINDO, Tokyo, Japan) following the user guide. Cells of each well were incubated with 10 μL of CCK-8 solution at 37°C for 2 h. At length, a microplate reader (Bio-Rad, Hercules, CA) was utilized to measure absorption at 450 nm.

Transwell assay

Transwell assay was used to measure the migratory and invasive abilities of indicated cells. In brief, cells (1 × 10⁴ cells/well) were plated in 24-well plates that were placed into the Transwell chamber (8-mm pore size; Millipore, Eschborn, Germany). For invasion and migration assays, the upper chamber was precoated with or without 50 mL of Matrigel (BD Biosciences). After transfection and resuspension, 200-mL cell solutions were added into the upper chambers. Meanwhile, in the lower chamber, 500 mL of DMEM solution mixed with 10% FBS was added. Following incubation for 48 h, cells on the upper surface of the chamber were removed with cotton swabs, while cells on the lower surface were fixed with 4% paraformaldehyde (PFA) and stained with 0.1% crystal violet (Beyotime Institute of Biotechnology, Haimen, China) for 15 min. Finally, the cells that had invaded and migrated through the membrane were calculated under a microscope (Nikon, Tokyo, Japan) at a magnification of × 100.

Western blot analysis

Total proteins were lysed with RIPA lysis buffer (Beyotime Institute of Biotechnology). Protein concentrations were measured with the BCA Protein Assay Kit (Beyotime Institute of Biotechnology). Afterward, proteins (20 μg) were separated with sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and transferred onto a polyvinylidene difluoride (PVDF) membrane. Subsequently, the membranes were blocked with Tris-buffered saline (TBS) containing 5% fat-free milk for 1 h at room temperature.

Afterward, membranes were incubated with specific primary antibodies: E-cadherin (1:1000 dilution), N-cadherin (1:1000 dilution), YY1 (1:1000 dilution), YY2 (1:1000 dilution), β-catenin (1:1000 dilution), C-myc (1:1000 dilution), cyclin D1 (1:1000 dilution), and GAPDH (1:1000 dilution) at 4°C overnight. All antibodies were bought from Abcam (Eugene, OR). Afterward, the appropriate secondary antibody conjugated with horseradish peroxidase (1:2000 dilution; Santa Cruz Co.) was incubated with the membranes for 4 h at room temperature. The expression level of the protein band was normalized to GAPDH.

Immunofluorescence

SW480 and HT29 cells (1 × 10⁵ cells/well) were seeded on glass coverslips in six-well plates for 24 h and then fixed in 4% PFA at room temperature for 30 min. Subsequently, slides were permeabilized with PBS-T solution (mixed with 0.3% Triton X-100) for 15 min and blocked with PBS-B solution (mixed with 4% BSA) for 20 min. After consecutive incubations with the primary antibodies E-cadherin (1:1000 dilution) and N-cadherin (1:1000 dilution) overnight at 4°C, cells were incubated with the appropriate secondary antibody (1:2000 dilution) for 1 h at room temperature. DAPI (Beyotime Institute of Biotechnology, Shanghai, China) was used to stain nuclei for 30 min at room temperature. Finally, cells were visualized by fluorescence microscopy (Olympus, Tokyo, Japan).

Chromatin immunoprecipitation

Chromatin immunoprecipitation (ChIP) assay was performed using the SimpleChIP^® Enzymatic Chromatin IP Kit (No. 9003; CST, Boston, MA) in accordance with the manufacturer's introduction. Briefly, SW480 and HT29 cells were fixed with 1% formaldehyde and cross-linked at 37°C for 10 min, and then glycine was added to stop the cross-linking reaction. Subsequently, SW480 and HT29 cells were harvested and sonicated by enzymatic digestion. Afterward, lysates were immunoprecipitated with specific antibodies at 4°C overnight. IgG was used as a negative control (NC). After washing, elution, and decross-linking, the recovered DNA was quantified using qRT-PCR.

Luciferase reporter assay

The ARAP1-AS1 promoter region containing the binding sites (wild type or mutant type) was constructed into the pGL3 vector (Promega, Madison, WI) and cotransfected into SW480 and HT29 cells along with YY1 or NC. Forty-eight hours after incubation, a dual-luciferase reporter assay system (Promega) was used to measure luciferase activity. Renilla luciferase activity was used for normalization.

Statistical analyses

Each experiment was repeated independently three times. All data are presented as mean ± standard deviation, and statistical analyses were performed using statistics 20.0 (SPSS, Chicago, IL). Besides, Student's t-test was used to analyze the difference of two independent groups, while one-way analysis of variance was utilized to analyze differences among multiple groups. A value of p < 0.05 was considered to be statistically significant.

Results

ARAP1-AS1 was overexpressed in CRC tissues and cell lines

Based on the TCGA dataset, ARAP1-AS1 was highly expressed in CRC samples (Fig. 1A). Furthermore, its high expression was further validated in CRC tissues and collected from 82 CRC patients, identified, and compared with adjacent normal tissues (Fig. 1B). Based on the mean expression level of ARAP1-AS1 in 82 CRC tissues, all patients were classified into the ARAP1-AS1 high or low expression group. Then, the authors analyzed the association between the ARAP1-AS1 expression and clinicopathological features of CRC patients. As listed in Table 1, the expression level of ARAP1-AS1 correlated with the TNM stage and lymph node metastasis. In addition, ARAP1-AS1 was expressed higher in CRC tissues with metastasis rather than in those without metastasis (Fig. 1C). Next, the authors examined the expression level of ARAP1-AS1 in both CRC cells and normal colorectal epithelial cell. As a result, CRC cell lines exhibited a relatively higher expression level of ARAP1-AS1 (Fig. 1D).

FIG. 1.

ARAP1-AS1 was overexpressed in CRC tissues and cell lines. (A) Based on the TCGA dataset, ARAP1-AS1 was highly expressed in CRC samples. (B) The expression of ARAP1-AS1 was examined in 82 pairs of CRC tissues and adjacent normal tissues. (C) The expression level of ARAP1-AS1 in CRC tissues with or without metastasis. (D) ARAP1-AS1 was expressed higher in five CRC cells than in the normal cell line, HCoEpiC. *p < 0.05, **p < 0.01. ARAP1-AS1, ARAP1 antisense RNA 1; CRC, colorectal cancer; TCGA, The Cancer Genome Atlas.

Table 1.

Correlation Between ARAP1 Antisense RNA 1 Expression and Clinical Features of Colorectal Cancer (n = 82)

Variable	ARAP1-AS1 expression		p
Variable	Low	High	p
TNM
I–II	18	8	0.001^a
III	15	41	0.001^a
Lymph node metastasis
No	21	16	0.007^a
Yes	12	33	0.007^a
Age, years
≥60	24	39
<60	9	10	0.595
Differentiation
Well	3	1	0.297
Moderate	30	48
Smoking			0.111
Smoking	2	10
Nonsmoking	31	39	0.214
Gender
Male	4	2
Female	29	47

Low/high by the sample median. Pearson χ² test.

p < 0.01 was considered statistically significant.

ARAP1-AS1, ARAP1 antisense RNA 1.

Knockdown of ARAP1-AS1 suppressed cell migration, invasion, and EMT process in CRC

To identify the biological role of ARAP1-AS1 in CRC, functional assays were conducted. According to data of Figure 1, SW480 and HT29 cells exhibited the highest level of ARAP1-AS1 compared with the other three cell lines. Therefore, the authors decreased the expression level of ARAP1-AS1 in SW480 and HT29 cells by transfecting with ARAP1-AS1-specific shRNAs (sh-ARAP1-AS1#1 and sh-ARAP1-AS1#2). qRT-PCR analysis showed that sh-ARAP1-AS1#2 most efficiently decreased the expression level of ARAP1-AS1 in two CRC cells (Supplementary Fig. S1A). Therefore, the authors chose sh-ARAP1-AS1#2 for subsequent experiments.

At first, cell viability was tested in ARAP1-AS1-downregulated CRC cells. It was found that knockdown of ARAP1-AS1 efficiently decreased CRC cell viability (Fig. 2A). Considering the association between ARAP1-AS1 expression and metastasis, the authors detected the effect of ARAP1-AS1 knockdown on CRC migration and invasion. According to results of Transwell assays, both migration and invasion were inhibited by ARAP1-AS1 knockdown (Fig. 2B). Moreover, EMT was detected in indicated CRC cells by measuring expression levels of EMT markers (E-cadherin and N-cadherin). ARAP1-AS1 knockdown increased the level of E-cadherin, but decreased the level of N-cadherin, indicating that ARAP1-AS1 reversed EMT progress (Fig. 2C, D). All these results suggested that ARAP1-AS1 promoted CRC cell migration and invasion.

FIG. 2.

Knockdown of ARAP1-AS1 suppressed cell migration, invasion, and the EMT process in CRC. (A) Cell viability was measured in response to the knockdown of ARAP1-AS1. (B) Transwell assays were used to assess cell migration and invasion after ARAP1-AS1 knockdown. Cells were measured under a microscope at a magnification of × 100. (C, D) The levels of EMT markers were examined in CRC cells transfected with sh-ARAP1-AS1 and sh-NC. **p < 0.01. EMT, epithelial–mesenchymal transition.

YY1 activated the transcription of ARAP1-AS1

Based on the data above, the authors confirmed that upregulation of ARAP1-AS1 contributed to tumor progression in CRC. The authors further explored the molecular mechanism involved in upregulation of ARAP1-AS1 in CRC. Increasing evidence shows that lncRNAs can be activated by their upstream transcription factors. Therefore, the authors tried to explore the transcription activator of ARAP1-AS1 in CRC. According to ChIP-Seq results of UCSC (http://genome.ucsc.edu), the authors found some potential transcription factors of ARAP1-AS1. Among which, YY1 has been reported to be able to activate the transcription of lncRNAs.^27,28 Thus, the authors chose YY1 for further study. The binding motif of YY1 downloaded from JASPAR (http://jaspar.genereg.net) is illustrated in Figure 3A. Next, the authors chose two binding sites between YY1 and ARAP1-AS1 promoter for further study due to their highest binding score (Fig. 3B).

FIG. 3.

YY1 activated the transcription of ARAP1-AS1. (A) The binding motif of YY1 was downloaded from JASPAR. (B) The response element of YY1 in the ARAP1-AS1 promoter. (C) ChIP assay showed the strong affinity of part 2 (P2) of the ARAP1-AS1 promoter with YY1. (D) Luciferase reporter assay indicated interaction between YY1 and part 2 (P2) of the ARAP1-AS1 promoter. (E) YY1 was upregulated in CRC tissues and cell lines. (F) YY1 was overexpressed or silenced in both SW480 and HT29 cells. (G) The expression change of ARAP1-AS1 was observed in response to YY1 overexpression or knockdown. *p < 0.05, **p < 0.01; n.s, no significance. ChIP, chromatin immunoprecipitation.

Based on the position, these two binding sites were divided into two parts of the ARAP2-AS1 promoter. ChIP assay showed that part 2 (P2) of the ARAP1-AS1 promoter exhibited a strong binding affinity with YY1 (Fig. 3C). Furthermore, luciferase reporter assay indicated that P2 was responsible for transcription activation of YY1 on the ARAP1-AS1 promoter (Fig. 3D). Similarly, YY1 was upregulated in CRC tissues and cell lines (Fig. 3E). Correlation between the expression of YY1 and that of ARAP1-AS1 was found to be positive in CRC tissues (Supplementary Fig. S1B). To analyze whether YY1 regulated ARAP1-AS1 expression in CRC cells, the authors overexpressed or silenced YY1 in both SW480 and HT29 cells (Fig. 3F). The expression of ARAP1-AS1 was found to be positively regulated by YY1 in CRC cells (Fig. 3G).

Then, the authors also examined the messenger RNA (mRNA) and protein levels of YY2 in CRC cell lines and the normal cell line. Results showed that the expression level of YY2 was not significantly expressed in CRC cell lines compared with the normal cell line (Supplementary Fig. S1C, D). To demonstrate the monospecificity of YY1, the authors examined the protein band of YY1 by using a specific antibody. It was found that the position of YY1, but not YY2, is corresponding to this antibody (Supplementary Fig. S1E). Collectively, the authors confirmed that YY1 enhanced the expression of ARAP1-AS1 by promoting ARAP1-AS1 transcription.

YY1/ARAP1-AS1 axis promoted cell migration and EMT progress

To validate the biological function of the YY1/ARAP1-AS1 axis in CRC progression, rescue assays were conducted in SW480 cells. At first, the authors examined the expression of ARAP1-AS1 in cells cotransfected with sh-ARAP1-AS1 and YY1 expression vector. As show in Figure 4A, cell migration and invasion suppressed by sh-ARAP1-AS1 were partially recovered by YY1. Moreover, overexpression of YY1 reversed the effect of ARAP1-AS1 knockdown on the EMT process (Fig. 4B, C). Therefore, the authors confirmed that YY1 was involved in ARAP1-AS1-mediated CRC cell migration and the EMT process.

FIG. 4.

The YY1/ARAP1-AS1 axis promoted cell migration and EMT progress. (A) Transwell assays revealed that cell migration and invasion suppressed by sh-ARAP1-AS1 were partially recovered by YY1. (B, C) The EMT markers were detected in indicated cells. **p < 0.01.

YY1/ARAP1-AS1 axis regulated the Wnt/β-catenin signaling pathway in CRC cells

It has been widely reported that the Wnt/β-catenin signaling pathway can be involved in lncRNA-mediated cancer progression.^29,30 In this study, the authors investigated whether the YY1/ARAP1-AS1 axis could regulate the Wnt/β-catenin signaling pathway in CRC cells.

Western blot analysis showed that protein levels of the core factors of the Wnt/β-catenin signaling pathway (β-catenin, c-myc, and cyclin D1) decreased by ARAP1-AS1 knockdown, but increased by YY1 overexpression (Fig. 5A). Moreover, overexpression of YY1 rescued the decreased levels in CRC cells transfected with sh-ARAP1-AS1. Functional assays were further performed to demonstrate the involvement of the Wnt/β-catenin signaling pathway in YY1/ARAP1-AS1-mediated CRC cell migration and invasion. As shown in Figure 5B, cell viability decreased by the knockdown of ARAP1-AS1 or YY1 was partially increased by the treatment with LiCl (activator of the Wnt/β-catenin signaling pathway). Similarly, both migration and invasion that were inhibited by sh-ARAP1-AS1 or sh-YY1 were recovered by introduction of LiCl (Fig. 5C, D). Therefore, the YY1/ARAP1-AS1 axis might promote CRC cell migration through the Wnt/β-catenin signaling pathway.

FIG. 5.

The YY1/ARAP1-AS1 axis regulated the Wnt/β-catenin signaling pathway in CRC cells. (A) Protein levels of β-catenin, c-myc, and cyclin D1 were examined in SW480 and HT29 cells transfected with sh-NC, sh-ARAP1-AS1, and YY1 expression vector or in cells cotransfected with sh-ARAP1-AS1 and YY1. (B–D) Viability, migration, and invasion of cells transfected with sh-NC, sh-ARAP1-AS1, sh-YY1, or with the addition of LiCl. *p < 0.05, **p < 0.01.

Discussion

With the development of high-throughput techniques, numerous systematic cancer genomic projects have been applied in investigating various molecular pathways in human cancers.^31,32 According to TCGA data, ARAP1-AS1 was upregulated in CRC samples. Therefore, this study focused on the role of ARAP1-AS1 in CRC progression. Consistently, the expression of ARAP1-AS1 was found to be higher in 82 CRC tissues and 5 CRC cell lines compared with normal controls.

Dysregulation of lncRNAs is closely correlated with the abnormal biological behaviors in human cancers. Previous studies have shown that lncRNAs are crucial regulators for cancer cell migration and EMT progress.^33

–37 In the present study, the authors found upregulation of ARAP1-AS1 in CRC tissues and metastatic tissues, indicating the potential participation of ARAP1-AS1 in CRC cell migration and invasion. In this regard, the authors investigated whether ARAP1-AS1 regulated CRC cell migration, invasion, and EMT progress. The authors designed and conducted loss-of-function assays in SW480 and HT29 cell lines that exhibited the highest level of ARAP1-AS1. Results of loss-of-function assays demonstrated that knockdown of ARAP1-AS1 efficiently suppressed cell migration, invasion, and EMT progress, suggesting that ARAP1-AS1 acted as an oncogene in CRC by promoting cell migration, invasion, and EMT progress.

Previous reports have revealed that transcription factors can lead to dysregulation of lncRNAs in human cancers.^38
–40 Based on the bioinformatic analysis, the authors found some potential transcription factors of ARAP1-AS1. Among which, YY1 has been demonstrated to be a transcription activator of lncRNAs.⁴¹ Therefore, the interaction between YY1 and ARAP1-AS1 was analyzed in this study. Based on mechanism investigation, YY1 activated ARAP1-AS1 transcription by binding to its promoter. More importantly, the authors found that the expression of ARAP1-AS1 was positively regulated by YY1 in CRC cells. These data suggested that YY1 is a transcriptional activator of ARAP1-AS1 in CRC. Rescue assays demonstrated the crucial role of YY1 in ARAP1-AS1-mediated CRC cell migration and the EMT process. All these findings indicated that YY1-induced upregulation of ARAP1-AS1 promoted cell migration, invasion, and EMT progress in CRC. In this study, the authors explored a novel YY1/ARAP1-AS1 axis in CRC progression.

The Wnt/β-catenin signaling pathway is closely associated with progression^42
–44 of human cancers, which can be involved in lncRNA-mediated tumor progression.⁴² In the present study, the authors investigated potential regulation of the YY1/ARAP1-AS1 axis on the Wnt/β-catenin signaling pathway. The authors found positive regulation of YY1 and ARAP1-AS1 on Wnt/β-catenin signaling, indicating that the YY1/ARAP1-AS1 axis might promote CRC cell migration by activating the Wnt/β-catenin signaling pathway. By using LiCl (activator of the Wnt/β-catenin signaling pathway), rescue assays were carried out. It was found that the function of sh-ARAP1-AS1 or sh-YY1 in CRC cell migration and EMT progress was recovered by addition of LiCl. In conclusion, the study revealed that the YY1/ARAP1-AS1 axis promotes CRC cell migration and EMT progress through the Wnt/β-catenin signaling pathway. These findings may contribute to developing novel therapeutic targets for CRC.

Footnotes

Acknowledgment

The authors thank all the laboratory members.

Funding Information

This work was supported by the Wenzhou Science and Technology Planning Project (Y20120030).

Disclosure Statement

No competing financial interests exist.

Supplementary Material

Supplementary Figure S1

Supplementary Table S1

References

Siegel

, Miller

, Jemal

. Cancer statistics, 2017. CA Cancer J Clin, 2017; 67:7.

Siegel

, Miller

, Fedewa

, et al. Colorectal cancer statistics, 2017. CA Cancer J Clin, 2017; 67:177.

Brenner

, Kloor

, Pox

. Colorectal cancer. Lancet, 2014; 383:1490.

Schmoll

, Van Cutsem

, Stein

, et al. ESMO Consensus Guidelines for management of patients with colon and rectal cancer. a personalized approach to clinical decision making. Ann Oncol, 2012; 23:2479.

Miller

, Siegel

, Lin

, et al. Cancer treatment and survivorship statistics, 2016. CA Cancer J Clin, 2016; 66:271.

Kong

, Deng

, Kong

, et al. ZFPM2-AS1, a novel lncRNA, attenuates the p53 pathway and promotes gastric carcinogenesis by stabilizing MIF. Oncogene, 2018; 38:164.

Qiu

, Liu

, Hou

, et al. Wip1 knockout inhibits neurogenesis by affecting the Wnt/beta-catenin signaling pathway in focal cerebral ischemia in mice. Exp Neurol, 2018; 309:44.

, Song

, Chen

, et al. Long noncoding RNA PVT1–214 promotes proliferation and invasion of colorectal cancer by stabilizing Lin28 and interacting with miR-128. Oncogene, 2018; 38:164.

Liang

, Yu

, Han

, et al. LncRNA PTAR promotes EMT and invasion-metastasis in serous ovarian cancer by competitively binding miR-101-3p to regulate ZEB1 expression. Mol Cancer, 2018; 17:119.

10.

Deng

, Chen

, Ye

, et al. Hypoxia-induced LncRNA-BX111 promotes metastasis and progression of pancreatic cancer through regulating ZEB1 transcription. Oncogene, 2018; 37:5811.

11.

Huang

, Xie

, Liu

, et al. Adam12 and lnc015192 act as ceRNAs in breast cancer by regulating miR-34a. Oncogene, 2018; 10:1038.

12.

Hung

, Chang

. Long noncoding RNA in genome regulation: Prospects and mechanisms. RNA Biol, 2010; 7:582.

13.

Spizzo

, Almeida

, Colombatti

, et al. Long non-coding RNAs and cancer: A new frontier of translational research?. Oncogene, 2012; 31:4577.

14.

Nana-Sinkam

, Croce

. Non-coding RNAs in cancer initiation and progression and as novel biomarkers. Mol Oncol, 2011; 5:483.

15.

Zhong

, Lu

, Wan

, et al. Long noncoding RNA kcna3 inhibits the progression of colorectal carcinoma through down-regulating YAP1 expression. Biomed Pharmacother, 2018; 107:382.

16.

Jing

, Huang

, Guo

, et al. LncRNA CASC15 promotes colon cancer cell proliferation and metastasis by regulating the miR4310/LGR5/Wnt/betacatenin signaling pathway. Mol Med Rep, 2018; 18:2269.

17.

Tian

, Du

, Ma

, et al. MALAT1-miR663a negative feedback loop in colon cancer cell functions through direct miRNA-lncRNA binding. Cell Death Dis, 2018; 9:857.

18.

Zinovieva

, Grineva

, Prokofjeva

, et al. Expression of long non-coding RNA LINC00973 is consistently increased upon treatment of colon cancer cells with different chemotherapeutic drugs. Biochimie, 2018; 151:67.

19.

, Xu

, Liu

, et al. Long noncoding RNA BC200 regulates cell growth and invasion in colon cancer. Int J Biochem Cell Biol, 2018; 99:219.

20.

Jiang

, Li

, Qu

, et al. Long non-coding RNA SNHG15 interacts with and stabilizes transcription factor Slug and promotes colon cancer progression. Cancer Lett, 2018; 425:78.

21.

Teng

, Ai

, Jia

, et al. Long non-coding RNA ARAP1-AS1 promotes the progression of bladder cancer by regulating miR-4735-3p/NOTCH2 axis. Cancer Biol Ther, 2018; 1:552.

22.

Liu

, Liu

, et al. EGR1-mediated transcription of lncRNA-HNF1A-AS1 promotes cell cycle progression in gastric cancer. Cancer Res, 2018; 78:20.

23.

Wang

, Huo

, Yang

, et al. STAT3-mediated upregulation of lncRNA HOXD-AS1 as a ceRNA facilitates liver cancer metastasis by regulating SOX4. Mol Cancer, 2017; 16:136.

24.

, Wang

, Ma

, et al. Upregulation of the long noncoding RNA FOXD2-AS1 promotes carcinogenesis by epigenetically silencing EphB3 through EZH2 and LSD1, and predicts poor prognosis in gastric cancer. Oncogene, 2018; 37:5020.

25.

Chen

, Wu

, Xia

, et al. STAT3-induced lncRNA HAGLROS overexpression contributes to the malignant progression of gastric cancer cells via mTOR signal-mediated inhibition of autophagy. Mol Cancer, 2018; 17:6.

26.

Zhang

, Yin

, Han

, et al. E2F1-induced upregulation of long noncoding RNA LINC00668 predicts a poor prognosis of gastric cancer and promotes cell proliferation through epigenetically silencing of CKIs. Oncotarget, 2016; 7:23212.

27.

Shen

, Kong

, Liu

, et al. YY1-induced upregulation of lncRNA KCNQ1OT1 regulates angiotensin II-induced atrial fibrillation by modulating miR-384b/CACNA1C axis. Biochem Biophys Res Commun, 2018; 505:134.

28.

Zhang

, Jin

, Li

, et al. The YY1-HOTAIR-MMP2 signaling axis controls trophoblast invasion at the maternal-fetal interface. Mol Ther, 2017; 25:2394.

29.

Zhu

, Yang

, Du

, et al. LncRNA CRNDE promotes the epithelial-mesenchymal transition of hepatocellular carcinoma cells via enhancing the Wnt/beta-catenin signaling pathway. J Cell Biochem, 2018; 120:1156.

30.

Chen

, You

, Zheng

, et al. Downregulation of lncRNA OGFRP1 inhibits hepatocellular carcinoma progression by AKT/mTOR and Wnt/beta-catenin signaling pathways. Cancer Manag Res, 2018; 10:1817.

31.

Kandoth

, McLellan

, Vandin

, et al. Mutational landscape and significance across 12 major cancer types. Nature, 2013; 502:333.

32.

Alvarez

, Shen

, Giorgi

, et al. Functional characterization of somatic mutations in cancer using network-based inference of protein activity. Nat Genet, 2016; 48:838.

33.

Qin

, Kang

, Xu

, et al. Long non-coding RNA HOTAIR promotes tumorigenesis and forecasts a poor prognosis in cholangiocarcinoma. Sci Rep, 2018; 8:12176.

34.

Luo

, Tang

, Ling

, et al. LINC01638 lncRNA activates MTDH-Twist1 signaling by preventing SPOP-mediated c-Myc degradation in triple-negative breast cancer. Oncogene, 2018; 37:6166.

35.

, Jiang

, Li

, et al. Tumor-derived exosomal lnc-Sox2ot promotes EMT and stemness by acting as a ceRNA in pancreatic ductal adenocarcinoma. Oncogene, 2018; 37:3822.

36.

Zuo

, Huang

, Zou

, et al. The Lnc RNA SPRY4-IT1 modulates trophoblast cell invasion and migration by affecting the epithelial-mesenchymal transition. Sci Rep, 2016; 6:37183.

37.

Zhan

, Wang

, Li

, et al. LincRNA-ROR promotes invasion, metastasis and tumor growth in pancreatic cancer through activating ZEB1 pathway. Cancer Lett, 2016; 374:261.

38.

Pan

, Liang

, Gu

, et al. Long noncoding RNA DANCR is activated by SALL4 and promotes the proliferation and invasion of gastric cancer cells. Oncotarget, 2018; 9:1915.

39.

Liu

, Han

, Li

, et al. LncRNA DLEU1 contributes to colorectal cancer progression via activation of KPNA3. Mol Cancer, 2018; 17:118.

40.

Zeng

, Liu

, Lu

, et al. The c-Myc-regulated lncRNA NEAT1 and paraspeckles modulate imatinib-induced apoptosis in CML cells. Mol Cancer, 2018; 17:130.

41.

Huang

, Wang

, Yang

, et al. Transcription factor YY1 modulates lung cancer progression by activating lncRNA-PVT1. DNA Cell Biol, 2017; 36:947.

42.

, Shan

, Pan

, et al. The lncRNA ZEB1-AS1 sponges miR-181a-5p to promote colorectal cancer cell proliferation by regulating Wnt/beta-catenin signaling. Cell Cycle, 2018; 17:1245.

43.

Zhu

, Li

, Zhao

, et al. LSINCT5 activates Wnt/beta-catenin signaling by interacting with NCYM to promote bladder cancer progression. Biochem Biophys Res Commun, 2018; 502:299.

44.

Liang

, Ren

, Wong

, et al. LncRNA-NEF antagonized epithelial to mesenchymal transition and cancer metastasis via cis-regulating FOXA2 and inactivating Wnt/beta-catenin signaling. Oncogene, 2018; 37:1445.

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